# Can I still use my receivers PEQ for the mains and surrounds?



## lovingdvd (Jan 23, 2007)

My Yamaha RX-V1400 has a pretty good parametric equalizer built in (YPAO). However it does not do any equalizing for the sub or very low frequencies, hence I am using REW and BFD for this.

I will not be doing anything with the mains/surrounds as far as REW and BFD is concerned. So my plan is to continue to use the YPAO for the mains/surrounds, and use REW/BFD for the sub EQ.

However the YPAO does make adjustments in the 60hz range for the mains. For instance after it runs it gives a report and I've seen it add dB at the 63hz level.

One important thing to note is that I cannot edit or manually override any of the YPAO data. 

The main concern I have is that in the future I may need to rerun YPAO for my fronts/surrounds, and it could very easily change some of the levels in the 60-100hz range (as well as higher) that could then mess up my beautifully calibrated sub that had been done based on a prior YPAO measurement.

Yet at the same time, I don't want to disable the YPAO because then I'll have no EQ for the upper (above 80hz; i.e. above the sub) end at all. The receiver does have a built-in graphic equalizer that can be used instead of the PEQ but I wouldn't want to go that route because I I have no way to take measurements above what the Radio Shack meter can reliably give.

So what do you guys recommend for this situation? Thanks!


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## Wayne A. Pflughaupt (Apr 13, 2006)

I assume this is one of the Yamahas that doesn’t let you go in and tinker with the YPAO settings after the fact?



> The main concern I have is that in the future I may need to rerun YPAO for my fronts/surrounds, and it could very easily change some of the levels in the 60-100hz range (as well as higher) that could then mess up my beautifully calibrated sub that had been done based on a prior YPAO measurement.


 Since you said the YPAO won’t EQ the sub, it won’t do anything to your sub’s response. What it _could_ do, however, is mess with _overall_ response by adding boost to the mains at 63 Hz. However, even that’s doubtful; because of the crossover, 63 Hz will be down several dB (assuming a 90 Hz crossover frequency). Not to mention, the sub itself will be hotter than the mains, so anything YPAO does to the mains at 63 Hz will be overwhelmed by the sub and rendered moot.

If your combined chart show that response at 63 Hz is altered, what you might do is disconnect the sub from the system, and connect a CD player directly to it. Play a 63 Hz sine wave tone while YPAO is doing its evaluating, to “fool” it into thinking there is too much energy there. Then it would do a cut to the mains.

Regards,
Wayne


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## Malice (May 1, 2006)

I've been following lovingdvd's posts as I have recently moved my sub and need to re-EQ with the BFD. The questions and points that lovingdvd has come up with over several threads mirror some of my own views.

Although my Denon has PEQ on the mains only and it will not EQ the sub, the amp nonetheless will "test" the sub for its response. As I get different results whether I have the sub switched on or off, one can only assume that the sub's response plays a part in the PEQ on the mains where there is an overlap of frequency production.

Although the PEQ can be turned off, there is no doubt that PEQ does enhance the upper frequency response in my room.

So, does one PEQ before or after BFD, and with or without the sub either (a) physically turned on or not, or (b) turn off the sub in the DSP to get a full FR across the mains which then will be PEQ'd to its optimum level without a sub? In theory then if you add a EQ'd sub which is flat, switch on the sub in the speaker config and set the crossover on the amp, the final outcome should be flat.

I have found that with in-room reinforcement of lower frequencies up to two octaves below the XO, the interaction of mains and sub has been unpredictable to say the least. If I can some how get a flat response from the mains on their own, and the sub on its own, then when a XO is applied I should be nearer the mark and with PEQ on the mains in tact for the upper frequencies.

What I may do is document my progress as I redo my EQ and show the different responses for each element and what happened at each stage along the way.

Bob


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## lovingdvd (Jan 23, 2007)

Bob - with hindsight, here's the bottom line advice I'd give anyone looking to get straight to the bottom of things (those looking to get setup quickly and not fully understand how their various pieces affect the overall picture - but just want to get to the results quickly).

1) Definitely do your PEQ before getting started.

2) Turn off the sub and measure your mains and look at the target as Bass Limited (i.e. mains only). Make sure that the mains seem to be following the curve (low dB on the low end, rising until near flat at the cross over point).

3) If based on #2 you seem to be getting way more bass than you should, turn OFF any of your receiver's enhanced modes. Boy this threw me for a major loop - at least a few days of confusion. I was running my receiver in "Adventure" mode and it was boosting 30-45hz and 60-80hz above 75dB even thought my crossover was 80hz!!. Once I set the receiver to "Straight" (as in don't do any processing to it) it followed the expected curve much better. This was the breakthru I needed to tune my sub as desired.

4) Set a house curve. I went with +8dB at 20 to 0dB at 80hz.

5) Turn the sub on. Set the target to Full Range. Then measure with both sub and main on. Do not bother measuring the sub alone unless you want the full educational value of the exercise. I spent a lot of time measuring and tuning the sub alone, only to find that it was irrelevant because everything changed once I added the mains and I had to start over with the EQ anyway.

