# Advice needed to build new 3 way active system



## Zeverin (Jan 14, 2008)

Hi.
I'm planning my new system. I want to build a 3 way active system (front speakers).
My current ideia is to use the ULTRADRIVE PRO DCX2496 as the crossover. The amplifiers will be 3 A500 also from behringer (one for each channel).
The drivers configuration will be MTMWW. The tweeter is the Seas 27TBFC/G, the midwoofers Dayton RS180 and the woofers RS270. The box will be sealed because I want the most clean and "fast" sound I can achive. The midwoofers and woofers will be wired in parallel (4 ohm load on the amplifier). I would like to add a third woofer (MTMWWW), but that would have a dificult impedance for the amplifier. Why another 3rd woofer? Because of the added dinamics and lower distortion numbers at a given listening level. Any solutions?
I currently have a TC 2000 15" subwoofer in a sealed box with 110 L crossed over at 60Hz.

Please post your comment and sugestions. Keep in mind that budget is a constraint.
Thanks in advance.


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## jeremy7 (Feb 7, 2008)

this project sounds fun. I dont have any ideas off the top of my head for the third woofer. 
I am a big fan of the dayton reference drivers, and im curious what your crossover points will be with 7" midwoofers and 10" woofers.
keep us posted


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## zero the hero (Feb 24, 2008)

RS180s are hardly midwoofers. Why not use something cleaner in the range you're going to use them, like the RS150's? The 180s have a nasty cone breakup that you can't deal with using an active XO. Also, 3 270s is way too low impedence, even for the A500. You also realize that 3 RS270s need about 9 cubic feet sealed, if you're going for a Qtc of .7? That's a big speaker!


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## JCD (Apr 20, 2006)

A few comments:

I'd pick a different mid -- the RS180 doesn't go high enough imo. I'd pick something that had a published range extending on the high end to 3000hz or 3500hz at least. That should give you some good overlap with the tweeter. I'd look for something in the 5-5" range. The RS150 already mentioned seems to be where I'd look.

The amps you've listed are a great price/performance model. If you can find something that's less expensive that puts out ~35-50watts, you could do that. Obviously, the tweets don't need the same power that a woofer does.

I'd probably stick with 2 woofers -- it does seem like it would make the speaker prohibitively big. What you could do to get the same dynamics you're looking for is to go with a bigger more efficient woofer. For example, if you went with just one of these, you would probably get a better response than with two of the Dayton woofers you're looking for. It would be a little more expensive, but I think you'd like the results better.

The active crossover you've picked is exactly the one that I will use whenever I finally build my all out acive 3 way system.


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## Zeverin (Jan 14, 2008)

I will try to answer everyone, not without to say Thanks to the comments already posted.

First the choice on the RS180. In fact the RS150 was my first choice because of the ability to reach a higher freq. But some DIYers were saying that the RS180 is a better choice, the RS150 has also some nasty picks that I should be able to deal with. I will look for more freq. response graphics. But now that I have other opinions I might choose the RS150 .

For the XO points I'm thinking in something like this: 250 Hz (4th order) and 2300 Hz (4th order also) for the RS150. For the RS180 I was thinking in 2000 Hz. Want do you think about this choices? Can I push the RS150 to the 2500Hz region?


Using 3 270 is a too low impendance, I'm aware of that. The size of the enclousure is a real problem, not for me, but for my wife. 6 cubic feet sealed is my size limit, so that sets "only" 2 RS270 .

I know that for the tweeters (and also for the midrange) I don't need all the power from one A500, but I thought that would be better to use only one amplifier model. But maybe a could use a diferent one that matches the drivers specifications better. Do you have some sugestions? Please, only amplifiers with passive cooling.

Now the driver that JCD recommended. In fact I don't know that driver. But as I'm living in Portugal bying from USA means that I must pay customs. For my TC2000 I had payed nearly as much for customs as I did for TC Sounds Inc. The Dayton drivers I'm buying from bmm-electronics.com
Also, using a 12" driver means that the enclouser front baffle must be very large, WAF comes into play again. 
More recomendations?

Thank you all.


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## zero the hero (Feb 24, 2008)

Don't get me wrong - the RS150 has nasty breakups too just like the RS180. But if you're only using them as mids you are definately better off with the 150 - better off-axis response and some people complain of poor midrange in the 180. 
2500 is too high though, esp for an MTM. I wouldnt go higher than 2100 for the RS150, 1500 or so for the 180.

Oh, and I don't have any driver suggestions for the woofer. I really like the RS270 myself and would love to build a speaker around a pair based on its low distortion and awesome sensitivity (at the price of needing a huge box - tradeoffs)


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## Zeverin (Jan 14, 2008)

I was missing the better off-axis response of the RS150. Thanks for reminding me of that  The good thing here is that I can try different crossover regions  Definitely 2500 Hz is too high, I will try 2100 just like you posted, and if I'm not happy with that I can always make some adjustments.


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## JCD (Apr 20, 2006)

Zeverin said:


> I know that for the tweeters (and also for the midrange) I don't need all the power from one A500, but I thought that would be better to use only one amplifier model. But maybe a could use a diferent one that matches the drivers specifications better. Do you have some sugestions? Please, only amplifiers with passive cooling.


I've got nothing off the top of my head -- mostly, just making a point about not needing the same power as you may need for the woofers. You probably won't be able to find anything cheaper unless you find something used -- which might not be a bad idea if you're on a budget. I was able to get a Rotel 75watt stereo amp for ~$150US that I'd argue is going to be better than A500.



Zeverin said:


> Now the driver that JCD recommended. In fact I don't know that driver. But as I'm living in Portugal bying from USA means that I must pay customs. For my TC2000 I had payed nearly as much for customs as I did for TC Sounds Inc. The Dayton drivers I'm buying from bmm-electronics.com


Ahh, that does make a slight difference. I'm not sure what's available in the EU. What online stores are there that are based in the EU?




