# Want build Towers and a Center.



## bambino

I was wondering if there is anybody here on the sight willing to help me through the process of building speakers, i know which drivers i'd like to use for bass and midbass just not sure yet about the tweeters or how to go about figureing how to do the Crossovers.:dontknow: Any takers?

The speakers i would like to use are as follow's:
4 Dayton RS225-8, 8" woofers per tower
2 Dayton RS125-8, 5" woofers per tower
Tweeters:dontknow:

For the center: 
4 Dayton RS180-8 7" woofers
2 Dayton RS100-8 4" midbass
Tweeters:dontknow:

As far as crossovers i'm not sure if i would be ok to buy them pre-made or to build my own (which i certainly haven't a clue about). I know i'm gonna have some Impedance issues with the driver selection, i can get the ones using 4 drivers back to 8ohms but the 2 drivers in each are the issue as i can only make them 16 or 4ohm loads. Any body with knowledge on all this stuff and willing to help? Or just plain opinions as to this setup would be much appreciated. Thanks in advance, Bambino.:T


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## GranteedEV

bambino said:


> As far as crossovers i'm not sure if i would be ok to buy them pre-made or to build my own (which i certainly haven't a clue about). I know i'm gonna have some Impedance issues with the driver selection, i can get the ones using 4 drivers back to 8ohms but the 2 drivers in each are the issue as i can only make them 16 or 4ohm loads. Any body with knowledge on all this stuff and willing to help? Or just plain opinions as to this setup would be much appreciated. Thanks in advance, Bambino.:T


My recommendation is that if you've never designed your own crossover, you've got a LOT of research ahead of you to even design a 2-way design... don't even bother with 3-way. 

Avoid pre-made crossovers at all costs, as they don't take into account the 100s of complexities of integrating drivers and cabinets

Which leaves you with 1 choice:

Build a kit / someone else's design

Sounds lame, I know. But the crossover is the HEART of the speaker. I can take the world's worst drivers/top notch crossover and make them sound better than the world's best drivers/bad crossover.

What's worse, a 3-way passive design is not a good idea unless you're willing to cross near 450-700hz or so. 

If you insist on the :choose drivers: approach, I recommend going to madisound, having them design a crossover in LEAP for you and make sure to give them box information especially baffle width, and go with that. Never buy a pre-made crossover, as there's just too many factors in crossover design for any universal crossover to not fail badly at.

A nice DIY "kit" I recommend is the Jentzen DTQWT HES.


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## bambino

Thanks Grant, i have heard the same thing several times about the crossover being basically what makes or breaks a speaker which is why i am so concerned about this part of the process (i know it has to be right). 
I'll have to call around and see what i can come up with, i don't like the idea of using somone elses design, call me picky or arrogant but i just want them to be my own.:sn:


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## GranteedEV

bambino said:


> Thanks Grant, i have heard the same thing several times about the crossover being basically what makes or breaks a speaker which is why i am so concerned about this part of the process (i know it has to be right).
> I'll have to call around and see what i can come up with, i don't like the idea of using somone elses design, call me picky or arrogant but i just want them to be my own.:sn:


I understand what you're saying. There's a certain pride in success. 

The thing is, you need a lot of tools to do it right. At the very least I'd recommend

- something like LEAP or LSPCad - expensive but imagine building a subwoofer without a winISD type program. Crossover modeling is very helpful. 
- something like a dayton woofer tester at the very least. Lots of other things as well.
- understanding and application of theory. This pertains to getting impedance right, getting flat mid-band response via level matching and correct slope (which is absolutely VITAL for a good speaker), notch filters, and diffraction compensation. There's other complications which certainly arise.

For your first build at least, do someone else's design. Learn about it, and understand it. Make yourself able to reproduce it with your own knowledge. That's the only way of getting good at something.. practice.

I definitely don't feel you should be afraid of crossover design. But don't jump in head first. Get crossover construction down pat, and this will help you gain understanding. It takes at least a few months of hands-on experience to do a decent 2-way imo.

Alternatively, you could make a tri-amped active system with a DCX or DEQX. Normally I would recommend that, but I don't know how your XPA-1s fit into the equation. You would still need lots of different measurements.

Remember, even using someone else's crossover and "driver selections", you're still the one making the box. As long as you get the baffle right, you can make it a very nice box with your own signature.

Someone elsewhere said it best: "Speaker Building isn't about having a partsexpress catalogue..."

Keep in mind, when I say kit, I'm not just talking about the stuff you see on madisound and partsexpress. When I say kit, I mean there's hundreds of choices of mid drivers and suitable tweeters and woofers for them out there. They tell you the drivers and a bit about the baffle, and give you a schematic. You assemble the crossover as the schematic states.

For example the kit i recommender earlier is barely a kit:

http://www.jantzen-audio.com/download/ja8008-tw034-kit/JA8008_TW034_article_v2_ja_web.pdf

As you can see, you have many, many options to make it your own. It's not like you're just assembling a jigsaw puzzle.


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## bambino

Thanks for your advice Grant, i'll be sure to take all you have said into consideration before i jump into this as well as do lots of research. Thanks again, Bambino.:T


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## lsiberian

For a solid 3-way you will need to use an active crossover and have several channels of amping. 

For drivers you might take a look at my list. 
I would suggest the HiFi RTI tweeter(it's what my reference speakers will use). You will need a batch of them to get 3 good ones, but they are capable of taking a lot of power. When unfaced the driver has incredible off-axis response which is key to efficiency. You'd need a grill.

For the mid driver I suggest the Dayton Midrange Dome(what my reference speakers will use), 

The Infinity MRS driver(I'd have used this if it was more affordable 100 bucks) I'm convinced it's the best driver in the world for midrange.

For the bass driver check out the Exodus Audio Anarchy(what my reference speakers will use) A bass driver built like a sub can't be a bad thing. 

If you can swing the infinity MRS driver(100 a pop) they are amazing and capable of taking a lot of power when crossed properly.


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## bambino

I have a lot of research to do!:unbelievable: If you guys don't hear from me for awhile check the local sanitarium or library, i'm not sure which one i'll end up at first. LOL!

Do you have some of your builds posted here? And do you build your own crossover networks? One more:
Is my list over the top or just not a capable list? any suggestions about it?


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## 1Michael

Trying to create a 3way for your first project is ludicrous at best. I do not think you understand how difficult it is. 
Check these out then get back to us...
https://sites.google.com/site/undefinition/diy-faqs-provendesigns
http://www.troelsgravesen.dk/choices.htm
Here is a similar design...http://www.htguide.com/forum/showthread.php4?t=15323
I think the real question here is, do you want to settle for something that most likely will sound like trash, or 
something that will sound great. Just because you did not design the Xover does not make it any less your own...


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## Binary

i was going to say as well, that the most forgiving design for a 3 way, (albeit the most expensive way to do it) is to use an active crossover/multiple amps so that you won't have to worry about screwing the crossover up. Its a huge advantage to have active crossovers, especially in the testing phase, but the downside is litterally one amplifier channel per band (6 channels to run 2 3-way speakers) Active does put you into a whole different category for sound though.


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## bambino

buggers said:


> Trying to create a 3way for your first project is ludicrous at best. I do not think you understand how difficult it is.
> Check these out then get back to us...
> https://sites.google.com/site/undefinition/diy-faqs-provendesigns
> http://www.troelsgravesen.dk/choices.htm
> Here is a similar design...http://www.htguide.com/forum/showthread.php4?t=15323
> I think the real question here is, do you want to settle for something that most likely will sound like trash, or
> something that will sound great. Just because you did not design the Xover does not make it any less your own...


Ok, just from reading the first link in your post has deterred me from this, but i don't want to do an allready proven design i want to be able to take the drivers i've chosen and make them sound awesome but, where to start?
I'll read the other links later on, i do know i'm jumping in the deep end of possible failure but i know i can get it done with time and practice and of coarse help from you guys. Thanks for the links.:T


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## GranteedEV

bambino said:


> Ok, just from reading the first link in your post has deterred me from this, but i don't want to do an allready proven design i want to be able to take the drivers i've chosen and make them sound awesome but, where to start?
> I'll read the other links later on, i do know i'm jumping in the deep end of possible failure but i know i can get it done with time and practice and of coarse help from you guys. Thanks for the links.:T


It's not a matter of "never"

It's a matter of "gradually". Llet time and experience do their magic, and _then_ attempt your own design. The first time a kid learns to swim, you don't just throw her/him in without a life jacket! But that also doesn't mean that the kid'll still want the life jacket 3 months later!

