Good idea. Would allow for single driver. Gonna be heavy with all that sand in the void
dave
Nonetheless it would be interesting to hear from the MLTL/TL experts about their take on this. ☺️
Assuming the Fostex is the FF165WK, the spec is way off – I calculate 91.5 dB/W(1m). The factory spec I see is 92, which is what 91.5 would round to.
I calculate the Dayton at 95.4 (1.1 dB below spec). The spec on the Alpair A10P is spot on.
Comparing the driver specifications will tell you that the Dayton is much more efficient than the Fostex. Fs and Qes figures are pretty close but the VAS on the Dayton is over 3x the Fostex number. Hoffman’s law will tell you the Dayton is going to be more efficient.
With a spread of about 4 dB, to reach the same SPL out of the Dayton at 4 watts would require 10 watts with the Fostex.
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Measured is a bit over 91.
My comment was based on others experiences. Bass shy, treble hot, less db once flattened out.
Measured at almost spot-on to 90 dB.
Yep. With the same miniOnken style alignment Dayton needs 60 litre, Fostex 17.
F10 ~ low 40s, high 40s, low 40s — Dayton, Fostex, Mark Audio.
The OP has ~38 litres which will fit 2 of the Fostex of Mark Audio and is too small for the Dayton.
dave
Of the drivers i have tested (samples of at least 4, but often as many as 20), the Alpairs have the closest bunching. Typically less than 10% using my metric of T/S differences. Sensitivity differences of less than 1 dB. Sometimes i can completely match up pairs (differences of 3%, sensitivity within 0.25 dB), sometimes not — i ended up with 4 singles in the last batch of 20 Alpair 7.3. Fostex are sometimes up around 18%. TBs even greater (althou many less samples). Peerless not as good as the Mark Audio. A “pair” of Audio Nirvana so different as to be different drivers.
dave
dave
Would a pair be wired push-pull (front and back), in phase (front and back) or same polarity on front baffle? I'm trying to visualize the effects of each. Di-pole could have some cancellation. Bi-pole would reinforce, but the whole thing seems like a special effect to me. I mean I've tried open-baffles and they are as good as they are bad.
Dual drivers on the front blurs the point-source, doesn't it?
Dual drivers on the front blurs the point-source, doesn't it?
Bi-polar would be more likely to work out.
I'm interested in the Alpairs. I like the purity of the paper cones.
What do you guys think about back waves traveling back through the driver?
Has to happen with all drivers, but is it worse with paper cones?
If in a bi-pole config, this has to be more of a concern, correct?
Is this why I sometimes see a perforated partition between opposing drivers?
I'm interested in the Alpairs. I like the purity of the paper cones.
What do you guys think about back waves traveling back through the driver?
Has to happen with all drivers, but is it worse with paper cones?
If in a bi-pole config, this has to be more of a concern, correct?
Is this why I sometimes see a perforated partition between opposing drivers?
For two wide band drivers on the same baffle I've read that one trick is to run one of the drivers as 0.5 driver. Cross over at baffle step.
4th post on this thread:
Best Sounding Single Drivers
Have not tried it out myself, hence cannot comment on its effectiveness.
4th post on this thread:
Best Sounding Single Drivers
Have not tried it out myself, hence cannot comment on its effectiveness.
AFAIK, a bi-pole setup sort of takes care of baffle-step, as the longer LF wavelengths wrap around to the front of the cap, while the MF/HF output of the rear driver is heard as room reflections and therefore somewhat attenuated and not wholly in phase with the front driver's direct radiation.
We have done quite a few bipoles. You get active vibration cancelation, but also get the bipole dip from the delay of the back driver coming around the front (if you have them on the sides you get near perfect baffle-step compensation). This affect is decreased by making the box wide and ahllow but that increases issues with the back radiation from one driver coming thru the cone of the other. One can kill the bipole dip by rolling off the back driver before the effect happens.
A bipole has to be pulled out into the room to allow for the rear driver to be far enuff off the wall.
In the end we found that mounting the driver on the top (or to a lesser extent the side) could reduce these affects without giving up the spacious quality of a bipole.
With 2 drivers on the front, it is often a good idea to roll one off. Some loss of single driver “pureness” may occur, only you can decide if any loss is outweighed by the gains . There are 2 ways to do this.
I have outlined the detail of the possible wiring in this pdf: http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
Chris can say more about the castle-style character. He has lived with various versions for sometime. Her eare the 1st ones he built.
Since then he has found he prefers a slight tilt forward on the top (10° IIRC) but the top could get as much as 45° tilt.
dave
A bipole has to be pulled out into the room to allow for the rear driver to be far enuff off the wall.
In the end we found that mounting the driver on the top (or to a lesser extent the side) could reduce these affects without giving up the spacious quality of a bipole.
With 2 drivers on the front, it is often a good idea to roll one off. Some loss of single driver “pureness” may occur, only you can decide if any loss is outweighed by the gains . There are 2 ways to do this.
I have outlined the detail of the possible wiring in this pdf: http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
An externally hosted image should be here but it was not working when we last tested it.
Chris can say more about the castle-style character. He has lived with various versions for sometime. Her eare the 1st ones he built.
Since then he has found he prefers a slight tilt forward on the top (10° IIRC) but the top could get as much as 45° tilt.
dave
I think you might like the sound of W5-2143 if you like purity of paper cone sound. It’s 90dB and very smooth flat extended response. Bigish Vas that would be well suited to this size cabinet as a BR. I have it and really like the sound. The TS parameters are quite different than published. Higher Qts around 0.45 and larger Vas. I can dig up if you are interested.
I'll check it out. Thanks for the tip. I should have elaborated a little more when I said I like the purity of the paper cone.
I like the design of that particular driver and the approach they took to make the driver as light as possible to create a more pure sound.
I believe that mark audio paper driver actually has fibers to strengthen the cone.
I like the design of that particular driver and the approach they took to make the driver as light as possible to create a more pure sound.
I believe that mark audio paper driver actually has fibers to strengthen the cone.
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