Hat Tip to Planet-10 (Dave Dlugos) and his re-interpretation of the EPI Micro Towers.
Built using two 8ft 1"x6" (nominal) boards with a 1.5"x4" vent. 7 liter (.25 cu ft) cabinet, about 6.5 liters minus driver, driver brace, and vent.
Picture shows them doing the work normally done by a pair of Fostex 127E Metronomes. The Mets are better (duh!) but the little TB's have improved markedly in just two hours of run-time. Bass is good for such a small driver but they (currently) lack "air" on top, and drums and piano lack that "twack" on the initial transient.
They look far better than I expected given my rudimentary wood working skills and tools. Thanks to my next door neighbor Ed, for his planing and belt-sanding which allows me to use the word "joinery".
-Tom-
Built using two 8ft 1"x6" (nominal) boards with a 1.5"x4" vent. 7 liter (.25 cu ft) cabinet, about 6.5 liters minus driver, driver brace, and vent.
Picture shows them doing the work normally done by a pair of Fostex 127E Metronomes. The Mets are better (duh!) but the little TB's have improved markedly in just two hours of run-time. Bass is good for such a small driver but they (currently) lack "air" on top, and drums and piano lack that "twack" on the initial transient.
They look far better than I expected given my rudimentary wood working skills and tools. Thanks to my next door neighbor Ed, for his planing and belt-sanding which allows me to use the word "joinery".
-Tom-
Attachments
Building Them.
Obtain two 8 foot 1"x6" boards (.75 x 5.5 actual). I used poplar from Home Depot.
For each speaker, cut four 20" long pieces for the front, back and sides. Cut a 4" piece for the base, a 7" (or just a skosh longer) piece for the top, and a 2.5" (or just a skosh shorter) piece for the driver brace. You might want to cut the remaining (hah!) piece to 4" as a temporary spacer between front and back during glue up.
Cut a hole for the vent centered in the base piece, and a 4" hole for the driver, 3" down from the top of the front piece.
Glue them up. I used Quick Grip cement I got from the hobby store.
Obtain two 8 foot 1"x6" boards (.75 x 5.5 actual). I used poplar from Home Depot.
For each speaker, cut four 20" long pieces for the front, back and sides. Cut a 4" piece for the base, a 7" (or just a skosh longer) piece for the top, and a 2.5" (or just a skosh shorter) piece for the driver brace. You might want to cut the remaining (hah!) piece to 4" as a temporary spacer between front and back during glue up.
Cut a hole for the vent centered in the base piece, and a 4" hole for the driver, 3" down from the top of the front piece.
Glue them up. I used Quick Grip cement I got from the hobby store.
Attachments
Finishing Up
The driver brace goes at the top, behind the driver, slightly offset to one side.
I originally was planning on going with a "shabby chic" painted finish, but they looked so good after sanding I switched to an all-in-one honey maple finish, 3 coats.
Some leftover accoustic padding went on each side of the driver brace and the remainder of my wife's polyfill pillow stuffing went inside.
A wire was led up through a hole in the bottom for the speakers with banana plugs on the other end.
Commercial feet were used (Peavey 3/4" x 5/8"). Make sure they are at least 1/2" high so you don't obstruct the vent on the bottom.
A commercial 1.5" x 4" flared plastic vent went in, the drivers were soldered to the wire and mounted on the speaker, and it was time to listen to music.
The driver brace goes at the top, behind the driver, slightly offset to one side.
I originally was planning on going with a "shabby chic" painted finish, but they looked so good after sanding I switched to an all-in-one honey maple finish, 3 coats.
Some leftover accoustic padding went on each side of the driver brace and the remainder of my wife's polyfill pillow stuffing went inside.
A wire was led up through a hole in the bottom for the speakers with banana plugs on the other end.
Commercial feet were used (Peavey 3/4" x 5/8"). Make sure they are at least 1/2" high so you don't obstruct the vent on the bottom.
A commercial 1.5" x 4" flared plastic vent went in, the drivers were soldered to the wire and mounted on the speaker, and it was time to listen to music.
Attachments
>>> but they (currently) lack "air" on top...
Just a suggestion:
http://www.zillaaudio.com/tb-1320-bamboo.htm
Piezo on the rear.
You can even sit a super tweeter on top but it might muck up the clean look.
Godzilla
Just a suggestion:
http://www.zillaaudio.com/tb-1320-bamboo.htm
Piezo on the rear.
You can even sit a super tweeter on top but it might muck up the clean look.
