# Opinions on 3-way bookself design?



## SinCron (Dec 20, 2010)

I had this idea for a bookshelf without a specific driver in mind. It would be something like an anarchy 5.25" or 6.5" midwoofer with either one or two midrange speakers side by side up top along with maybe a ribbon tweeter above them in a sealed box. The jack would be at the back and will have the wire glued in the corner going up the port, along the top to a crossover embedded in the little wall and then down to the woofer/midwoofer. Inside the smaller box would be another crossover for the mids and tweeters. Hoping to get it done with a 5.25" and have a decent bass range with minimal space taken up. That way I can put 100+ watts into it and have an excellent sound all around. I have a rough draft made up in paint.


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## bambino (Feb 21, 2010)

Looks like a nice design, have you had your hands wet in DIY speakers before? In about 2 weeks as long as the weather keeps getting nicer i'm going to take my first real leap so i will certainley be curious of your turn out.:T


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## fbov (Aug 28, 2008)

This is a slot-ported box. It'll work well, just model the result before building using T/S parameters in something like Unibox of WinISD simulators. This long a port is rarely required by anything but a subwoofer. The mid-tweet box is good practice. 

My real question is why you'd make such a small 3-way; there are a bunch of very nice MT designs this size out there....


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## Jstslamd (Nov 30, 2010)

Looks like a decent design but picking drivers that will work nicely together is the trick. Then building a adequate crossover to finish it all off but don't get me wrong it is much more complicated than it sounds. 

Hey bambino what drivers did you end up choosing. I remember you had a thread about building towers. I'm almost done Doing the finishing on mine.


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## bambino (Feb 21, 2010)

Jstslamd said:


> Hey bambino what drivers did you end up choosing. I remember you had a thread about building towers. I'm almost done Doing the finishing on mine.



HIGHJACK!: I ended up with Peerles HDS 6.5" bass drivers, Peerless HDS 5.25" mids and Vifa t25 1" tweets. Still waiting for a bit warmer weather before i start things off. I look forward to seeing your finished results.:T


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## Jstslamd (Nov 30, 2010)

SORRY FOR THE HIGHJACKING!! Haha


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## bambino (Feb 21, 2010)

No problem, so long as That Weirdo doesn't mind, but we should stay on his topic, hopefully soon we will see some more progress on my Thread.:T


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## SinCron (Dec 20, 2010)

fbov said:


> This is a slot-ported box. It'll work well, just model the result before building using T/S parameters in something like Unibox of WinISD simulators. This long a port is rarely required by anything but a subwoofer. The mid-tweet box is good practice.
> 
> My real question is why you'd make such a small 3-way; there are a bunch of very nice MT designs this size out there....


What are MT designs? I want to go with small foot print with a decent bass response. If the port is too long, I can shorten it and do some more to increase the internal space before the port starts and get about 1/2" of polyfilll lining the inside if needed. Now why would I have to worry so much about matching speakers if it's going to be a straight up cutoff with the crossovers?


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## gibroni (Sep 25, 2010)

I can remember some decent sounding bookshelf speakers from 25 years ago by a company called Design Acoustics that utilized a downfiring woofer.


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## SinCron (Dec 20, 2010)

gibroni said:


> I can remember some decent sounding bookshelf speakers from 25 years ago by a company called Design Acoustics that utilized a downfiring woofer.


Well if I was going to do that, I would get one that would fit under the midwoofer, keep the port the same except have it vent out the back. When I thought about one that would fit, a downfiring woofer in a bookshelf just seemed like an awful idea as far as sound direction goes considering these would hopefully drop off at about 50hz given the size (if I'm lucky).


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## 1Michael (Nov 2, 2006)

SinCron said:


> with either one or two midrange speakers side by side up top along with maybe a ribbon tweeter above them in a sealed box.


Having 2 midranges was a bad idea in the 70's and 80's, and it still is...
https://sites.google.com/site/undefinition/diy-faqs-provendesigns


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## SinCron (Dec 20, 2010)

I'm going to have to wait to open that link. The reason I'd want two mids is power handling. I know the midwoofers take most of the heat in regards to power consumption. I see other builds involving multiple 4.5" full range speakers. That is what I was thinking of using in regards to having two mids. If need be, I would seal them off from eachother. I was going to use the 16 ohm driver seen here.


