Hello All,
I just ordered a B4 while there are still some around.
I remember, years ago, reading in the Loudspeaker Design Cookbook, by Vance Dickason, that two amplifiers in an active x-over setup clip at about double the total power level as in a passive setup, all else equal.
Is this borne out in theory or empirical practice?
If so, can one expect to see 3dB-ish additional useful SPL for the active setup?
TIA
I just ordered a B4 while there are still some around.
I remember, years ago, reading in the Loudspeaker Design Cookbook, by Vance Dickason, that two amplifiers in an active x-over setup clip at about double the total power level as in a passive setup, all else equal.
Is this borne out in theory or empirical practice?
If so, can one expect to see 3dB-ish additional useful SPL for the active setup?
TIA
As a general rule, yes.
I once did a quick survey of peak power seen with music in a bi-amp
setup crossover over at lower mid frequencies, and it came out that
both high pass and low pass tend to peak around the same level,
so that as much as a 6 dB higher peak can be realized - that's about
4 times the power of 1 amp alone.
I once did a quick survey of peak power seen with music in a bi-amp
setup crossover over at lower mid frequencies, and it came out that
both high pass and low pass tend to peak around the same level,
so that as much as a 6 dB higher peak can be realized - that's about
4 times the power of 1 amp alone.
Nelson,
Let’s say we have a two-way speaker with a crossover point as you have described, with drivers that both produce 90 dB SPL/1 watt @ 1 meter. For the passive case, a 10W (10dBW) amplifier and for the active, 2 x 5W (7dBW) amplifiers.
Can you please guide me through the mathematical intuition for maximum SPLs at clipping? (I am having trouble with the interaction of the bandwidth versus the SPL).
Thanks so much,
John
Let’s say we have a two-way speaker with a crossover point as you have described, with drivers that both produce 90 dB SPL/1 watt @ 1 meter. For the passive case, a 10W (10dBW) amplifier and for the active, 2 x 5W (7dBW) amplifiers.
Can you please guide me through the mathematical intuition for maximum SPLs at clipping? (I am having trouble with the interaction of the bandwidth versus the SPL).
Thanks so much,
John
As a best case scenario, let's imagine that the audio signal has a
transient which enjoys a 1 volt peak at 50 Hz and a 1 volt peak at
5 KHz simultaneously so that there is a resulting 2 volt peak in the
audio signal, and that this is fed through a 500 Hz high pass filter to
the top end amp and 500 Hz low pass filter to the bottom end amp,
both amplifiers having 20 dB (X10) of gain.
Each amplifier will see a 1 volt peak, and their outputs will be 10 volt
peaks. This is a 12.5 watt peak into 8 ohms ( 10 * 10 / 8).
If the original signal is fed to a 20 dB full range amplifier, the output
will be a 20V peak, which is a 50 watt peak into 8 ohms, which is 4 times
the output.
transient which enjoys a 1 volt peak at 50 Hz and a 1 volt peak at
5 KHz simultaneously so that there is a resulting 2 volt peak in the
audio signal, and that this is fed through a 500 Hz high pass filter to
the top end amp and 500 Hz low pass filter to the bottom end amp,
both amplifiers having 20 dB (X10) of gain.
Each amplifier will see a 1 volt peak, and their outputs will be 10 volt
peaks. This is a 12.5 watt peak into 8 ohms ( 10 * 10 / 8).
If the original signal is fed to a 20 dB full range amplifier, the output
will be a 20V peak, which is a 50 watt peak into 8 ohms, which is 4 times
the output.
Thanks, Nelson.
Never a free lunch, but this seems to show a potential to improve efficiency:
Δ SPL > Δ W
Never a free lunch, but this seems to show a potential to improve efficiency:
Δ SPL > Δ W
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