DIY Speakers! Any other mad scientists here?

[Oktyabr]

Thanks guys for the warm welcome!

Building your own speakers (as some of you are obviously aware) can be a very rewarding aspect of the hobby, and I'd be happy to share anything I've learned, mistakes, etc. with the hopes that you will do the same. DIY speakers *can* sound better than store bought speakers and can be done for less, but one thing I will put right out front, right now... I would never recommend anyone build their own speakers just to try and save money! You can build a better speaker for less but you will never get something really good for free. I dove into this end of the hobby with a budget idea of $300 for my first build. The drivers cost me $168 for the pair and I spent another $100 on the wood, some glue, binding posts, etc. By the time I was done I'd also spent about $600 on various wood working tools, clamps (can *never* have too many clamps!), drill and router bits, a circle jig (VERY valuable!), special purpose saw blades, sand paper, waxes and oils. Purchased another amplifier, more speaker cable, a digital crossover from overseas, several more sheets of baltic birch ply, more drivers, binding posts, wire, etc. My $300 budget ended up tallying about $2000 in a years time to build a speaker I was truly happy with! And don't forget the time!!! MANY hours actually in the wood shop and for every hour I spent there I bet I spent another three online, learning, comparing prices, and reading reviews. ~whew~

So unless you are already an experienced cabinet maker with a fully furnished shop (or know someone who is that will help you for cheap!), it can all add up quick!

There are dedicated DIY forums but that's sometimes not what I'm looking for. Just like non-DIY forums almost everyone has their favorite brand of driver, design of cabinet, special software or technique. All good and well but it can often be overwhelming, especially for the relative novice. And that's why I started this thread! Ultimately I have the desire to share what I've learned, maybe encourage someone else to explore the unknowns of DIY, for it does have it's rewards

 

[laatsch55]

That's what forums like this are all about, sharing what we've learned, or in my case sharing what I'm learning as I learn it. Very neat stuff.

 

[mlucitt]

Some "Garage" Speakers I Made

I used some JBL components here and covered the boxes in truck bed liner. The box is as small as possible dimensionally, that's why the horns hang over the edge a bit. I was going to vent them with two triangular vents but they just sound too good like they are. I have since put screens on the woofers.

Mark

 

[laatsch55]

What horns are those?/

 

[mlucitt]

Titanic Sub

This is a Titanic sub knockdown kit I purchased and assembled. I vented it to get down to about 38Hz. I think it turned out nice with black hammered paint and the magnetic cloth cover.

Mark

 

[laatsch55]

Realistically, how low will a sub go?

 

[Oktyabr]

Yea.... Real glad your here !!! Sutton and I built these speakers in my avatar ! Wish I had better pics. Im working on that !

I'd love to see some photos of these and of course, read about the experience and your listening impressions! I leaned towards line arrays myself once but never built any. Tough design to knock when close out sales on a full case of drivers brings them down to the price of dirt! I know you didn't use anything that cheap... looks like Beston ribbon tweeters and... Tang Band mids?

 

[mlucitt]

Lee,
Those are JBL 2370A horns in front of JBL 2426J 1" 16 Ohm compression drivers with titanium diaphragms.

There are electric motor driven subs that will go to 1Hz.

http://www.aespeakers.com/phpbb2/viewtopic.php?t=398


Mark

 

[laatsch55]

I'm pretty happy with as low as the K's go. The way cool part about those is they stay loud down low. I'd like to measure the response curve one of these days.

 

[Oktyabr]

Realistically, how low will a sub go?

Due to the longer wave length of the lower frequencies subwoofers become very room dependent. A 20Hz sine wave, for instance, has to travel a little over 56 ft before the next one leaves the driver (by comparison a 1KHz sine wave travels less than 2 feet). In a smaller room that usually means it will leave the cone, cross the room, bounce off the far wall and return to the cabinet before the next wave is produced. This creates cancellation of frequencies and other more complex interference patterns (since rarely does anyone play a pure 20Hz sine wave!) as the waves interact with each other. Proper damping, a good design with the room in mind and proper placement can do a lot to squeeze the most out of a subwoofer, like any other speaker... but subwoofers certainly present their own problems. This is why big bass notes can sound so good in a theater or concert... the room is usually big enough to let the notes fully resolve before they start bouncing around and interfering with each other. In a smaller room sometimes a thin floor (relatively speaking, as opposed to a concrete slab for instance) can actually help simulate a larger room as some of the signal will penetrate the floor and likewise the walls and ceilings as well. This gives you that nice "rumble" in home theater applications... and also why boom boxes on wheels that the kids seem to like these days only seem to produce muddy bass notes as they drive by.

 

[Oktyabr]

I'm pretty happy with as low as the K's go. The way cool part about those is they stay loud down low. I'd like to measure the response curve one of these days.