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## fusseli (May 1, 2007)

SinCron said:


> I'm going to have to wait to open that link. The reason I'd want two mids is power handling. I know the midwoofers take most of the heat in regards to power consumption. I see other builds involving multiple 4.5" full range speakers. That is what I was thinking of using in regards to having two mids. If need be, I would seal them off from eachother. I was going to use the 16 ohm driver seen here.


Now that's a nice looking midwoofer... 6mm xmax on that little guy! Does that mean you'd be crossing real low on the bottom half for those, like ~100Hz, or are you thinking MT/TMM/MTM now?


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## SinCron (Dec 20, 2010)

fusseli said:


> Now that's a nice looking midwoofer... 6mm xmax on that little guy! Does that mean you'd be crossing real low on the bottom half for those, like ~100Hz, or are you thinking MT/TMM/MTM now?


Unfortunately good sir, I do not know what those terms mean. The thought of having a crossover that low has occured to me, maybe a little bit higher around 120-150hz. What I wouldn't mind is finding a 4 or 16 ohm version of this tweeter to have a diagonal layout where it's a tweeter in the top left and mid right and a full range driver in top right and mid left if that makes any sense.


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## fusseli (May 1, 2007)

SinCron said:


> Unfortunately good sir, I do not know what those terms mean. The thought of having a crossover that low has occured to me, maybe a little bit higher around 120-150hz. What I wouldn't mind is finding a 4 or 16 ohm version of this tweeter to have a diagonal layout where it's a tweeter in the top left and mid right and a full range driver in top right and mid left if that makes any sense.


That's what I was wondering, hopefully you have active Xovers planned. Otherwise the component values will be HUGE for a passive Xover that low. At any rate, two of those isn't a bad idea to keep sensitivity up... which will also be a concern for whatever woofer you have in mind.


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## SinCron (Dec 20, 2010)

What do you mean by component values? I WAS going to go for a passive (and probably still will) as I want to have everything except an amp tucked away in the box. Also, what does MT/TMM/MTM mean?


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## fusseli (May 1, 2007)

SinCron said:


> What do you mean by component values? I WAS going to go for a passive (and probably still will) as I want to have everything except an amp tucked away in the box. Also, what does MT/TMM/MTM mean?


Component values, as in uF and mH for coils and caps. Higher values get expensive quick.

MT, etc. are different arrangements for mids and tweeter.


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## Jstslamd (Nov 30, 2010)

MT= midwoofer/tweeter
TMM= tweeter/midwoofer/midwoofer
MTM= midwoofer/tweeter/midwoofer

These are terms used to explain the way the drivers would be arranged in the enclosure.


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## SinCron (Dec 20, 2010)

Thanks for the explanations. I think I'll try for a x-over around 150-200 for cost efficiency. I'm going on referance to the Anarchy 6.5" midwoofer with an Spl of 84.7 dB/1W/1M. Then with two of those full range speakers with an spl of 85.8 dB @ 1W, 1m. I tried to find an appropriate tweeter close to 4 ohms but the ones I did find had an SPL in the 90's. I found one with an spl of 89 dB 1W/1m that says 8 ohms but says Re: 5.5 ohms. I'm thinking I'll wire it up to 11 ohms and that will drag it down a bit volume wise. Is my thinking in this matter correct?


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## Jstslamd (Nov 30, 2010)

I used a pair of off of the shelf xovers in a set of 3 way party speakers from PE and they are working out great. They only ran me like 45 bucks for 2 of them. They also had link-reily xovers from Dayton for not too much money.


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## SinCron (Dec 20, 2010)

I've been trying to find the crossover values on Parts Express to no avail. Any suggestions?


