Very High Quality DIY speakers anywhere? - Page 4

Hey Jeff,
how's the sono sub? Had a chance to work on it yet?
James

Why yes, I have worked on it some. MY bidness travel has kept me jumping lately. I just successfully fought through the Atlanta traffic to make it home from the airport once again. However, I'm leaving again in the morning to go to a family get-together on my wife's side. I have to wait until Monday to work on it again. Here are the pics of what I've done so far
http://lotuseuropa0.tripod.com/diy_sonosub001.htm
Jeff

James,

Thank you for your great information. My hat off to your great effort and speakers.
I wonder if you did other normal 3-way type DIY project. Have you ever evaluated ATC's SM75-150 midrange dome driver? If you did, I hope you'd share some experience with us.

Hi jheoaustin,
thanks for your kind words.
I have not heard the ATC's SM75-150 nor am I likely to afford a $3000 pr set of drivers. I would hope it would sound very good.

I tend toward getting the biggest bang for the buck. My current project is kinda a poor man's Pipedream, but I am trying to save about $68,500 dollars. Besides, more money doesn't necessarily mean better, especially in audio.

James

James,

Thank you for your reply. I agree mostly with you. Just a bit of correction, though, is that ATC driver is just under $1,000 per pair, probably $700, not $3000.

James,

I remember McIntosh had some statement with line source speaker that, many tweeters in line source speaker would relieve burden around the crossover frequency, and thus enables wider bandwidth of tweeter(basically lower crossover), and more flat/seamless 2-way loudspeakers. Do you agree?

jheoaustin, for me, $700 for a pair of drivers, that are not full range (meaning you gotta buy some other drivers too) is just out of my price range. I can only justify so much money for DIY projects, especially if there is a possibility that the project won't go as planned and you don't like the results!

Scott,

Thank you for your comments. I agree with you. I don't have a good woodwork skill or fine-tuning knowledge for DIY speaker, so I wouldn't dive in right now. Maybe I would rely on some kit makers.

One of my future expectation is, rapidly developing DSP technologies drving down room EQ features to reasonable price point. I believe this means that some DIY speakers, not tuned optimally due to some reason, could benefit greatly from room EQ features. I think room EQ can give us a lot more chance to tune the system with DIY speaker a lot better, and the driver quality and potential can be much more important than network fine tuning(and hopefully enclosure). It would be even better if multiamp system with active crossover is employed along with DSP room EQ.

J.L.,

I am in the process of building the Audax HT system also. Here is a quote from the Audax webpage:

-----"Cut all panels to size and make all holes before assembly. Flush mount all drivers to eliminate diffraction caused by the raised edge of the driver flange. A router will be needed to rabbet driver flanges flush with the baffle. (The TM025F1 micro tweeter does not require flush mounting.) Use weather stripping available at hardware stores to seal the joint between driver flanges and the speaker baffle. A tight seal is especially critical in vented enclosures. -------

I am going to use the larger front design for all 4 speakers. I am also adding some braces to the center cab. Some people feel this isn't necessary, but I'm doing it anyway!

Hopefully you not flush mounting the drivers won't cause a problem with the sound. I'm hoping someone much more knowledgeable than me will chime in on this.



Griff

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jheoaustin says: ATC driver is just under $1,000 per pair
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So I probably shouldn't use these guys as a price source.
driver reference

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jheoaustin says:
I remember McIntosh had some statement with line source speaker that, many tweeters in line source speaker would relieve burden around the crossover frequency, and thus enables wider bandwidth of tweeter(basically lower crossover), and more flat/seamless 2-way loudspeakers. Do you agree?
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I remember hearing the Mcintosh tweeter lines many years ago. Very sweet sounding. They must have designed their tweeters rather differently than regular tweeters. Other tweeters have a very high resonance breakup, 1K or higher. Around the resonance, all they will create is distortion, even at low volume. If you ever crossed over a tweeter too low, you will know it. The sound is not at all pleasant. So it is usually recommended you crossover an octave above this point. The Mcintosh tweeters must have been more like a full range 2" driver. So I agree with your basic premise, but I don't think that you could line up a normal 1" tweeter and get the amount of frequency range that Mcintosh did.

