First pair of DIY speakers

drproton

Member
2008-01-03 5:40 am
hello everyone,

I guess the subject is a lie. I've built DIY speakers before, but not since I was 16. I'm looking for a pair of speakers to use with my computer and or as surround speakers. I've spent a few hours reading through the forum, here is what I have come up with:

I would much rather use a "canned" design. I don't have time to (re-)learn all the engineering involved in proper speaker design. I'm actually an electrical engineer and I once knew a fair bit about speaker design. However, my goal is to spend some time and save some money to get a good set of speakers, not spend a lot of time tinkering to get my own design right.

I would like to spend somewhere around $300 on a pair of speakers (cabs excluded). I was definitely thinking of a bookshelf design, preferably something a little smaller (<15" tall). This is not set in stone, sound quality is still the higher priority. A basic two-way or MTM design is what I had in mind. If I go to the higher side of my price range, something biampable would be good. I suppose in the worst case I just use my own speaker terminals and spilt up the crossovers.

In the future I may want to expand this system. Something that matches well with a center channel and/or sub kit would be preferred. They should also work well with my main speakers, B&W DM602s (1st gen). If the kit sounds better, then the 602s get hooked to the computer. I would also entertain the idea of building the sub at the same time if it made the sound really come together for the kit I choose.

I listen to all kinds of music from jazz/big band/swing to classical to obscure punk rock and heavy metal. However, I only listen to the former critically and at what I'd consider "medium" volume. I can still hear the phone ring over the music.

I will be building the cabinets. One tool I have at my disposal is a CNC router. I can draw the panels in autocad and in a matter of minutes have dimensionally perfect parts. I will have to buy a couple more tools :) to do the assembly. I done a lot of woodworking / machining / model building. The only part of the cabinets I'm not skilled in is the finishing. I'll do some more research on this.

Some of the kits I am considering are;

Solen HI-VI melody research
Solen impression MKIII - at bit more than I'd like to spend
Solen premium
Solen vifi premium mini-monitor
any of the bookshelf madisound kits in the 200-500 range
Northcreek echo
Northcreek okara II

All things being equal I would like to buy from a canadian supply, for less shipping cost/hassle.

I'd like to hear and recommendations/reviews on kits in this price range, and not unnecessarily just the ones listed above. I did come across some other sites that sold kits, but I can't seem to find them right now. Another other comments would be appreciated. Sorry for the rant, and thanks for your help.
 

drproton

Member
2008-01-03 5:40 am
I've been reading some of those DIY sites. The zaph audio one is especially great. It is quite impressive the level of thought that has been put into some of these designs. I've also come across some other interesting kits here:

http://www.occamaudio.com/shop.html

Anyone used these?

I had another thought about the biamping. maybe I could use two sets of dual binding posts. There could be a before XO and after XO connection. If using an active XO before the amps it might come in handy.
 
drproton said:
Anyone used these?

Not the kits, but those are CSS SDX7 & WR125ST drivers they are using... i am very familiar with those. I reckon the kits with the WRs is going to be better. The SDX7 is only recommended for use up to about 1 kHz (at least stock -- it does produce prodigous bass, they are in a number of woofers we are developing as helpers for the boxes i mentioned in my earlier post). Both od these drivers use XBL2 technology and are really very good (but can be made better).

The last time i visited Bob, we started out listening to a little MTM Bob had put together with the WR125ST & the AC 2si ribbon. These were biamped with a 2-way plate amp from Solen (or Bob). These were quite good. One of the purposes of my visit was to deliver to Bob one of the 1st set of EnABLed FR125SR. We popped those into a set of the 7 liter PE boxes (the less than stellar rectangles, not the nice new curved back ones). The room fell away and the MTMs were a distant memory. I've never seen Bob sit still for an hour and just listen to music :)

I have a set of the WR MTM drivers to treat up for Bob, to see how the MTM does with tweaked drivers... without it was flat & lifeless compared to the single FR125S. So if you go ahead with the MTM plan on tweaking them (all the info to diy tweak them is available)

At this point it is important to disclose that my company is the only source for pre-tweaked drivers (well not the SDX7 yet -- i'm still working on them) so one must factor in any potential bias i may have (it is interesting to note that after hearing the tweaked FR125SR, Al Wooley of RAW is having me do the ones for his kits)

If you plan on biamping te raw drivers can be had stock from Bob, or tweaked from me. Use the tweeter of your choice. If you want all the parts for passives from a single source by all means consider the Occams.

Note that in the deluxe kit they provide variovents for aperiodic loading... this is my prefered loading for this driver (ie aperiodic -- the variovents can be diyed a number of different ways -- these are essentially a chunk of fiberglass sandwiched between 2 pieces of gutter mesh.

For other designs for these drivers check out the Box Library at my commercial site (link below)

dave
 

drproton

Member
2008-01-03 5:40 am
Can you explain the EnABL thing to me? How much does it cost to get this done, assuming I don't do it myself.

