not bad - I think the little pipe is just big enough to work. The driver's center is dead on axis with seated height. In the US, a pair could be made for $100 including one sheet of plywood. The tweeter isn't running - just left over from when it ran an Eminence B102. BG20 is a bit rough on top but a bargain at Partsexpress. I'll muck with pipe damping and a tuff of polyfil between the whizzer and main cone.
Greets!
Got any measured specs? When I loaded Mms, BL, Qms in lieu of Vas, Qes, WinISD V0.7calcs a much lower 0.398 Qes, 0.357 Qts and larger 113. 96 L Vas, which of course equates to a smaller cab tuned higher.
GM
Got any measured specs? When I loaded Mms, BL, Qms in lieu of Vas, Qes, WinISD V0.7calcs a much lower 0.398 Qes, 0.357 Qts and larger 113. 96 L Vas, which of course equates to a smaller cab tuned higher.
GM
naw - but when I get a new digital scale then will get some - its a good/cheap driver - phooey on those rotted BOFU 😀- oh - take that back - got electric sweep and Qs - just not Vas - got to find a jump drive or a pen
(lost drive) no break in - fresh out of box - Re=6.564, fs = 42.39, qes = 0.4936, qms = 3.993, qts = 0.4393, Le = 0.3601mH
(lost drive) no break in - fresh out of box - Re=6.564, fs = 42.39, qes = 0.4936, qms = 3.993, qts = 0.4393, Le = 0.3601mH
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they were made of 3/4" 7-ply birch and both came easily from one 4'x8' sheet. Inside dimensions of pipe ~5.5" deep by 9.5" wide by 48" tall. The bottom opening is the full cross-section and the 12"x12"x3/4" base is on adjustable spikes so that floor gap determines the tuning/damping and typical gap between the floor and base will run 3/8" to 3/4". driver center is ~6" down from the top of the enclosure.
some years back I posted indoor and outdoor frequency response measurements which seemed to correlate to the early Zu product measured by Soundstage. I think the real product may have a pyramid stack of damping material setting on a screen (?)
they were pretty good for ~$200 of drivers and wood - that was the early B102 which was stronger than the current model as it had a 56oz magnet vs the current B102's 42oz slug. Power handling was fine with 200 wats per channel. I used an Eminence oem version of APT50 and also the CTS KSN1005 piezo.
here's how the base gap affected response from an outdoor perspective. The pipe only had 1" bonded Dacron
lining at this point.
here's another set with ~ ground plane and "near vent" outdoors
just to thrown in another graph - here's a Hawthorn Silver Iris 15cx outdoors in a similar spot
some years back I posted indoor and outdoor frequency response measurements which seemed to correlate to the early Zu product measured by Soundstage. I think the real product may have a pyramid stack of damping material setting on a screen (?)
they were pretty good for ~$200 of drivers and wood - that was the early B102 which was stronger than the current model as it had a 56oz magnet vs the current B102's 42oz slug. Power handling was fine with 200 wats per channel. I used an Eminence oem version of APT50 and also the CTS KSN1005 piezo.
here's how the base gap affected response from an outdoor perspective. The pipe only had 1" bonded Dacron
lining at this point.
An externally hosted image should be here but it was not working when we last tested it.
here's another set with ~ ground plane and "near vent" outdoors
An externally hosted image should be here but it was not working when we last tested it.
just to thrown in another graph - here's a Hawthorn Silver Iris 15cx outdoors in a similar spot
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Thanks, with some flexing I imagine it will drop some, so surprisingly it appears that its specs are better than published, a rarity!
As your measurements confirm, much too small for any of the different BG specs since according to the pioneers of audio the smallest vented net Vb shouldn't be < that required to raise Fs 1.56x.
GM
want me to pull the stuffing, plug the end with cardboard/duct tape, and see where sealed resonance occurs? (can the stuffing stay?)
what sounds better, the bg20 or the betsy ?
I'm asking because I'm contemplating building this, 4 full range drivers (but sealed) with a single cap on a ribbon (hivi rt2h).
the bg20 is $27, the betsyK is $55, and the hemptone fr8 is $128+$20 s/h.
Norman
I'm asking because I'm contemplating building this, 4 full range drivers (but sealed) with a single cap on a ribbon (hivi rt2h).
An externally hosted image should be here but it was not working when we last tested it.
the bg20 is $27, the betsyK is $55, and the hemptone fr8 is $128+$20 s/h.
Norman
That is a nice looking speaker. Not sure if whizzers make sense if HF are handled by ribbon tweeter. What is XO point?
