Thank you, I am enjoying them far more than I anticipated. Although their low frequency performance is surprising, I didn't expect miracles from a 3" driver. I didn't get one, either. 
The detail and imaging, on the other hand, is something truly special. The sounds of people breathing, strings being plucked, percussion getting hit - all truly startling. Sometimes I'd swear I'm hearing things I've never heard on that track before, but I already swore that the last time I made some wonderful change.
There is still a lingering problem with spectral balance. It must be some kind of peak or resonance somewhere, and I'm finding it difficult to put it into words. I'm guessing the drivers are not fully/properly loosened up, or perhaps the stuffing is all wrong. I've also noticed that these little guys are extremely fidgety about their position in the room. They started in the basement (big space, 15'x40') but shortly moved to the bedroom. I placed them tight against the wall, up on 22" stands but that just didn't work. Pulling them out six inches helped immensely. I'll continue to play...
All in all, much good fun. Cheap, too - I received the drivers in trade, and the boxes cost little lumber to build. Just the personal satisfaction of seeing the finished product was worth the price of admission. If you're thinking of building a set of full range enclosures, but have never made a horn before, I'd think these should be given some consideration.
The detail and imaging, on the other hand, is something truly special. The sounds of people breathing, strings being plucked, percussion getting hit - all truly startling. Sometimes I'd swear I'm hearing things I've never heard on that track before, but I already swore that the last time I made some wonderful change.There is still a lingering problem with spectral balance. It must be some kind of peak or resonance somewhere, and I'm finding it difficult to put it into words. I'm guessing the drivers are not fully/properly loosened up, or perhaps the stuffing is all wrong. I've also noticed that these little guys are extremely fidgety about their position in the room. They started in the basement (big space, 15'x40') but shortly moved to the bedroom. I placed them tight against the wall, up on 22" stands but that just didn't work. Pulling them out six inches helped immensely. I'll continue to play...
All in all, much good fun. Cheap, too - I received the drivers in trade, and the boxes cost little lumber to build. Just the personal satisfaction of seeing the finished product was worth the price of admission. If you're thinking of building a set of full range enclosures, but have never made a horn before, I'd think these should be given some consideration.
I finally got around to making a set of audio test tones. I just took the fundamentals of each white key on the piano and generated a sixty second sine tone at -6 dB. I made them using CoolEdit and burned the resulting .wav files to a CD. I wish I had done this a long time ago.
I played these tones through my amp and my Makizou to find out quantitatively what kind of low frequency extension they can manage. I've been running them in the bedroom every night for the better part of a month, so I imagine they are reasonably well broken in by now. The output is well pronounced down to A2 (110 Hz). After that, it begins to fall noticeably down to D2 (73.4 Hz). Somewhere just past deep C or B1 (61.7 Hz), the residual audio output is pretty much useless.
Not bad for a pair of set of drivers that's barely 2.75" diameter, I'd say. I'm glad I did this easy experiment. I hope to apply this test to some of my other speakers so I can develop some measure of "how low can they go."
I played these tones through my amp and my Makizou to find out quantitatively what kind of low frequency extension they can manage. I've been running them in the bedroom every night for the better part of a month, so I imagine they are reasonably well broken in by now. The output is well pronounced down to A2 (110 Hz). After that, it begins to fall noticeably down to D2 (73.4 Hz). Somewhere just past deep C or B1 (61.7 Hz), the residual audio output is pretty much useless.
Not bad for a pair of set of drivers that's barely 2.75" diameter, I'd say. I'm glad I did this easy experiment. I hope to apply this test to some of my other speakers so I can develop some measure of "how low can they go."
That's a great idea! Any chance you've got a website or somewhere you could post those wav files? I'd love to get a copy.
The .wav files are 524 MB. I've got no place where I can share that much data. I can convert them to reasonable quality .mp3, where the full set will require 30 MB. You are probably only interested in less than half of that, from middle C down. In that case I might be able to email it to you in three installments. Send me a PM with your email address.
Well, since my test tones are based on piano keys they only extend up to the eighty-eighth key (C8, 4186 Hz). My tones are pure sine waves, but real music should have harmonics well above that. I guess this is a long way of saying "I didn't test for that."