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## Jstslamd (Nov 30, 2010)

Values have to do with resistors and capacitors and inducers when you are building a crossover from scratch. The of the shelf xovers will just give you the frequencies at which they are crossed. It's not an exact science by any stretch of the imagination but it is alot more simple than learning how to build your own ( although for the best possible sound you have to build a specific xover for the setup at hand).


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## bambino (Feb 21, 2010)

Google how to design a crossover, or try DIY crossovers and some results should popup with free online calculaters for designing a crossover. From what i've found out from these calculaters is they give you a pretty basic design but also enough to get you started.:T


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## SinCron (Dec 20, 2010)

Well I grabbed the following information from here.

120Hz 8-ohms 
120uF series, 15mH parallel

120Hz 6-ohms 
160uF series, 11mH parallel


150Hz 8-ohms 
95uF series, 12mH parallel


150Hz 6-ohms 
125uF series, 9mH parallel
_____________________________________

Does that all sound good/reasonable?


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## fbov (Aug 28, 2008)

This is called designing by the book. It makes one egregious error, assuming driver impedence is constant. Any good spec sheet will show impedence is a peaked curve spanning a decade of resistance that may rise at high frequencies, so it's clear this is a bad assumption. 

I learned how to design XO's here, but it's only the mechanics. I have no idea how this plays into circuit design theory, and perhaps I don't have to. 
http://www.pvconsultants.com/audio/frdgroup.htm

Have fun,
Frank


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## SinCron (Dec 20, 2010)

Oh thank you so much good sir. I can't wait to get home and use that.


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## fusseli (May 1, 2007)

Good, someone brought up the proper tools. Here's a quick overview of a simulated Xover design process:

1) Get frequency response and impedance plots from datasheets, capture them with SPL Trace.

2) Open your newly created .frd and .zma files in the Response modeller in order to simulate baffle diffraction, woofer alignment, and extract minimum phase.

3) Open the processed .frd and .zma files in Passive Crossover Designer and start hacking away.

It's as "simple" as that


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## Seaxe (Sep 13, 2008)

G,day SinCron, as a word to the wise, speaker design is not an easy process by any means. I once thought it was simple, (within reason), until I wisely obtained Vance Dickason' " Loudspeaker Cookbook ", which demonstrated that I knew next to nothing about speakers. I highly recommend that you familiarise yourself with the theory before design, in order to avoid disappointment. Poster fuseli has offered a way to go foward, however this relies on, amongst other things, manufacturers data sheets which are general and only give small (T/S) signal parameters. Two way designs are not easy and three way designs are an order of magnitude more difficult. Accordingly, I would urge you to read Dickason at the very least, as a guide to principles of loudspeaker design. Remember, " In the mind of the beginner there are many possibilities, in the mind of the expert there are few " Cheers, Mike.


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## SinCron (Dec 20, 2010)

Thanks guys. To be honest, hearing these speakers is my reason for wanting to build my own. I've even seen four ways. I will post pics of my Altec Lansing 83's which are 3 ways (pics available on Google) which have an 8" midwoofer that could provide more in the bass department. I just want to make something a bit more compact with more of a kick to it.


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## 1Michael (Nov 2, 2006)

fusseli said:


> It's as "simple" as that


Not if sound quality is an issue...
Again https://sites.google.com/site/undefinition/diy-faqs-provendesigns


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## fbov (Aug 28, 2008)

SinCron said:


> Thanks guys. To be honest, hearing these speakers is my reason for wanting to build my own. ...my Altec Lansing 83's...could provide more in the bass department. I just want to make something a bit more compact with more of a kick to it.


Taking this as an idea of what you're looking for, you may not realize it yet, but you're the reason for proven designs. 

If you'd like a long-term hobby, speaker design can be a fun thing to do. However, you'll be spending money initially on test equipment, books and software, not loudspeakers, and it's you'll be on the steep part of the learning curve initially. That means you're first design will likely be an improvement over the AL83's, if only due to advances in driver design. It's unlikely you'd stumble upon a result as good as the Focals for several itterations, if ever, although you'd get to something very respectable if you kept at it. 

Proven designs allow you to jump right to a top-quality design and put your time and effort into good execution, knowing the result will be a keeper. 