6) Use the sub's volume knob to turn the sub up to the point (within reason) where the lowest dip is at its target level. Then use the Find Peaks and equalizing filters. I also use the "smooth to 1/3 octave" feature in the Graph menu as it makes it easier to focus on the dips and peaks that matter most.

7) Play with the filters until you get things where you want, remeasuring and adjusting through the process.

8) Plays some movies or music (depending on what you're most interested in listening to the sub with) with deep heavy bass. Play with the level on the sub control to find the point where you feel you have the right "presence" for the sub.

9) Enjoy! I most certainly am!! Not only is the bass nice and tight, but it produces a very pleasing "harmonic" if you will as the bass from the sub blends very well with the bass from the mains. For instance there was a scene last night that has a lot of background steady bass (as a mood setter) probably around the 40-55hz range. The room filled up with this bass very nicely and evenly. It was the prefect blend between the mains doing its job, the sub doing its job, and everything working in harmony - both literally and figuratively! The addition of my new sub with great EQ has really transformed my room.


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## Malice (May 1, 2006)

Cheers for the advice!




> 1) Definitely do your PEQ before getting started.


So the mains get (P)EQ'd below the XO with an untamed sub in the equation?




> 2) Turn off the sub and measure your mains and look at the target as Bass Limited (i.e. mains only). Make sure that the mains seem to be following the curve (low dB on the low end, rising until near flat at the cross over point).


My mains appears to be being boosted by my room from about 50Hz and below. My main speakers are producing sound at 25Hz about 15db above the target!



> 3) If based on #2 you seem to be getting way more bass than you should, turn OFF any of your receiver's enhanced modes.


I have been using "plain" stereo mode which is apparently the best I can do to get the XO working with no additional processing



> 4) Set a house curve. I went with +8dB at 20 to 0dB at 80hz.


As I get a lot of grief from "she who must be obeyed" on the LF propagation in the rest of the house, I'll probably aim for a flat liner.




> 5) Turn the sub on. Set the target to Full Range. Then measure with both sub and main on. Do not bother measuring the sub alone unless you want the full educational value of the exercise. I spent a lot of time measuring and tuning the sub alone, only to find that it was irrelevant because everything changed once I added the mains and I had to start over with the EQ anyway.


Haha, that's why you PEQ's in step one presumably with the sub in place!


> 6) Use the sub's volume knob to turn the sub up to the point (within reason) where the lowest dip is at its target level.


My Denon's PEQ runs through a target level of 75db on the test tones. What target level did you shoot for?


:T 

Bob.


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## lovingdvd (Jan 23, 2007)

Malice said:


> Cheers for the advice!
> 
> 
> 
> So the mains get (P)EQ'd below the XO with an untamed sub in the equation?


It added a few dB at 63hz but that was as low as the PEQ goes.



> My mains appears to be being boosted by my room from about 50Hz and below. My main speakers are producing sound at 25Hz about 15db above the target!


Then your receiver is most likely adding this bass boost. This makes it very difficult for dealing with. The idea of course is that you want your sub to be producing the sound at 25hz. If you're fronts are producing a lot at 25hz you'll have to have your sub produce less. So you have the mains producing freqs designed for the sub.



> As I get a lot of grief from "she who must be obeyed" on the LF propagation in the rest of the house, I'll probably aim for a flat liner.


Personally I think you will be bored to tears with a flat response. Before I tried this I had read what others said - that it was rather dull. "Rather dull" is putting it mildly. In my case it sounded flat and didn't give much presence. What you may want to do instead is use the house curve, but keep the sub volume dialed down to compensate a bit.

Bottom line is to try it both ways. There is no right or wrong way, so just experiment and go with what sounds best and keeps the Mrs. happy.



> Haha, that's why you PEQ's in step one presumably with the sub in place!


No the receiver doesn't factor the sub into the PEQ.



> My Denon's PEQ runs through a target level of 75db on the test tones. What target level did you shoot for?


I did 75db with the house curve I mentioned earlier. This means that my 20hz was up around 83hz. None of this matters in the end though because once its all dialed in you can turn the sub volume up or down, yet what matters most is that the relative dB levels throughout the house curve will remain the same. i.e. if the sub sounds too over bearing I can turn the sub down 5dB and then 20hz is 78dB and 80hz is 70dB...

:T 

Bob.[/QUOTE]


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## Malice (May 1, 2006)

> It added a few dB at 63hz but that was as low as the PEQ goes.


In my first attempts at PEQ'ing without a sub, and moving speakers around to get the best overall response, my PEQ was even putting in adjustments at 37Hz.



> No the receiver doesn't factor the sub into the PEQ.


As I got different PEQ suggestions below the XO frequency with and without the sub switched on, and although the PEQ does not touch the sub channel at all, it appears to make an attempt to adjust the mains frequencies below the XO in order to offset the sub's output, which it does measure in the autosetup even though it doesn;t EQ it.


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