DIY speaker kits

[zepman1]

I'm thinking about building some speakers for a secondary (currently non-existent) home theater setup. Ideally, I would like to start with a kit (BR-1, Ar.com, etc) for the front speakers, and then custom build surrounds, center channel and subwoofer for a 6.1 setup. I figure that I can learn while building the kit, and then hopefully use that knowledge (and help from message boards) to build the rest.

Anyhow, I am trying to decide on a starter kit and which I should get. The BR-1's look good, but I am concerned about the power handling. I would like to feed these at least 100W per channel, and will likely run them pretty hard. Other than power handling, accuracy and stereo imaging are my primary concerns. I would prefer a three way design for the front channel but it is not critical. Any suggestions? Oh, and cost is a concern I would prefer the kit to cost less than $300. I will build my own cabinets for the surrounds and sub if necessary.

[Swerd]

Here are a few DIY web sites that I have found useful. All of them are well written and documented and seem to contain a variety of good designs. Understand that I have not heard most of them. Several of the articles at speakerbuilder.net were especially helpful when I was first starting DIY. This site has a design that uses the same woofer as the AR.com but a different tweeter and crossover.

My personal favorite designs are Dennis Murphy's 2-ways, the MB20 (less $, similar in price to AR.com and IMO better) and CAOW1 (more $) at murphyblaster.com. He has plans that allow you to convert his 2-ways into a 3-way with the addition of a 10" woofer in a separate cabinet (MBOW1 3-way). I've heard them and they are excellent. He also has a corrected crossover design for the BR-1 kit. All the designers except Wayne J at speakerbuilder.net will answer emails.

http://www.zaphaudio.com/
http://www.lonesaguaro.com/speakers/
http://murphyblaster.com/content.php?f=main.html
http://www.speakerbuilder.net/web_files/default.htm
http://www.rjbaudio.com/

Have fun reading them

[kexodusc]

Swerd pretty much covered most of the weblinks I'd give you.

I've build a project by every single one of these designers. My favorite by far is John Krutke (zaph), Dennis Murphy sure knows his stuff though.

For a home theater on a budget, you can't go wrong with something like the BR-1's. I say this because there are a zillion designs using the Dayton woofers and tweeters that you can study/copy/borrow ideas from for customizing your own home theater.

I just built a home theater for a friend based on some of Wayne J's designs from speakerbuilder.net (you can see my thread below in this forum). Very good sound for not a lot of money.

I've also built the PeeCreek (the Peerless design Swerd referred to) and the Ar.com...I actually preferred the Ar.coms overall presentation, but the imaging in the PeeCreeks is extremely good for an inexpensive speaker.

Lots of options....
I'd recommend a few books if you really want to get into the hobby:

Designing, Building, and Testing Your Own Speaker System - David Weems
Loudspeaker Design Cookbook - Vance Dickason
Speaker Building 201 - Ray Alden
Great Sound Stereo Speaker Manual - David Weems

I don't have a favorite yet...maybe the 1st Weems book and SB 201...all are good. You can find them used for cheap if you look.

[Swerd]

My favorite by far is John Krutke (zaph)Hey kex

Which of John Krutke's designs did you like? Was it the Seas L18/27TBFCG?

I haven't heard a whole lot of metal speakers and I was thinking of trying one out for my next project. So far, I prefer the coated paper woofer designs I've heard, but you never know what you haven't heard. Obviously, the choice will be between a Seas aluminum design and one with the Dayton RS drivers which sell for a lot less. Have you heard any of those that you like?

[zepman1]

Thanks guys, looks like I have lots of reading and experimenting ahead of me.

What about the power handling of the BR-1's? I don't believe I've ever seen a rating for these other than that listed with the Dayton drivers. If I remember it was really low, something like 60w. Is this correct or can they be safely (and effectively) driven with average amplification (100w per channel)?

Thanks, the BR-1's seems like a good starting point for me, but I want to avoid them if the power handling is a concern. Thanks again.