Looking around some more the zaph audio SR71 kit seems popular. I am tempted to try one of these. It seems like a proven design and all the parts are available in kit form.

I should also point out that I also have a pair of DM302s. They sound pretty good for what they cost me, but are definitely a different class than the 602s. I would be kinda disappointed if my DIY speakers don't sound better than the 302s.
 

MJL21193

Disabled Account
2007-03-10 1:20 am
drproton said:

I'd like to hear and recommendations/reviews on kits in this price range, and not unnecessarily just the ones listed above. I did come across some other sites that sold kits, but I can't seem to find them right now. Another other comments would be appreciated. Sorry for the rant, and thanks for your help.


Hi,
This is not a kit, but a very nice speaker to build. Not complicated either.
It's a Seas coax driver that's $150.00 at Solen. Crossover as detailed by Tony is very simple to construct and not at all expensive. The box is also easy to build.
You can expect great performance from this one.
 

drproton

Member
2008-01-03 5:40 am
I was aware of the baffle step compensation problem. If these speakers do outperform my 602s (they may very well do this) they go in the living room, where they can have a more appropriate placement. This is the location where I will be testing them. I will test them against the wall as well, if I hear any problem I will give Jay's XO a try.

The coaxial speaker also looks interesting. Madisound sells a kit using a similiar driver the T18RE/XFCTV2 (H1333). In the end the price is about the same.

I'll research the EnABL thing some more. I don't think the speaker I'm building will be using those drivers, so its not really an issue. I hate when my threads get hijacked and turned into a flame war. Lets stop before this happens.
 
drproton said:
I hate when my threads get hijacked and turned into a flame war. Lets stop before this happens.

I have split off the side discussion. Here are the links that got split off with the off-topic discussion

The side posts were slpit off to here:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=115022

John's entire post is over there. I did take the unusual liberty of leaving a copy of the relevant part of the post here so that drproton would still have that info.

drproton said:
Can you explain the EnABL thing to me?


http://www.diyaudio.com/forums/showthread.php?s=&threadid=100399

http://www.pesupport.com/cgi-bin/config.pl?read=393330

dave :cop:
 

MJL21193

Disabled Account
2007-03-10 1:20 am
drproton said:

The coaxial speaker also looks interesting. Madisound sells a kit using a similiar driver the T18RE/XFCTV2 (H1333). In the end the price is about the same.


Hi,
I ordered one of these today (the T18RE COAX H1144) for a new centre speaker. Everything that I've read about these is good.

You mentioned the Solen Premium earlier. I have those drivers and used them in a 2-way TL of moderate size with VERY good results. You'll need to look at the Xover though, as Solen uses the nominal impedance to design them.

Good luck :)
 

AJinFLA

Banned
2005-02-09 4:35 am
Tampa
Whoa. My post is still here. I'm still here :faint:

Drproton, first let me say that I am hopelessly bias towards concentric type drivers. They are imperfect as all others, just less so IMHO. I'm not a huge fan of softer cones, but I think for your specific needs the Seas coax kit (driver/xo) might be just the ticket, especially given the nearfield possibility.
I would strongly suggest a subwoofer, or even better yet woofer(s) on each channel below 300hz or so, even in bookshelf configuation.
I am seriously envious of your CNC capabilities.
Best of luck.

cheers,

AJ :2c:
 

drproton

Member
2008-01-03 5:40 am
While I wait for my drivers to arrive I'll probably build the cabinets. I was thinking of changing the construction a little. Rather than normal butt joints I'd like to use Dado/rabbit construction throughout. It should make assembly a fair bit easier as well as making it a bit stronger. The back panel would sit in a Dado about 1/4" behind the end of the side walls. This will make it uglier, but its not the showing side. All other joints would be rabbited. I'll obviously adjust the dimensions to keep the interior box volume the same.

Are there any problem with the dado/rabbit construction? Why is it not more common? Most of the kit drawings I've looked at are all butt joints? Is it just a matter of simplicity? For me its only a few extra minutes of machine time to do this.

To hold things together while gluing I'll either use finishing nails or wood screws (robertson of course) if necessary. Once everything is set I'll bondo over the heads. My Dad taught me to use cleats to hold speaker boxes together, but I have yet to see a DIY design that does this. Is this simply overkill? I expect with proper gluing the glue holds way more than the screws do.

Is it necessary to have a removable baffle? While this would be a nice feature it will create an ugly seem around the cabinet. How do you seal the baffle?

Where in Canada can I buy 1" MDF? I don't recall seeing it at any of the major H/W store (home depot, rona, co-op). How about veneers?
 

MJL21193

Disabled Account
2007-03-10 1:20 am
drproton said:

Rather than normal butt joints I'd like to use Dado/rabbet construction throughout.

Are there any problem with the dado/rabbit construction?

To hold things together while gluing I'll either use finishing nails or wood screws (robertson of course) if necessary. Once everything is set I'll bondo over the heads.