Godzilla
Downfiring Port Equals Poor Man's BVR?
When reading the Metronome thread I was struck by someone's remark that the sound improved when a hard surface instead of carpeting was put under the speaker.
The downfiring port tube that I used flares to 2" at the end. A circle of 2" has an area of 3.14 sq inches. The circumference of that circle is 6.28 inches and a height of 1/2 inch equals the same 3.14 sq inch area.
Past that it is a linear expansion until the edge of the speaker. There is also maximum reinforcement from the floor or desktop, and often from the rear wall as well.
You could also lower the speaker more and make a resistive slot port of the floor.
When you put your ear to the floor with this speaker, most of the bass, and only the bass, is coming from the bottom.
Has anyone played with these ideas or modeled them?
-Tom-
When reading the Metronome thread I was struck by someone's remark that the sound improved when a hard surface instead of carpeting was put under the speaker.
The downfiring port tube that I used flares to 2" at the end. A circle of 2" has an area of 3.14 sq inches. The circumference of that circle is 6.28 inches and a height of 1/2 inch equals the same 3.14 sq inch area.
Past that it is a linear expansion until the edge of the speaker. There is also maximum reinforcement from the floor or desktop, and often from the rear wall as well.
You could also lower the speaker more and make a resistive slot port of the floor.
When you put your ear to the floor with this speaker, most of the bass, and only the bass, is coming from the bottom.
Has anyone played with these ideas or modeled them?
-Tom-
>>> but they (currently) lack "air" on top...
>Just a suggestion:
>ZillaAudio.com, Outdoor Speakers | Rock Speakers | Garden Speakers | Patio Speakers | In-Wall Speakers | Ceiling Speakers and more!
>Piezo on the rear.
Resistors? Capacitors? What are they? This is my third set of speakers, and so far they are all an amp, a wire, and a speaker - no equalization. Stupid simple. But it may be time to branch out.
Actually I was thinking that for $25 dollars more I could have CHR-70's..........
-Tom-
>Just a suggestion:
>ZillaAudio.com, Outdoor Speakers | Rock Speakers | Garden Speakers | Patio Speakers | In-Wall Speakers | Ceiling Speakers and more!
>Piezo on the rear.
Resistors? Capacitors? What are they? This is my third set of speakers, and so far they are all an amp, a wire, and a speaker - no equalization. Stupid simple. But it may be time to branch out.
Actually I was thinking that for $25 dollars more I could have CHR-70's..........
-Tom-
>>> Resistors? Capacitors? What are they? This is my third set of speakers, and so far they are all an amp, a wire, and a speaker - no equalization.
LOL Tom! In many ways, i agree! I only use them when needed. If not, i pass too. But the piezo on the back does not detract from the overall 'full range' sound of this driver. It's barely audible but there. Without the piezo i felt the driver was a little too recessed on top. Certainly, a tweeter was not necessary but welcome.
LOL Tom! In many ways, i agree! I only use them when needed. If not, i pass too. But the piezo on the back does not detract from the overall 'full range' sound of this driver. It's barely audible but there. Without the piezo i felt the driver was a little too recessed on top. Certainly, a tweeter was not necessary but welcome.
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Thanks for the kind words.
They are sounding better the longer they run. They however are a bit overmatched to filling a whole room. As soon as the Sure Electronics amp arrives from China they will be moved to my computer corner, on each side of my 27" iMac, with the drivers bore-sighted on my ears. I hope near-field monitor suits them.
These were not meant to be the "best" speakers, but rather a cheap and cheerful build that rewards the (minimal) time and effort put into them.
(On edit: and I was curious about the W4-930SF driver)
They are sounding better the longer they run. They however are a bit overmatched to filling a whole room. As soon as the Sure Electronics amp arrives from China they will be moved to my computer corner, on each side of my 27" iMac, with the drivers bore-sighted on my ears. I hope near-field monitor suits them.
These were not meant to be the "best" speakers, but rather a cheap and cheerful build that rewards the (minimal) time and effort put into them.
(On edit: and I was curious about the W4-930SF driver)
Drivers breaking in is a know phenomenon, as there are many mechanical parts involved, often including rubber/foam etc, that will require time and use to "free up" completely. If the compliance of the surround changed during break-in, you'll get a change in resonant frequency, the cone will be able to move faster (less resistance), improving the highs. I think.
The running in of electrical components is subject to much debate.
The running in of electrical components is subject to much debate.
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