There is a greater problem with any array involving cones and domes. If the center to center distance between drivers, is greater that the wavelength of the highest frequency that the driver is producing, you will get combing and beaming interference patterns. At 10khz the wavelength is about 1.5". Therefore any conventional driver array will have combing and beaming at higher frequencies. This includes some speaker systems that cost many thousands of dollars, as well as the very popular 2" and 3" supercheap driver arrays. What does this sound like? Well it is pretty dramatic, from across the room, if you move your head up and down you will hear a dramatic variation in the highs of the array as your ear passes past each driver. A true line source tweeter such as a ribbon, or planar is required for higher frequencies.

James

I think the prices are for the kits that the drivers are used in, not the price of the actual drivers. Either that, or we are talking Peso's instead of dollars!
If you look a little farthur down, the Audax HM170C0 is the midrange driver I used and it is says: Audax A652 kit ($685/pr). That is the speaker kit that it is used in, and the driver by itself (price I paid) is about $60.

Griff,

The statement on that page contradicts the drawings and illustrations on the plans themselves.

In my theater, and probably in most listening environments, it is unlikely I would be able to hear the difference between a driver flush mounted and one that is surface mounted.

If you look at the woofers, you will see that even if flush mounted, the rubber surround would protrude past the front panel of the speaker enclosure. It is for that reason I do not think the difference in performance will be detectable.

I am open to advise from the experts out there. It is relatively easy to use my router to flush mount. I do have to wonder why the plans (on the Audax web-site) drawn by Joe D'Appolito only flush mounted the midrange driver in the center channel.

J. L.

Scott - I visited your site. Lo and behold, your Maverick 2C uses the exact driver/tweeter pair I've picked out for a project I'm planning. They look great!
I noticed that you used Oak Plywood, rather than the standard MDF. I applaud the finished appeal this gives them and would like to shamlessly copy that design. I'm a novice, and have been dutifully conditioned through the reading I've done that hardwoods can cause tonal variances - is this an over-rated thing?

Thanks,
Kevin

Try in your mind to visualize a perfect point source soundwave. An infinitely small point in space creating the soundwave radiating out perfectly in all directions. It should sound beautiful.

Now place that point on an infinite vertical plane like a wall. The sound now only radiates in 180 degrees. A part of the wave follows the plane's surface but it doesn't ever really go to the listener.

OK so now visualize a raised object on this surface (such as a raised speaker rim). As the sound wave that was following the surface encounters this raised object a portion of the wave reflects off this object. It is almost like the point of deflection itself is generating sound. This sound also radiates outwards, but as it encounters other parts of the orginal soundwave they interfere, causing some cancellation, and some reenforcement and rippling somewhat up and down the frequency response.

Are you going to hear this, maybe yes and maybe no. It might be a little bit of distortion, some harshness, muddiness, or less precise imaging.

The protruding rubber surround of a cone driver causes about a 3 db dip in the driver's frequency response at approximately the frequency of 1 wavelength. For a 5" speaker this is about 2k. Some manufacturers try to account for this in the speaker design. I have even heard of some people placing absorbent material on the rubber surround.

Now we further limit our perfect soundwave environment by placing it on a speaker baffle instead of the wall. As the sound wave reaches the edge of the speaker you get diffraction from the edge, with similar negative effects as in hitting a raised object. So on a standard speaker we have each edge deflecting, the raised drivers, speaker covers, etc... etc. All of this will muddy our clarity and imaging.
The edge diffraction is is especially acute with line source speakers in a rectangular baffle, because they will uniformly encounter the edge for the entire length of the line. Whatever the type of speaker, rounded edges are better, the rounder the better.

Also higher frequencies will radiate at 180 degrees due to the baffle, but as the frequencies go lower they will be less affected by the surface of the baffle and tend to radiate more toward 360 degrees. This causes a significant loss of energy. From about 1000hz down to 100hz you gradually lose 6db of sound energy. This is called baffle step loss. Many builders modify the crossover to account for this.

So do what you wish, but it all has an influence on the sound of the end product.

James

Scott,

Thank you so much for your valuable information and opinion. May I ask another question to you?

I think you know bending wave transducer or air motion driver such as ones from Manger, German Physics or Heil drivers. Could you tell me your opinion? I think they are aiming at ideal point source reproduction using non-pistonic motion.

jmiyake,

Thank you for the great description of how flush mounting the drivers will help with imaging.