Zeverin said:


> Also, using a 12" driver means that the enclouser front baffle must be very large, WAF comes into play again.


It still might be better than 2 10" drivers.. it would just depend on the TS parameters of the specific drivers. I'd still keep it in mind when you're looking at alternatives for the low end.

Good luck, and let us know what you've come up with or are thinking about.


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## digital79 (Aug 26, 2009)

Hi

Funny, I just joined this forum to get ideas on a 3-way system, and this project is a great start.

Have you considered to have three 8" woofers rather than 2 10"? Making speaker more deep and less wide should have better WAF


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## Zeverin (Jan 14, 2008)

JCD: I just know a few online stores in Europe that have competitive prices. Another problem is to find reviews of the available drivers. Most reviews I can get refer to drivers manufactured in USA. My range of choices is very limited right now if I want drivers with good value without ordering from USA.
At some point I was thinking in the Lambda drivers from Acoustic Elegance. But they cost 245$ each plus shipping PLUS customs :foottap: I know they are great, by the price is very high. My budget is 2000€, including drivers, amplifiers, crossover, and enclosure.


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## Zeverin (Jan 14, 2008)

digital79 said:


> Hi
> 
> Funny, I just joined this forum to get ideas on a 3-way system, and this project is a great start.
> 
> Have you considered to have three 8" woofers rather than 2 10"? Making speaker more deep and less wide should have better WAF


Hi. And welcome. This is a great forum. You I will find it very helpful.

Answering your question, yes I did, and agree that would have a better WAF. But the problem of impedance is still there. The only solution would consist in using one amplifier per driver. The cost of such thing is very high. I think that 3 drivers stacked vertical will need some compensation/attenuation because the floor resonances. I have seen designs using 4 8" drivers in a WWMTMWW configuration. With this configuration the impedance problem is solved, but my wife dislike those tall speakers.

More ideas are welcome.


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## digital79 (Aug 26, 2009)

Let me tell you my plans, perhaps you can use something here. Each speaker consists of:

1) separate box with 2 Peerless 830667 (8" subs) 
2) separate box with Scan Speak 15W8530K00 and Vifa XT25 (Zaph's ZD5)

Crossed around 250Hz. Having separate boxes and running them active will allow me to mix and match later on.

Each box has own amp, so active W and active MT (MT has internal passive crossover)

All driven with DIY LM3886 amps.


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## Zeverin (Jan 14, 2008)

digital79 said:


> Let me tell you my plans, perhaps you can use something here. Each speaker consists of:
> 
> 1) separate box with 2 Peerless 830667 (8" subs)
> 2) separate box with Scan Speak 15W8530K00 and Vifa XT25 (Zaph's ZD5)
> ...


What is the cost of that system?


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## digital79 (Aug 26, 2009)

About $700 per speaker + labor.


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## lsiberian (Mar 24, 2009)

Zeverin said:


> Hi.
> I'm planning my new system. I want to build a 3 way active system (front speakers).
> My current ideia is to use the ULTRADRIVE PRO DCX2496 as the crossover. The amplifiers will be 3 A500 also from behringer (one for each channel).
> The drivers configuration will be MTMWW. The tweeter is the Seas 27TBFC/G, the midwoofers Dayton RS180 and the woofers RS270. The box will be sealed because I want the most clean and "fast" sound I can achive. The midwoofers and woofers will be wired in parallel (4 ohm load on the amplifier). I would like to add a third woofer (MTMWWW), but that would have a dificult impedance for the amplifier. Why another 3rd woofer? Because of the added dinamics and lower distortion numbers at a given listening level. Any solutions?
> I currently have a TC 2000 15" subwoofer in a sealed box with 110 L crossed over at 60Hz.


I'd suggest you do a passive 2-way for the top and then go active with a bottom driver. 

1 Your wasting amp on the tweeter and upper-midrange driver. 
2 There are a lot of issues your are gonna have trying to actively cross the tweeter and upper-midrange driver.

The A500 has a known defect with a distorted note at around 1000hz I believe. This has been shown in one case to be caused by being placed on another warm device. I do suggest you give them some breating room in your rack as such. I'd also propose you look into the EP2500 amp instead. The versatility and limitless power of these amps will do the trick with no concerns for defects.



JCD said:


> I was able to get a Rotel 75watt stereo amp for ~$150US that I'd argue is going to be better than A500.


Maybe in terms of non defects, but a consumer level amp is going to complicate things a lot. 

You can't use the XLRs on them with Pro-Audio devices so you'd need to attenuate the signal after passing it with an XLR to RCA cable. It's doable, but for only 75 watts per channel I think it's a bad tradeoff. Besides despite repeated arguments about amplifier sound I've never seen a DBT show anyone able to detect differences between solid state amps. 

If you're truly on a budget you may comb Craigslist and ebay for QSC amps. They are kind of a first level pro-audio gear company. 

As this is a high expense project I suggest you do it the best you can and not cut corners. Even if it takes longer. 


If this is gonna be your first build. I suggest you get your feet wet with the Recession Buster Kit from Madisound first. It comes with the crossover and drivers for 59 bucks. Not bad at all in my book. 

For fill you can get fiber very very cheap at home depot. It's not quite OC 703 or rockwool, but it's still more effective than Polyfill and a cheaper. I saw a roll for 10 bucks the other day.


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## Zeverin (Jan 14, 2008)

lsiberian said:


> I'd suggest you do a passive 2-way for the top and then go active with a bottom driver.
> 
> 1 Your wasting amp on the tweeter and upper-midrange driver.
> 2 There are a lot of issues your are gonna have trying to actively cross the tweeter and upper-midrange driver.