- hey Norm - I'd have to AB with each in the same enclosure - its been real long since I've run a BetsyK - IIRC, Betsyk goes higher, BG20 is cheaper- graphs seen with its whizzer removed looked impressive.
fwiw here's the new Eminence B102 on axis vs the old - the new is almost like a BOFU in the mids and LF cabinet requirements but far better for power handling - it needs a real tweeter. The heavier magnet early version of B102 had a multipleat surround while the new, a double roll. That surround is shared on the later version of Beta10cx and probably an improvement over the multipleat. A 15dB difference
@10KHz is pretty significant. The current Eminence B102 might be nice in either a Karlsonator or XKi alignment with ~2->3K crossover
to a compression driver on a K-tube. In the case of the Karlsonator, there would be space to internally mount the K-tube.
It would probably have to go on top of the XKi alignment enclosure.
fwiw here's the new Eminence B102 on axis vs the old - the new is almost like a BOFU in the mids and LF cabinet requirements but far better for power handling - it needs a real tweeter. The heavier magnet early version of B102 had a multipleat surround while the new, a double roll. That surround is shared on the later version of Beta10cx and probably an improvement over the multipleat. A 15dB difference
@10KHz is pretty significant. The current Eminence B102 might be nice in either a Karlsonator or XKi alignment with ~2->3K crossover
to a compression driver on a K-tube. In the case of the Karlsonator, there would be space to internally mount the K-tube.
It would probably have to go on top of the XKi alignment enclosure.
An externally hosted image should be here but it was not working when we last tested it.
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hey GM - with a wad of polyfill pulled leaving 1" bonded Dacron on the pipe's walls and the bottom exit sealed with cardboard and duct tape I get for BG20in the faked Druid-style enclosure:
fc = 53.83Hz and qtc ~0.86 - can't find my USB drive but will save the result as a screen shot. That's not a huge raise (only 28%) from ~42Hz out of the box fs. The impedance looked right down to 1Hz on WT3
fc = 53.83Hz and qtc ~0.86 - can't find my USB drive but will save the result as a screen shot. That's not a huge raise (only 28%) from ~42Hz out of the box fs. The impedance looked right down to 1Hz on WT3
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Djk said we could get b102 with 59oz magnet built, but 50 each and 100 drivers minimum. Ouch.
Doing a search, I found an interview with bombard, said 3khz.
The full ranges would lessen their out put when a cap\tweet is in parallel. The Z of the driver should be skyrocketing, hard to say with the shorting ring, compared to the 8 ohm load of the tweet.
Here is a review on the jaf bombard from 2011.
http://www.6moons.com/audioreviews/jaf/1.html
It says the full ranges are in parallel, I doubt that.
It also says there is a baffle step circuit (for them all).
If the top driver is at ear level, and there is a 5db rise 1.5-4khz, maybe combing brings that down some.
The whizzer help push dispersion an octave or so higher than without it, probably 90 degree at 4khz instead of 2khz.
Tread lightly, parts alone would be $700 per speaker, plus cabinet (with fr8).
But you can start tweet + fr8 for $250.
Doing a search, I found an interview with bombard, said 3khz.
The full ranges would lessen their out put when a cap\tweet is in parallel. The Z of the driver should be skyrocketing, hard to say with the shorting ring, compared to the 8 ohm load of the tweet.
Here is a review on the jaf bombard from 2011.
http://www.6moons.com/audioreviews/jaf/1.html
It says the full ranges are in parallel, I doubt that.
It also says there is a baffle step circuit (for them all).
If the top driver is at ear level, and there is a 5db rise 1.5-4khz, maybe combing brings that down some.
The whizzer help push dispersion an octave or so higher than without it, probably 90 degree at 4khz instead of 2khz.
Tread lightly, parts alone would be $700 per speaker, plus cabinet (with fr8).
But you can start tweet + fr8 for $250.
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guess there's not enough folks wanting B102 type (?) - is the smaller magnet the only change killing the highs? Maybe the fullrange community would get excited about a 59oz magnet 12LTA (???)
Whizzered 10" could make for a 2khz crossover.
But yes, stronger magnet usually gets more highs.
Celestion seems a better option for the price than the 12lta.
Just wish the double whizzer fane had QTS closer to .4
Norman
But yes, stronger magnet usually gets more highs.
Celestion seems a better option for the price than the 12lta.
Just wish the double whizzer fane had QTS closer to .4
Norman
eh, to me 4x8's would give good mid-bass.
I wouldn't expect much and would be using my sub with it (4x8's).
Norman
I wouldn't expect much and would be using my sub with it (4x8's).
Norman
http://http://j-a-f.pl/bombard_en.html
Reviewed here
http://http://www.6moons.com/audioreviews/jaf/1.html
Interesting enough concept, and stylishly executed
Reviewed here
http://http://www.6moons.com/audioreviews/jaf/1.html
Interesting enough concept, and stylishly executed
Ahh I see in the review they do explain that it is actually some sort of restricted or "modified" open baffle.
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