Can 10 inch subs play very low frequencies? ?
I have a pair of Earthquake dbxi 10's in my car. The specs don't give the frequency response of the speakers, but looking at how they are built and sound, I would imagine they sound pretty low. I was also wondering what I should set the lpf on my amp to. I've been hearing 80 hz being a good setting but with my subs being 10's, I'm wondering if 100 hz is better since they can handle higher frequencies better. Would setting the lpf lower allow the subs to play lower frequencies better because it narrows the frequency spectrum they're receiving?
Answers & Comments
Verified answer
There is some truth to what the other posters have said. Larger woofers can indeed reproduce very low frequencies better than smaller woofers. However, it's not the enormous difference that many seem to believe.
For starters, let's take a look at the Fs spec of the Earthquake dbxi subwoofers. Fs is the resonant free-air frequency of the subwoofer. In other words, enclosure aside and all other things equal, what is this sub's resonant frequency? For the dbxi 10" it's 27-28Hz. For the 12" it's 24-25Hz. For the 15" it's 20-21Hz. Let's keep in mind that 20Hz is considered the lowest frequency limit of human hearing. Also keep in mind that most people cannot even tell the difference between two tones that are one or two cycles (Hz) apart. So as you can conclude, yes, larger woofers can play lower cleanly.... but it's a pretty minimal difference.
A far larger impact on low frequency extension is going to be the enclosure that the subwoofers are in. A properly built vented or ported enclosure will ALWAYS give better low frequency extension than a properly built sealed box. As for sealed boxes, the larger the box, the better the low frequency extension. Of course, with either of these two examples, there is a limit. There is a point of diminishing returns. So don't think you can slap a 10" sub in a 12cuft box and hit down to 10Hz.
I recommend a ported box with about 4cuft of net airspace for a pair of 10" dbxi's. The LPF is fine between 80-110Hz. Anywhere in that area is fine. However, no, setting the LPF lower will not allow the subwoofer to hit lower notes. In extreme cases, a crossover setting may allow the speaker to play the notes cleaner.... but we're only talking about a small small band of frequencies with a subwoofer. It's simply not enough to make any noticeable difference.
Lowest Frequency Subwoofer
The 10's will hit the higher notes, example the 12 in subs job is to hit lowest notes. typically the larger the speaker the deeper it can possibly get.
Smaller subs give more punch rather then lows.
LPF should be set to 80.