Hi,

This is actually a good survey.

I have been a clean bass guy since I worked at an Audio Shop repairing audio equipment when I was in high school.

I thought a couple of things could be added though:

1) Under the aspects of what matters most to me... SQL matters alot to me. There are alot of filthy sounding subs out there. I have tried alot of different configurations (single and multiple 10" subs, single and multiple 12" subs, a couple of different 15" subs, etc) and they all sound different. Not many know that Electro-Voice makes or made at one time a 30" driver. When place in a 6 foot cabinet, it was efficient, it sounded decent though not great.

The rest of the speaker system also matters. The low end has also produces harmonics that are required to be reproduced correctly by the mid-bass drivers or the system will sound crappy. An example of this is Hotel California on the Heck Freezes Over CD. The low frequency drum is composed of the low frequency sustained kick type sound, but, also a hollow higher frequency sound too. If the system is not correct, the higher hollow sound will be attenuated, cancelled, muffled, or gone.

The box size and type makes a difference too. Is it ported or non-ported? Does it provide the correct acoustic impedance for the frequencies of interest? The speaker impedance can vary wildy based on the impedance of the enclosure and temperature (based on compliance of the surround and spider). This affects power transfer from the power amplifier to speaker voice coil Magnet motor structure.

By the way, there is also a lot of difference in power amps too:

a) How much front end filtering they have (DC resistance of their differential or common mode choke
b) RDS(on) of their power supply MOSFETS
c) How effectively they have matched parallel MOSFETs in the Power Supply
d) Switching Transformer design DC Resistance, Leakage Inductance
e) Digital (PWM based - how many high voltage parallel MOSFETs,
output inductor and filter cap) vs Linear (traditional - how many high voltage parallel transistors or MOSFETs) vs overall design for use as a low frequency current amplifier not as a wideband amplifier
f) Lots of other more subtle issues

Speaker wire gauge (not fancy cable configuration) makes a difference too for power transfer. Twisting makes a difference though.

Power and Ground wire gauge is a big factor too. How they are connected long term (especially the ground chassis wire - which often corrodes unless either maintained or surface prepped and sealed.

A power bulk decoupling and energy storage capacitor always makes a difference. Besides making it so your headlights won't dim on high demand low frequency notes, it provides a local current storage to "feed" the amplifier what it needs to provide the power for the note.


In short, I have 0 AWG wire from my Red-Top battery, through a fuse, to the distribution block to a Maxwell 58F (yes, 58 Farad) Ultra-Capacitor, 0 AWG cable to a well designed amplifer, 0 AWG to the prepped and sealed chassis ground connection.


You could add type of enclosure: ported (sometimes called Bass Reflex) or non-ported (sometimes called acoustic suspension).

You could add Amplifier type: Digital (PWM) or traditional (Linear)

You could add Enclosure size

You could add type of music listened to


Another useful survey would be one on complete systems installed.


Ross
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In SI, a little termination and attention to layout goes a long way. In EMC, without SI, you'll spend 80% of the effort on the last 3dB.