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Can anyone explain more about frequency response and "usable" low frequency?

I see this stuff about cabinets and some go into detail about freq and some don't.

Any info is greatly helpful.

frequency response is the range of frequencies (bandwidth) something can handle (or reproducr in the case of a speaker (cab)). as far as bass goes, the lower the low number can go the better, especially if you play any really in any detunings...

usable low frequency is lower limit of the frequency response


Frequency response is the total range of audible frequencies that the cabinet will produce. IIRC, a low B string is around 30hz, so if the cabinet is flat down to 30 hz you're good to go. Most humans cannot hear much above 15,000 hz (15K hz), and as most home stereo speaker cabinets are usually rated much higher than 15K, they are producing frequencies you can't even hear. When I was younger I used to be able to hear the high pitched squeal given off by TV sets that use a picture tube, which is 15,750 hz. I cannot hear it anymore... age and too many loud bands for too many years.

When you get to the ends of the range of frequencies that any given speaker will produce, it starts to drop off in the volume at which it can produce those frequencies. Typically, when the ability of the speaker to produce those frequencies drops off more then 10dB, that is considered the lowest "useable" frequency. In other words, the response of the speaker at that given frequency is still loud enough and the quality is such that it is considered "useable". Usually useable frequency is only applied to the low end or lowest frequency end of the overall frequency response of the speaker. Anything lower than this frequency will loose more volume and tone quality and therefore not be considered "useable", even though in the true techical sense it is within the speakers overall frequency response specification as it can produce the frequency, just not very well.

Some companies will not list a given low useable frequency, but they'll give their specs as something like 20Hz - 20K hz +/- 20 dB. Well, in that situation what they're saying is that the speaker will produce 20 hz, but at a 20 dB loss over the rest of the frequency range. 20dB is a LOT of loss. They also don't tell you where the dropoff in response starts. Could be at 50Hz for all you know without seeing a graph of the speakers frequency response.

Other companies do the right thing and post the frequency response as the total frequency range where the speakers response is strong and has no drop in performance. Carvin is one of these. They list one of their subwoofers as having a frequency response of 50 Hz to 450 Hz ±3 dB. This means that within the frequency range of 50Hz to 450hz the speaker is pretty flat with any spike or drop for any given frequency in that range being no greater than +/- 3dB. They then list the lowest useable frequency at 42 Hz (-10 dB). So this speaker will produce 42 hz and still be strong, good to listen to, and therefore "useable". Anything below 42 hz will not be considered useable even though the cabinet will produce some of it, but not well.

Hope than helps, it's early and I haven't had all my coffee make it to my brain yet!

Thanx guys...
...I love you Kahuna.

Quote (TiSpine @ Oct. 27 2005,1:06) wrote:                ...I love you Kahuna.
That's alright; we don't judge.


You're more than welcome, and right back atcha! Ain't this place great?!

Yeah,but nobodys here at 6 am when I first get to work.
he he he....I'm at work.
I guess I'll go home now.
Till tomorrow guys........

Ok well i have a question in regard to what Kahuna said. I have looked at several cabs jsut now and none of them went bellow 40Hz for the usable frequency....and you also said the B string is 30Hz, so does this mean that there arent (at leas tin the ones i have looked at) any cabs that can produce the B string clearly

You'll still hear the low B string with those cabs, but what you're hearing will be all harmonics and overtones with no root fundamental of pure 30hz. Or the cabinet will produce it but not at any type of "useable" level. You probably won't really notice a big difference in what you hear vs. what you feel. At some point, and I'm not sure where it is, you drop out of the audible spectrum for low frequencies and into the "feel" spectrum. Certain low frequencies can't be heard by the human ear, but are felt by your body (ie: Earthquakes fall into this catagory for the most part!....)

Best bet would be to try the cab out (if possible) with your amp and bass and see what you think.

Below 20hz is considered sub-sonic. I wouldn't go too crazy relying on specs though. Even a cab with a -3db rolloff at 40hz could conceivably give you enough fundamental from a low B to jiggle your bum. Depends on the cab. The second order of harmonics is usually louder than the fundamental anyway.

I cant seem to find many cabinets that have that low of a "usable" freq.(30Hz):
          theres an ampeg that goes down to like 48Hz response but has 28"usable" (-10db)
   and I found a carvin 118BRX that says 24Hz to whatever, but doesnt mention "usable"
I looked at avatar and the dont even talk about it .so I had to go to the eminence site to get specs.
They dont seem all that Impressive,but will the cabinet make the difference?

Can the whole cabinet be lower than the speaker itself?

Can it be geater than the sum of its parts?

and how many licks does it take to get to the tootsie roll center of a tootsie pop?

and where the hell was I ?

Oh sorry...

My swr says 40Hz to whatever of "frequency response".They dont mention Usable freq.

this seems a lot lower (freq. response-wise)
than alot of other bass cabs out there
I can only assume that if they dont offer the info its cuz there not proud of it.

Dont get me wrong ..this thing sounds so choice, However if I can maximize my sound quality any possible way I'll do it.

it is a combination of the subwoofer and the cabinet construction (dimensions, porting, etc). if a subwoofer is not rated to go down to 20 Hz, then i doubt (but could be wrong) that any cab is going to provide that extension down that low (beyond the speaker specs). ultimately speaker mfr's provided recommended cabinet dimensions for each speaker they design. so a crappy cabinet design can probably HINDER a speaker.

as far as avatar go, i would just email Dave and ask him. he'll probably tell you.

i've seen plenty of cabs with <40 Hz, but just can't remember which avvy b212 is tuned for 50 Hz, but goes low just fine. however this is not advertised usable low freq. this is a cabinet parameter, IIRC.

they proly do not mention it because they don't feel it is that important. it is to some, and not to others.

they might include usable with the stated response and leave out the level it drops off at (referring to BK's post) whether it is negligible or not.

HTH and i wasn't rambling too much. its early.......... :Db

yeah,I mailed Dave and he said to check the eminence website.
Thats why I was wondering If a cab could "help" a speaker .
Thanx 4 the input though.

hey, .....isnt Kahuna awake yet?
and where's professor Stalin?

[url=""]Genz Benz 610 XB2[/url]

The bottom of the page that I linked shows the specs to my favorite cab ever. Look at the specs from their other cabs too.

Dude thats awesome!!..I think I wet myself just reading the numbers.
See, thats what I like is having the specs right there where you can see them.

Have you ever played one ...or heard it?

I gotta try me one of those.

Yup. I'm sitting right next to it. The main advantage to a multiple 10 inch speaker configuration is what it does to the efficiency of a cab. That's the _db @ 1 watt @ 1 meter rating that you see. An efficiency rating of 96db means you're gonna have to put a lot of power to it. As that number rises, you can reasonably expect to get good volume with less power. The 105db rating of the Genz Benz in addition to the frequency range, 35hz-18khz @-3db, makes this by far the most impressive 6x10 on the market. Here again though, you don't really hear specs, you hear good or bad sounds.

I use a GK 1001rb to drive my 610. I love the combination, but I think another amp would push the lows better. I'm all about the punch though.

Hey rug, how much was that baby?

I think I paid about $850 for it a few years ago. I got it new when they first came out with the XB2 series. Well worth the trouble.

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