When to, and when not to.......EQ

[kgveteran]

What are the guide lines for adjusting subwoofer responses with PEQ's.As of now I have two issues, of sorts.One is a null centered at 45hz.It's goes down to 42hz and up to 50hz.At the deepest point I would say it's about -7db.Now there is a mode of about +7db centered at 63hz and is about 15hz wide.That on can be seen in the 1/3rd oct setting.

When I select 1/3rd oct (TrueRta) you can't see the null.As i begin to get into 12db/oct then I notice it.The 24db/oct is a bit too much and beyond my ability to distinguish the little peaks and valley's.

I reduced the peak with a small amount of EQ.I couldn't even tell I had done it.Is it worth it to EQ these small problems.

I now have no EQ's on the mains and surrounds (anyone looking to purchase some Ashly PEQ's ).



NEXT QUESTION: Setting the response flat (or so to speak) leaves too much bass with movies.I always end up lowering the subwoofer setting.Is the LFE on most movies that much higher ? I reduced by about -5db and that was better.What gives.On music DVD's I reduce it even more.

KG

[plincoln]

**WARNING!!! The following is my opinion***

Personally I think too many people become obsessed with what is considered a flat sub response and tend to EQ too much. Let's face it, when using EQ 99% of the time we're trying to compensate for less than stellar room acoustics at the sweetspot.

So it's fair to say in most applications even with some room treatments the room is still the weakest link in the chain. I have plenty of bass traps etc, and I can easily manipulate the sub response by moving the mic a couple inches in one direction or anther...so to me it makes no sense using 1/24 octave measurements since you'll constantly be fighting with it. 1/12 to 1/6 is generally what I use when I use TrueRTA to take sub measurements. Hell if you happen not to sit exactly where you placed the mic, the response will be off anyways so why spend all the time with 1/24 when it really doesn't offer anything.

As for which dips I attack, anything less than +/-3db I leave alone since in most cases your ears are not going to be able to discern the difference. If I happen to have a dip next to a rise and it's more than 3-4db from peak to peak I may try to add some cut there to reduce the delta. I also try not to fuss with narrow dips or peaks since using too much EQ there can cause ringing..and a again, if the width is only a couple hz, most ears won't hear the difference between the EQ'ed and non Eq'ed response.

So essentially I only EQ the widest and highest peeks. I use about 4 filters to tame the room gain from 25hz down...then I have a two more filters that tame a couple peaks around 40 and 60hz.

I keep a couple presets that I call up with my remote depending on what I plan on doing...movies or music...I program the sub preset into the macro. For music, the subs run totally flat and level matched to the mains. For DVD's I EQ'ed a response that slowly rises from about 22hz down, essentially I reduce the cut on the filters I used to tame the room gain.

[kgveteran]

Hey Patrick,
I pulled out the PEQ's from the seven channels and now I'm debating the BFD on the subs.I can see what it does on the screen, but not with my ears.To me it's just another gain stage to muck it up. I can justify the BASSIS because the low end I get is pretty cool.I would like a nice remote volume dedicated to the subs.

What is this delta you mentioned ?

[plincoln]

Hey Patrick,
I pulled out the PEQ's from the seven channels and now I'm debating the BFD on the subs.I can see what it does on the screen, but not with my ears.To me it's just another gain stage to muck it up. I can justify the BASSIS because the low end I get is pretty cool.

Well it only matters what sounds best to you. In my case, I am picking up gobs of room gain down low. Without the EQ it's difficult to level match the sub to the mains because there is nearly a 10db increase in response from 25hz down and it throws off the calibration, not to mention that it tends to sound just like it looks...way to much low end and lean on the other.

The peaks at 40 and 60 are so slight that I probably could not hear the difference either, but since I had the extra filters available I used them.

I'm also using the EQ for more than just basic EQ...I can store 6 different curves, I use 2 as I described in my first post. So I can go between music and movies seamlessly without having to dick around with levels all the time. Also my IB/amp don't have any phase control, and the response at the XO freq needed some tweaking..sure I could have used the distance control on the AVR, but my SMS also has phase adjustments so I use that instead.

What is this delta you mentioned ?

by delta I was just referring to reducing the difference between a peak and dip that are right next to each other...sorry...old engineering habits are hard to break

Seems to me you already have the BFD so why not use it. You probably won't get much for it on the used market and I doubt it's adding any sort of detectable noise/distortion since you are using it pretty conservatively.

[kgveteran]

I get tons of room gain also.My Marchand adds about 7-8db in the single digits, I guess it will stay.

I've got the ashly PEQ's forsale on ebay now, but will hold onto the BFD just cuz.

How many locations should be measured ? You are right about moving the mic and inch to get different result. I try to use my seating location, but since the sofa is so small it's pretty uniform.

[Ovation]

One thing to remember is to avoid trying to fix a null by boosting it with an EQ. It won't really get rid of the null and it will have an adverse effect on the surrounding frequencies.

[kgveteran]

One thing to remember is to avoid trying to fix a null by boosting it with an EQ. It won't really get rid of the null and it will have an adverse effect on the surrounding frequencies.

As of now I'm EQ free, except for the Marchand BASSIS (which is an EQ).We'll see how long that lasts.