[kexodusc]

The power handling is 100 watts max on the BR-1's, but that's a real estimate. Most speaker wattage ratings are absolutely useless, and refer to the thermal handling capability of the voice coils, not the actual amount of full-range power you could feed a speaker.

If you were to take a typical brand name speaker like B&W, Klipsch, Paradigm, etc and try feeding their power handling numbers into the speaker, you'd run the risk of driver excursion in many designs.

The BR-1's will play plenty loud, don't worry, I'm guessing you don't use 100 watts average amplification to your current speakers.

[kexodusc]

Hey kex

Which of John Krutke's designs did you like? Was it the Seas L18/27TBFCG?

I haven't heard a whole lot of metal speakers and I was thinking of trying one out for my next project. So far, I prefer the coated paper woofer designs I've heard, but you never know what you haven't heard. Obviously, the choice will be between a Seas aluminum design and one with the Dayton RS drivers which sell for a lot less. Have you heard any of those that you like?

I did hear Zaph's Seas all metal design...and for the money it is by far the best speaker design I've ever heard, DIY or otherwise. If memory serves, it was the larger woofer model Zaph uses, the L18, not L15...it was a fellow DIY-er at the local "club" I guess you might call it who built the design and brought it in for us to demo...I could verify for certain if you want, though I can't imagine one design being executed better than the other.

I very close to building a modified version of the L18 design myself. By most accounts, the Seas tweeter is a bit better than the RS28 or a bit less money (though might require more xo parts to narrow that gap). Zaph also liked the Seas woofers better than the RS woofers he tested by a good margin, but you're right, about costs again. I think they'd be comparable...one's got a high priced tweeter, the other a woofer. If you're doing an MTM, I'd probably lean with the Daytons. I plan on eventually trying all these drivers.

Since shipping from PE is a bit steep for me the Seas is designs are a bit more attractive to me right now....but there's just so much raving about the RS drivers...decisions, decisions...

[Swerd]

Yes there is no shortage of new designs with metal drivers.

I just read last night that Dennis Murphy is in the process of designing a 3-way speaker with Dayton RS drivers. It will have a RS150 mid and two RS225 woofers. There are two versions with different tweeters, one with the Dayton RS28 and one with the Seas H1212 tweeter. http://www.pesupport.com/cgi-bin/config.pl?read=265584

Here I thought I was beginning to understand things. I thought Dennis preferred coated paper woofers with gradual high freq roll-off and gentle breakup peaks that allow 2nd order crossovers. He also prefers very flat performing designs and seems to avoid bass heavy designs. And now he is making a metal 3-way with two 8" woofers! Dennis has always said that just because an aluminum driver is shiny looking doesn't make it bright sounding.

I'm eager to find out more. If anyone accuses me of being a Dennis Murphy fanboy, I guess I'm guilty as charged.

[zepman1]

The power handling is 100 watts max on the BR-1's, but that's a real estimate. Most speaker wattage ratings are absolutely useless, and refer to the thermal handling capability of the voice coils, not the actual amount of full-range power you could feed a speaker.

If you were to take a typical brand name speaker like B&W, Klipsch, Paradigm, etc and try feeding their power handling numbers into the speaker, you'd run the risk of driver excursion in many designs.

The BR-1's will play plenty loud, don't worry, I'm guessing you don't use 100 watts average amplification to your current speakers.


Thanks. I know I am not currently running at 100 watts average (even though AVR is rated for that). But, in the not too distant future want to upgrade to some more serious amplification and don't want to run into any issues if I want to use the speakers I am building.

[MikeyBC]

I've posted his link before but it belongs on this thread too. http://home1.stofanet.dk/troels.gravesen/ some designs may not fit your budget but there is a 2 way tower design based around Vifa drivers that looks good here http://www.troelsgravesen.dk/PL18XT.htm I'm slowly working on the modified Proac 2.5 clone, cant wait to finish someday.

