Flat lining the PEQ ?

[evilkat]

So I was doing a little forum reading, and a lot of people claimed that they didn't like how their speakers sounded after receivers automatically adjusted their PEQ for their speakers, and in most cases it sounded better when the line was flat.

Always looking to mess with what's not broken , I decided to ignore the settings made by my receiver's YPAO algorithms and just flat lined it for all my channels. I was rather surprised to find out that the music I played sounded very 'flat' and lifeless with the new settings.

I don't know if it was because I used mp3s to test this out that it sounds so bleh (even with the 2 channel enhancer set to ON, it sounded rather flat) but I can't imagine how this sounds better I haven't tried out any movies yet, so perhaps the sound is better with movies?

Or maybe I'm being a big idiot and I am missing something here I've always heard that PEQ should be the LAST thing you mess with when setting up your system, and even then, you should use it only as a very last resort.

Is this true? Am I missing something here? I'm gonna give these new settings about a week or so before I decide on what to do with it, but I would appreciate your input on the matter

 

[Nomo]

I've always liked what YPAO did with equalization. It sounds much better than no EQ at all.
Size, distance, and level are another matter. Those I can do better manually.
But the PEQ to me is essential. Maybe if I had golden ears and were able to set the GEQ better myself I'd have a different opinion.

I don't.

 

[ErinH]

This is my experience in the car audio world, so take it with a grain of salt:

Assuming you want flat, you should shoot for RTA flat. When working in an environment there's no guarantee that the flat from the receiver is flat in your environment. Heck, it's probalby not.

What "flat" usually refers to in FR is flat in your room, car, whatever. That way you have discovered all the null & voids in your room and have thus been able to equalize it to where all frequencies are at the same energy level.

Going a bit further, I've found that RTA flat is a good option for all around listening (various genres of music, and I'm sure movies follow this example), however it's not without it's flaws. I always wind up doing some boosting in the 300-500hz range along with a higher level in the subbass/midbass region. The highs taper off. That's just how I prefer it.

And, going a bit further, lol.... when I say "boosting" I don't actually boost any frequencies. I usually do the most cutting that I can so I am then able to set the gain (level) a bit higher. Rather than sacrificing a large band of frequency I trim it all back and get some more volume.

My $.02.

 

[evilkat]

I'm beginning to think you're right Nomo...I believe I will be reverting back to YAPO and adjusting the levels manually. I wonder how much of a difference will be made if I set the levels first and THEN do the EQ stuff.

Erin, thanks for your input. Can u explain what RTA is though?

 

[ErinH]

I'm beginning to think you're right Nomo...I believe I will be reverting back to YAPO and adjusting the levels manually. I wonder how much of a difference will be made if I set the levels first and THEN do the EQ stuff.

Erin, thanks for your input. Can u explain what RTA is though?

RTA= Real Time Audio

Basically a FR graph so that you can see the frequency response (that sentence is a bit redundant).

This is my analysis from my car stereo with only t/a (time alignment) and x-overs set:

The above is with the mic facing to the right to mimic my right ear.

Left ear response:

What you do is play a pink noise track and use a mic, and software to measure response and display it. What you then do is start EQ'ing those peaks down so that you have somewhat of a "flatlined" response.

From there you start eq'ing things to sound the way you want. Or you can just leave it flat.

With home audio I don't know you'll have those nulls, and you really shouldn't. A car's environment is what makes it so damn hard to tune, and you can see that from the above graphs.

I think I covered the purpose of doing this above, but if you want more explanation I'll be happy to give it.

 

[evilkat]

Thanks Erin! That actually cleared up a LOT for me...I think I finallly understood the whole point of this thing very clearly for the first time, so your comment certainly helped a lot. I can certainly hookup a mic to my computer and find some software that does freq analysis. It should be mighty interesting to see what comes out of that. Maybe interesting to see it before and after YAOP has been applied!

But I also see why people would want to do PEQ last...because you're essentially messing with the signal, and if you don't understand your room acoustics, you could probably end up screwing up the sound u get from the receiver.

