In Reply to: What is GAIN and BANDWIDTH on a sub for? posted by airtime on July 23, 2012 at 08:49:59:
Might be some semantics involved.
Does this new plate amp have both a "gain" and "level" adjustment? I would find that odd... Typically, amps are voltage amplifiers (not current amplifiers). Amps increase the voltage a specific amount with a predefined "gain". The level control reduces the input level to the gain stage so the *net* voltage gain is controllable. These level controls are also known as attenuators.
As for bandwidth, subs can have 1 or 2 selectable rolloff regions. All subs will have what is called a low-pass filter, with slopes that are commonly 12 or 18db/octave, with some as steep as 24db/octave. This keeps the high frequences out of the sub. A 2nd filter is a high-pass filter which prevents super-low subsonic frequencies from eating up amp power and causing needless excursion of the woofer. When used with subs, high-pass filters are referred to as "infrasonic" or "subsonic" or "rumble" filters. The "bandwidth" of the sub is based on the highpass and lowpass filter settings. Most subs would operate from about 15 or 20Hz to anywhere from 60 to 180 Hertz, depending on application and placement. Without a high-pass filter, the low-end of the subs rolloff is determined by subwoofer driver parameters (such as Fs, Vas, Qts, etc.) and enclosure parameters (such as enclosure type, volume, port lengths, port mouth area, etc. etc.)
But all semantics aside, what sub are you buying this amp for? What driver? What enclosure? And what sub amps are you looking at?
Cheers,
Presto
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Follow Ups
- RE: What is GAIN and BANDWIDTH on a sub for? - Presto 11:40:58 07/23/12 (2)
- RE: What is GAIN and BANDWIDTH on a sub for? - airtime 12:12:39 07/23/12 (1)
- Looking at the back panel answers your questions - E-Stat 15:34:45 07/23/12 (0)