I know that I'm wasting amp on the tweeter and upper-midrange driver. I'm still trying to find a cheaper amplifier with good sound quality and adequate power.
What are the advantages going with a passive 2 way just like you said, aside cost?

Do you think that is not possible to achieve a good integration between the tweeter and the midrange using this crossover? Can you be more specific in those issues? A little more info in my speaker configuration. The tweeter and mid drivers wont be centered to reduce baffle diffraction.




lsiberian said:


> The A500 has a known defect with a distorted note at around 1000hz I believe. This has been shown in one case to be caused by being placed on another warm device. I do suggest you give them some breating room in your rack as such. I'd also propose you look into the EP2500 amp instead. The versatility and limitless power of these amps will do the trick with no concerns for defects.


Whichever amplifier I choose I will give them enough breathing room. Thanks for reminding that. I already have a EP2500 to driver my subwoofer. For this purpose I think the EP2500 is too much, and will raise the system cost, and I would like to stay with passive cooling.


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## lsiberian (Mar 24, 2009)

Quoted from Mark(one of the smartest and most experienced speaker builders on the planet) I don't want to reinvent the wheel so I'll use his summary.
Advantages of biamping.

1). Reduces insertion loss of passive crossovers. This is negated unless active crossovers are used.

2). Reduces distortion and problems of reactance of passive crossovers, especially with lower crossover points. Again this advantage is only gained with active crossovers.

3). Increases power available to the speaker as long as the crossover point is around 400 Hz. 400 Hz is the area of the power divide. As the crossover point is raised the power advantage is rapidly lost, as the power required to produce those frequencies rapidly diminishes.

4). Theoretically biamping can reduce inter modulation distortion. However this is a non issue with competently designed amplifiers.

Disadvantages of biamping.

1). Requires a complex electronic crossover that has to be designed to the drivers just like a passive one. So advantages of biamping are only truly realized with a design done from the ground up with active crossovers.

2). One amplifier with twice the power versus two amps of half the power biamped is less likely to clip. The reason is that program is variable. Say we have one 200 watt amp versus two one hundred watt amps biamped at 400 Hz. If the program calls for 150 watts below 400 Hz, then the HF amp sits idly by while the LF amp clips. The 200 watt amp might well not have clipped.

3). If different amps are used there is great opportunity to introduce serious phase problems at crossover, unless the amps phase responses are known and corrected.

4). Generally costs will be increased as well as complexity.

In general the advantages of biamping are only realized with crossover points below 500 Hz using active crossover as part of a total design solution.

The reason being that passive crossovers in the 1.5 to 5 kHz range are far less deleterious than passive crossovers below 500 Hz. In my view crossover points below 350 Hz are best accomplished with active crossovers.


So basically you are correct for bi-amping the lower part of the 3 way. But the upper part is just silly if you think about it. If crossover design is a concern remember that madisound will do a design for less than 40 bucks usually. I'd just pass off the design to them for the upper 2-way portion and then you eliminate extra amps and make you life easier.

You should only need 1 driver per speaker per range. Pick good ones and you'll be set.

Tweeter, Midrange, Mid Bass Module(I use a small sub for this), Subwoofer.


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## JCD (Apr 20, 2006)

lsiberian said:


> Disadvantages of biamping.
> 
> 1). Requires a complex electronic crossover that has to be designed to the drivers just like a passive one. So advantages of biamping are only truly realized with a design done from the ground up with active crossovers.
> 
> ...



I will not claim to be an expert regardless of whatever "mod" status I may have, but I have some followup questions/comments


Isn't this satisfied by buying a commercial product like the Behringer unit Zeverin mentioned? I would agree that building from scratch would be a LOT more difficult, but something like the Behringer with it's variable crossover point takes most of the complexity out of the equation.
I have some potential problems with that one as well. My understanding is that you gain ~3dB's by going active. If you go from a 100 watt amp to a 50 watt amp, you loose ~3dB's. That's pretty much a wash. And if we're talking about a tweeter, you're still going to never use 50 watts unless you want ear-damaging loudness.
The potential phase issue can be "fixed" by physically moving either driver forward or backwards a little. Also, the Behringer unit has the ability to adjust the phase of the drivers independently, so you should be able to get the drivers in phase with a little bit of testing -- , you can maybe even get the drivers not just in phase, but perfectly time-aligned. With a passive crossover, you're much more limited in adjusting the phase of the drivers. Granted, whatever phase issues that come from the amp are negated, but there are still going to be some phase issues that you will have less ability to deal with at the electronic level.
I do agree -- it will cost more to go active. However, as you can see from the above comments, I think it simplifies the process, assuming you buy a unit like the Behringer DCX2496.

Again, just my semi-informed opinion.


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## Zeverin (Jan 14, 2008)

This is getting interesting. 
I want to think the sugestions already made.

lsiberian in fact I have readed those informations about bi-amping. But sometimes I miss some points.

I'm just going to discuss the disavantages. 
1- If I go the bi-amp way, I would save money from one amplifier (aprox. 200 €). Great. But, I will need to spend on the passive crossovers. Maybe 80 € for both. That saves me 120 €. Also I will be loosing 2 outputs on the DCX, right?
I agree that 120€ is a considerable amount of money, with that I can almost build the rear speakers for a 5.1 system. But also look at this, I'm young, and certanly I will want to do more teaking and some upgrades in the future, going tri-amp (or 3 way fully active) I'm not going to loose the money spent on the passive crossovers. But I'm still considering any reasonable option.

2 - I completly agree that "one amplifier with twice the power versus two amps of half the power biamped is less likely to clip"

3 and 4 - I make JCD my words.

JCD by your comments I assume that you encourage the 3 way full acive, right?

Please, lsiberian and JCD (and others), don't be affraid to discuss more issues, better now then later when money is spent.