I will say that the top end sounds good, natural, and real. I have absolutely no complaints here. I have zero desire to add a super tweeter or anything like that, nor do I wish to adjust the treble in any way. The highs do not sound "rolled off". They are not "too bright" or harsh. The deficiencies of the Makizou seem to lie predominately in the bottom end and in their obvious inability to go freakin' plaster-cracking loud.
I did grumble earlier about a boxy sound I heard from them. Either I've adjusted or they've broken in, since that doesn't seem to be bothering me any more. I didn't do anything to adjust their stuffing. I do still have issues with placement. Where they are located in the bedroom I prefer to sit close to the back wall. That's where the bed is, and I sit up near the headboard. If I'm too close to the back wall, they don't sound so good. Big surprise there. I wish I had these guys in a better listening room with a proper chair.
For as little cost as these things are to build, you ought to just make a set and see for yourself.
edit: Sorry, Bill. I forgot you've already made not one set of these, but two! How did you like them?
I will say that the top end sounds good, natural, and real. I have absolutely no complaints here. I have zero desire to add a super tweeter or anything like that, nor do I wish to adjust the treble in any way. The highs do not sound "rolled off". They are not "too bright" or harsh. The deficiencies of the Makizou seem to lie predominately in the bottom end and in their obvious inability to go freakin' plaster-cracking loud.
I did grumble earlier about a boxy sound I heard from them. Either I've adjusted or they've broken in, since that doesn't seem to be bothering me any more. I didn't do anything to adjust their stuffing. I do still have issues with placement. Where they are located in the bedroom I prefer to sit close to the back wall. That's where the bed is, and I sit up near the headboard. If I'm too close to the back wall, they don't sound so good. Big surprise there. I wish I had these guys in a better listening room with a proper chair.
For as little cost as these things are to build, you ought to just make a set and see for yourself.
edit: Sorry, Bill. I forgot you've already made not one set of these, but two! How did you like them?
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What size thickness of wood is that for?
Just wondering the thickness of the wood on these conversions.... I'm tooling around in the garage today, and wanted to do a little project with these fostex that I have laying around. Any other suggestions for DIY projects?
Thanks!
Just wondering the thickness of the wood on these conversions.... I'm tooling around in the garage today, and wanted to do a little project with these fostex that I have laying around. Any other suggestions for DIY projects?
Thanks!
I don't know your location, but it seems that in the US most plywood is sold as 1/2", 5/8", or 3/4" thick. The material is generally 1/32" thinner than what it's labeled. For example, the 1/2" stuff is really only 15/32".
The Japanese construction sketches (and other countries, too) often seem to specify 15mm material. The German designs I've found (Dr. Buschhorn) use a combination of 19mm for front baffles and 13mm for internal partitions.
The material I've been using was sold as 3/4" ply. It's just a little over 18mm thick. Sometimes I've attempted to adjust the dimensions to accommodate differences in lumber thickness. Often I just ignore small differences.
I had fun making a set of the original Buschhorn cabinets. I made a thread here:
http://www.diyaudio.com/forums/full-range/168132-fostex-ff85k-buschhorn-mk-i.html
You could also look at the Frugel Horn site. There are many plans listed there.
The Spawn Family of Double Horns
And, still more interesting projects at t-linespeakers.org
Transmission Line Speakers
Imported plywood will by 12,15, or 18mm. Some domestic plywood, particularly construction grade will be slightly thinner, possibly to metric dimensions then rounded to Imperial. Domestic cabinet grade plywood will be on spec 1/2",5/8" or 3/4". Baltic birch will always be metric. I have not run across any 19mm BB, but who knows.
Bob
Well here in the UK you can get veneered Baltic Birch Ply 19mm thickness, which is veneered on both faces. In fact veneered BBP comes in the following thickness's:
5mm, 7.5mm, 10mm, 13mm, 16mm, 19mm 22mm, 25mm, 31mm, 41mm and 51mm.
Standard (non veneered) BBP comes in the following thickness's:
4mm, 6mm, 9mm, 12mm, 15mm, 18mm 21mm, 24mm, 27mm, 30mm, 35mm, 50mm.
Guess we are spoilt for choice.
Guess we are spoilt for choice.