Treat as at least a 3-step process.

Step 1a - Find and Build any great 2 or 3-way kit as your first attempt Don't need to spend too much, but pay careful attention. There's many awesome ones out there that fit thousands of criteria. Even consider doingg something a bit out-there, like a classic transmission line or open baffle, even. Weigh the pros and often vast cons of different driver placements IE MTM, TMM, WMTMW, TMMWWW, MTMWWW, MTMTMTM, MTTM, TMMMM, Fullrange, coaxial, omni, etc. The effects of things that you wouldn't even consider on a subwoofer build (IE flush mounting, waveguides, exponential horns, baffle diffraction). You learn a lot by doing. 

And remember, not all of these designs are "proven".. some of them have barely even been attempted by the DIY community outside of the original designer. 

or

Step 1b) Choose some madisound drivers and have them design the crossover for you for a nominal fee. This will also help you learn a bit about whether driver a and driver b are even compatible with each other! 

Step 2 - Design and build a 2-way, two or three driver speaker as your second attempt. This is where this board can help you. But it's step 2, not step 1, unless someone just happens to have the drivers on hand and can design the crossover for you, which in reality is really just a forum version of step 1b. What are the chances someone just happens to have your drivers on hand? Measure and listen to the end result and accept constructive criticism. Decide if passive or active crossovers are the right choice going forward. Invest the right money on all the stuff you begin to realize you need if you want to do this right!

Step 3 - This step belongs to you. You may find that you like the idea of full range drivers, and that a 2 or 3-way is just way out of your league, or you may feel so confident that you'll attempt an active 5-way or something. Who knows. But what doesn't even seem odd right now may at that point seem to be an INSANE option. This is where the fun is.

Step 4 - Not a step, just thought I'd mention... You would now have 3 DIY speakers in your house. LOL!


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## lsiberian

Binary said:


> i was going to say as well, that the most forgiving design for a 3 way, (albeit the most expensive way to do it) is to use an active crossover/multiple amps so that you won't have to worry about screwing the crossover up. Its a huge advantage to have active crossovers, especially in the testing phase, but the downside is litterally one amplifier channel per band (6 channels to run 2 3-way speakers) Active does put you into a whole different category for sound though.


I'd always start with active crossovers and then make passive ones informed by the active crossover if you want too. You will still need to bi-amp a 3-way though. One of the major rules is not to go passive between the Bass and Midrange drivers. People do it, but I'd advise against it.


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## bambino

My problem with going with active crossovers is that i have Mono amps. Why is it a bad idea to go passive between the bass drivers and the mids?

I'm gonna break down my idea for you guys and you correct me and tell me where and which direction i need to go or where i'm going wrong:
1: Start with enclosure size for the drivers in mind
2: Buy a prebuilt crossover (i allready know not the right idea)
3: Learn from that crossover what i need to change
4: Hope the speakers sound great

Am i headed in the right direction by figureing what size the box needs to be and if i'm gonna go sealed or ported? Then going for the crossovers.:huh: Thanks for all the help.


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## sparky77

If you want to do a three way speaker design, get this book and read up on speaker design, then get this software and run your models. There is a bit of a learning curve with the software as far as using the "change to common values" in the crossover components, then check how your frequency response curves change. The biggest concern is the t/s specs for tweeters normally don't give you quite enough info for the software, but you normally don't need it, the program fills in the blanks pretty well for missing parameters. Don't let everybody scare you right off the bat, read the recommended literature and try some models first........


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## Lucky7!

bambino said:


> I was wondering if there is anybody here on the sight willing to help me through the process of building speakers, i know which drivers i'd like to use for bass and midbass just not sure yet about the tweeters or how to go about figureing how to do the Crossovers.:dontknow: Any takers?


Working out passive xovers for a 3 way is a difficult task for a beginner and requires frequency response and impedance measurement of the driver, most preferably in the box they will finish up in then using some software like Jeff Bagby's PCD. Even with the software making the calculations easy, you still need to know where and why to place the xover slopes and points.

As some others have stated, active can be much easier, but is still not PHD (Push Here Dummy) easy.



bambino said:


> The speakers i would like to use are as follow's:
> 4 Dayton RS225-8, 8" woofers per tower
> 2 Dayton RS125-8, 5" woofers per tower
> Tweeters:dontknow:


My first thought on reading this was 'Statements'.



bambino said:


> For the center:
> 4 Dayton RS180-8 7" woofers
> 2 Dayton RS100-8 4" midbass
> Tweeters:dontknow:


A horizontal WMTMW will give combing as you move off axis which defeats the purpose of having a centre. A much better idea is for the MT sectio to be vertical and the W's to the sides to keep the box height low. Something like the Statement Centre.



bambino said:


> As far as crossovers i'm not sure if i would be ok to buy them pre-made or to build my own (which i certainly haven't a clue about).


Off the shelf generic xovers are not suitable and will give questionable results.


bambino said:


> I know i'm gonna have some Impedance issues with the driver selection, i can get the ones using 4 drivers back to 8ohms but the 2 drivers in each are the issue as i can only make them 16 or 4ohm loads. Any body with knowledge on all this stuff and willing to help? Or just plain opinions as to this setup would be much appreciated. Thanks in advance, Bambino.:T


No, your pretty much correct re the series/paralleling of drivers to get a given impedance.


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## GranteedEV

> My problem with going with active crossovers is that i have Mono amps. Why is it a bad idea to go passive between the bass drivers and the mids?


As far as I know, the reasons include:

- the cost of polypropelene capacitors and air core inductors gets extremely high as you get into lower crossover frequencies, so you may have to settle for electrolytic caps and iron core inductors. Additionally, even if you can afford them, too-long winds of 14 awg start to present too much overall resistance at these huge sizes. The alternative, settling for electrolytic caps and iron core inductors supposedly has a bad effect on sound quality, causing audible distortion, although the specifics are not something I know well... I just know I don't want to bother.

- very low impedance dips and wild phase angles presented to the amplifier. Even some world reknowned expensive speakers like the B&W 801s indeed suffer from this effect. This in turn ruins the sound quality with insufficient amplification. 

- Inefficient use of resources. Remember, to level match the drivers in any passive loudspeaker, you can only make it less efficient. 



> I'm gonna break down my idea for you guys and you correct me and tell me where and which direction i need to go or where i'm going wrong:
> 1: Start with enclosure size for the drivers in mind
> 2: Buy a prebuilt crossover (i allready know not the right idea)
> 3: Learn from that crossover what i need to change
> 4: Hope the speakers sound great
> 
> Am i headed in the right direction by figureing what size the box needs to be and if i'm gonna go sealed or ported? Then going for the crossovers.:huh: Thanks for all the help.


Here's a scenario for you to ponder: 

Tweeter A can't handle too much power below 4000hz. It wants a 5000hz 4th order high pass frequency to keep power handling under control. This tweeter is very efficient and feeding it one watt will get you 93 db SPL

Midrange B has a breakup mode around 4200hz. It wants a 1800hz 4th order low pass to get distortion down enough in level that it's inaudible. It will be placed in an 8 inch baffle. This woofer is also very efficient, feeding it one watt will get you 93 db SPL

You just bought tweeter A and midrange B because they looked like they sounded great. 

Prebuilt Crossover C crosses Tweeter X and Midrange Y perfectly at 2.6khz, 3rd order one way, 2nd order the other way. It has a notch filter at 6000 khz to kill Midrange Y's breakup mode. Midrange Y is very sensitive compared to Tweeter X, so its level is reduced by 6db to keep the speaker from sounding bright. Tweeter X and Midrange Y are also such high impedance that nothing was done to control impedance. Oh, did I mention diffraction compensation anywhere?

Anyways you fire up Tweeter A, Midrange B, and Crossover C to see what you get.