This is the measurement microphone I use: http://www.parts-express.com/pe/showdetl.cfm?partnumber=390-801

You still need a computer, a way to carry a signal from the computer to the speakers (RCA cables to the pre?), an SPL meter (I use the one on my smart phone), enough XLR cable to connect the computer to the microphone and some sort of microphone pre-amp (several under $100 to choose from).

Then you need some measurement software, of course. I like REW which you can google for. It's free but requires an account on their forums to download it. The nice thing is that it is designed to not only measure speakers (in near field) but actually to fine tune your stereo/room to suit your tastes (when the mic is placed at your listening position)... After all, unless you have a full blown anechoic chamber to test in you never *really* listen to a speaker... you listen to a room with a speaker in it.

Parts Express also sells a more complete kit that includes software, mic, etc. : http://www.parts-express.com/pe/showdetl.cfm?partnumber=390-792

 

[Oktyabr]

Here are some conceptual drawings I did that helped me proto the ones I actually ended up building:

More drawings of a potential three way using a more dedicated midrange (probably Morel) and a B&G planar tweeter:

And finally playing around with the idea of *massively customized* dipoles, with a more artistic flare:

 

[laatsch55]

Yep, it appears you are SERIOUSLY into speakers. I believe Skratch was getting the parts express package to measure response. He built the original set of Soniphase and shook em down and was wanting a way to see what they were doing.

 

[ksrigg]

Welcome to the forum Oktyabr. Kevin called me this morning all excited that a fellow "speaker guy" had joined the forum. Kevin and I have built literally dozens of pairs of speakers and subs, and for a few years were involved in the Southeastern US DIY Speaker Competition in Atlanta, Georgia, winning second place one year and winning the meet the next year with our Linus Arrays. I have done some designing, and built other folks designs as well. Zaph Audio is one of the best designers out there, I think. His designs are aloways top shelf, and he uses some inexpensive drivers, which is pretty cool. It seems the hobby has bottne more expensive in recent years however in that the cost of all components has gone through the roof. After building the Linus we backed off too, because they were tough to beat, but lately I've been into discovering the older designs like the Altec Lansing Voice of the Theatre A-7's and the Klipsch La Scalas. Seems these guys pretty much perfected speaker design in the 60's and only now are they improved with better crossover designs and better driver construction (in some cases).

One thing is for sure.....you can not buy a commercial speaker which sounds better than a good DIY speaker unless you fork out about 10 times the money it costs to build the DIY project....I think Kevin and my pair of Linus cost us about $750.00 a pair in drivers, crossover parts, MDF and veneer and I think you would have to spend at least $7,500.00 to buy a commercial speaker which could compete........if that makes any sense..

Anyway, welcome aboard, and I look forward to your posts..

 

[ksrigg]

Oh yeah......check out Zaph Audio's site. He has tested hundreds of speaker drivers and can help in choosing drivers for specific projects. I was really shocked with the results of ribbon and planar tweeters, for example...and again, his designs are fantastic...

and you have to get a Phase Linear 400 or 700 to see what is going on....it is mandatory....

just kidding.........(not really)

 

[Oktyabr]

Heya! Always nice to meet another DIY junky!

Yeah, I've read pretty much everything that Zaph has written including his famous "shoot outs".

My biggest regret about DIY speakers is that sometimes a design calls for components you simply can't get any more! There are plenty of builds around some of the older Fostex stuff, for example, that were specifically designed just for that driver. No matter how great one of them sounds you can't, years later, recommend them to someone else just because they would be *extremely* lucky to find the original drivers any more, even used. Another good example is the Merril DC4 based "Zigmahornet" that made some serious waves in the DIY audiophile community a few years back. A great sounding speaker that was purpose designed for the DC4 (or maybe the other way around?) that could be built for under $150. Try to find any DC4s these days! I know folks have tried to adapt other drivers to a similar build but man, I personally wish I could hear a pair of the originals...

http://www.6moons.com/audioreviews/zigmahornet/zigmahornet.html

Please share some of your photos and stories! I'd love to hear about the competitions especially

 

[laatsch55]

Glad to see you excited again Sutton. oktyabr gonna have his hands full. That's too hard to type, gotta real name??

 

[Oktyabr]

Glad to see you excited again Sutton. oktyabr gonna have his hands full. That's too hard to type, gotta real name??

Oh yeah, I'm Jon. I'm just used to being one of many "Johns" in most larger forums so "Oktyabr", "Oct", "Okt", "Okty" or some other variation tends to stick instead. I answer to pretty much anything though!

 

[mlucitt]

John, you will find Lee and the rest of us easy to get along with and pretty straight forward. Glad you are here.

 

[laatsch55]

Yep, a fresh perspective is always good!