Where in Canada can I buy 1" MDF? I don't recall seeing it at any of the major H/W store (home depot, rona, co-op). How about veneers?


Hi,
I am a professional carpenter and can build speakers with the best of them. I don't use either dados or rabbet joints. They are pretty much a waste of effort. Butt joints and yellow carpenters glue are strong enough.

You will be using MDF? What will the finish be? If you want to paint it and do a good job, avoid screws with bondo filler. This will always telegraph through, no matter how smooth it seems. Better to use airgun nails to hold it together till the glue dries.

You should forget 1" MDF and use two layers of 1/2" instead. This gives better damping results.

Most building supplies have a small selection of veneer. All the usual suspects, such as oak and maple. For exotic ones look on Ebay.
 

anatech

Administrator
Paid Member
2004-06-06 8:31 pm
Georgetown, On
Hi John, drproton,
I once used 1" high density particle board for some club speakers. You can get almost anything by special order. This stuff has some interesting characteristics. Firstly, it throws sparks as you cut it. You can guess that it's hard on blades. You can machine it and it will hold whatever shape you make. That means the corners will stay sharp. See the sparks coming off the router now? More expensive for those "blades".

We had a great machinist (carpenter) who cut quite accurately. The top when "whang" and slid a little when it was dropped on top. It was perfectly flat. So we now had a braced enclosure. When you hit it, it would ring. This is wood remember! We used undercoating spray on the inside to dampen the ringing. They were now great boxes that didn't ring or leak. All 250 lbs of them (each, there were four in the first run).

Don't do it. They were impressive but laminating is much less expensive on everything. It is true that today's glues (Gorilla Glue) is much stronger than the wood. I know another guy that does not use nails or screws. He builds the boxes up and clamps them. Done. I used to use cleats, but I haven't for 15 years or so. Mind you, I haven't built much of anything in the last 15 years either!

I think John is steering you down the right path.

-Chris

Edit: I should second SY's remarks about editing. We do not edit a member's post without their express permission or unless there are other issues. We will also leave a note in that post to indicate we were there and why. You may have seen some, but they are very rare. The general policy is to not edit any post but your own (like I'm doing).
 

MJL21193

Disabled Account
2007-03-10 1:20 am
anatech said:
Hi John, drproton,
I once used 1" high density particle board for some club speakers.


See attached pic of TL sub made from used toilet partition stock - 1" thick particle board with Arborite on both sides. :D

anatech said:
Hey John,
My shoulders are messed up. I should get you to build some small boxes for me if we can work something out. Zero rush.

-Chris

No problem Chris, PM me the details.
 

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anatech

Administrator
Paid Member
2004-06-06 8:31 pm
Georgetown, On
Hi John,
A deep thank you. I haven't even worked out the details because I knew I couldn't build the boxes. I do have the woofers though.

Neat looking boxes. You removed the Arborite from the joint areas, or did you get them glued somehow? Why is the woofer so far away from the other drivers? I haven't designed or built anything for a number of years, so please excuse my curiosity. I'm not criticizing at all.

The last ones I built were a double tuned box design from Douglas Weems. To kill resonance modes, I located the woofer 1/3 the way down the internal box and the ports 1/3 up from the internal box bottoms. (an internal port connected the two internal box volumes) I still have the prototypes in my bedroom. A 2 way 8" set with 1" soft domes. They sound okay but the real ones were designed for Peerless drivers. Those sound pretty good.

Some day I'll work them out and send them to you. Probably a pair of B4 enclosures or aperiodic ones. Nothing complicated. If you have something you are building at some point, please let me know. I may be able to use the same box. Then it's just more of the exact same cuts for you.

-Chris
 

drproton

Member
2008-01-03 5:40 am
"Don't do it." To which are you refering? The 1" MDF?

I'll probably forgo the wood screws. I would only use them if a piece was twisted and needed to be pulled flat. As for the Dado/rabbits. I will probably still go ahead with these. Remember I'll be doing these parts with a CNC router, so it is really very little extra effort. I plan on using MDF throughout.

I would like to veneer the cabinet. If I make the baffle removable it will be painted and the rest of the cabinet veneered. If the baffle is fixed I would like to put a heavy roundover (maybe even 1") on the vertical sides and wrap a single piece of veneer around the baffle/sides. Will having a hard corner at the top of the baffle be a problem?

I know what you mean about the "sparky" particle board. My sister's Ikea cabinets used something like this. I had the unenviable job of cutting the microwave shelf. The circular saw was spitting up sparks and puking out blue smoke. It took about 5 minutes to do a 24" cut. and the blade was in pretty bad shape afterwards. This was a tie for the time I had to circular saw through 3" of well dried 30 year old Fir. That presented quite the challenge for the cheap purpose bought circular saw.

Several years ago I found a DIY speaker that had been built in a concrete sewer pipe. That would be a pretty sturdy enclosure. Maybe the pics are still out there.