HAve fun,
Frank, whose most recent build was a proven design...


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## gwilliams20 (May 4, 2010)

Sincron, Starting off with a failure is no fun. I, too, recommend starting with a proven design.

I recently built some Aria 6 speakers that use focal drivers. They are professionally designed and will sound very, very good. I lubs me some Focals. 

If you're interested, go to the Zalytron site and under kits click on "premium". You can see the specs, cabinet drawings and schematics for the crossover. Plus the prices for the parts kits. Elliot at Zalytron is a good guy to deal with.


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## GranteedEV (Aug 8, 2010)

Hi SinCron. I don't mean to put down your ambitions. I know it's exciting to pick a bunch of drivers that probably sound great and expect that to really blow you away. But the #1 rule of DIY audio is that a part is but a part, and the execution is far more relevant. 

Speaker _design_ is anything but someting you can jump right into. Here's a few issues that occur on poorly designed speaker

Fluctuating on axis response that over-emphasizes certain frequencies, and underemphasizes others. 
random impedance profiles which kill amp life and reduces 
inconsistent off-axis response which resulting in undesired coloration of reflected sound. These speakers need a ton of "room absorption" to sound good rather than boxy.
levels of high stored energy which result in audible ringing... both electrical and mechanical
too much money spent on crossover components when it could have been done more efficiently with better results.
shouty vocals
very low sensitivity
"random" imaging - you can actually tell a sound is coming from a driver rather than from the intended stereo imaging.

"reduced fidelity, plain and simple"

Ask yourself:

Have I ever read a text or paper about psychoacoustic theory? How many have I read? How many have the truly dedicated read? 

Have I ever read a text on the basics of speaker design? How many have I read? How many do the truly dedicated likely have read?

How much do I know about circuit design? Do I even know what the various functions and issues related to crossovers even are?

What measurement equipment do I own. What measurement software do I have access to?

How many good speakers are there out there, and how many very poor speakers are out there? Can I say this definitively, and do I even know? What is my frame of reference for accurate sound reproduction? How do I know the speakers I think are good, aren't actually all that great? 

All of the above considered, do I have sufficient experience to take on loudspeaker design and actually do well? Never mind design, how well do I truly understand loudspeaker construction?

After asking yourself these questions, I think you'll find that you're a time away from designing your own loudspeaker, at least that's how I feel based on reading your posts. There is absolutely nothing wrong with that, we ALL have to start somewhere. 1Michael has posted a link which essentially reflects my personal position on that matter. That there's nothing wrong with building someone else's proven design, as these people have invested the time and money to make a good speaker which you likely have not yet invested. 

And then someday, you may look back at your original plan and think to yourself "yikes...glad I didn't go through with that  ". 

The gist of it is this:

it's easy to take a 10/10 woofer, a 10/10 midrange, a 10/10 tweeter, and make an abysmal speaker. It's diffucult, yet very possible, for good designers to take an 8/10 woofer, an 8/10 midrange, an 8/10 tweeter, yet produce an excellent speaker.

In fact, some speaker companies I have found use absolutely world-class drivers, and still manage to produce poor speakers. And these... are people expecting to get paid for their products! Here is one such example examined:

http://murphyblaster.com/content.php?f=marble.html

This is because drivers alone do not dictate sound quality.  Their interaction with the room, the crossover, and of course each other are far more relevant. Take it step by step, learning as you go along.

It sounds to me like you want a compact speaker capable of reproducing lower bass and high output. If you're interestred in proven design, we'd be more than willing to suggest you some to overview and consider. Since it's about the learning process, we recommend learning by building an established design because there truly is meaning to it. It will help you in the long run. A speaker you ought to truly consider is the Zaph TMM.


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## SinCron (Dec 20, 2010)

I put in an order to Parts Express for a new mid speaker and woofer for my speakers to I can experiment. I want a smallish bookshelf design so I can have good bass in a smaller package with at least two speakers and handling of 100 watts.


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## Jstslamd (Nov 30, 2010)

Which driver are you planning on using ?