[zepman1]

Thanks, one of my biggest concerns is if I have to build my own crossover. I have no idea how I would do that properly, so using finished crossovers is a huge advantage for me, but will really restrict me into what I can and cannot do. To really build what I want, I have a feeling I will need to build my own crossovers, and that could get ugly.

[kexodusc]

Yeah, crossovers are the hardest part for sure. Most DIY-ers I know (myself included) used their first project to study and learn how the speaker worked.

If you had an SPL meter and some idea of how loud you listen to music, it would be easier to predict how much power you're actually feeding the BR-1's. They'll get near concert levels with about 10-20 watts though.

[jocko_nc]

Building a crossover is no problem. Just a matter of carefully laying out the components and rudimentary soldering skills. Making the crossover look nice is a lot more difficult, however. Mine are all pretty darn ugly, but that does not affect the performance at all. I suspect you'll wind up with better caps and coils with DIY than you would with a pre-made. Also, you can match exactly the requirements of your drivers. You can easily make modifications. It is the way to go.

Ask for design help at PartsExpress on the speaker-building forums. The good folks there will model the crossover for you and probably draw you a schematic.

A good crossover makes all the difference.

jocko

[kexodusc]

Oooops...I confused "building" a crossover with "designing" a crossover. Yeah, layout and soldering isn't hard. Mine are all pretty ugly too...but I use custom made circuit boards (scrap pegboard, cardboard, plastic, whatever).
If you knew what components to select, you could easily assemble a crossover. Get yourself a soldering iron if you don't have one already, and practice on paper clips....once you get the hang of how the iron works, the rest is easy.

[jocko_nc]

I used 1/4" poplar stock from Lowe's. Cut to just less length than the width of the inside cabinet and put a 1/2" wide "foot" on either side. Hot-melt glue gun to hold the wood together. All the wiring terminates on the back side, the feet allow clearance to mount to the cabinet. Drill small holes front to back to pass the wires to the front. The "+" side of the circuit is pretty clean, solder the ends together. The "-" side will require a bus wire to accomodate all the grounds. Wire ties to hold the heavy components to the wood. Hot melt glue to keep everything snug and away from each other. Silicone adhesive to mount the crossover assembly to the cabinet, it can be removed for rework.

I'm curious what tips you other guys have found.

jocko

[jocko_nc]

They are inherently ugly because these "circuit boards" have no electrical traces, all the electrical connections have to be made via external wiring.

If someone was serious about making an attractive crossover, he could buy a proper circuit board from Parts Express ($9.00 I think). The traces for a "standard" circuit are already there. If he was hard-core, he could even buy parts and etch his own circuit boards. That would be cool, but is unnecessary from a performance standpoint.

jocko

[kexodusc]

the $9 per IC board thing was enough of a deterrent for me, but sometimes I've found myself having to be creative in how big or small I made the xo too, the circuit boards don't always fit.
Cardboard rules.

[jocko_nc]

You're as cheap as I am...

I am going to pick up a pair of MTM's in Atlanta next week. These were from a small (can't find any info on them) boutique manufacturer in NY, probably built in the early 80's. These had paper cones and cloth dome tweeters in them. They are long since shot, but the cabinetry is excellent, 3/4 MDF with satin piano black lacquer. I am going to grab these for a future project, when I can find a good home for them. Can't wait...

Given 1.00 dome tweeters and dual 4 1/2 inch cones, what might you recommend?

Jocko

[kexodusc]

Well, I dunno, depends on your budget...Audax and Hi-Vi have some great sounding inexpensive 4-1/2" woofers you might like.
For more money, I'd look at Seas, they have excellent paper or aluminum 4-1/2" drivers...you'd probably get response down to the mid 50's. If the cabinets are sealed (or could be sealed) you could probably do a bit better by raising the resonse below 150 Hz and using the natural rolloff of the drivers in a sealed design...with closer wall proximity than normal.
Seas has a poly 4.5" that is suppose to be something else too, but I haven't heard it yet.