MXR 10 band EQ problem UPDATE- It's working

If you're using V30's here's your usable range...from Celestion BTW, so not likely to be refuted.

http://professional.celestion.com/guitar/products/classic/spec.asp?ID=4

Oh, now you've done it! Tell people they can't refute something, and they will line up to do it.

:mrgreen:

The frequency range spec is not a useable range, it is the range in which there is not excessive attenuation of the signal. Any speaker will produce 20Hz, it will just not do it efficiently. You can always boost low frequencies and burn more power in the amp to get something out at frequencies outside the specified frequency.

Of course the danger is that when a speaker is not efficient, the power lost comes out as heat. If you push the heck out of a speaker at 20Hz, a lot of that power you put in comes out of the voice coil as heat. With enough heat, you can damage it. BUT you would have to push it well beyond its rated power to do it. So a bit of boost at low frequency is probably harmless. Most of us run speakers at a fraction of their rated continuous power (music signals tend to have high peak power but relatively low continuous power).

Not to mention, which many seem to forget, that a guitar is essentially a mid-range instrument and thereby best used as such.

What about my drop-A 7-string (OK, I go with standard tuning, but some people drop A). I still want to hear it when I dive-bomb. I think I can get to 1 Hz that way.

:twisted:

I keep one of my 6er's tuned in C and even that only goes down to 65Hz or so.

Why dont you just plug a bass into the 10 band, turn the two lowest sliders all the way up, slap the low E string and see if you blow your speaker?

There are all kinds of things that will prevent you from hearing those freqs, especially since 31 and 62 are below the fundamental of the low E on a guitar. If you turn the lowest slider all the way up you should hear at least a little bit of difference with heavy chord digging and palm mutes. Do anything on your guitar that sounds like a kick drum, and make sure you have the low EQ on your amp turned up. As long as you are not using 6 or 8 inch speakers, you should hear something change.

You probably cannot work on this eq pedal yourself, I was told (by a person who mods MXR's for pay) that the MXR EQ uses some type of monolithic construction inside, similar to the monolithic crap all the old Alesis toy mixers were using. If that's true, I would think either all the sliders would work or all the sliders would fail, not just one or two of them.

So somebody believes he can get his guitar to play 1hz? I have a 98 Ford Ranger for sale, mint condition.....best car ever made, great bargain. Call me.

So I took it apart and didn't see anything wrong at all. I put it back on the pedal board
and I cranked the bass on my VHT's clean channel and while hitting low E and adjusting
those two sliders up and down I could hear the two freqs in question working. So, I guess
nothing was wrong after all. I guess being that it's a EL34 based amp and maybe the freq
response of the speakers (PE50's made for VHT by Eminence) made it difficult to hear.
I'll probably hear it better through my DC-5 being a 6L6 amp that has more low end. Though
that amp doesn't need it. Anyways, thanks for all the input!

I know this is an ancient thread, but I found it in a search for info and figure others might find it and benefit from what I'm about to write.

There has been discussion about whether or not the 31.25 and 62.5 hz sliders of the MXR should affect low guitar tone because the 62.5 hz slider is lower than a guitar's lowest fundamental frequency of 82 hz.

Those low sliders absolutely *should* affect low guitar tone. The lowest 3 bands on the MXR are 32.25, 62.5 and 125. 80 hz is just above 62.5 and would obviously be affected by that slider since the EQ action tapers from the center point and 80 hz is between two sliders

However, more than that, each slider in a graphic EQ affects frequencies above and below the neighboring sliders (just not as strongly). If the bandwidth affected by each slider was super tight so that it had virtually no effect by the time it reached the next slider, the resulting EQ would probably sound strange (if you raised a series all by +6 you would get big dips between the sliders). So long story short, if you raise the 62.5 hz slider it will raise frequencies at 80 hz and even well beyond 125 hz. It very much has an effect on guitar tone. If you want more low end, use the lowest sliders like a shelf. Raise all of them.

Don't worry about your guitar amp speaker. Most guitar speaker cabs/amps should have bass limiting components that cut out anything low enough to put the speaker easily at risk due to bass overload. PA's which are designed as full spectrum and need to be able to output very low bass may need protection... that's usually when you would use the mixing board to roll off or cut the low frequency content. When singers play with their mic stands for example, the movement can cause a lot of annoying low pitched sounds which you can mostly cut out with a judicious low cut.