I am just at the point in constructing the Left/Right speakers where I will be attaching the veneer. You convinced me that the effort is worth a few minutes time. I will get out the router once more and cut the rabbet to flush mount the two 6 1/2 inch drivers. It can't hurt.

Now... we do not have a "point source" with conventional cone drivers. Instead, we have a cone shaped surface with millions of infinitely small point sources on its surface. Furthermore, the speaker cone is not infinitely stiff and weightless. Therefore, it cannot be all moving in the same direction at the same time when driven from the movement of the voice coil. It must have "ripples" on its surface radiating outward, similar to those on the surface of a pond of water when you drop in a stone.

The points on the cone closest to the voice coil must be moving before the points on the cone closest to the surround. This, in my mind, is probably one of the major factors why one driver sounds different than another of different construction.

Do we not have the same cancellation, reenforcement and rippling of the sound we hear at our listening position you described no matter what we do? Is it a matter of choosing good drivers and mounting them as best we can?

J. L.
Now... there are also room reflections to deal with... (I doubt I have a perfect room)

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Now... we do not have a "point source" with conventional cone drivers
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You are very correct in pointing this out. Things are far from perfect. Multiple drivers, crossovers, limited frequency range, driver mass. On and on.

A cone is indeed a compromise, although one that has been greatly refined over the years. It's disadvantages lead many to go to alternative drivers, but each of these have compromises of their own.

Part of the fun is improving on the standard factory approach with better craftsmanship, or better quality components, thicker cabinets, more bracing, better damping, better caps, wire, terminals, rounded edges, at least that's one of the things I like about it.

James

I don't know how over-rated that is, but the simple fact that I am no using a true hardwood remains. The plywood itself only has the veneer on both sides that are hardwood. Would I make the whole thing out of hardwood, no. Why? Probably a combination of cost and the fact that it may cause the variances in sound that is reproduced. One of the biggest reasons I have used the plywood is the fact that I have never done any veneering in my life, and it just seems like one less step by going this route. Actually, it not one less step, since instead of using one peice for the front panel, you actually end up with 4, since you now have the front panel as well as the three oak 1/4 rounds to make up the rounded edges. It is a pain, well, yes. Will I try a veneer finish in the future, yes. Will it be soon, probably not, I have other projects to do!
As far as copying the design, no, I won't have it. Of course I am kidding. If I didn't want anyone to copy my design, I wouldn't have all the info on the web! The center channel design is basically a copy of the Audax A652 speaker design by Joe D'Appolito that they have posted on their web site, except it uses a Vifa tweeter, instead of the Audax.

jheoaustin, I don't know all that much about the single driver style designs. I have never actually heard a Manger in use, except at CES. The thing I do know about them that makes them great is that they do not use any crossovers, so that the signal goes to them and there is nothing electronically that can alter the signal. I would assume you would want to add a subwoofer to the set-up, since I don't think any of those drivers can handle the air moving capabilities that are needed for the low end of the spectrum. Anyone else have an opinion on this style driver?

I am using an active digital crossover with built-in EQ and room EQ with my DIY speakers at the moment. It is the dbx Driverack PA and it works exceptionally well. Check it out at www.driverack.com.

It's not quite as good at room EQ as the TACT I used to own, but the combo of fully active triamping, DIY, great drivers and dipoles creates the best sound I've had.

Steve

Well... it was a bit harder than I expected, but... the drivers can now be flush mounted.

I ran into a tiny snag when using my router to flush mount my drivers in my DIY Audax HT Left/Right speakers. It appears that the hole in the front of the cabinet was just about 1/8th inch smaller than I would have liked. It still fit the driver with plenty of room to spare, but when I used a 1/2 inch rabbeting bit, it turned out the flange of the speaker did not fit in the resulting opening.

I ended up using a sanding drum in my cordless drill to open the rabbet up a bit wider so the speakers would fit. I follow that with some hand sanding to make things look a bit more even... IT took a bit more time than I expected.



At this point, everything is ready for the veneer. The crossovers are mounted and wired, the front edges rounded over, and everything sanded smooth.

