That was a very popular design and any number of those got build. I wish I could find another cheap 5-6" driver that worked nearly as well. I think that the Alpair 10 would work, but they are not "cheap".
Bob
I really like the new Mark Audio drivers and the Alpair 7 ($170/pair) could become a winner in the 5-6" winner category.
A little more
than the 40-1354, but it's not the 70's anymore. BUT for right now a $19 driver with some mods is MUCH MORE in my ballpark!!!
>>> I am actually going to put the B20 and a piezo tweeter into a Realistic T-100 cabinet (66 liters) ported to 34 Hz...
That should work! My curve looks similar.
http://www.zillaaudio.com/pioneerb20-3cubox.htm
Will you be using the lemon squeezer piezo or something else? I think the B20 will work with any of the piezos.
Godzilla
That should work! My curve looks similar.
http://www.zillaaudio.com/pioneerb20-3cubox.htm
Will you be using the lemon squeezer piezo or something else? I think the B20 will work with any of the piezos.
Godzilla
Yeah, the 6th order alignment I want to try with mine is ~2.26 ft^3 net, but with a ~29 Hz F3 and a > 96 dB peak SPL from 32 Hz-up plus room gain it seems theoretically worth making room for. Otherwise, F3 = Fs. Only one way to know for sure though..........
GM
I will be using the following piezo facing forward with a 20 ohm resistor and the T-100's already built-in L-pad and I'm going to play around with the crossover point with some caps I have on hand.
http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=270-011
I plan on getting these speakers done over the weekend since there isn't a lot of woodworking to do - mostly solder & plug-n-play. My kind of project
Well here's the finished project that I completed on Saturday.
Used the B20FU20-51FW and the Goldwood GT-1005 wide dispersion piezo tweeter with a 20 ohm resistor across it's terminals and a 1 uF capacitor before the L-pad. The big 10" wood circle covering the other woofer hole is a 99 cent piece from Hobby Lobby. The (2) port tubes are 2 1/16" x 5". The internal dimensions of the Realistic T-100 cabinet is 34.25" x 10.25" x 11.5" for 2.34 cubic ft or 66 liters.
Mods still to do are: stain the BIG blond circles, simple stands at bottom of speaker to raise B20 height about 7". Try to restore cabinet wood. Put felt around the B20 speaker frame legs. Look into installing phase plugs. Install different terminal plates on the rear of cabinet (Radio Shack has their terminal at the BOTTOM of the speaker - yuck!!!).
I have been playing them for over 24 hours and will continue to do so for about 72 total hours to break-in the speakers.
First impressions are that they sound Sweeeeeetttttt!!!!!
I am already a full ranger speaker lover and I got to tell you these 8" drivers for $19 really have a lot more bass than other smaller speakers. Just as a sound test for deep bass, I play the first song of the Titanic soundtrack and there is a deep kettle drum sound played numerous times and if I can "feel" this bass (which I did with the B20's) I am fairly satisfied with the bass that I will get out of these speakers. I also played Pat Metheny & Charlie Haden's "Beyond The Missouri Sky" album and this album has plenty of bass notes and as I listened I could to easily hear them and they seemed to not be muffled (like they were previously with the T-100 woofers).
I gotta say that with the right cabinet these B20's can really "sing" and everyone is right, you just want to keep listening and listening and bringing out old CDs and records to listen over again and it's like rediscovering the music on them. I typically am not too optimistic about most reviews of speakers until I hear them myself, but in all honesty for less then $100-$150/pair TOTAL these have got to be ONE of the best speaker bargains around. I spent $30 for cabinets, $52 for drivers, caps, resistors,tubes and another $5-10 on miscellaneous stuff.
Used the B20FU20-51FW and the Goldwood GT-1005 wide dispersion piezo tweeter with a 20 ohm resistor across it's terminals and a 1 uF capacitor before the L-pad. The big 10" wood circle covering the other woofer hole is a 99 cent piece from Hobby Lobby. The (2) port tubes are 2 1/16" x 5". The internal dimensions of the Realistic T-100 cabinet is 34.25" x 10.25" x 11.5" for 2.34 cubic ft or 66 liters.
Mods still to do are: stain the BIG blond circles, simple stands at bottom of speaker to raise B20 height about 7". Try to restore cabinet wood. Put felt around the B20 speaker frame legs. Look into installing phase plugs. Install different terminal plates on the rear of cabinet (Radio Shack has their terminal at the BOTTOM of the speaker - yuck!!!).
I have been playing them for over 24 hours and will continue to do so for about 72 total hours to break-in the speakers.
First impressions are that they sound Sweeeeeetttttt!!!!!
I am already a full ranger speaker lover and I got to tell you these 8" drivers for $19 really have a lot more bass than other smaller speakers. Just as a sound test for deep bass, I play the first song of the Titanic soundtrack and there is a deep kettle drum sound played numerous times and if I can "feel" this bass (which I did with the B20's) I am fairly satisfied with the bass that I will get out of these speakers. I also played Pat Metheny & Charlie Haden's "Beyond The Missouri Sky" album and this album has plenty of bass notes and as I listened I could to easily hear them and they seemed to not be muffled (like they were previously with the T-100 woofers).