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## bambino

Well guys i'm pulling the trigger on the speakers i listed and going to go for it. I know what many may think but this is one of those things i'm quite confident i can pull off, rest assured i will be lost and saying to myself what did i get myself into but that is what you guys are for. Right?:bigsmile:


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## Theresa

I personally like the ScanSpeak Rediscovery kit from Madisound. It has a pre-assembled crossover. You could stick it in a 20 liter cabinet from Madisound pre-cut but would have to stuff the port so that it acts like a sealed box. I have one of these for my center speakers but with an even smaller cabinet because it needs to fit above the screen. I actively crossover all my front speakers so I never even tried the included crossover. Its a very high end speaker but well worth the cost in my opinion. I would couple this with an active sub. Subs are easy to design and put together. I'm not big on Dayton drivers from PE but my L/R fronts have PE .5cf curved enclosures and I had to pay someone to cut the holes and countersink them. I'm not a carpenter. Its all fun when building a kit.


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## GranteedEV

bambino said:


> Well guys i'm pulling the trigger on the speakers i listed and going to go for it. I know what many may think but this is one of those things i'm quite confident i can pull off, rest assured i will be lost and saying to myself what did i get myself into but that is what you guys are for. Right?:bigsmile:


*Sigh*

This is probably gonna be a disaster, but the least I'll say is good luck, and start at the mid-tweeter interaction before you get to the mid-woofer crossover.


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## bambino

GranteedEV said:


> *Sigh*
> 
> This is probably gonna be a disaster, but the least I'll say is good luck, and start at the mid-tweeter interaction before you get to the mid-woofer crossover.


Thanks for the vote of confidence.:bigsmile:


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## looneybomber

A9X said:


> My first thought on reading this was 'Statements'.


My first thought was this.








http://clearwave.forumotion.net/cld-build-threads-f3/lb-s-dynamic-4t-mk2-s-t108.htm


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## bambino

My first thought was the same but much taller.:dumbcrazy:


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## bambino

Where is a place to get Active Crossovers or what are some companies that make them for home audio? :dontknow:


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## GranteedEV

bambino said:


> Where is a place to get Active Crossovers or what are some companies that make them for home audio? :dontknow:


Digital active crossovers you should look into

DEQX
behringer DCX 
miniDSP
Hypex DSP

otherwise you're talking about design your own analog active XO with opamps etc.


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## bambino

Will a Mono amp work for those and do i need 2 seperate ones or will one do both left and right? Also are those 3-ways? Thanks Grant.:T


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## GranteedEV

Active crossovers require multiple amps, unfortunately. It is probably a waste of a beast of an amp like an XPA-1. However keep in mind that you often need much less power for the tweeter section, so if you got something cheap like Emotiva UPA-5, that would be more than enough for the tweeter and mid section, and the XPA-1s could handle the bass. For a 3-way I recommend a crossover around 350-500 hz although that ultimately depends on the nature of the drivers and the slopes being used. You'll find that 500 total watts into the same drivers with an active crossover will be much louder than 500 watts into a passive crossover simply because there is no energy wasted in the passive crossover section. So the XPA-1 is truly overkill in any active system. The Linkwitz orion IIRC uses the 12-channel/60wpc ATI 6012. It only actually uses 8 of those channels, and the other 4 can be used for surrounds or a matching center. The orion can get VERY loud without clipping simply because of its active nature... that's a total of 240 watts per speaker even though each section is only getting 60.

As for whether they're 3-ways, the hypex is a 2-way active plate amplifier that can be made a 3-way if you add an amp IIRC. The DEQX is 3-way stereo. The behringer is 3-way as well IIRC, although I wish it were 4-way. the JBL MS-8 is for cars and is 4-way so it's kind of sad there's no HT equivalent by JBL at that price ($800). the MiniDSP i don't know much about but it looks great.

Remember, for bi amping you don't always need the most powerful amps in the world. Three 50 watt amps with a tri amped speaker will outperform a single 150 watt amp with a passive speaker!


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## bambino

Thanks for all the info Grant.:T I think that with the way it sounds it may be cheaper to just go Passive and work with it till it's right. It may be more time consumeing but also a great learning experiance with trying to get it right. Once i start rolling on this project be ready for some major questions. As of right now, with all the reading i've been doing i have the basics but not have the science. This will certainly be a trial and error project. Thanks again, Bambino.:T


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## GranteedEV

Make sure to use air core inductors and ESPECIALLY poly or mylar capacitors. Don`t cheap out, especially with electrolytic caps. the distortion they introduce is too high.


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## robbo266317

Hi Bambino, here are some useful links. 
I wish I had them when I was building passive crossovers 20+ years ago, instead of using paper and pencil.
http://www.diyaudioandvideo.com/Calculator/APCXOver/

And another with Zobel compensation and level matching circuits for speakers of different sensitivity.
http://ccs.exl.info/calc_cr.html#second.

As stated above, only use air cored inductors with a resistance as low as possible. I wound my own and tested them with a signal generator and a series capacitor to get them to the correct value. They weigh almost 1 lb each but the dc resistance is only ½Ω for a 3.0 mH inductor.


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## GranteedEV

I just noticed that the hypex DSPs are on sale over at DIY cable for $250 each.

I know $500 may seem like a lot but I genuinely think it's a worthwhile investment. These will give you amplification for the tweeter, amplification for band pass, and let you use the XPA-1s for your woofers. Even just buying a single may be worthwhile in helping you figure out a good passive crossover to use.


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## bambino

robbo266317 said:


> Hi Bambino, here are some useful links.
> I wish I had them when I was building passive crossovers 20+ years ago, instead of using paper and pencil.
> http://www.diyaudioandvideo.com/Calculator/APCXOver/
> 
> And another with Zobel compensation and level matching circuits for speakers of different sensitivity.
> http://ccs.exl.info/calc_cr.html#second.
> 
> As stated above, only use air cored inductors with a resistance as low as possible. I wound my own and tested them with a signal generator and a series capacitor to get them to the correct value. They weigh almost 1 lb each but the dc resistance is only ½Ω for a 3.0 mH inductor.


Thanks Rob. I've been on the first link you posted several times i'll have to chack out the other.:T
Thanks again, Bambino.


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## robbo266317

Hi I have had a look at the drivers you want to use and think the following are good candidates for an 8Ω system with a relatively easy to make crossover.


4 x Dayton RS225-8 8" Reference Woofer - Description 

The Dayton Audio Reference Series was conceived with one goal in mind—low distortion. Each speaker was carefully designed and optimized to offer the highest performance with the lowest distortion levels. At the same time, by focusing on features that contribute to sound quality and eliminating unnecessary frills, the drivers offer value unparalleled in the industry. Dayton Audio Reference Series RS225-8 8" woofers deliver exceptional clarity, detail, and dynamics—and of course, incredibly low distortion. Specifications: *Power handling: 80 watts RMS/120 watts max *VCdia: 1.5" *Le: 0.83 mH *Impedance: 8 ohms *Re: 6.34 ohms *Frequency range: 27-2,000 Hz *Fs: 27.6 Hz *SPL: 86.2 dB 1W/1m *Vas: 2.18 cu. ft. *Qms: 1.44 *Qes: 0.48 *Qts: 0.36 *Xmax: 7 mm *Dimensions: A: 8-3/4", B: 7-3/8", C: 3-1/2".



2 x Dayton RS125-4 5" Reference Woofer 4 Ohm - Description 

The Dayton Reference Series sets a new standard of value in high-performance loudspeaker drivers. Utilizing a low-distortion motor system with two short-circuit paths and a rigid aluminum cone, the Reference Series can outperform drivers that cost several times the price. Their low-distortion characteristics and high excursion capabilities provide exceptional clarity, detail, and dynamics. Woofer features a black anodized cone, heavy-duty 6-hole cast frame, low-loss rubber surround, solid aluminum phase plug, rubber magnet boot, and gold terminals. Specifications: * Power handling: 30 watts RMS/45 watts max * VCdia: 1" * Le: .41 mH * Impedance: 4 ohms * Re: 3 ohms * Frequency range: 65-4,500 Hz * Fs: 76 Hz * SPL: 91 dB 2.83V/1m, 88 dB 1W/1m * Vas: .10 cu. ft. * Qms: 3.97 * Qes: .75 * Qts: .63 * Xmax: 4mm * Dimensions: A: 4-15/16", B: 3-3/4", C: 2-1/8".