Would it be fair to say then, that those who deliberately leave the EQ alone are the ones who have really great acoustics in their room?

 

[ErinH]

Thanks Erin! That actually cleared up a LOT for me...I think I finallly understood the whole point of this thing very clearly for the first time, so your comment certainly helped a lot. I can certainly hookup a mic to my computer and find some software that does freq analysis. It should be mighty interesting to see what comes out of that. Maybe interesting to see it before and after YAOP has been applied!

But I also see why people would want to do PEQ last...because you're essentially messing with the signal, and if you don't understand your room acoustics, you could probably end up screwing up the sound u get from the receiver.

Would it be fair to say then, that those who deliberately leave the EQ alone are the ones who have really great acoustics in their room?

No problem. It seems the past few years I've spent on car audio has really benefitted me in the home audio world as well. And I'm able to bring some of my knowledge over.

As for the PEQ messing with signal; yes that's correct. The EQ is basically a cut & boost element. With PEQ you are able to select the Q (band, width, whatever) of the EQ. This is really nice.

For instance, let's look at my first graph (for no other reason that to give an example):
1khz has a pretty wide band. I'd set the P-EQ to say a .5 width and then drop it down to a desired point, say 50db. Further down the line I've got a steep slope at about 2.8khz. I'd set the width for 3 or so and then cut about 10db off. Basically the purpose is to get everything relatively flat across the board. Then what you can do is play some musical tracks that you are very familiar with. Start tinkering with P-EQ again until you get desired results. You don't have to leave the settings to where the FR is flat... that's just done so that you have a neutral starting point. One thing that I almost always wind up doing, however, is setting the sub & midbass levels a bit higher than everything else.

In the paragraph above I've assumed that the P-EQ has variable bands (which they should, as G-EQ's are the only EQ I know of with a set bandwidth).


As for the question about others deliberately leaving EQ alone?... I dunno. It could be that they just don't know any better, or have the tools to do some RTA testing. Maybe the don't care. Other than that I can't see any reason to not play with it, lol.

 

[evilkat]

With PEQ you are able to select the Q (band, width, whatever) of the EQ. This is really nice...........

For instance, let's look at my first graph (for no other reason that to give an example):
1khz has a pretty wide band. I'd set the P-EQ to say a .5 width and then drop it down to a desired point, say 50db.

Okay I managed to follow most of this post, but you lost me at the band widths discussion.

Are you talking about the width between 1Khz and 2Khz? Seems like the x axis is going up by octaves (and the width appears to be constant for some reason - is this standard?) The y-axis is decibels which i understand. So when you say you gave your p-eq a .5 width for 1Khz, what exactly do u mean? Are you restricting the frequencies displayed some how, or is it that the tolerance in Dbs for freqs in the 1Khz is now with .5dbs of each other?

I probably need to read up on this topic

 

[ErinH]

P-EQ (just read the overview), then read this on bandwidth (Q).

That should explain it pretty well.

Actually, you might be better off checking this out:
http://mobile.jlaudio.com/support_pages.php?page_id=144

^ Great explanation of a P-EQ.


I'll be glad to explain any more if you need me to.

 

[evilkat]

Thanks for the links. I was looking at the last one, and it seems like you will be boosting a whole bunch of frequencies if u use this, which to me seems like precisely the opposite effect of what you're trying to achieve (mainly to correct a few specific freqs for the dips or extra gain). I will read up on the other links as well just to get a more thorough understand of this.

 

[ErinH]

Thanks for the links. I was looking at the last one, and it seems like you will be boosting a whole bunch of frequencies if u use this, which to me seems like precisely the opposite effect of what you're trying to achieve (mainly to correct a few specific freqs for the dips or extra gain). I will read up on the other links as well just to get a more thorough understand of this.

Right, but only if you set a wide Q. You can set a very narrow Q and effectively boost a small area along with the specific frequency. Play around with that active tutorial again and mess with the "Q" setting.