Solid walnut Domus resto

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Picked up a pair of little solid hardwood (walnut and mahogany?) Domus speakers for $4 at the thrift store this morning. I'd like to fix 'em up for use with a little chip-amp as computer speakers, but could use some help picking out drivers. One is blown completely, so I thought I'd just buy all new drivers.

An externally hosted image should be here but it was not working when we last tested it.

The enclosure is 0.114 cubic feet (198 cubic inches) by my measurement. The wood is 3/4 thick, solid.

The Tweeter is a Pioneer FB26KP34-51D, a cheap 10mm 6 ohm part. I thought this might work as a replacement?
Audax TW010F1 10 mm Polymer Dome Tweeter: Madisound Speaker Store

The crossover comprises a single very large capacitor in an unmarked cardboard tube. I don't see any writing on it. It's visible glued in the corner, here:

An externally hosted image should be here but it was not working when we last tested it.

Would the capacitor still be good? Is there an easy way to test them? I believe Domus was around in the early 80s. It was founded by Don Kliewer, who went on to found high-end Minnesota speaker maker DLK.

The tweeter, woofer, and terminal cup are non-working in one of the units. There are two challenges. One, finding a square spring-clip terminal cup for a 1-3/4 cutout. They all seem to be 1-7/8 these days.

An externally hosted image should be here but it was not working when we last tested it.

Finally, I have not been able to identify the woofer, and am not too sure how to go about figuring out a replacement. It says 523TNF on the back, and 10.20, which may be the cutout size in cm.

Does anyone know of a decent (hopefully low cost!) shielded 5-inch woofer suitable for a very small enclosure with 4.75" cutout? Ideally, it should be the rounded rectangle variety, with four screw holes, as the tweeter sits fairly close.

Thanks for any suggestions!

-Henry
 
crossovers v. First order capacitor

Hi AllenB

Thanks for the reply!

I'd love to go full-range (I'm a fan), but worried about too much frequency overlap with the tweeter. I can't quite recall... is the capacitor a "first order" crossover? If so, will it be phase-aligned with the woofer? Or 90 degrees off? Maybe if both drivers are in phase, overlap wouldn't be such a big deal?

The little 10mm domes seem to drop out below 6K. I looked at "supertweeters" that kick in even higher up the range, but they were generally too big to fit in the 2-inch cutout. And anyhow, the five-inch full-ranger drivers I've seen mostly all appear to be optimized for ported enclosures, or at least fairly large sealed boxes.

So my thought was to try to "stay true" to the builder's original design, just to keep things simple. I do own a soldering iron, and while I don't know the first thing about crossovers, would love to learn, if it'd make a significant difference in the final result. I'd love for these little babies to sound as good as they look :)

My impression, though, is that speaker builders usually start with the drivers, then design the optimal cabinet. Being in the position of going about it backwards, do you think I could obtain a reasonable result?

Cheers, and thanks

-Henry
 
Okay, after poring over specs far too long, I think I'm going to try these:
Fountek FR135EX 5" Full Range: Madisound Speaker Store

It's either those, or the $4 Aurasound full-rangers. Maybe I'll get a pair of those, too... if it turns out my ears aren't good enough to tell the difference, I'll sell the Fountek's on ebay :)

so now, I'm wondering what caps to get. What is the difference between going with 1mfd vs. a 1.5mfd one?

Thanks!
 
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Well let's see now. In one hand you have a $4 speaker and your other hand holds a $100 unit. I think those cabinets are worth something in the middle but the Aurasound look to be a heck of a deal to start with.

As far as the caps go, buy 2 of each and get some 2.2's while you're at it. Buy electrolytic NP 50V in the 3 values I have suggested and also pick up 2 of each inexpensive sand cast 10W resistors at 1, 2 and 4 ohm. That all will cost but a few dollars and allow you to adapt the driver sound to your preference.

Welcome to the world of diyAudio. :)
 
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The issue you'll be dealing with when using a full ranger is llikely to be the compromise between more smooth top end and less consideration for bass. Think about how this will help. If you were to use a conventional 5" woofer, you'd want to cross it somewhere below 3k in an effort to avoid the possibly harsh top end.

This requires that you use a 'tweeter', not a 'super-tweeter', and you have already indicated a limited space on the baffle.

A fullrange driver may be smooth enough to relieve you of your crossover point limitation so you can choose whichever tweeter you want, but you may have to take whatever bass you get.

Regardless I would be suggesting an attempt to roll off the woofer top end as well as the tweeter. As far as phase issues are concerned the drivers are not 'flat' to begin with, nor are their interactions with a crossover so it just isn't as simple as you are suspecting it might be. You should probably first concentrate on getting drivers that will work well with each other after they are first set to work within their best range.
 
Reasonable enough

Thanks for the suggestions, you guys. It helps!

Cal, the $4 and the $100 units were the only "full-range" speakers (so-called by Madisound and Parts-Express) I found that would physically fit. With its 4-3/4 cutout, the little baby Domus boxes are too big for the Fostex 5-inchers, and way too small for the 5-inch Tang Bands and 6.5-inch Fostexs.

Quite a bit of car audio gear would fit, and I even found a $10 blue poly "Ford Mustang GT" overstock model available for $10, with a $25 pre-built crossover, and $18 1-inch aluminum dome tweeter. All that would fit. But I guess for some near-field monitors, it seems like image and timing might be more important than resolution and power handling and chunky bass? (How chunky is bass *ever* going to be in a tiny sealed monitor?)

I also looked at quite a few "5 to 5-1/2" woofers that would fit, including many marketed as low/mid bass units, and with response graphs fairly flat up to 7kHz and beyond. Perhaps this Fostex model would make a good "Mama Bear" choice?
Fostex FW137 5.5" Woofer Shielded: Madisound Speaker Store

The x-maxx is only 1mm, but if that means it's fast and 3D, hey, that's what I'm talking 'bout. Oddly, I notice in places Fostex has marketed this as a "subwoofer," which seems a reach for a 5-inch unit with 1mm of xmaxx and a flat response to 8kHz! It's a little scary that the recommended enclosure for this unit is so different from mine (0.4 cubic feet vs. 0.11, bass reflex vs. sealed). But maybe that's only for subwoofer applications ;-) From my (very limited) understanding of speaker specs, I don't see any deal-breakers at all for this application.

Anyway, I decided Cal's right -- why not give the $4 parts a try first? maybe they'll be great? :)

I guess now it's time to read up on filter networks.

Cheers,

-Henry
 
Circling back after a successful rebuild and hundreds upon hundreds of hours of listening... these have become my favorite speakers ever, an improbable outcome, for sure, but there it is. Why? Sound stage. Put them in the top corners of 14x10 bedroom, on the short wall. Von Schweikert VS-1 SUB corner-loaded lower right corner, low-passed at 80. Cheapie Audax tweeters, Fostex fw137 woofers. Curves on the fw137s and listening confirm Fine for full-range use. Original caps protecting tweeters, seem to cross around 8k. Lying in bed on opposite short wall, stage is Directly Overhead (!). Pure magic. Bedphones! I post in hopes more people will try putting crossover-free speakers way up next to the ceiling. Right on the wall. It's bliss
 
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