1 x Dayton DC28F-8 1-1/8" Silk Dome Tweeter - Description 

Superior European design and performance at a fraction of the cost of similar audiophile silk dome tweeters! Clinically tested and compared to Morel with amazingly similar results! Recommended for crossover points as low as 1800 Hz! Specifications: *Power handling: 50 watts RMS/75 watts max *VCdia: 1-1/8" *Impedance: 8 ohms *Re: 5.5 ohms *Frequency range: 1,300-20,000 Hz *Fs: 637 Hz *SPL: 89 dB 1W/1m *Dimensions: A: 4-5/16", B: 3-1/8", C: 1-5/8"

I haven't built any MTM systems but I would try either:-

M
T
M
W
W
W
W

Or:-

T
MM
W
W
W
W

Any comments on driver selection or configuration is apreciated.
Cheers,
Bill


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## bambino

Thanks Robbo for posting your ideas here. I think because the speaker is going to end up tall the M T M WWWW idea would be best but then i have never built speakers of this caliber before either:dontknow:. Cosmetically i like the other arrangment best. What do you guys think?


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## GranteedEV

If you're going all out... my recommendation is to go even taller...

W
W
M
-T @ ear height and offset to help with diffraction effects (probably not necessary with a waveguide but with most tweeters it's recommended)
M
W
W
|
|
|
|

this will probably help eliminate floor bounce and and give good control over vertical dispersion... it might be like 55-60" tall though. 
If you go 3.5 way instead of 3 way you should also be able to avoid BSC sensitivity loss too. 

On the tweeter, I recommend a pair of these over the daytons. It'll cost you about $60 more for the pair I realize but I really feel like it's worth it because of the controlled wide dispersion.

And if you do end up ordering that, you may want to swap the RS125 with the ZA14w08 driver. They're VERY similar performers, but the real advantage is that the latter is a madisound driver, which means you can get them to design you a crossover schematic at least for the MTM part. The WWMMWW part on the other hand is going to be your headache


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## bambino

That would not be bad either. Somewhere in the 60" area is where i figure they will end up, at any rate the lowest driver will be somewhere in the 16" range from the floor. Do you think that is high enough to eliminate defraction?:dontknow:


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## GranteedEV

Hmm

-W--W-
-M-----
T-------
-M-----
-W--W-

Would likely work better. This basically implies dual opposed woofers. What's more, it would make the box rather inert, similar to the seaton submersive/epik empire type subwoofers. IN this scenario I'd keep the tweeter about 37.5" off the ground and work outwards from there.


----------



## bambino

With that setup the Towers will take up much more floor space then i'd like to give up, i like the idea of all the drivers being inline, it will also make building the box easier as each set of drivers will require seperate chambers.:dontknow:


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## lsiberian

bambino said:


> With that setup the Towers will take up much more floor space then i'd like to give up, i like the idea of all the drivers being inline, it will also make building the box easier as each set of drivers will require seperate chambers.:dontknow:


Why not get a midrange dome? They are already isolated. 

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=285-020

a pair of those would take care of the midrange pretty well.


----------



## bambino

lsiberian said:


> Why not get a midrange dome? They are already isolated.
> 
> http://www.parts-express.com/pe/showdetl.cfm?Partnumber=285-020
> 
> a pair of those would take care of the midrange pretty well.


Good call i'll have to look more into those drivers. Thanks for the suggestion, i forgot all about closed back midranges.:dumbcrazy:


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## GranteedEV

bambino said:


> With that setup the Towers will take up much more floor space then i'd like to give up, i like the idea of all the drivers being inline, it will also make building the box easier as each set of drivers will require seperate chambers.:dontknow:


I meant that the rear drivers would be at the back, just to make sure we're on the same page.


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## bambino

GranteedEV said:


> I meant that the rear drivers would be at the back, just to make sure we're on the same page.


I see, similar to how Definitive has some of there models? Drivers on the front of the box and drivers on the back, hence the opposed woofers you were talking about. I've got it and like it.:T Correct me if i'm wrong.

Thanks grant.


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## GranteedEV

bambino said:


> I see, similar to how Definitive has some of there models? Drivers on the front of the box and drivers on the back, hence the opposed woofers you were talking about. I've got it and like it.:T Correct me if i'm wrong.
> 
> Thanks grant.


Yes, in a 3.5 way speaker The two RS225s on the front would be crossed to the RS125s via low and high pass filters respectively.

For example perhaps the cutoff point could be 750hz 4th order (just theoretically). The mid would start to go down 24db/octave (high pass filter) and the woofer would start rising @ 24db/octave (low pass filter)

now difrraction loss usually implies somewhere around 4-6 db of loss as a result of the backward wave where your baffle is no longer infinite relative to the wavelength. Let's just go with a common frequency of 500hz (this is ultimately dependant on YOUR baffle.. it may be 350hz, it may be 400 etc)

so you would start to roll in your rear woofers at the frequency where they radiate spherically. This should augment the sound of the front woofers and give you flat response. Essentially it's a different way of baffle step compensation.

A good example of a 3.5 way build is the Zaph ZDT3.5 - I suggest you read his build page. .


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## robbo266317

OK I have put together a "How to design a passive crossover guide"

Step One:- Identify the drivers you are going to use and identify their DC resistance (Re), Inductance (Le), Sensitivity (SPL ) and frequency range.

e.g.

Dayton RS225-8 8" Reference Woofer - Description 

Specifications: *Power handling: 80 watts RMS/120 watts max *VCdia: 1.5" *Le: 0.83 mH *Impedance: 8 ohms *Re: 6.34 ohms *Frequency range: 27-2,000 Hz *Fs: 27.6 Hz *SPL: 86.2 dB 1W/1m *Vas: 2.18 cu. ft. *Qms: 1.44 *Qes: 0.48 *Qts: 0.36 *Xmax: 7 mm *Dimensions: A: 8-3/4", B: 7-3/8", C: 3-1/2".



Dayton RS125-4 5" Reference Woofer 4 Ohm - Description 

Specifications: * Power handling: 30 watts RMS/45 watts max * VCdia: 1" * Le: .41 mH * Impedance: 4 ohms * Re: 3 ohms (2 in series = 6 Ohms) * Frequency range: 65-4,500 Hz * Fs: 76 Hz * SPL: 91 dB 2.83V/1m, 88 dB 1W/1m * Vas: .10 cu. ft. * Qms: 3.97 * Qes: .75 * Qts: .63 * Xmax: 4mm * Dimensions: A: 4-15/16", B: 3-3/4", C: 2-1/8".

Dayton DC28F-8 1-1/8" Silk Dome Tweeter - Description 

Specifications: *Power handling: 50 watts RMS/75 watts max *VCdia: 1-1/8" *Impedance: 8 ohms *Re: 5.5 ohms *Frequency range: 1,300-20,000 Hz *Fs: 637 Hz *SPL: 89 dB 1W/1m *Dimensions: A: 4-5/16", B: 3-1/8", C: 1-5/8"

Step two:- Choose your speaker configuration.

4 x Bass Drivers:-

Re = 6.34 Ohms









Le = 0.83 mH
SPL: 86.2 dB 1W/1m
Frequency range: 27-2,000



2 x Midrange:-

Re = 6 Ohms










Le = .41 mH
SPL: 88 dB 1W/1m
Frequency range: 65-4,500 Hz



Tweeter:-

Re = 5.5 ohms
Le: .41 mH
SPL: 89 dB 1W/1m
Frequency range: 1,300-20,000 Hz



Step three:- Choose Crossover Frequencies. 

Since the midrange driver's upper frequency is 4,500 kHz and the tweeter's lower frequency is 1,300 Hz you choose the mid point which is 2,900 Hz, which can be rounded up to 3,000 Hz without any problems. (A lot of designers try to avoid this as it is right in the middle of normal speech band and they try to cut in lower at 1,5 kHz or higher at 4.5 kHz)

The large overlap available for the Bass/Mid point provides a lot of flexibility.


Step four:- Put the figures into appropriate software and choose what order crossover you wish to build. e.g. http://www.diyaudioandvideo.com/Calculator/APCXOver/

With the large overlap these drivers have it is possible to use a first order design to maintain simplicity.

















Step five:- Matching the driver sensitivities.

The least sensitive driver is usually the Bass which is also the case in this scenario.

Bass: 86.2 dB 1W/1m
Mid: 88 dB 1W/1m
Tweeter:89 dB 1W/1m

So to ensure a flat response we need to drop the mid by 1.8 dB and the tweeter by 2.8 dB.

http://ccs.exl.info/calc_cr.html#lpad

The values calculated are very precise. The human ear however, is not, and the closest value of resistor will be fine in 99% of cases. 
Depending on the power rating of your speakers you should use either 5 Watt or 10 Watt non-inductive wire-wound resistors.

