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## JCD (Apr 20, 2006)

Zeverin said:


> This is getting interesting.
> I want to think the sugestions already made.
> 
> lsiberian in fact I have readed those informations about bi-amping. But sometimes I miss some points.
> ...


That is actually something I hadn't really thought about, but adds to my pro active approach. And depending on the parts you get, and how complicated the crossover scheme is, 80€ for the crossover parts may be on the low side. 



Zeverin said:


> 2 - I completly agree that "one amplifier with twice the power versus two amps of half the power biamped is less likely to clip"


I posed this question to someone I know that has the technical backround to address this point -- his contention is that a 200 watt with a full range signal is more likely to clip than two 100 watt amps with an active crossover between them. There is a thread someplace on the web that this arguement has been addressed -- if I can find it, I'll post a link. I think lsiberian addresses the issues in most real world examples by actively crossing the <250hz signals, but I really don't think this is going to be an issue if you've got ~50 watts for the tweet and ~80 watts for the mid. , the tweet probably can't even handle a sustained 50watts.. but I digress.




Zeverin said:


> JCD by your comments I assume that you encourage the 3 way full acive, right?


Absolutely. There are dozens more advantages to active systems that we haven't fully discussed, such as the ability to perfectly time align the drivers using a well designed crossover, the ability to accomplish perfect phase and impulse response without much effort and without the terrible side effects of passive components attempting to pull it off, improved power response, elimination of microphonics, the ability to create the absolute most ideal filter with virtually no tolerance, the elimation of shift in tolerance related to input voltages. the elimination of back-current artifacts in the crossover, increase in realized damping factor, and many more. (note, this paragraph is shamelessly copied from another thread on another forum)

This doesn't even take into account the ability to subsequently tweak the system using different types of crossovers (e.g., Bessel or LR or Butterworth) or different orders (6dB, 12dB, 18dB, 24dB, etc).

I don't want to completely oversell an active system -- it will still take time, skill, testing, etc to create a good system, but I do think it's simpler to do and offers a lot of tangible benefits over a passive system. And I will put my money where my mouth is -- when I finally build my "all out system", I'm going fully active in a 3 way system and I'm going to use that same crossover you've picked.


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## lsiberian (Mar 24, 2009)

Zeverin said:


> This is getting interesting.
> I want to think the sugestions already made.
> 
> lsiberian in fact I have readed those informations about bi-amping. But sometimes I miss some points.
> ...


1. Not sure how you are getting that a passive crossover is going to cost you 80 euros. Most can be assembled for far less. 

2.You can still manipulate the entire sound of your system with the DCX. You'd be giving yourself the ability to hook up your subs to the DCX. Meaning you could have a 4-way setup with the subs fully eqed.

3. Fully active is just as time consuming as making a 2-way upper module filter. I"m not talking about passive between your bottom driver and the top. Only between the tweeter and the midrange. 

4. Don't forget that XLR cables aren't cheap either.

Ultimately the choice is yours.

But I would encourage to at least give the passive crossover a go. If anything it will be a valuable learning experience. 

If this is your first project I still suggest you start with a simple 2-way build before you undertake this beast. I don't think stepping into this as your first project is wise. There is a lot to learn that you will want to get before you build your longtime main speakers.

Either way make sure you treat your cabinets with fiber or rockwool and that you brace the out of them.


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## JCD (Apr 20, 2006)

lsiberian said:


> 1. Not sure how you are getting that a passive crossover is going to cost you 80 euros. Most can be assembled for far less.
> 
> 2.You can still manipulate the entire sound of your system with the DCX. You'd be giving yourself the ability to hook up your subs to the DCX. Meaning you could have a 4-way setup with the subs fully eqed.
> 
> ...



1. Totally agree.. but I think you can also argue it could be a lot more depending on quality/expense of the various parts. I've designed a passive crossover that had a three inductors, 4 caps and a couple of resistors. The part cost for that ran ~$55/speaker or $110 for a pair. Granted this crossover did have a notch filter and a zobel network in addition to the 2nd order LR crossover, but I wasn't going crazy with my cap selection
3. My opinion is a little different. It's not a ton faster, but some. Not having to deal with how the impedance curve of the different drivers might effect the crossover I think is a time saver. Also, if you want to try a different crossover point, you don't have to redesign, reassemble, etc the passive crossover.

I think lsiberian makes some good arguments, and I certainly don't want you to ignore his advice/suggestions or think that I'm trying to portray him in any way negative -- these kind of point/counterpoint arguments can come across that way online. 

And I do agree with lsiberian on his other points:

designing a passive crossover is a great experience and you will learn a lot. I've done one now and enjoyed the process a lot. If you're going to continue this hobby going forward, then this is an invaluable exercises.
if this is your first project, I think building a simple 2-way would be a great idea


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## Zeverin (Jan 14, 2008)

Hi. I'm short on time right now, but lsiberian and JCD are exposing very valid and wise arguments.

You know what? I will follow the 3-way aproach, BUT, not without trying the use of a passive crossover, just to learn a bit more, and see by myself the diferences both in sound and work involved, and also the results :nerd:.

I have built a few subwoofers, and also passive (2 way and 3 way) crossovers. Also in the last years I have been reading alot about loudspeakers design and construction. I know this is going to be hard, but I belive that I'm skilled enough to acomplish this project, even if it takes some time. This is a small beast I want to build. The enclouse shape will also represent one challenge by itself :coocoo:.

Latter I will comment some of yours arguments.