I hope it is worth it. It put me a few hours behind my self imposed schedule... (I wanted to get these done before Christmas)

J. L.
I will hear the difference flush mounting makes... I know I will...

J.L.,

I wasn't trying to throw a monkey wrench in your plans!! But on the other hand, how would you have felt if everyone told you to flush mount the drivers after you'd already veneered and mounted them!?! Will the difference be noticeable? Hell, I don't know! But everything I've read about baffles says to flush mount unless specifically designed for surface mounting. Am I an expert? NO! This is the first set of speakers I've ever built. I want them to sound as good as possible, so the wife won't kill me for this expensive new hobby I"ve taken up!!

Hmmmm, wonder how she's gonna feel about a 30" Sonotube sub.....


And what about a line-array for 2-channel only use...

Pray for me!!

Griff

ooops, double post!

Guys, today, I finally got around to ordering my Audax center and front L/R components. I hope to have the sonosub finished next week. I'm already working on the cabinets for the Audax speakers.
Jeff

J.L.
well the thought that I may have contributed to your extra effort pains me. However your speakers look great. Nice roundovers at the edges too. Very professional!

It does seem that it takes a bit of working to get the flush mount just right.

Please let us know how it turns out.

James

I'm not sure I'll get the L/R front speakers finished by Christmas... It will be close...

I'm going to hold the entire Internet responsible for my missed date. For that reason, neither you Griff, nor you jmiyake, should feel too bad. (My wife says I get lost when browsing... Problem is, there is so much to learn, millions of pages on the web... and they keep adding more. It is hard to keep up )

This morning, before setting out for work, I applied "yellow" glue to the top, bottom, and backs of my speakers. I also did the same with pieces of red-oak veneer cut to size for the various surfaces. By the time I get home this evening, they should be dry enough for me to iron on.

I plan on working on one speaker at a time and once I have three sides done, I'll apply glue to the front and sides. I'll let that dry as I go out and do a bit of last minute Christmas shopping. If I am lucky, it will be dry by the time I get back from the stores and I'll get a single piece of veneer wrapped around the front and sides.

J. L.
PS.
My wife is already prepared for the upcoming sonotube sub project. (after the Audax HT rear channels are built) I've showed her pictures (of an 18 inch diameter, 5 1/2 foot tall version similar to the one Jeff Hovis is building) and she has approved. I'm pretty sure Santa is bringing me a 15 inch Adire Tempest driver in a few more days. (Santa...I've been good... honest... )

I had done an extensive amount of research on DIY speakers including the Internet, Books, and Speaker Builder Magazine. The design I finally went with was the ME2, which is the shorter version of the famous ARIEL.

Link:
http://www.aloha-audio.com/Arieltxt1.html

I have never been so impressed. I did just as the instructions called out. 2.5" thick front oak, MDF board. Triangle cavities in the rear filled with sand, pure unprocessed wool. The sound is unbelievable! Extremely flat, 3D sound. Sounds like the artists are in the room with you. Movies jump off the screen. I couldn't emphasize these speakers more for DIYourselfers.

However, I do enjoy Martin Logan, ribbon type speakers also. I've been looking at a sort-of non-DIY speaker from:
http://www.justrealmusic.com/content/home1.htm

As I posted earlier, I ordered the Audax speakers from Madisound today. At 5:35EST, I received a shipping confirmation and tracking number! Looks like I'm gonna have a lot more MDF dust to vacuum. I'm so glad I moved this project from the basement to the garage.

I too am about to put together the Audax center channel. I ordered the parts from Parts Express so I have to actually assemble the crossover. It shouldn't be too bad as I successfully built the L/R crossovers and they actually worked! I pre cut the MDF when I built the L/R speakers, but as I pointed out in a previous post they didn't come out so straight. I need to get a table saw. I think the center channel cuts were much better, but I'll let you know if it has to be rebuilt too. I plan on rebuilding the mains when my new house is done in February.

At the same time I'm going to be building a EBS alignment Shiva Sonosub. I couldn't believe how hard it was to find that stuff. 10 phone calls later and I was able to find a place that actually sold it by the foot.

I'll try to get pics!

later,

Don

I've added more to my diy sonosub site. I should be giving it a test run next week.
http://lotuseuropa0.tripod.com/diy_sonosub001.htm

Jeff

Jeff,

Thanks for the pics of the sonosub build process. I now understand how the circle jig works and will make my own tomorrow when I start mine.

later,

Don