Step six:- Zobel Networks and Baffle step compensation. 

The need for these is highly debated. I will leave this for a future endeavour. (Unless someone else would like to take up the challenge.) :bigsmile:


----------



## bambino

Awesome post Robbo, thank you for all the work i'm ordering the drivers next week as some of them are out of stock. This will give me plenty of time for crossover work and cabinet design.:T

Thanks again, Bambino.


----------



## bambino

Well i allready know you guys know i'm nuts so i went ahead and orderd my drivers today i pretty much have the crossover worked out using the online calculaters available. The drivers i have on the way for the Towers are 8 Rs225-8 8" drivers (4 for each tower) 8 Rs100-8 4" drivers (4 for each tower) and 4 Vifa NE 19VTT-04 tweeters (2 per tower).
For the center channel i have 4 of the Rs180-8 7" drivers and 4 of the Rs100-8 4" drivers and 2 of the Vifas.

Any thoughts on this other then i'm nutty for even trying to put this together any thoughts would be much apprieciated. Thanks, Bambino.:dumbcrazy:


----------



## Moonfly

I'll be watching this one with interest Bambino as I am delving into this myself as well. I am taking it a little slower and starting with a cheaper kit, and hopefully what I learn can be combined with what you learn here for future projects.


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## 1Michael

So for your first project you are designing a 3way with 4 woofers, 4 mids and 2 tweeters per box?:rolleyesno: Good luck...


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## Moonfly

I wasnt that brave :R


----------



## 1Michael

Designing a 2way for the first project has always been the recommended procedure to minimize wasting cash. Of course for those people that have plenty of that to throw away then hey:spend::spend::spend: Where is that head slap smiley when I need it hehehe.


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## bambino

buggers said:


> So for your first project you are designing a 3way with 4 woofers, 4 mids and 2 tweeters per box?:rolleyesno: Good luck...


I was expecting a comment like that from you buggers:bigsmile:. I'll be sure to PM you if i fail that way the world of audio doesn't know.:heehee:


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## bambino

Moonfly said:


> I'll be watching this one with interest Bambino as I am delving into this myself as well. I am taking it a little slower and starting with a cheaper kit, and hopefully what I learn can be combined with what you learn here for future projects.


Thanks Moonfly, i'll be keeping all informed after i get started here in a week or two. I just hope it doesn't hurt too bad from jumping head first into the shallow end.:whistling:


----------



## FlashJim

bambino said:


> I was expecting a comment like that from you buggers:bigsmile:. I'll be sure to PM you if i fail that way the world of audio doesn't know.:heehee:


oooooh! Sparks 'n flames! We'll need pictures and a YouTube video!!


----------



## bambino

Ok. I've gone off the deep end, i changed my entire speaker lineup to 6-6.5" Peerless drivers, 4-5.25" Peerless drivers and 4-1" Vifa tweeters per tower. All stacked up this makes for a speaker box in the 70" tall range:yikes:. I've decided to go with an Active crossover for simplicity:heehee:.

Please come on with the suggestions, questions or bashings, all will be highly appreiciated.:dumbcrazy::T


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## bambino

I forgot to mention the drivers are here. Time for the fun to begin.:bigsmile:


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## sparky77

All I can say for now is 4 tweeters is too many, massive comb filtering issues. Even if your going for extremes, 2 is probably enough. We're gonna need a lot of specs and model numbers to find out just how deep you dug yourself in......


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## robbo266317

You get a lot more flexibility with an active crossover. Have you chosen which one you are going with?

Cheers,
Bill.


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## 1Michael

Multiple tweeters with multiple mids is an extremely bad idea unless you are doing a line array, but like I said before, if sound quality is not an issue then go for it.


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## bambino

buggers said:


> Multiple tweeters with multiple mids is an extremely bad idea unless you are doing a line array, but like I said before, if sound quality is not an issue then go for it.


You inspire me buggers. What do you suggest? It's not too late.


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## bambino

robbo266317 said:


> You get a lot more flexibility with an active crossover. Have you chosen which one you are going with?
> 
> Cheers,
> Bill.


I'm thinking the DCX2496.:dontknow:


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## bambino

sparky77 said:


> All I can say for now is 4 tweeters is too many, massive comb filtering issues. Even if your going for extremes, 2 is probably enough. We're gonna need a lot of specs and model numbers to find out just how deep you dug yourself in......


Funny thing, for some reason when i orderd the drivers the specs were on the PE web page now they are gone. I'll post model #'s in awhile that way you guys can help dig me out.:whistling:


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## robbo266317

bambino said:


> Funny thing, for some reason when i orderd the drivers the specs were on the PE web page now they are gone. I'll post model #'s in awhile that way you guys can help dig me out.:whistling:


It is less of a problem since you are going with the DCX2496, It has a lot of features and options so matching the drivers should not pose too big a problem. I see it's listed as ~us$300 and considering I spent au$50 on copper wire for my crossovers 20 odd years ago it represents good value as you can also set the delay for each speaker to time align them.

I look forward to seeing the finished product. :T


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## Moonfly

I have an FBQ2496 lying around. Assuming I follow this route in the future, would that be usable as an active eq. It would be a shame not to use it if its possible. I originally got it for subwoofer eq, but I just havent needed to use it.


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## 1Michael

bambino said:


> You inspire me buggers. What do you suggest? It's not too late.


Well first you need to determine what it is you are trying to accomplish.
How much cash will you spend?
How big of a box can you handle?
How loud do you want it to be?
Size of room, amp driving it etc.

If you feel you must design your own xover, Start With A 2Way!!!!!!! Otherwise you will waste your money, and the project will sound like garbage. I guaranty that. Do not listen to the "it's not that difficult to design an speaker" crowd. I have built Many speaker systems in my attempt to find high sound quality and I will tell you that the majority of supposed designers are deaf. But there are proven designs ( those that have been built and listened to by many people, like me...) that will sound quite awesome and provide years of listening enjoyment. So do you want quality sound or not? 
Do you have all the necessary test equipment? No. Then how do you expect to design the Xover? Use published data? Ok there is another major problem. Unless you know the data has been tested by an outside person, like Zaph or many others, the data will likely be inaccurate. I could go on and on but the fact is that for a diy speaker project there needs to be some established goals defined and then we start talking about what drivers to buy. What we do not want to do is say is " Hey i bought these really cool looking drivers and I need help to design this 7.5 way speaker":rolleyesno: That is just a complete waist of money and extremely bad advise:T


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## bambino

buggers said:


> Well first you need to determine what it is you are trying to accomplish.
> How much cash will you spend?
> How big of a box can you handle?
> How loud do you want it to be?
> Size of room, amp driving it etc.
> 
> If you feel you must design your own xover, Start With A 2Way!!!!!!! Otherwise you will waste your money, and the project will sound like garbage. I guaranty that. Do not listen to the "it's not that difficult to design an speaker" crowd. I have built Many speaker systems in my attempt to find high sound quality and I will tell you that the majority of supposed designers are deaf. But there are proven designs ( those that have been built and listened to by many people, like me...) that will sound quite awesome and provide years of listening enjoyment. So do you want quality sound or not?
> Do you have all the necessary test equipment? No. Then how do you expect to design the Xover? Use published data? Ok there is another major problem. Unless you know the data has been tested by an outside person, like Zaph or many others, the data will likely be inaccurate. I could go on and on but the fact is that for a diy speaker project there needs to be some established goals defined and then we start talking about what drivers to buy. What we do not want to do is say is " Hey i bought these really cool looking drivers and I need help to design this 7.5 way speaker":rolleyesno: That is just a complete waist of money and extremely bad advise:T


The money is spent, the boxes can be whatever, i want them to be loud and clean, power isn't an issue as i've got more amps lying around then 3 house holds should need. I have allready gone booboo by getting the "cool" drivers but they are quality and also were cheap. I have no test equipment which is why i decided on an Active crossover. As far as laying out 12 drivers on the Baffle i haven't a clue.
Thanks for your input buggers as like i said it does truly inspire me and am willing to take any help or comments that come my way. 
When i get a minute i will list the drivers that i have and maybe you can help push me in the right direction as i allready know i have jumped in to the shallow end head first. Thanks again.:T


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## bambino

The other problem is like i posted before, i have know way to determine box size as for some reason PE can't provide me with the proper specs for the drivers.:rolleyesno:


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## SirKevi

Hi Bambino I think the fun is just starting. If you have the money pick up a woofer tester, some box software,
read about crosovers till your head hurts. The best part is with a digital loudspeaker processor none of your crossover is set in stone. I have 8 drivers per side run through a bbe processor and quad amped. It has taken me over a year of tweaking but when you get it right nothing else is more rewarding or fun. if worst comes to worst don't use all of the drivers in this project and just let the fun begin.


