Originally Posted by HomeTheaterGuy74
I remember my very first pair of speakers - AAL (American Acoustic Laboratories).
They were supposedly the best speakers the "higher-end" store sold at the time.
I don't remember the size of the other components - but the woofer was 15"
They were great sounding speakers.
Today, they don't make speakers like that anymore.
Everything is thin and usually have either a number of 6.5" woofers, or some have 8" woofers (Salon2).
Do more very small (in comparission to 15") woofers really take the place of one larger (12" or 15") woofer
Maximum excursion limited SPL from a monopole operating into free space at 1 meter is
102.4dB + 20log(displacement) + 40 log(f) with displacement in m^3
102.4dB + 20log(travel) + 20 log(area) with travel in meters an area in meters^2 if you prefer.
Output at the maximum linear excursion into full space for various representative drivers one meter away is as follows at 120, 80, 40, and 20Hz. Many drivers have less excursion and lower output. Subtract 3-5dB getting to your listening position in a typical living and more for a larger space.
You can add 6dB for a floor mounted woofer (as in many 3-ways), 6dB if there are a pair of bass drivers, 10dB for three, and 6dB at the cross-over point to a sub-woofer.
Size Driver Sd (cm^2) x xmax (mm) 120Hz 80Hz 40Hz 20Hz
4 1/2" Seas W12CY001 50 x 3 89dB 82dB 70dB 58dB
5 1/4" Peerless 830873 88 x 3.5 95dB 88dB 76dB 64dB
6 1/4" Seas L16RN-SL 104 x 6 101dB 94dB 82dB 70dB
7" Seas W18EX001 126 x 5 102dB 95dB 83dB 71dB
8.5" Seas W22EX001 220 x 5 106dB 99dB 87dB 75dB
10" Peerless 830452 352 x 12.5 118dB 111dB 99dB 87dB
12" Peerless 830500 483 x 12.5 121dB 114dB 102dB 90dB
Where jazz sounds great at 85dBC average and good recordings have 20dB of dynamic range peaks are hitting 105-107dB a meter from each speaker. Feeding _Take Five_ through 60Hz second order Butterworth IIR low-pass filters I noted right channel low frequency peaks 10dB down from that; although that's still 30 times the acoustic power you can squeeze out of a 6" driver at 40Hz.
In this case it'll take about ten of the 6" Seas to equal one of the 12" Peerless drivers.