I gotta say that with the right cabinet these B20's can really "sing" and everyone is right, you just want to keep listening and listening and bringing out old CDs and records to listen over again and it's like rediscovering the music on them. I typically am not too optimistic about most reviews of speakers until I hear them myself, but in all honesty for less then $100-$150/pair TOTAL these have got to be ONE of the best speaker bargains around. I spent $30 for cabinets, $52 for drivers, caps, resistors,tubes and another $5-10 on miscellaneous stuff.
Attachments
there's also the bofu loaded chang; http://www.diyaudio.com/forums/full...ld-chang-variant.html?perpage=25&pagenumber=1
and the bofu BIB: http://www.diyaudio.com/forums/full-range/110703-pioneer-8-bofu-bib.html
and the bofu BIB: http://www.diyaudio.com/forums/full-range/110703-pioneer-8-bofu-bib.html
I ran some generated sine frequencies through the converted T-100's and could definitely tell (at least by my finely tuned ear) that the speakers do go down to about 36-37 Hz before they drop off in volume. Pretty amazing when considering it's just a full range 8" driver.
Wish I had some more sophisticated measuring instruments besides my ears to see what the real frequency curve was on these speakers.
Wish I had some more sophisticated measuring instruments besides my ears to see what the real frequency curve was on these speakers.
at 10 feet it looks like a helper tweeter might roll in around 8->11KHz - wish Pioneer would make a $50 version with cleaner sound and more extension - at $19ea guess will pick up a pair anyhow for Karlson-coupler fodder
An externally hosted image should be here but it was not working when we last tested it.
look good - without any play Qts ~0.47, Fs ~43Hz - will get Vas later - with a helper tweeter B20 should work in a range of K-coupler. A good tweeter strategy for any bass/midbass K-coupler is to use a slotted tube (Karlson's open ended waveguide) - one K-builder runs a tube with his 208 sigma coupler
Here's a K-tube tweeter mounted in a standard K8 size by Carl - a 5.3" long tube with a half-ellipse slot and 1/8" starting gap will suffice
Here's a K-tube tweeter mounted in a standard K8 size by Carl - a 5.3" long tube with a half-ellipse slot and 1/8" starting gap will suffice
An externally hosted image should be here but it was not working when we last tested it.
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http://www.zillaaudio.com/bib/bib-pioneer.asp
There's the 2001 Space Odyssey BIB using the B20 too... sorry about the broken links but it's a BIB turned on it's side... 4 piezo's not necessary on rear, one should do the trick.
The phase plug in the center did not seem to do any more than just cutting out the dustcap. The shape of the socket probably is not the right size or shape to provide acoustic improvement. I wish i compared a proper phase plug when i did this.
http://www.zillaaudio.com/b20-mod.htm
There's the 2001 Space Odyssey BIB using the B20 too... sorry about the broken links but it's a BIB turned on it's side... 4 piezo's not necessary on rear, one should do the trick.
The phase plug in the center did not seem to do any more than just cutting out the dustcap. The shape of the socket probably is not the right size or shape to provide acoustic improvement. I wish i compared a proper phase plug when i did this.
http://www.zillaaudio.com/b20-mod.htm
here's a fresh BOFU mounted in a Karlson-coupler somewhat smaller than K12 - it has around 1 cubic foot rear chamber and 1/2 or so cubic foot front chamber - I think this is a doable size - a k-tube helper tweeter waveguide could be mounted on the inner board/reflector or on top. overall I think BOFU sounds better than the Beta8cx/CD8 combo sitting on top
when I find a pad I'll try this helper tweeter
An externally hosted image should be here but it was not working when we last tested it.
when I find a pad I'll try this helper tweeter
An externally hosted image should be here but it was not working when we last tested it.
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I know what you mean. Rip off Europe is alive and well.
Spectrum audio (Breitbandlautsprecher und mehr - SpectrumAudio) have them, albeit at a premium. If you have a credit card though, you should be able to order via partsexpress easily enough, although postage will be a little pricy.
Spectrum audio (Breitbandlautsprecher und mehr - SpectrumAudio) have them, albeit at a premium. If you have a credit card though, you should be able to order via partsexpress easily enough, although postage will be a little pricy.
bofu is doing OK - I have about 12 sq.inches of lowpass gap area in my coupler's rear chamber, a 2uF Obbiigato cap to L-pad to a Selenium D210Ti on a replica of a 1960's X15 Karlson tube (it was the easiest to hook up due to having bracket) - bass is a bit soft but not bad on drum video toms and kick-drum such as:
YouTube - Drum lesson#5: Check THIS out!! 6 stroke roll!
I'd imagine 30-75 watts per channel would be about right for BOFU - it's cone excursion is well behaved in the Karlson-type coupler. I've seen it go out of control in pipes.
YouTube - Drum lesson#5: Check THIS out!! 6 stroke roll!
I'd imagine 30-75 watts per channel would be about right for BOFU - it's cone excursion is well behaved in the Karlson-type coupler. I've seen it go out of control in pipes.
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