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## bambino

My head started hurting from the day i decided to start this project, LOL! Seriously, i have done so much reading and research that is part of why i decided to go with the Active crossover rather then passive. I think that this will be a very rewarding experiance and thank you for your comments. The one thing i do wish i had done was pick up some box software when it was on sale last month along with a woofer tester which is on sale this month. I will have invested in 3 speakers (L, C, R) what one of my current Towers are worth so i think just with that said i have saved a ton:spend:. Thanks again, Bambino.:T

Time to get Reading and building somemore.


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## GranteedEV

Multiple tweeters may work. The RBH T2 uses something like this (3 tweeters with... odd... spacing) and most people who have heard it love it.

My recommendation of course would be to cut it down to 2 tweeters a box, and go with waveguide dipoles a la Revel Ultima Salon (the original, not the second). That is, one tweeter fires backwards and the other fires forwards.


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## mjcmt

I've built 4 sets of speakers from Madisound. They offer a number of kits if that is your choice. Or if you choose the drivers, their talented team will design and build the x-overs for very cheap, depending on the quality of the x-over components. A simple phone call to one of their designers and you will be on your way, or you can use one of their tested kits. Here is a link to some of their kits. Good luck.
http://www.madisound.com/store/index.php?cPath=35


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## bambino

mjcmt said:


> I've built 4 sets of speakers from Madisound. They offer a number of kits if that is your choice. Or if you choose the drivers, their talented team will design and build the x-overs for very cheap, depending on the quality of the x-over components. A simple phone call to one of their designers and you will be on your way, or you can use one of their tested kits. Here is a link to some of their kits. Good luck.
> http://www.madisound.com/store/index.php?cPath=35


Thanks for the info, i was under the impression that madisound would only design crossovers for folks that bought there products but that will be something to look into. Thanks again.:T


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## GranteedEV

bambino said:


> Thanks for the info, i was under the impression that madisound would only design crossovers for folks that bought there products but that will be something to look into. Thanks again.:T


They only have sufficient information for speakers they themsleves sell. It takes a lot of self-measured in-baffle information to do it and I doubt they've got it on drivers that probably haven't been inside their facility.

With that said I can think of a few individuals who would design you a crossover if you sent them measurements made by yourself. I don't know if they would do the four tweeter thing though.


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## mjcmt

GranteedEV said:


> They only have sufficient information for speakers they themsleves sell. It takes a lot of self-measured in-baffle information to do it and I doubt they've got it on drivers that probably haven't been inside their facility.
> 
> With that said I can think of a few individuals who would design you a crossover if you sent them measurements made by yourself. I don't know if they would do the four tweeter thing though.


This is not true. If you had had the driver's parameters, they could use their LEAPs program to design and build you x-overs. But why not use their selection of fine drivers form the top manufacturers they carry. Manufactures like Pearless, Vifa, SEAS and others offer budget drivers as well.


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## 1Michael

Using the driver parameters given by the manufactures is the worst way to design a Xover. The specifications are Rarely reliable.
You must send the drivers to Madisound along with the box parameters, but this will only give you mediocre results. I speak from first hand knowledge.


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## mjcmt

I speak from experience too. The bass driver Vas will give you box size and they can design the x-over. you can fin tune by ear to modify if you want.


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## bambino

Update: I built a test box for the 6-6.5" drivers and tested it, i must say i wasn't that impressed with the lower frequencies but they sure shine in the mids. This was all done using no crossover at all and just running a test tone disc mixed with some techno type music. One thing is for sure it is gonna tax the XPA-1's, i could tell that from just the mild volume and an 8ohm load.
Going to experiment with another size box just not sure weather to go up or down in size, right now i'm at 3cu.ft. per 6 drivers, guess the only way to go is down or build another test box that is bigger:dontknow:. Oh, this is also a sealed box, i can't get the parameters of the drivers to try a ported one.:hissyfit:


----------



## mjcmt

bambino said:


> Going to experiment with another size box just not sure weather to go up or down in size, right now i'm at 3cu.ft. per 6 drivers, guess the only way to go is down or build another test box that is bigger:dontknow:. Oh, this is also a sealed box, i can't get the parameters of the drivers to try a ported one.:hissyfit:


Are you using Dayton drivers from Parts Express that you initially said? I did a quick look-up an it seems that most of them list the Vas parameter. (for example the Dayton PA165-8 6" has a Vas of .28 cu ft) The Vas is the internal volume of a cabinet that Dayton recommends for this driver. If you use 6 bass drivers take the volume of one and multiply times six. This will be the internal volume of your cabinet needed for these drivers to perform. Remember to factor in the volume of the speaker cone, port, internal bracing, x-over, etc. when calculating the internal volume as you size your cabinet. Internal dampening material is not included because it breaths so don't factor this in.

If you are building a basic box style cabinet try to have its dimensions closer to by multiples of 1.66 to minimize the internal reflections multiplying on itself, though it is not necessary to be too exact because you are using dampening material. For example a cabinet size of 8" x 13-1/4' x 22" uses multiples of 1.66.

If you want to use a port you will need the drivers resonant frequency (Fs)., but cabinet size will remain the same except the free air space of the port is not included.

I hope this helps.


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## robbo266317

So for a Vas of .28 and using 6 drivers the volume should be 1.68 cu ft and you have double that.
(That is if you are using those drivers)


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## mjcmt

1.68 cu ft is correct.
What do you mean by "you have double that"?


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## robbo266317

I'ts not quite double, but close


bambino said:


> right now i'm at 3cu.ft. per 6 drivers


----------



## mjcmt

As an illustration w/ the Dayton PA165-8 drivers:
They have a Vas of .28 cu ft or 484 cu in. Six drivers needs a volume of 1.68 cu ft or 2903 cu in.
Using the 1.66 rule a cabinet with an internal volume of 8-3/4" x 14-1/2" x 24" has an internal volume of 3045 cu in. Remember that this is internal volume.
You can fine tune it exactly and remember to add more internal volume as the cone and magnet, bracing, x-over, and port take up space, so you will have to measure these items...not an exact art, but you can come very close. You may also need to shift the cabinet dimensions to accommodate the drivers physical mounting dimensions.

Also remember that the drivers I chose for the illustration are PA midrange drivers with a Fs of 87 which is not so low for subwoofers, and not a real bass driver which will go lower and have a greater Vas. (I just picked the first one I saw on Parts Express)
What is your exact driver that you bought?


----------



## bambino

Thanks for the replys. The driver is a 6.5" peerless 831735, not even parts exress can provide the specs i would like to have to build an accurate box unless you guys think the ones provided in the description of the driver are enough. The guy from PE told me that he would reccomend a .5 cu.ft. box sealed but thats the best info he could give and i think after hearing these last night i would at least like to try a ported just so i can hear what that sounds like. Any suggestions? Oh and i think i may back off to using only 4 drivers per Tower.


----------



## mjcmt

bambino said:


> Ok. I've gone off the deep end, i changed my entire speaker lineup to 6-6.5" Peerless drivers, 4-5.25" Peerless drivers and 4-1" Vifa tweeters per tower. All stacked up this makes for a speaker box in the 70" tall range:yikes:. I've decided to go with an Active crossover for simplicity:heehee:.





bambino said:


> Thanks for the replys. The driver is a 6.5" peerless 831735, not even parts exress can provide the specs i would like to have to build an accurate box unless you guys think the ones provided in the description of the driver are enough. The guy from PE told me that he would reccomend a .5 cu.ft. box sealed but thats the best info he could give and i think after hearing these last night i would at least like to try a ported just so i can hear what that sounds like. Any suggestions? Oh and i think i may back off to using only 4 drivers per Tower.


Peerless makes good products. The first speakers I build used a 6-1/2" peerless mid/bass and a vifa 1" dome tweeter.

