# 55hz and 75 hz ??



## Robert1950 (Jan 21, 2006)

What the difference between a bass response of 55hz and 75hz in an otherwise identical speaker?

Thanks


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## Xanadu (Feb 3, 2006)

If you play a note with a frequency of 65Hz you'll be able to hear it in the speaker that has a bass response of 55Hz, and you wont in the speaker that has a bass response of 75Hz


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## Wild Bill (May 3, 2006)

*"Sorta.."*



Xanadu said:


> If you play a note with a frequency of 65Hz you'll be able to hear it in the speaker that has a bass response of 55Hz, and you wont in the speaker that has a bass response of 75Hz



Actually, you'll hear both notes just fine! Frequency response is not a digital, on/off thing. If a speaker has a rated response of say 80hz-5khz you also have to spec within what range, such as +/- 3db. The speaker will still reproduce frequencies above and below this range but the strength will gradually fall off as you go farther out of range.

To be more specific with your question 65hz and 55 hz is referring to the low resonance frequency of the speaker. A resonance point is where you get a "peak" in amplitude (volume). Speakers always have a low frequency peaky point. If you properly design your cabinet with a tuned port or whatever you can smooth out this peak and get a wide even low end response that starts to be working well at either 55 hz or 65hz, to use your examples. Obviously the lower the resonance point the lower this low end response will work well. With a bass guitar this can be important as the volume might drop off a bit on those low E string notes. Or if again the cab is untuned you might get a loud "peakiness" at certain low notes around the speaker's low resonant frequency. If the speaker's resonance is low enough AND you tune the cabinet you end up moving the "peakiness" point below the lowest note you expect to send through the speaker/cabinet. Then it's no longer a problem.

Note how we talk about speakers and cabs as a combination. You usually can't mention one without the other. A great speaker in a badly designed cab will sound like ass. You can put any speaker you want in such a cab and it will still sound like ass! It's like playing with different brands of strings when your pickups suck anyway. It's not a big deal for lead guitar speakers as I explain next paragraph.

Resonance is not usually important with lead guitar cabs 'cuz the lowest note on a standard guitar is a lot higher than the usual resonant frequency. My memory of the frequency of low E on a lead guitar fails me right now but I don't think it's much below 100hz. For this reason we only care about this stuff with bass, PA and hifi speakers/cabs.

Hope this is useful...


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## Robert1950 (Jan 21, 2006)

Wild Bill,... I was hoping you would chime in this one. Thanks


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## Xanadu (Feb 3, 2006)

i was guessing...kinda...None


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