Speaker Frequency Range Question

[slhguitar]

Hey, I have a question about the frequency range of guitar speakers. I was just looking at some spec sheets for celestion and eminence speakers, and the lowest frequency that I see is 80 hz. My question is, when a guitar is downtuned to dropped D, or even dropped C, do the speakers not reproduce the fundamental frequencies of those low notes? A dropped D note is 73 hz, and a C would be 66 hz, which are both below the frequency range of the speakers that are being used to play the notes.

Also, is there any sort of danger in playing these low notes through speakers that claim they are below the frequency range?

Any help/explanations are greatly appreciated.

Thanks.

[Jef Bardsley]

Good question. Let's see if I can give a good answer.

First of all, the quoted figure is the "-3 dB down point", not the lowest frequency the speaker can reproduce. Speakers roll off in the low end, sometimes smoothly, sometimes with bumps from resonances. "-3 dB down" means the point at which the speaker is putting out half the power it does for most other notes across the spectrum (or 'up the fretboard', to a guitarist).

Understanding the bass response of a loudspeaker with just the low-end spec is like understanding the shape of the East Coast by knowing only the co-ordinates of Washington, DC.


Check out the Eminence listings here:
http://www.usspeaker.com/homepage.htm

If you click on the speaker names of many of the speakers, you'll get a specs page that has a graph at the bottom. If you look at a few of these graphs, you'll see how unpredictable the bass response of a guitar speaker can be. Many of them, however, do exhibit a usable output below the "rated" low end frequency.

IF the loudspeaker and box don't have a resonance higher than the average output, then you should be safe to the speaker's power rating, assuming a long throw voice coil (a safe bet in a guitar speaker). I play in C# myself with no problems, but I'm not playing at band levels.

Ultimately, you'll run out of suspension, and with enough power this will damage the speaker. Of course, with enough speakers, this too can be avoided. Still, as a rule of thumb, I don't let bass players play through guitar rigs. ;)

[slhguitar]

Thanks for the response. I was mostly worried about down-tuned guitars, because my band plays in dropped D, and a band we routinely share cabs with plays in dropped C. I was worried about possibly damaging the coils on my speakers. I figured it would be fairly safe to go a few notes below the stated "range" of the speaker. Thanks again for the explanation.

Cheers.