> I think lsiberian makes some good arguments, and I certainly don't want you to ignore his advice/suggestions or think that I'm trying to portray him in any way negative


 Of course not, and neither I, he is being very helpfull. Thank you. :bigsmile:


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## Zeverin (Jan 14, 2008)

JCD said:


> I posed this question to someone I know that has the technical backround to address this point -- his contention is that a 200 watt with a full range signal is more likely to clip than two 100 watt amps with an active crossover between them. There is a thread someplace on the web that this arguement has been addressed -- if I can find it, I'll post a link. I think lsiberian addresses the issues in most real world examples by actively crossing the <250hz signals, but I really don't think this is going to be an issue if you've got ~50 watts for the tweet and ~80 watts for the mid. , the tweet probably can't even handle a sustained 50watts.. but I digress.


Are you refering to this: http://sound.westhost.com/bi-amp.htm see point 1.4 Actual vs Effective Power ?


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## Zeverin (Jan 14, 2008)

lsiberian said:


> 1. Not sure how you are getting that a passive crossover is going to cost you 80 euros. Most can be assembled for far less.


Maybe it is too much. 60 euros is more reasonable for the 2 crossovers.



lsiberian said:


> 2.You can still manipulate the entire sound of your system with the DCX. You'd be giving yourself the ability to hook up your subs to the DCX. Meaning you could have a 4-way setup with the subs fully eqed.


 This is a good solution to fully use the DCX flexibility.



lsiberian said:


> 3. Fully active is just as time consuming as making a 2-way upper module filter. I"m not talking about passive between your bottom driver and the top. Only between the tweeter and the midrange.


 You are right, it still takes a lot of time. But with one active system like this you can try diferent crossovers point and slopes and see what works best in the room :innocent:



lsiberian said:


> 4. Don't forget that XLR cables aren't cheap either.


 Yes, unfortunately very true :thumbsdown:



lsiberian said:


> But I would encourage to at least give the passive crossover a go. If anything it will be a valuable learning experience.


 A very valuable experience. I will follow the 3 way fully active path, but I will take into consideration your advice and try it also, just to learn a bit more.

In a few days I will have the cabinets modeling completed, then I will share you you.


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## mayhem13 (Feb 2, 2008)

Zeverin, going with a fully active system for your first system when considering a three way is a sound idea and given the cost of amplification, a very cost effective one since the DCX will already be available. Since you're in Portugal, i would strongly suggest you consider locally available drivers from european manufacturers. For Midrange drivers, there's FAR better choices available to you than the Dayton Reference series and high efficiency Pro Audio 10" woofers would allow for a much more efficient system with no need to pad down the MT section to match. There's a lot of excellent work being done with Pro drivers as you've read with B&C, Beyma and Faital Pro showing ultra low HD at higher output levels that HiFi drivers just can't match. Given the availabilty of the TC sub already, it stands to reason that 60hz of extension is all that's needed for the bottom end of your system.....something a 10" Pro woofer can easily do in a relatively small enclosure as compared to the RS270 and given local purchase as opposed to import, equally cost effective. For matched efficiency, look at some of the high efficiency 1" domes available. The SBAcoustics SB29 comes to mind at 93.4db which measures incredibly well for $50 U.S. Mated to a Pro 6.5" high efficiency Midrange driver and crossed in the 2khz range efficiency,directivity and off axis response as well as ultra low non linear HD is hard to beat. You've got great choices of drivers right in your own back yard. I'd explore those first over the Dayton stuff. Proof is in the measurments and simply put, the Dayton RS series are nice, but there's much better options right around the corner in Spain and Italy.


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## Zeverin (Jan 14, 2008)

Hi mayhem13. Thank you for the suggestions. Do you know any online stores that sell those drivers? Also can you point me some cool projects using drivers of the listed brands?
I really like the PRO stuff, but the looks!!!!:wits-end: I know that you can't have everything, but I look forward for some cool projects with PRO drivers.


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## mayhem13 (Feb 2, 2008)

uspeaker.com/prosoundservice.com/partsexpress.com........for US sales but given the manufacturers are right in spain and italy, i'd look in your own back yard for dealers. The sites listed will at least give you an idea of how well they perform and with some creative installation , the pro stuff looks just as good as the hifi stuff.....no bells and whistles to impress.....just the stuff that counts. For 6.5" midrange drivers look at Zaphaudio.com for test results of the 18Sound 6nd40 and the B&C 6md38 whose efficiency and low HD are unmateched in the hifi world. There's quite a few 10 and 12" woofers that are very cost effective as well and offer a level of dynamics that must be heard to be believed. Imagine a 3way capable of 60-20khz at 114db with only 100w input power...that's the dynamic range offered by these types of drivers where power compression is nearly nill in the average home environment.


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## Zeverin (Jan 14, 2008)

Hi. Sorry for the late reply. I had contacted a distributor in Portugal of 18sound, and asked for the price of the 6ND430 driver. They are charging 75 €uros, that is the price of two RS150. Do you think it's worth it?

In a few days I will be posting the 3D model of the enclosures


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## mayhem13 (Feb 2, 2008)

Yes.......as a single 6nd is more efficient,handles more power, and plays higher before breakup than two RS180's........and has lower HD too. It won't play as low but since this is a three way it doesn't have to.


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## Zeverin (Jan 14, 2008)

Well, I had been looking over and over the measures taken by Zaphaudio. And in fact the performance of the 6ND430 is trully impressive. This means that I'm going to spend the double in the midrange drivers, but the added performance (distortion and dynamics) is worth it. Thank you mayhem13 for those great advices. The only problem now, is WAF. My wife dislike the looks of the 6ND430, in fact I don't like it also, but that's not the important factor here. Soo I must convince her, wish me luck.
I havent found a replacement for the RS270, and I'm open to new suggestions. But only 10" drivers please. I like the 10W400 also from eighteensound, but I'm lacking of information about their performance. Any recomendations or information about the 10W400? I can get it for 84 €, rougly the same price of the RS270.


