I apologize for bumping...just my experience...
Here is a good article that covers this issue and is worth a read. I've pasted part of the article.
Page not found - HomeTheaterHifi.com
there is also an explaination about speakers
Best Car Speakers (Sept. 2018) - Buyer's Guide and Reviews
1. Their crossovers (or the low-pass slopes in the surround processor or receiver) aren’t fast (sharp) enough in their transition. It’s not that 100 Hz is really that easy to localize, but that frequencies a bit above it are. Keep in mind that the shape of the low-pass filter is an issue, and in reality a curve which varies from crossover to crossover in how quickly it transitions from no slope to it’s steepest slope, the rate specified, such as 12 dB/octave or 24 dB/octave. Still, consider a theoretical impossibility, for the sake of illustration- the immediate crossover that goes from completely flat to a straight angle down exactly at the stated crossover frequency.
Take 400 Hz and 800 Hz tones as content to be filtered out by our subwoofer crossover as an example of localizable content. A crossover at 50 Hz, 12 dB/octave will be …
-12 dB @ 100 Hz
-24 dB @ 200 Hz
-36 dB @ 400 Hz
-48 dB @ 800 Hz
Contrast that with the same 12 dB/octave slope kicking in at 100 Hz, and you get…
-0 dB @ 100 Hz
-12 dB @ 200 Hz
-24 dB @ 400 Hz
-36 dB @ 800 Hz
In such a case, the 100 Hz crossover point is certainly worse than the 50 Hz crossover point, and very likely problematic.
On the other hand, consider a 24dB/octave crossover slope implemented at 100 Hz, and the results show…
-0 dB @ 100 Hz
-24 dB @ 200 Hz
-48 dB @ 400 Hz
-72 dB @ 800 Hz
As you can easily see, a subwoofer with a 12 dB/octave crossover would not be suitable for a remotely higher crossover frequency. However, that would not preclude 100 Hz as a crossover frequency, as the sharper filter slope that started at 100 Hz would have less content above 200 Hz than the first, shallower filter that started at 50 Hz.
2. Some subwoofers aren’t suitable for higher crossover frequencies because of distortion. Harmonic distortion components are multiples of the original content, be it an original fundamental or harmonic itself. For example, harmonic distortion of a 20 Hz tone will generate energy @ 40 Hz, 60 Hz, 80 Hz, 100 Hz, etc., usually with the lower components higher in amplitude in the case of loudspeakers. In fact, many less experienced listeners, even some experienced musicians, will actually PREFER the distorted low frequency reproduction, as it provides MORE low bass, with the added spectrum in the more audible range. It sounds louder, and richer. When these subwoofers are allowed to run at higher frequencies via higher crossover settings, their harmonic distortion components reach a higher spectrum as well. It’s not that they necessarily produce more distortion than at lower crossover settings, but that the distortion is easier to hear, and easier to locate, and unlike the original content that fed the subwoofer, impervious the attenuation by the crossover, as the distortion is generated after the filter circuit by the power amplifier or the driver itself. In such a case, many may blame the crossover frequency for the increased localization problem, when in fact it’s just making the distortion problem more obvious. While I mention this in the context of subwoofers that have problems with higher crossover points, for those looking for any measure of fidelity, I would go so far as to offer this as an indication of a subwoofer unsuitable for use, period.