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## 1Michael (Nov 2, 2006)

:mooooh::mooooh::mooooh:


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## fbov (Aug 28, 2008)

SinCron said:


> I put in an order to Parts Express for a new mid speaker and woofer for my speakers to I can experiment. ...


Here's where you can learn how to do that productively:
http://www.pvconsultants.com/audio/frdgroup.htm


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## SinCron (Dec 20, 2010)

Jstslamd said:


> Which driver are you planning on using ?


Two of these woofers and two of these mid speakers.


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## bambino (Feb 21, 2010)

I know that with my speaker project i have going it would have been wiser of me to go with a proven design but i tend to go against the grain because in the end i know it will work out. I ended up just buying some nice drivers and hopeing it works out, i'm also using an active crossover.
The reason i am pointing this out is i don't want failure for anyone and unless you have a good understanding of what to do and look for in a driver i would steer more toward the proven design rather then the buy the cheap nice drivers and hope it works out in the end approach. Just my 2 cents from experiance.:T


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## Jstslamd (Nov 30, 2010)

No tweeter ?


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## fusseli (May 1, 2007)

bambino said:


> I know that with my speaker project i have going it would have been wiser of me to go with a proven design but i tend to go against the grain because in the end i know it will work out. I ended up just buying some nice drivers and hopeing it works out, i'm also using an active crossover.
> The reason i am pointing this out is i don't want failure for anyone and unless you have a good understanding of what to do and look for in a driver i would steer more toward the proven design rather then the buy the cheap nice drivers and hope it works out in the end approach. Just my 2 cents from experiance.:T


Active Xovers would be a 200% safer way to go for a noobie build. Still need stuff like BSC, but at least the effect of an active Xover is the equivalent output of a textbook filter whereas a textbook passive Xover rarely (if ever) is.


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## bambino (Feb 21, 2010)

Passive? Textbook? Yeah thats a tough one, only if it's designed for the speaker system. With Active, you have so many options that can literally save the day. However one day i would like to try a passive but i want the right equipment to measure and get results so i don't have to go back and forth with different values of this and that.:T


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## SinCron (Dec 20, 2010)

Jstslamd said:


> No tweeter ?


Sorry, those were replacing my speakers. All drivers are in the beginning of the thread. Either two tweeters or a single ribbon tweeter.


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## Jstslamd (Nov 30, 2010)

What ever you do when your shopping for driver make sure they are close in sensitivity so they blend a little easier with each other. I would say working 2db +\-


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## SinCron (Dec 20, 2010)

Bumping this back up as when I replaced the woofers in my bookshelfs, I kept the woofers for later. Then I got two towers with fried 8" woofers so I threw one in as a replacement and it roared at 40hz because of the larger enclosure. This makes me want to return to my original plan for a ported bookshelf design. Maybe even a bandpass setup. Still wanting to go with a single 8 ohm woofer but might cut it down to a two way with a planar transducer or ribbon tweeter above. Just have to figure out a few details about that though. Can you mount those horizontally? Smaller and cheaper ones are hard to get in 8 ohms, how much of an issue is it to use a 6 ohm tweeter with an 8 ohm woofer? Can one do a bandpass design using a folded slot port? Of course there's the issue of what woofer to use but there in lies the fun in the chase.


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## Jstslamd (Nov 30, 2010)

http://diyaudioprojects.blogspot.com/2010/04/diy-hivi-research-swans-m1-speakers.html

Check this out. It may be along the lines of a build you would wanna do. If you build your own enclosure it would e a really inexpensive build. I believe these were said to be tuned to 40hz but I could be mistaken.


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## fusseli (May 1, 2007)

SinCron said:


> Can you mount those horizontally?


You can but it may change how the FR pans around the room.


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## Theresa (Aug 23, 2010)

Crossover design is far more complex than the beginner imagines. The Loudspeaker Design Cookbook is a good place to start. There is no use buying "generic" crossovers, they will not work. Use a Zobel and it will be easier to get right but add complexity. I'm glad I'm free from passive crossovers. I just use active these days, what with computer configuration. It makes it easy as "sin."


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