I guess! I almost had to give up my first born to get my local supplier to carry 18mm BB. He has lots of 12mm, since the local cabinet makers use it for drawers. Out here in the weeds of central Arkansas, there isn't much call for specialty stuff and that means a driver in to Little Rock to get a lot of stuff.
Bob
Hopefully those in this thread are still active on the forum, I'm building a pair of these speakers using ty_bower's 18mm ply diagrams, I'm not brilliant with the sawing aspect but I've done most of the pieces so far and they're within 1mm of the lengths specified on the diagram, hopefully this wont cause any issues, I'm planning to use tannoy ICT 4" [more like 3" really] drivers from a tannoy i30 ipod dock, the drive units however are surprisingly good and are of a compact crossoverless dual concentric design, I have to confess that I have no idea of the T/S/Fs parameters of the units, I contacted tannoy over them and they don't provide schematics or datasheets anymore unfortunately but as the materials all in all cost under £10 it's not an awful loss if this doesnt work perfectly. What I'd like to know is the cavities in the horn mouth, can i place a straight sheet of wood over this area as it appears ty_bower has in post #59 to then create two hollow cavities I can fill with sand or some other weighting?
I believe the Japanese plans suggested filling the few small cavities at the bottom with "river pebbles". Mine just have scraps of carpet over them. Let us know how your project turns out, and be sure to post a pic if you can!
Thanks for your reply! I'll be sure to once I get them finished, hopefully wont be too long, after tomorrow I'll just be waiting on the gluing, ah okay, I read the links to the japanese article however in not as much detail as perhaps I should've, did you find the strips of carpet added any additional dampening or tonal change? I'm looking forward to finishing these and if ever I could put the money together combining them with a class D amp, tube buffered pre and NOS dac sorry if I've missed you saying but what sort of amplification are you using these on the end of?
Hi again, I'm getting into the gluing stage and also realising how bad my woodworking skills are, hopefully generous gluing and corrective sanding will compensate, I was hoping someone could give me some comments on volume/ type of stuffing to fill the front cavity with? As I'm trying to keep cost down, would something like the stuffing in bedding do the job reasonably well?
Poor woodworking might be overcome with generous use of the hand plane, and heavy application of numerous clamps. In any regard, make sure you've built it airtight or the effort was wasted.
I think I used cheap polyester fibrefill, and likely too much of it. You can see my application back in post 59. Pillows are disturbingly cheap at Wal-Mart, and provide a nearly inexhaustible source of synthetic fill.
I think I used cheap polyester fibrefill, and likely too much of it. You can see my application back in post 59. Pillows are disturbingly cheap at Wal-Mart, and provide a nearly inexhaustible source of synthetic fill.
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Yeah, I'm hoping to plane/sand the edges flat to get a good seal, I have to say motivation's getting a little low although ive a few photos to add at some point, my project has been slightly more difficult than those in previous posts due to the lengths i had to go to, to mount the drivers [photos will explain when I get around to it], however just earlier I finished sealing/ securing the drivers and basically blutacked the whole thing together to get a glimpse of how it'll sound when finished, really quite nice, lovely for acoustic music but very very little bass even with a larger 4" driver, however given that for me i was trying this at midnight so volume couldnt be particularly loud, there was no damping and the thing was about as air-tight as a football net, not too bad, hopefully when finished this will improve, I'll also be adding a sand/wood glue mixture to the cavities my design changes [photos will also explain... eventually] have created to add mass.
Thanks Ty [am I alright calling you that?] for the tip, your photos do go a long way to help with this project, not to mention your diagrams!..
Thanks Ty [am I alright calling you that?] for the tip, your photos do go a long way to help with this project, not to mention your diagrams!..
Unfortunately I can very safely say that the tannoy drivers I was using are definitely not a match for this enclosure, as if I should be surprised, there's significant bass peaks at 60, 90, 120, 150, 180 and 200Hz, and very significant troughs in between, aside from active equalisation to counteract this [which would be costly and a ruin the point of a single driver speaker, obviously] I've no idea how to counteract this, admittedly this test was done without any internal damping but given this information can anybody suggest any possible things I could do to try even this out at all? It seems a shame for a months effort to be completely wasted. On the plus side the front and side panels arent yet attached so i guess i could always replace the front panel and fit a more makizou friendly driver in the place of the tannoy.
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