Cabinet, room, taste.
I have never had to add any direct BSC to any Alpair.
When i think Alpair and 1.5 way is use of a series connection and a big shunt cap across one.
http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
Am developing just such a box with 3 x Alpair 6.2p.
dave
I have never had to add any direct BSC to any Alpair.
When i think Alpair and 1.5 way is use of a series connection and a big shunt cap across one.
http://www.planet10-hifi.com/downloads/Dual-Driver-Wiring.pdf
Am developing just such a box with 3 x Alpair 6.2p.
dave
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As you suspect and as Dave alluded, this offers no baffle compensation. It simply hands off to more drivers for the bass.
This is basically a series filter (instead of parallel which is more conventional).
Which is not always advisable because of the non-linear behavior of Le(X) as well as power compression (change in Re).
Although in this case it's probably fine
One could do with a speaker less in a parallel filter design for BSC
Yes, we ran into that. XO point should not be too close to the LF resonance.
XO point should be below thw quarter wavelength of the centre-to-centre, and above the bafflestep.
dave
Another problem is that Le actually shifts with higher cone excursion.
Unless this is stabilized with demodulation ring (copper ring) in the motor.
A nominal 1.8ohm impedance load
Theoretically +6dB relative to a single unit in the LF (+3dB for the doubled cone area & + 3dB for the doubled current draw).
I have been simulating this in Boxsim (just because it was quickest for me) and although the idea seems nice, it doesn't quite work so well unfortunately.
This is mostly because of how the attenuation works across all loads and therefor you don't get the +6dB you need at the lower frequencies. There is also quite some weird interaction happening in the impedance plot itself.
Also cost wise it doesn't make sense when the Le of the woofers is already very low.
This means a big capacitor. A simple inductor would be far more cost effective.
So I would just stick to the parallel circuit instead.
This is mostly because of how the attenuation works across all loads and therefor you don't get the +6dB you need at the lower frequencies. There is also quite some weird interaction happening in the impedance plot itself.
Also cost wise it doesn't make sense when the Le of the woofers is already very low.
This means a big capacitor. A simple inductor would be far more cost effective.
So I would just stick to the parallel circuit instead.
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Yes, big cap, it says that in the picture.
These 2 solutions have completely different aims. Use an inductor and all of a sudden you have 6dB too much room response. Not the case for the series connection.
But usually neither is the goal, 2-3 dB of LF gain more useful.
dave