Here it is:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-281&FTR=831735
Vas of .9 cu ft/ 1555 cu in
For 6 drivers 5.4 cu ft/ 9331 cu in

I would separate your 6 bass drivers from your 4 midrange drivers w/ a partition for better clarity. You will have to find the Vas for your 5-1/4" mids as well to determine cabinet size for them. If you don't separate the mids from the lows you will have to incorporate their volume with the bass drivers in your cabinet dimensions. The tweeters are sealed so they don't cause a problem.

Here's a thought: Two 5-1/4" mids and one tweeter in a Di'Apolito MTM configuration in its own cabinet spiked and sitting on top of your bass unit w/ four 6-1/2" bass drivers in there own cabinet.


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## bambino

I will try a test box in the .9cu.ft range and see how it sounds with a single drive unit. Thanks for the advice Mike.:T


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## 1Michael

You need to use an enclosure design software program to determine the box size:whistling:


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## mjcmt

1Michael said:


> You need to use an enclosure design software program to determine the box size:whistling:


No you don't. All you need is a pencil, paper, calculator, and the drivers parameters. A program will not tell you what materials, bracing, etc. This comes from experience and seeing other good designs.


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## bambino

1Michael said:


> You need to use an enclosure design software program to determine the box size:whistling:


I know I know.:sad: Just tried what was recomended to me by PE.:coocoo:



mjcmt, no offense but the calculation of allmost 6cu.ft. has got to be way off, i don't believe using just Vas to come up with a box size is right as all Vas is, is the stiffness of the driver and how easy it moves.

Gonna need a program:spend:.


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## 1Michael

You do not use the vas for the enclosure size unless you are a complete nOOb. Now where did I place that head slap smiley?


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## 1Michael

bambino said:


> Gonna need a program:spend:.


This is free http://www.pvconsultants.com/audio/boxmodel/unibox.htm


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## bambino

1Michael said:


> You do not use the vas for the enclosure size unless you are a complete nOOb. Now where did I place that head slap smiley?


:sn: How's that? Best i could come up with.


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## mjcmt

bambino said:


> mjcmt, no offense but the calculation of allmost 6cu.ft. has got to be way off, i don't believe using just Vas to come up with a box size is right as all Vas is, is the stiffness of the driver and how easy it moves.
> Gonna need a program:spend:.


Vas is not stiffness of driver. Vas is the air volume w/ the same compliance as the driver. Speakers w/ high Vas have looser suspension and need larger cabinets, speakers w/ low Vas drivers have stiff suspension and need smaller ones.
Xmas is the driver extension. Qms is the cone moving mass. fs is speakers resonant frequency in free air. Qts is drivers total Q.

And yes, a software program will determine the port volume if you go vented. I suspect that a program w/ give you volume Vb more accurately. I calculated on a free cheap program (they aren't all the same) and came up w/ 1.1 cu ft not .9 for a vented box for a single Peerless 831735. Also a 4-1/3" x 2" pvc port to get a f3 (3db down) of 34hz.

I have always used a designer from Madisound w/ LEAPS program to do my x-overs, and he told me to use the Vas for cabinet size because dampening material in essence makes the drivers acoustic properties think it is in a larger cabinet. I never gave it much thought so I always used the Vas. So I'm not sure now, but trusted him and his design sense w/ years of experience and a LEAPS program.


----------



## bambino

mjcmt said:


> Vas is not stiffness of driver. Vas is the air volume w/ the same compliance as the driver. Speakers w/ high Vas have looser suspension and need larger cabinets, speakers w/ low Vas drivers have stiff suspension and need smaller ones.
> Xmas is the driver extension. Qms is the cone moving mass. fs is speakers resonant frequency in free air. Qts is drivers total Q.
> 
> And yes, a software program will determine the port volume if you go vented. And I stand corrected that a program w/ give you volume Vb more accurately.


Looser suspension is what i meant by "stiffness", i should have been more clear, at any rate i have determined Vas will not yield me my box size by doubleing it.


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## mjcmt

bambino said:


> Looser suspension is what i meant by "stiffness", i should have been more clear, at any rate i have determined Vas will not yield me my box size by doubleing it.


Its is actually the air volume.


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## bambino

mjcmt said:


> Its is actually the air volume.


:scratch: Now you are starting to confuse me, not sure where all this is going so i'll quit untill i come up some good info and actually get somewhere. Thanks:T


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## mjcmt

bambino said:


> :scratch: Now you are starting to confuse me, not sure where all this is going so i'll quit untill i come up some good info and actually get somewhere. Thanks:T


I agree and wasn't going to say any more. I didn't want that cause problems to you. It is a bit hard for me to converse on a forum on weighty matters of technology. It may be best to follow others advise. Forget I interjected.
Incidentally, I never did say anything different than that Vas is the volume of air needed for a particular driver (determined by particular variables). Let's leave it there. 
I appreciate your challenging project and good luck to you.


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## GranteedEV

the program you should get is martin j king's workaheets ;D

anyways vas correlates to final box size but so does qts and of course fs will affect the shape of the curve, le and BL can affect sq, znom will affect required amplification, and xmax/sd/Pe can affect output.

i always reccommend a box q from .4 to. 66 for naturality.


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## Moonfly

for clarification:



> *Vas/Cms* - Represents the volume of air that when compressed to one cubic meter exerts the same force as the compliance (Cms) of the suspension in a particular speaker. The compliance or stiffness of the driver suspension is determined by the surround and the spider. It is simply a measurement of its stiffness.


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## bambino

mjcmt said:


> I agree and wasn't going to say any more. I didn't want that cause problems to you. It is a bit hard for me to converse on a forum on weighty matters of technology. It may be best to follow others advise. Forget I interjected.
> Incidentally, I never did say anything different than that Vas is the volume of air needed for a particular driver (determined by particular variables). Let's leave it there.
> I appreciate your challenging project and good luck to you.


No problems at all, in fact i appreciate all of your help and am still open to anything you have to share. What i meant was i was just going to leave this alone untill i get somewhere with the project or some useful help, actually once REW beta is full bore i think that will help a million. 
Remember, all thoughts and suggestions are welcome as well as helpful so don't want you to step out as you have been helpful. In fact i was curious to know if you used just the info given by PE in there description of the driver to come up with your previous post where you stated a box size for 1 driver ported and what program you used.:T


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## Jstslamd

Well bambino up until now I thought I was the only one that was about to get my **s into something over my head. I just received all of the drivers and two pre built xover's ( yes yes I know it's a bad route) to build a set of garage speakers. I figured at worst it'll be a learning experience or at best I will get some decent speakers out of it. So long story short I wish you luck in this as I hope things all work out for myself. let me know how you make out maybe we can swap some amateur thoughts on the subject.


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## 1Michael

mjcmt said:


> Its is actually the air volume.


I don't want to sound argumentative but I do believe in the details because sound reproduction is my passion.
Vas represents the equivalent volume of air having the same acoustic compliance (i.e. stiffness or springiness) of the driver suspension in free air. In other words, it indicates the equivalent volume of air that would produce an air-spring with springiness (compliance) equal to that of the driver’s suspension; it is NOT the recommended box volume for a driver. 
I made the mistake of using Vas for the enclosure volume on my first full range speaker project (a Wilson Watt Puppy Clone) with dual 10's, but after running the numbers through a enclosure software program, I found out that I had made the box double the size required:rolleyesno: add head slap smiley here. Live and learn


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## BuddahX

I would listen to 1Michael. He helped me with my stuff n he knows what hes talking about.


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## mjcmt

1Michael said:


> Vas represents the equivalent volume of air having the same acoustic compliance (i.e. stiffness or springiness) of the driver suspension in free air.


Thank you for confirming what I said in an early post. That is exactly what I said in my very first definition about VAS until it got misinterpreted. By the end I just gave a brief 4 word answer.