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## brianpowers27 (Sep 7, 2008)

If you ask me.. (Cost obviously isn't an issue here.) skip the dual woofers since sensitivity isn't an issue. Trade them in for a high quality sub. This will increase overall displacement as well as give you the flexibility to account for various room issues.


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## Zeverin (Jan 14, 2008)

Hi bdp. Thank's for the suggestion. I'm afraid that I don't agree completely with you. If I lower the sensitivity of the woofers I need to use more power, more power equals more expensive amplifier (perhaps noisy fan cooling), and the distortion number can raise quicker (maybe, maybe not), and they "only" need to handle frequencies above 60 Hz, below 60Hz my TC 2000 15" is going to take care. I also like the idea of using a bigger surface to move gently the air, than a smaller one moving the air in a more violent manner. Those this assumption makes any sense?


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## brianpowers27 (Sep 7, 2008)

Zeverin said:


> Hi bdp. Thank's for the suggestion. I'm afraid that I don't agree completely with you. If I lower the sensitivity of the woofers I need to use more power, more power equals more expensive amplifier (perhaps noisy fan cooling), and the distortion number can raise quicker (maybe, maybe not), and they "only" need to handle frequencies above 60 Hz, below 60Hz my TC 2000 15" is going to take care. I also like the idea of using a bigger surface to move gently the air, than a smaller one moving the air in a more violent manner. Those this assumption makes any sense?


That makes sense to me. I didn't realize you had a sub already. In that case, the high sensitivity is a benefit because you will already have lf extension.

What target listening levels are you shooting for and how much power do you have on tap?


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## Zeverin (Jan 14, 2008)

I want to achieve 110 db (continuous) at 2 meters listening position from 30 Hz to 20KHz. The TC 2K can assure that extension down to 30 Hz (powered by one EP2500). The "weakest" component here is the tweeter, but with a sensitivity of 93 db, I think that is enough for me. I'm going to use 3 behringer A500. Power availability will be something like this: 200 W for woofers (2 RS270 8ohms in parallel), 200 W for mids (2 6ND430 8ohms in parallel), 120 W for the tweeter (SBAcoustics SB29 8ohms), *each channel*, all RMS values.


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## Zeverin (Jan 14, 2008)

Here you can see the last draft I have, with the RS150 as mid drivers, not updated yet. Some changes are going to take place, than I will update the 3D model again, including other views.
I hope that you like.
I'm aware of diffraction problems with a so width baffle.

Please make some comments.







3D modeling credits to Suriv


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## brianpowers27 (Sep 7, 2008)

Adding a rear firing tweeter could be challenging but it has the potential to help ease the strain on your current weak link tweeter. IN theory you would have nearly twice the output.

Good luck getting the bass to sound right. It seems like you have to go sealed, due to the large airspace requirements of the rs270. This will hamper response between 30-60hz. OTOH, you will experience boundary reinforcement from the woofers that are close to the floor. I am not aware of any current tool that can simulate this boundary effect.


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## Zeverin (Jan 14, 2008)

brianpowers27 said:


> Adding a rear firing tweeter could be challenging but it has the potential to help ease the strain on your current weak link tweeter. IN theory you would have nearly twice the output.


 I will leave that for future teaking, but thank you for the suggestion :rubeyes:



brianpowers27 said:


> Adding a rear firing tweeter could be challenging but it has the potential to help ease the strain on your current weak link tweeter. IN theory you would have nearly twice the output.
> 
> Good luck getting the bass to sound right. It seems like you have to go sealed, due to the large airspace requirements of the rs270. This will hamper response between 30-60hz. OTOH, you will experience boundary reinforcement from the woofers that are close to the floor. I am not aware of any current tool that can simulate this boundary effect.


You are right, I'm shooting for sealed encloures with 150 litres. :T


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## ktaillon (Apr 3, 2007)

I have a similar setup. I'm running two RS225's, one RS150 and a Peerless PL tweeter. They all run from the DCX2496 via 6 channels of amplification. The sound is very good, I'm very happy with the setup.

I think running multiple amps gives a systems better dynamics and sound. I would run all the drivers actively if you can. Plus changing around crossover setups and cross points is so fast.

I ended up using a 3rd order crossed at 350hz and 2000hz, this gave me the best sound to my ears and also the best frequency response.


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## DrWho (Sep 27, 2006)

Just a few random thoughts...I'll confess I didn't read every post in its entirety.



Zeverin said:


> I want to build a 3 way active system (front speakers).


Any particular reason you want to go 3-way and not 2-way?



Zeverin said:


> My current ideia is to use the ULTRADRIVE PRO DCX2496 as the crossover. The amplifiers will be 3 A500 also from behringer (one for each channel).


If you're gonna go that route, then you might consider going with 3x Crown XTi:
http://www.crownaudio.com/amp_htm/xti.htm
It has a DSP built into the amplifier. They can easily be found for $300 each on the used/b-stock market.



Zeverin said:


> I want the most clean and "fast" sound I can achive.


Have you thought about building some horns? It should be cheaper to achieve a cleaner/faster sound with a single driver bass horn than it would an array of four direct radiators. You get the added benefit of more control over the polar response too.

The trade off is a larger cabinet...



Zeverin said:


> Why another 3rd woofer? Because of the added dinamics and lower distortion numbers at a given listening level. Any solutions?


You can always wire the woofer in series if you're worried about low impedance. When using an active crossover, you don't take any efficiency hit to balance the drivers with each other.

Btw, if you have a sub covering 60Hz and below, then I would highly recommend going 2-way.



Zeverin said:


> I want to achieve 110 db (continuous) at 2 meters listening position from 30 Hz to 20KHz.


Keep in mind that 110dB continuous A-weighted still involves 20dB of crest factor in the music. If you don't want any clipping or compression, then your system will need to be capable of 130dB peaks (yikes).

