O.T. Question for the Pro Sound Guys

[voice of the theater]

I don't usually start off topic threads but I know there are several pro-sound guys here who probably know the answer to this question. It's about using equalizers so hopefully the answer will be relevant/useful when using a graphic EQ to equalize Altec speakers as well so only partly off topic?

Anyway, we just finished mixing by (rock) band's new CD (12 new original songs). It was mixed on my Model 19's and I've been doing playbacks on the 19's, 14's, Santana II's, boombox, car stereo, computer speakers etc. to make sure that all 12 songs sound good everywhere I play them. Well, the bass is a little low on a couple of songs (bass guitar and kick drum) and it's a little too loud on one song. I'm going to a local studio tomorrow night to have the CD mastered. I know it's customary in the mastering process to adjust not only the dynamics, but also the EQ of each song as needed. So, I've been experimenting here at home with the EQ on the three songs in question (which are now mixed down to 2 track stereo on conventional CDR's). I have an Alesis MEQ 230 which has 2 complete 30 band 1/3 octave equalizers. For the two songs where the bass is a little low, I've tried adding +2 dB simultaneously at 80, 100, and 125 hz and it seems to be just right. My question is, when I'm at the local studio tomorrow night for the mastering session, the engineer will be using Pro Tools and possibly T Racks (both digital computer programs). I'll ask him to add bass to the two songs that need it. He'll be "drawing" a curve on the computer and I'm going to tell him that I like the way the two songs sound with 2 db added simultaneously at 80 hz, 100 hz, and 125 hz. My question is, when I'm adding two db at these three frequencies with my analog Alesis MEQ 230, is there a cumulative effect? By setting the Alesis EQ sliders to + 2 db at 80, 100, and 125 hz are the 80 and 125 overlapping enough on the 100 that I'm really adding more like + 3 or + 4 db at 100 hz? Is there likely this type of overlap/cumulative effect? In other words, will the engineer tomorrow who will be trying to duplicate this analog EQ effect with his digital EQ computer programs be drawing a straight line +2 dB from 80 to 125 hz which tapers down below 80 and above 125 hz or will he be "drawing" a "hump" that is + 2 dB at 80 but more like + 3 or + 4 at 100 and then + 2 at 125? That's the best job I can do phrasing this question. Can anyone help me with an answer before my mastering session tomorrow (Tuesday) evening? BTW, the engineer may know the answer to this question (or he may have an educated guess) but I'd feel a lot safer getting the answer from a pro(s) here. On the same topic, for the one song where there's too much bass and kick drum, if I set the Alesis MEQ 230 for -2 db at 40, 50, 63, and 80 hz simultaneously--is there similar overlap? By doing this am I really subtracting 2 dB at 40 and 80 hz but more like 3 or 4 dB at 50 and 63 hz?

Here's a little more info on the Alesis MEQ 230 that I'm using at home (analog graphic EQ) that the engineer tomorrow will hopefully be able to mimic the effect with his digital computer EQ program.

Each channel features 30 bands of 1/3rd octave equalization with
ANSI and ISO standard center frequencies. Each band is
adjusted by a center detented fader with ?12dB of gain available,
and a master fader controls system gain for that channel.

LINK FOR MANUAL/SPECS:

http://www.alesis.com/stuff/contentm...230_manual.pdf

[Old Guy]

the problem with a simple answer is the brand name on the EQ. Alesis is pretty low end. the frequencies and amount of cut/boost aren't gonna be accurate. Many inexpensive EQ's do indeed overlap.

Digital EQ's on the other hand are fiendishly accurate.

I suggest explaining what you want in detail to the engineer.

[voice of the theater]

Thanks Old Guy. So, from your answer it sounds like you're saying in a perfect world there should be no overlap with the EQ bands by design, but there may be some on this unit because it may not be as accurate as it could be? I've had really good luck with this Alesis MEQ 230. It is incredibly clean (.004% distortion) and quiet and very natural sounding but I'll take your word for it that the sliders may not be as accurate as I'd want......

[Old Guy]

There is always some overlap. Think about crossovers. an 18 DB/octave is going to overlap way less than a 6 DB, due to the steeper slope. But the issue is the filters in that Alesis may be labeled 100 and actually centered at 80 or 120. So settings on it may or may not translate to even another analog eq, much less a digital.

[Alien_Shore]

Do you have access to a RTA? Dedicated units can be be very expensive, but you can get software for your PC pretty cheap by comparison.

True Audio RTA

Their highest resolution version (1/24th octave) is only $99.

No affiliation by the way.

[cradeldorf]

You could always let the engineer guy set it to what he thinks is perfect or he'll let a computer do it for both of you and then maybe just get a master copy for now. then take that home and shove it in everything you own and judge it that way?

[voice of the theater]

Do you have access to a RTA? Dedicated units can be be very expensive, but you can get software for your PC pretty cheap by comparison.

True Audio RTA

Their highest resolution version (1/24th octave) is only $99.

No affiliation by the way.

I don't have an RTA but I should probably consider buying one.

Thanks everyone for the assistance. The first mastering session went well--the engineer knew what I was trying to do and yes, we factored in the overlap from my Alesis and he drew some nice sounding EQ curves with Pro Tools and/or Adobe Audition.....