by GlassWolf » Sun Mar 06, 2005 11:00 am
ok, let's see.
first, don't assume anything. if you want to do a scientific approach to a comparison, use a controlled environment where all factors are equal or at least measured against a control, and vary as few factors as possible when looking at two speakers side by side.
if we're going to ask about displacement, let's understand that both compared subs should be in the same box, or both in ideal volume boxes of the same order at least.
Then we come to environment. same car, same box position, etc.
Power should be the same to both drivers if we're going to compare them, or should be altered based on sensitivity to compare Xmax or displacement.
yes with the same power a 12mm and a 24mm Xmax sub may be about the same volume for output, but that 24mm xmax sub is usually going to have higher power requirements, and thus will reach greater excursion, thus displacing more air and thus resulting in a 'louder sub' in the end.
of course box order or type matters, as does power, sensitivity, motor control, vehicle cabin Fs, and plenty of other factors.
In the end, every variable has an effect on the final outcome, but with proper design, superior specs usually result in a superior sub.
Honestly, the right box and proper power and all of those factors should be assumed ideal if the installer has half a brain. It's when you get people doing installs who don't know what they're doing that you run into the biggest problems.
by the way, what was the point of this thread? are we looking for best SPL? best sound quality? what exactly are our goals? they were never clearly defined, and that's another fault in the approach to this query.
Personally I use a pair of RE XXX 12" subs in an aperiodic rear loaded enclosure in a car that's 17' long and 6' wide and made of pure old school detroit iron. The enclosure is entirely designed for SQ, but with ~1280wRMS to each sub from good class AB amps, it can get plenty loud if I want it to.
I do love the sound of the car's exhaust though.. it's such a shame to drown that out.
ok, let's see.
first, don't assume anything. if you want to do a scientific approach to a comparison, use a controlled environment where all factors are equal or at least measured against a control, and vary as few factors as possible when looking at two speakers side by side.
if we're going to ask about displacement, let's understand that both compared subs should be in the same box, or both in ideal volume boxes of the same order at least.
Then we come to environment. same car, same box position, etc.
Power should be the same to both drivers if we're going to compare them, or should be altered based on sensitivity to compare Xmax or displacement.
yes with the same power a 12mm and a 24mm Xmax sub may be about the same volume for output, but that 24mm xmax sub is usually going to have higher power requirements, and thus will reach greater excursion, thus displacing more air and thus resulting in a 'louder sub' in the end.
of course box order or type matters, as does power, sensitivity, motor control, vehicle cabin Fs, and plenty of other factors.
In the end, every variable has an effect on the final outcome, but with proper design, superior specs usually result in a superior sub.
Honestly, the right box and proper power and all of those factors should be assumed ideal if the installer has half a brain. It's when you get people doing installs who don't know what they're doing that you run into the biggest problems.
by the way, what was the point of this thread? are we looking for best SPL? best sound quality? what exactly are our goals? they were never clearly defined, and that's another fault in the approach to this query.
Personally I use a pair of RE XXX 12" subs in an aperiodic rear loaded enclosure in a car that's 17' long and 6' wide and made of pure old school detroit iron. The enclosure is entirely designed for SQ, but with ~1280wRMS to each sub from good class AB amps, it can get plenty loud if I want it to.
I do love the sound of the car's exhaust though.. it's such a shame to drown that out.