by Jonathan » Sun Jan 15, 2006 7:46 pm
Group delay is related to transient response, how well the sub can track the input signal. A low group delay indicates good transient response. Good part is, assuming it was audible, this would be "tighter" sounding bass. At least to the BS slinging golden ears, anyway. This is usually far below the limits of audibility, but this alignment does give lower bass and has a lower Fsc. Impedance peak can tend to be higher, though. Keep in mind any time you use equalization to flatten the frequency response of a subwoofer, you add phase shifts in that region, which eliminates the benefit of a good group delay.
Flat FR you already know the benefits of. This is anechoic, though, not a car environment with resulting cabin gain. Due to cabin gain, you will likely have peaks and dips in the frequency response due to this, and you go back to the equalizer reference.
You'll see that on most of JLs enclosure recommendations, the Qtc of the subs differ according to the sub used and it's characteristics. In my experience with their subs, these recommendations do a pretty good job of providing a relatively flat FR in the average vehicle, but of course nothing is perfect. The best thing you could do is get an RTA and look at the effects your car has on the system response, comparing that with what the sub would have in a predictable environment. From there, you could decide upon an enclosure size and type based upon the car you're using, in which the ideal enclosure could be smaller or larger depending on the characteristics of the environment. Not really something I or anyone on the forum could help you with, not specifically anyway.
Group delay is related to transient response, how well the sub can track the input signal. A low group delay indicates good transient response. Good part is, assuming it was audible, this would be "tighter" sounding bass. At least to the BS slinging golden ears, anyway. This is usually far below the limits of audibility, but this alignment does give lower bass and has a lower Fsc. Impedance peak can tend to be higher, though. Keep in mind any time you use equalization to flatten the frequency response of a subwoofer, you add phase shifts in that region, which eliminates the benefit of a good group delay.
Flat FR you already know the benefits of. This is anechoic, though, not a car environment with resulting cabin gain. Due to cabin gain, you will likely have peaks and dips in the frequency response due to this, and you go back to the equalizer reference.
You'll see that on most of JLs enclosure recommendations, the Qtc of the subs differ according to the sub used and it's characteristics. In my experience with their subs, these recommendations do a pretty good job of providing a relatively flat FR in the average vehicle, but of course nothing is perfect. The best thing you could do is get an RTA and look at the effects your car has on the system response, comparing that with what the sub would have in a predictable environment. From there, you could decide upon an enclosure size and type based upon the car you're using, in which the ideal enclosure could be smaller or larger depending on the characteristics of the environment. Not really something I or anyone on the forum could help you with, not specifically anyway.