Subjective
The popularity of SPL contesting has brought us a new generation of woofers that are built like the proverbial brick house. In some cases, these behemoths perform reasonably well in an SPL application, but most of them leave something to be desired if sound quality is what you’re after. The octave from 40 Hz to 80 Hz seems to be the area in which most car audio woofers have problems. If you want to keep the bass in front, 80 Hz is about as high as you’d want to go and, interestingly enough, there’s not much going on below 40 Hz in most recordings. This means that the vast majority of what most people call “bass” is contained in this small slice of the audio spectrum. Response errors of 3 dB to 5 dB aren’t uncommon in this range, and putting the woofer in a car seems to make the errors even more noticeable.

Contrary to its brute force appearance and my expectations, the 1240D performed exceptionally well during our subjective evaluation. Its reproduction of the all-important upper octave can be best described as smooth and punchy. Heavy kick drums produce a satisfying thump to the chest. I actually listened to my favorite stand-up bass tracks all the way through, and that’s not a common occurrence. Thirty seconds into the first one is usually enough to start me grumbling, but when we get a woofer that does it right, it’s nice to sit back and be amazed at the quality of the recordings all over again. The 1240D still isn’t quite a match for our reference woofer on audiophile-type tracks, but it’s about as close as anything has come in quite some time.

The 1240D seems a bit short on extreme boom track gut-rattling potential, but I suspect that the relatively small enclosure has a lot to do with it. Personally, I wouldn’t have it any other way, but if you’re looking for that sphere of droning boom that can be heard from blocks away, a tuned enclosure might be more to your liking.

Objective
With the coils in parallel, impedance measurements on this system show a maximum of 29 ohms at 55 Hz and a minimum of 2.5 ohms at 20 Hz. Average impedance measured 5.5 ohms between 20 Hz and 100 Hz. Out-of-car response shows a slight rise below 100 Hz followed by a 12 dB-per-octave rolloff below system resonance. In-car measurements show an impressively flat overall response and a one watt sensitivity that averages 93.4 dB between 10 Hz and 50 Hz. At a power level of 300 watts, the 1240D exhibits about 2 dB of power compression over most of its operating range, increasing to about 3 dB at the lower extremes. Maximum SPL at 300 watts measured 120.2 dB at 54 Hz.