A 93dB tweeter would need a 5000W peak power handling to achieve that (not gonna happen).

Btw, 110dB continuous is rock concert loud...is that really how loud you plan on listening?


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## Zeverin (Jan 14, 2008)

First, thank you all for your comments.



DrWho said:


> Any particular reason you want to go 3-way and not 2-way?


My goal is to create a speaker with low distortion playback and good dynamics. I know that this can also be achieved with 2 way, but I feel more confident in a 3-way. Maybe a misconception . As some of you might know the TC 2K isn't great above 80 Hz, so this speaker must play loud and clean down to 60 Hz (yes 60, not 80 Hz, I prefer to cross the sub at 60 HZ).:nerd:



DrWho said:


> If you're gonna go that route, then you might consider going with 3x Crown XTi:
> http://www.crownaudio.com/amp_htm/xti.htm
> It has a DSP built into the amplifier. They can easily be found for $300 each on the used/b-stock market.


I believe that is a good solution, but I'm afraid I can't get those in Europe, and I don't want to order outside Europe, because of customs. But I will keep my eyes opened. :blink:



DrWho said:


> Have you thought about building some horns?


 Yes I did. But I don't have enough knowledge to do that. Also I must keep WAF on the high side.
Maybe after this I can jump into the horns field, I'm very interested indeed. 



DrWho said:


> You can always wire the woofer in series if you're worried about low impedance. When using an active crossover, you don't take any efficiency hit to balance the drivers with each other.


 Yes I can. But that way I'm not extracting all power from the amplifier, and in this particular case, instead of 220 W I would have something around 100 W. Did I miss something?:innocent:



DrWho said:


> Keep in mind that 110dB continuous A-weighted still involves 20dB of crest factor in the music. If you don't want any clipping or compression, then your system will need to be capable of 130dB peaks (yikes).
> 
> A 93dB tweeter would need a 5000W peak power handling to achieve that (not gonna happen).
> 
> Btw, 110dB continuous is rock concert loud...is that really how loud you plan on listening?


I think that I didn't make myself clear here, my mistake, sorry. When I meant 110 db continuous, was a system capable of maintain that playback level for a few minutes continuously. Here I'm taking into account thermal limits and available power in RMS values, not some peak values. This way you should "read" 90db continuous A-weighted (with 20 db headroom for crest factor in music). I think it makes more sense now.


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## DrWho (Sep 27, 2006)

Zeverin said:


> Yes I can. But that way I'm not extracting all power from the amplifier, and in this particular case, instead of 220 W I would have something around 100 W. Did I miss something?:innocent:


You don't lose any SPL since doubling up on drivers halves the acoustic space that each is firing into. What you gain is extra headroom in the drivers.

You're just shifting the impedance matching around. Essentially, the amplifier is doing half the power but the drivers are doing effectively twice the power so it ends up a wash.

Have you done any thinking about polar response? Dual 6" drivers can't get any closer than 12" center-to-center which is going to start beaming above 1kHz. The beaming will create on-axis boost, but reduce the amount of output in the off-axis. You're gonna end up in a compromise between dialing in the direct sound that follows precedence effects against dialing in the off-axis "reverberation" of the room. The ideal world would be one where the off-axis energy and on-axis energy have the same tonal balance (flat power response).

The B&W 802D seems like a very similar speaker to what it seems like you're aiming for and it very closely approximates a flat power response:
http://www.bowers-wilkins.com/display.aspx?infid=1157&terid=1305&sc=hf
Notice the single 6" midrange. There's no need to go all crazy style with the woodworking, but I would recommend a similar baffle arrangement.

If nothing else, I would try to find ways of making the polar response between the various sections try to line up at the xover frequencies. The difficult part about direct radiators is they tend to be very wide at the low end of their response and very narrow at the top end of the response. This is where MTM arrangements can be beneficial, but they need to be carefully thought out with respect to the xover frequencies you plan to implement.


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## brianpowers27 (Sep 7, 2008)

If you ask me...

You may need the dual midwoofers (rs150?) to keep the sensitivity high enough to get the job done. You could also use the RS125 and perhaps get a cleaner top end out of the mid.

The only real need for 2 tweeters is sensitivity matching. I imagine that 2 mids along with 2 woofers will be too sensitive for a single seas tweeter as posted. This combination hasn't really been done before(at least that I know of) but that doesn't mean that it is bad. I imagine that the reason it hasn't been done before is because the sensitivty of the woofers will likely outpower all but the most sensitive tweeters on the market. You would need about a 95db tweeter to match sensitivity.

+1 on the power response comments. I would suggest considering tese xo points.

woof-mid 400hz lr2
Mid tweet 2000hz bw3.


This will give you a very smooth power response and provide adequate protection for the tweeter and limit mid excursion.


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## evilskillit (Oct 7, 2008)

I would just like to chime in and point out that there are already several 3-way designs that are very similar.

The Dayton RSTMWW uses a Seas Tweeter, Dayton RS150 for mids and RS225 for bass.
The Kahnspire uses the same mids and woofers with the Dayton Reference Tweeter.

I'm interested in building a RSTMWW myself but if I was thinking of designing something from the ground up I would probably use a "better" midrange driver like the new Zaph 5" driver, or the 4" titanium tang band or something. Or maybe even the Dayton dome mid-range like Zaph uses in the ZDT3.5


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## Zeverin (Jan 14, 2008)

Hi again, finally got some time to came here. The next two months will be also very busy.



DrWho said:


> Have you done any thinking about polar response? Dual 6" drivers can't get any closer than 12" center-to-center which is going to start beaming above 1kHz.