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## 1Michael

I was responding to this incorrect statement by you...


mjcmt said:


> The bass driver Vas will give you box size


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## robbo266317

mjcmt said:


> Thank you for confirming what I said in an early post. That is exactly what I said in my very first definition about VAS until it got misinterpreted. By the end I just gave a brief 4 word answer.
> 
> I was responding to this incorrect statement by you...
> Quote:
> mjcmt wrote: View Post
> The bass driver Vas will give you box size


Ok, we all make mistakes, even me, :unbelievable: What we need to do is help each other and point out where we have delivered incorrect information. Then we move forward to jointly help out the person whose thread we are hijacking.. :bigsmile:


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## bambino

robbo266317 said:


> Ok, we all make mistakes, even me, :unbelievable: What we need to do is help each other and point out where we have delivered incorrect information. Then we move forward to jointly help out the person whose thread we are hijacking.. :bigsmile:


Very well said Bill. Thank you and to all that are helping along the way.:T


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## robbo266317

*Peerless 831735 in winisd*

Ok, I put the parameters in Winisd and came up with the following:- 








Note: this is for 1 driver only for 2 drivers double the box size. If you want the winisd file I will send it to you or I can run it again with however many drivers you want in the box. If you would like the port sizes then let me know if it is a tube or slot port.

I hope this is useful.
Cheers,
Bill.


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## bambino

Hey Bill. Just curious if your using the Alpha version or beta? Those plots look really nice, i would like to do a ported box for 4 of the 6.5" drivers so i can hopefully get them to dig deeper. I did a model in the beta version and came up with somewhere in the area of 4.5 cu.ft. with a 3"X? length, if you want to model that configuration and see what you come up with and post the graph and port size that would be great. Thanks again for all your help.:sn:


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## robbo266317

OK, for a configuration with four drivers you can have the standard alignment or for -1.5dB you can gain an extra ~10Hz 









The cabinet size is on top and the port size below.

Cheers.

Edit: winisd chose a 4"port


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## GranteedEV

Hey, you're doing this active, with a DCX, right?

How about making an open baffle dipole speaker?


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## bambino

GranteedEV said:


> Hey, you're doing this active, with a DCX, right?
> 
> How about making an open baffle dipole speaker?



Yes to the DCX. I'm not sure where to begin designing an open Baffle design which is why i have stuck to the traditional box speaker. Are you refering to Open Baffle such as found in the Statements then i really haven't a clue where to begin:dontknow:. Any suggestions just for conversations sake?


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## GranteedEV

bambino said:


> Yes to the DCX. I'm not sure where to begin designing an open Baffle design which is why i have stuck to the traditional box speaker. Are you refering to Open Baffle such as found in the Statements then i really haven't a clue where to begin:dontknow:. Any suggestions just for conversations sake?


the Statements use a transmission line, where the rear wave of the driver is controlled and brought back into the air in phase with the forward wave for an ambient effect. Think of it as one relatively long port that doubles as an enclosure for a unique effect! there of course is an acoustic impedance mismatch between the air and the transmission line which in turn means the wave inside the line can actually reflect right back into the line. 

you can read up a bit on transmission lines at a site called quarterwave... i honestly still dont quite grasp the concepts.

an open baffle speaker otoh would be a dipole. normal dipoles are electrostatic/planar type speakers but those have their own share of issues. here you are putting the dynamic cone drivers in a 'frame'. what happens then is that the rear wave is in free air - no box, no line. what the driver 'sees' is similar to an infinite baffle - an infinitely HUGE box! but since the rear wave of any cone is normally kept isolated or forced into phase, we normally dont think about it. here however we dont want to isolate it - yes the pistonic nature somewhat changes but the goal is to have a figure 8 polar response. the rear wave will actually cancel much of the forward wave, at least to the sides. this takes away the 90 degree side wall as any issue, and this is where most speakers' response least mirrors their on axis response.. now the rear wave, about 4 feet from a wall, reflects back and hits your ears as a controlled reflection - essentially bringing the recording into your room for an extremely natural sound and playing to human perception of sound in a space more realistically. no box is actually one of the best kinds of boxes! 

the tradeoff with open baffle is that you must use active equalization to EQ some cancelations and combinations at specific frequencies to a flat response. that is why only an active speaker tenss to do it best although some claim their passive dipoles sound great.

the other tradeoff is that instead of a baffle step transition region like in a box speaker, you instead have a 6db/octave rolloff towards fs starting at some point. this is where your drivers and amplification and dcx can be used to eq it out.

at fs, the free air resonance is the same as the box resonance just like an infinite baffle. you will get a 12db/octave rolloff like any sealed box, plus 6db/octave rolloff of the dipole for an 18db/octave rolloff. this should be fine for any sufficiently low fs driver. dipole bass also has measurably good room response with much less cancelation due to room nodes and modes! so have your dipoles operate down to around 35hz and cross them 4th order around 55hz for some of the best bass out there.

the most extensive sites explaining this kind of speaker would be LinkwitzLabs, Musicanddesign, and also the same quarterwave website.


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## bambino

Allthough I will still probly end up doing boxed speakers i will give those sites a look as that is a very interesting concept. I actually have several baffles cut out for the different test boxes i have been doing so after i do abit of reading i may just give them a shot as i have nothing to lose but time.
I remember years ago Legacy built some speakers that had like four 15" drivers arranged in this type of way, i always remember thinking how do those produce any kind of great sound without being enclosed but now i think i understand. Thanks Grant.:T


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## GranteedEV

bambino said:


> Allthough I will still probly end up doing boxed speakers i will give those sites a look as that is a very interesting concept. I actually have several baffles cut out for the different test boxes i have been doing so after i do abit of reading i may just give them a shot as i have nothing to lose but time.


Whether dipoles are your thing or not, Seigfried Linkwitz is the type of guy whose work anyone interested in sound reproduction should read. He's truly one of the best at it and his white papers and editorials are just plain educational. When I think of people who truly explore loudspeaker design, he's right there at the top of my list with a few others. He's most known for the 4th order linkwitz-riley crossover which is 6db down at crossover point with useful phase shift characteristics, but everything else he's contributed may be a lot more significant. And that's saying a lot considering how many speakers today use LR4 crossovers.

His Linkwitz Orion is considered by many to be among the best speakers out there when it comes to recreating stereo recordings, and if I could afford it It would right there on top of my list of speakers I want to build.

Like I said earlier though, active EQ is sort of the heart and soul of a dipole speaker. Done correctly it'll bring a good recording right into your home. Done wrong and you get the "this is why we use a box" effect of strange cancelations and peaks and seeming "bass-less-ness". But since you have a DCX, like you said, all you really have to lose is time and baffles lol! You definitely have enough drivers to get great dynamics and output!


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## robbo266317

Hi Bambino,
It was using winisd alpha. 
As Grant said you should check out the quaterwave site. I am still using my TLs which I built 25 years ago (doing all the calculations from first principles, didn't have any of these fancy online calculator things back then) and people still comment on how good they sound.

Another good site to check out is http://www.t-linespeakers.org/ there are some unique designs including the Seraphim.


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## bambino

Thanks again guys, i've got a ton more reading to do.:T


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## robbo266317

How would four of these go in a tapped horn?


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## 1Michael

Very few drivers will work in a horn, due to the forces exerted the drivers tend to disintegrate.


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## bambino

I'm having trouble enough trying to get a box size that makes me happy, no way will i attempt a horn build. Just yet that is.:heehee:


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## digital desire

If you want to keep it analogue in the active crossover, I can recommend these guys:
http://www.marchandelec.com/
Thy make some pretty high end stuff, and still offer a lot of it in kit form if you like to roll your own.


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## bambino

That is some nice looking stuff unfortunatly the price of one of there crossovers is more then i paid for all of my drivers. I have allready purchased a DCX2496 also just begging to get used. Thank you for the link that really is some nice stuff.:T


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## digital desire

OK, cool. Here is some more reading about it:
http://redspade-audio.blogspot.com/2010/06/active-options.html

If it were mine, I might be inclined to go with a one box solution, like linkwitzlab does in a few of their solutions, once you get the design nailed down. Get three amp modules and the crossover all in one box per speaker. Sounds like a neat project, keep us updated.

Amp module for instance:
http://www.marchandelec.com/pm224.html
In kit form, they are 40% off list price.


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## bambino

Thanks again, that is some interesting reading that i'm gonna have to get back to and wish i had known about before making several of my purchases, the miniDSP is one that comes to mind i kind of wish i had gotten that over the DCX. Well i'm going back to read some more, that is good stuff.:T


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## bambino

So i've got my DCX 2496 Pro and now i'm wondering if it will do a stereo 3-way setup like i'm planning it seems like i've read that it will but the inputs/outputs on the back tell me it won't. I will be getting out the owners manual but was just hopeing for a quick answer.:T






NEVERMIND, it's amazing what a little quick reading will do.:dumbcrazy::clap:


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