Backing Track EQ Question

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Professional Hobbyist
Member Since: Nov 21, 2009

This is a small gig question. I play solo, and sometimes I'll use backing tracks. I use two EV ZX1's and one SB122 sub, powered by a Yamaha EMX312 powered mixer. It's underpowered, I know, but for my small gigs I rarely turn it up past 5 or 6 and the limiters never kick in.

Here's my question. I'm trying to get a little more low end. I can buy another sub eventually, but right now I'm tapped out. I noticed something weird. When I connect my laptop to my EMX and use iTune's built-in graphic, I can boost the low end a little and it sounds good. When I use the graphic that is actually built into the EMX instead (7 channel), the low end gets farty sounding. I don't know a better way to say it. Why is it that the eq boost on the laptop works great but the one in the mixer seems to overdrive the sub? For what it's worth, boosting the "low" slightly on the mixer channel where the laptop is plugged in also seems to work OK. Not sure exactly where the low on the channel is - my guess is 100 Hz?

I'm more curious than anything else. The thing about small gigs, solo guys, backing tracks, and low end is this - if you can make the kick sound deep and real, it goes a long way toward making your backing tracks sound more like a band and less like you're playing along with a CD. Live, I use in iPod Touch, not a laptop. Why not just get a real band? That's a whole nuther thread.

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The Czar of BS
Since: Dec 31, 2007

Nov 22, 2009 07:32 pm

I think that I know what is going on here.

In your set up, you don't list a crossover. Without it, your not getting just low end to your sub. Your also getting it to your tops as well.

So, the farting sound is the tops not being able to handle to low end.

The reason that your IPod does not make this sound when you boost the low end, is the fact that it's doing it by a narrow band frequency.

The narrow band is out of the range of your top box. But right in the range of your sub.

An inexpensive crossover can be purchased on Ebay. You don't need to go digital on this piece. So, a simple DBX active crossover will work.

Professional Hobbyist
Since: Nov 21, 2009

Nov 22, 2009 09:07 pm


The EV SB122 has a crossover built in - it's designed to work with the ZX1's. The signal goes from the amp to the sub, then to the ZX1. So I don't think that's it. But I think you hit it with the narrow band... the eq on the laptop (and also the iPod) is probably pretty narrow, but the eq on the Yamaha is probably much broader, so I'm boosting more bass frequencies.

The Czar of BS
Since: Dec 31, 2007

Nov 22, 2009 09:46 pm

Yeah, I know what you are saying about the built in crossover.

I'm not sure what slope EV puts them on. It has been in my experience that manufactures usually put a gentle slope on the built in ones.

Typical is between -6 dB to -12 dB per octave. And coupled with a broad band EQ, could be causing your issue. I won't say "is" because I'm not sure of what slope they have it on.

To prevent any over excursion of the top box, I usually run the slope at -24 dB per octave. And the only way to get that with a crossover card, is to have a 4th order card.

Most manufactures don't do this. Due to expense. This is not to say that EV has not done this. But, it's not a typical practice.

So, something that gives a deeper slope will help clean that up. This is a little hard to do with a self powered mixer. If it has inserts for the left and right, then it's possible. Without the inserts, then it's not.

It does seem that the cheaper solution is to go with the IPod boost. And maybe just a very small turn on the bass knob of the board.

Professional Hobbyist
Since: Nov 21, 2009

Nov 25, 2009 12:13 pm

Here is something funny that is related to my post...

I have indeed verified that the onboard eq is boasting a large rather than narrow band and using the mixing channel's low boost gives me much better results (thanks, Rob. I like to know why things are the way they are. Always better to know than not.)

But I was starting to hear a buzzing sound. I thought it was the subwoofer starting to fart out, but the thing can handle a zillion watts and my master out knob was at 5. What in the name of the Yancy Street Gang was going on? Was my sub starting to go?

A physical exam of the sub revealed the problem - a speaker wire inside the sub was touching the side of the cabinet on the inside. When I cranked the speaker, the wire rattled. D'oh!

The EV SB122 will not fool anyone into thinking it's an 18 inch sub, contrary to the EV marketing department, but I have to say for small gigs, it does a darn good job.

The Czar of BS
Since: Dec 31, 2007

Nov 25, 2009 02:06 pm


Glad to hear that you found the issue.

I have this problem once before. To where the wire was laying up against the cone of the driver.

And I thought the same. That the driver just **** the bed.

How does it sound now with the board EQ?

Prince CZAR-ming
Since: Apr 08, 2004

Nov 25, 2009 03:17 pm

heh heh . . . Yancy Street Band

My 2x10 bass bottom had that problem too, a wire had gone funny, but a little re-connection and was good to go.

Ipod Touch, nice idea for backing.

Sorry, nothing more to see here. I return you to your normally useful posts =).

Professional Hobbyist
Since: Nov 21, 2009

Nov 25, 2009 07:30 pm

It sounds really good. I'm very happy with the sound and the portability. I am really happy with the setup. I'm like a poster boy for EV. I've got the EV speakers and I'm singing through an EV N/D767a microphone. Everything is very lightweight, including the Yamaha combo mixer, and it all fits in my trunk. Very cool.

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