Mike, I really appreciate your comments, but I can't agree with you in this one. The c-t-c distance is not only dependent in the midwoofers size, you need to take into account the size of the tweeter, in this case it's not bigger than 4", if we add 0.5" for drivers spacing, the c-t-c for this particular combination of drivers is around 11", but with smaller tweeters we can achive smaller c-t-c. I have been thinking about the polar response and comb filtering issues, but I'm willing to try this WWMTM configuration, and than share the results with you. Also, I think that I can reduce the ctc distance if I can cut the tweeter flange. what do you think? That would allow a higher crossover point by a few Hz (50~100Hz flange cut dependent), reducing strain in the tweeter. I think that a ctc distance near 10" is possible.


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## Zeverin (Jan 14, 2008)

I will be no longer using the Dayton RS150, my current choice is the 18Sound 6ND430 :neener:


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## Zeverin (Jan 14, 2008)

Construction thread here:

http://www.hometheatershack.com/for...y-active-loudspeakers-construction-diary.html


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## WmAx (Jan 26, 2008)

*EDIT:* I apologize for my response. I did not notice that you had already purchased drivers and started the project. I will leave the reply in tact for possible future references, however.

Perhaps you should consider using high grade professional audio mid-range that is specifically designed for extreme SPL and has very high sensitivity. For the woofers, please keep in mind that only the higher quality drivers have low power compression. If feasible for space, the Audio Elegance AV 15" driver has higher sensitivity than most comparable drivers and overall good power compression and motor linearity characteristics for a bargain of a price. One of these in each cabinet will be very good. Also, the drivers can play to much higher frequency than most 15" subwoofers due to this being a specific target objective when they were engineered. You could cross at 200-250hz, no problem, to blend with a high grade 6-7" pro cone driver. Just be sure to use very high levels of high grade acoustic damping in the subwoofer volume, such as Owens-Corning 703 or 705 or comparable, at very thick amounts(for example, minimum 6" on rear of cabinet and bottom of cabinet, 4" on other surfaces. This will ensure a broad band capability with minimum standing wave resonances within the large volume. Standard acosutic damping materials common for speaker use are not sufficient for this particular application.

As for the tweeter; I have no idea what kind of HF polar response properties you desire. But if the vertical limited axial response is okay with you, Fountek has a reasonably priced professional ribbon tweeter with extreme high sensitivity and broad bandwidth capability, allowing for very high SPL capabilities that you desire, but yet retaining the characteristics of SQ you desire. It's horizontal directionality is not limited; only vertical. Unless you intend to listen critically while walking around the room, this will not be a real problem for normal seated listening within an estimated 8-12" vertical window target.

Chris


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## GranteedEV (Aug 8, 2010)

Zeverin said:


> Hi.
> I'm planning my new system. I want to build a 3 way active system (front speakers).
> My current ideia is to use the ULTRADRIVE PRO DCX2496 as the crossover. The amplifiers will be 3 A500 also from behringer (one for each channel).
> The drivers configuration will be MTMWW. The tweeter is the Seas 27TBFC/G, the midwoofers Dayton RS180 and the woofers RS270. The box will be sealed because I want the most clean and "fast" sound I can achive. The midwoofers and woofers will be wired in parallel (4 ohm load on the amplifier). I would like to add a third woofer (MTMWWW), but that would have a dificult impedance for the amplifier. Why another 3rd woofer? Because of the added dinamics and lower distortion numbers at a given listening level. Any solutions?
> ...


here's a speaker that fits what you're trying to do; high end mids with phase plugs and a scanspeak 9500 tweeter, very high end aluminum drivers. The mids and woofers on that are proprietary though made by status acoustics.

http://www.rbhsound.com/product_detail.php?id=8300-SE/R

I'd contact them and ask them how what the impedance for the drivers / wiring they used to get it to work out.


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## Theresa (Aug 23, 2010)

Check out the miniDSP "in a box" from DSP4YOU. They're in Hong Kong so its about $40 shipping but they are tiny units using USB (use a cell phone charger for powering after programming) for power and PROGRAMMING. You can change crossover frequency, delay, phase and has many parametric equalizers all programmed with your computer. Super easy to set up. From what I heard they were started by three engineers seeking to provide an inexpensive DSP crossover with much flexibility. The unit that's in a box rather than just a circuit board is about $160 after shipping to the US. I have two of them, one for the main channels and another for the sub and center.


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## GranteedEV (Aug 8, 2010)

I'd consider this:
http://www.bcspeakers.com/product.php?id=175


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## Zeverin (Jan 14, 2008)

Thanks Chris.

In fact I already had the mids and the tweeters, still waiting for the Dayton RS270 woofers.


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## Zeverin (Jan 14, 2008)

Theresa said:


> Check out the miniDSP "in a box" from DSP4YOU. They're in Hong Kong so its about $40 shipping but they are tiny units using USB (use a cell phone charger for powering after programming) for power and PROGRAMMING. You can change crossover frequency, delay, phase and has many parametric equalizers all programmed with your computer. Super easy to set up. From what I heard they were started by three engineers seeking to provide an inexpensive DSP crossover with much flexibility. The unit that's in a box rather than just a circuit board is about $160 after shipping to the US. I have two of them, one for the main channels and another for the sub and center.


Hi Theresa.

A few months ago I was looking at the miniDSp you indicated. But I don't think that is a good option. Those units only support 2 inputs and 4 outputs. Definitely not enough for a 3 way, soo I would need to buy 2 units, costing 190$, plus shipping, *plus customs*. I can get the BEHRINGER DCX2496 for 265 € from a local store. I think that I'm going to choose the DCX2496. But thanks anyway for the suggestion.


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## Zeverin (Jan 14, 2008)

GranteedEV said:


> I'd consider this:
> http://www.bcspeakers.com/product.php?id=175


Sorry, it's too late. Already started the construction. Please refer to: http://www.hometheatershack.com/forums/diy-speakers/32955-jubilo-3-way-active-loudspeakers-construction-diary.html


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