What to look for in subwoofers?

[bstran11693 10+ year member]

Ok I've started looking at the specs of different subs and I keep finding similarly priced ones with the same power ratings but a few different other specs and I was just wondering what is better?

Let's say sub A has a sensitivity of 86.7 dB and a frequency response of 31-150 Hz

and sub B has a sensitivity of 87.6 dB and freq. response of 25-500 Hz...

Which one is better and why? Thanks!

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[smd4life 5,000+ posts]

sub "b" seems better because it has a higher sensitivity and can play a much broader range?...but with that said i would not choose my subs at all based on those 2 specs...the range a sub plays has 90% to do with the box...and as far as im concerned they can tell you anything about the specs? i try to pick a company with a good name, good customer service if im buying new...also if i have a good experience with a certain brand i will not be as hesitant to buy more of there products, id say you will be happy with whatever you buy as long as you dont buy junk and the install is done properly

 

[audioholic 5,000+ posts]

Subwoofer sensitivity specs can all but be ignored. The standard for measuring speaker efficiency is to measure it at 1khz. Since your subwoofer will never even come close to playing 1khz in normal operating conditions, the spec means very little. Add to that the reality that the enclosure size/type/alignment has a HUGE impact on over all system efficiency, and it becomes clear that raw subwoofer efficiency specs are all but worthless.

To address what smd4life said, even if we could compare subwoofer efficiency specs reliably, a higher efficiency/sensitivity is not always advantageous. In fact, many times a lower sensitivity is better. Hoffman's Iron Law tells us high efficiency, low frequency extension, small enclosure... pick two. So, many times manufacturers of car audio subs will intentionally keep efficiency low so that the speaker can operate in a small enclosure while still maintaining proper low frequency extension.

 

[bstran11693 10+ year member]

so is it ideal to match the sub freq. response with a box's freq. response?

 

[RAM_Designs 5,000+ posts]

Fs, Qts, and Vas are much more important specs to look at.

 

[audioholic 5,000+ posts]

so is it ideal to match the sub freq. response with a box's freq. response?

No, there is no such thing as an enclosure's frequency response. The enclosure is only half the equation for creating the frequency response, and you cant ignore the speaker and still determine a frequency response of an empty enclosure. You are trying to over simplify a more complex issue. I dont blame you, that's a VERY common mistake. My best advice, if you want to know about sub specs and what they mean, is to do a little research. Google theil/small parameters and read up on what they mean and how they are derived. This will give you a good basic understanding, and then you can come back here and ask more specific questions on what you dont understand.

 

[bstran11693 10+ year member]

ok thanks.. i remember someone posting a guide that a bunch of pages and it started at the most basic info of like car audio and electronics but i cant seem to find it?

 

[audioholic 5,000+ posts]

ok thanks.. i remember someone posting a guide that a bunch of pages and it started at the most basic info of like car audio and electronics but i cant seem to find it?

Im not sure which guide you are referring to, but bcae1.com is always a good source of information.

Glad to help.