I first upgraded my car audio in 2002, primarily to get Sirius satellite radio, but also as a step up from the factory audio system. The system worked very nicely until about a fortnight ago when one of the channels in my amp died. And, since it had been about five years since I had bought it, the amp was well out of warranty.
Since I had to buy a new amp anyway, I told myself that I may as well upgrade my subwoofers as well (hey, why not?). Though my previous subwoofers, a pair of 10" MB Quart subs, had served me well, I had always hoped for a little more bass extension. So, after doing a bit of research, I picked up a pair of 12" JL Audio 12W3v3 subs. In my old configuration, I was running my MB Quart subs off a multichannel amp — not to worry, it was a 5-channel amp — but I figured that I'd go for a separate amp for the subwoofer this time. So, I picked up JL Audio’s 500/1 monoblock amp for that.
I just had the new gear yesterday and, as a whole, I’m very pleased with it. It certainly has the bass extension that I was looking for. Depending on how you look at it, it’s almost too much of a good thing — after driving around town for a bit this afternoon, all the while listening to Sirius at normal volume levels, I noticed when I got home that my ears were ringing a little bit. Feh. My best guess is that it may not have seemed as loud as it actually was since the frequencies were so low. Either way, the last thing I want to lose it my hearing, so I’ll be adjusting that straight away.
PS The lighting in the shot above may look a bit weird, but rest assured that I don't have a sodium vapor lamp in my trunk. (Those are the ugly yellow/orange lamps commonly seen around parking lots and the like.) Rather, the sun had already started to set (I took that picture with a 13 second exposure around 6:30 p.m.) and, while I was able to correct the color balance for the exterior sunlight, that meant that the incandescent light within my trunk was going to look a little exaggerated.
Update 2007-02-19: I took my Radio Shack sound level meter (similar to this one, but an older iteration) out to the car to look into my volume issues yesterday. That particular meter has both “Fast” and “Slow” response modes that control how fast the needle moves. The “Slow” mode is good for getting an average sound level, but I set it to “Fast” in this case so that I could get differentiate the second-by-second sound levels within songs.
I turned my key to the “Accessories” mode and then chose a Sirius radio station that was playing a song that I liked. As it turned out — listening at ordinary volume levels — the normal parts of songs were around 70–72 dB. When the bass started to come in, though, I could see fraction-of-a-second spikes of up to 95 dB. Well, yikes, that would kinda explain the ringing in my ears from the other day.
I soon went about reducing the subwoofer gain and ended up on what happened to be its lowest setting. From there, I took some more measurements and found that bass-heavy musical phrases were only reaching into the lower 80s (whew). I may do some more adjustments later (if only to see if I can further level the frequency response), but at least my hearing should be safe for now.