YPAO Subwoofer trim levels

[Jonathan Galea]

Hi, I need some assistance with YPAO trim levels. The issue is what my two subs. I have two monitor audio Gold W15 and I have a Yamaha processor CXA 5100 and both subs are placed at the front equal distance from each other.

I did this:
First I ran the leo (room optimistaion on the sub) on each sub as instructed in the manual and then I ran the nYPAO on the yamaha. What happened is that the YPAO auto calibration gave me +3db trim level on both the left and right sub.

I usually re-check the levels of all speakers through an spl meter (C weighted/ slow). While all the other speakers were very close (just some tweaking) when it comes to both subs I encountered a problem.
With the volume on the subs set at 0, and the sub level on the AVR set at +3db after YPAO calibration the SPL meter was marking far less than 70 db (in fact the pointer was on negative four).

With the left subwoofer (subwoofer 1) to get close to 75db on the spl meter I had to bump up the volume on the sub to +6 and I had to bump up the sub trim level on the AVR to +9.5dB (10 dB is the max)
With the right subwoofer (subwoofer 2) to get close to 75 db on the spl, I left the volume on the sub to 0 but had to bump up the subwoofer trim level on the AVR from +3 to +9 which is nearly the maximum.

I am very concerned with these types of settings, since it is always suggested to have the gain readings in the negative let alone on the maximum.
Why does I have to bump up the trim levels on the avr nearly up to max to get near the 75DB on the spl meter.
Since both subs are identical and located in front at exact distance from each other. Why does the left sub struggles more to reach the 75 db in fact I had to turn the volume on the sub to +6 while the other I left it to 0. Any suggestions would help since this is not right! Thanks in advance

 

[j_garcia]

Have you reviewed the various articles on AH about proper sub placement? To me, it sounds like your placement is causing cancellation, creating your issue. Placing them where you "think" they should go or where they look better isn't necessarily the right placement for best performance, especially when you have duals.

Subwoofer Placement - The Place for Bass Part 1

Where it comes to fine-tuning a home theater sound system for peak performance, finding those locations within a typical home listening space where a subwoofer can provide the most satisfying

www.audioholics.com

 

[ryanosaur]

I've heard decent things about the MA Gold Subs, at least in terms of them being near the performance level of many of the ID Subs available. While I have not ever experimented with them, I would almost urge you to dumb down, if possible, their native tuning program.
Most Subs would start at about 50% gain prior to running room correction, and then be adjusted down until each sub is producing around 73dB (in Audyssey). For final AVR Trim, the goal should be to have the Subs dialed in so that they are in the -7 - -10dB range, allowing you more headroom to operate with. Never should a Sub be the "quietest" Speaker in the room with a ) or positive Trim.

What J says above is spot on. Symmetrical placements on the front wall can be detrimental. In fact, I'm a big fan of asymmetrical placement for Subs, as well as a proponent of moving them off the front wall completely.

That said, if you have a rectangular shaped, closed room with a flat (not sloped) ceiling, using the Welti/Devantier approach can yield excellent results. But once you change the geometry of the room to something more complex, you need to search for the best performing locations. I also find that the Geddes approach to placing multiple Subs in a room is more useful in this instance.
The easiest way to do that is the Subwoofer Crawl:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiYgrLe6pfyAhUJ-WEKHat1BoQQtwJ6BAgFEAM&url=https%3A%2F%2Fwww.audioholics.com%2Fhome-theater-connection%2Fcrawling-for-bass-subwoofer-placement&usg=AOvVaw3wJ0Ci5b36b8FNek0UZ4jC

It is a crude, but supremely helpful technique. I was able to locate both good and horrible locations for LF Performance in my room by using this technique, alone, without falling back on micro managing my placements with REW and a measurement mic. When I have the opportunity and add more Subs, I will go that route. But for now, it's unnecessary.

Regardless, If you really want to quest for the best performance, I would suggest doing the crawl. Look for 2-3 spots where you get good SQ, and also pay attention to spots that naturally have poor performance. Keep your mind open!: you may find that the best spots aren't necessarily where you think they should be, but if performance is important to you, using those ;locations my be a boon.

 

[lovinthehd]

Are you using the avr's test tones for all the spl meter measurements? Or? How consistent is your placement of spl meter?

The gain on your subs could simply have been set too low for your avr's pre-out level, but not sure what the built in dsp could do to properly set level with the avr's output particularly without running the avr. Keep in mind you generally simply start with a suggested gain setting on the sub as there's such a wide variety of output levels on pre-amps as well as sub amp sensitivity levels....and it is indeed possible two subs of the same make may not have identical gain even with the same "number" on the controls showing (altho digital ones I'd hope would be more accurate and aligned than older just dial-type).

 

[Jonathan Galea]

Thanks for your input and advice. I set the subs this way. First I ran the Leo (sub room correction software) on both subs. Volume set to 0, phase to 0, eq to off and LEO to on. Than I ran ypao auto calibration. Afterwards I adjusted the speakers crossovers to 80 hz and checked the trim levels with an spl meter in the same location. While all other speakers were fairly accurate the subs (one at each time) were giving me around 65 db as I explained earlier. Regarding the monitor audio gold w15 they are very good subs and to be honest if i leave them as the avr set them they punch really hard but as I said on the spl meter it is only giving 65db at reference volume 0! So way foward:
1. Do crawl test for both subs
2. Try to put the volume up on the subs before ypao calibration to let say +5db if i understand this correctly.
3. I am finding it nearly impossible to manage to get 75db on the spl meter with the trim level on the negative since at the moment is on plus 10!!
If I misunderstood something kindly let me know.

 

[lovinthehd]

Crawl, and raise gains on your subs and re-run YPAO is a good start I think. Phase may need to be adjusted....do you have variable phase or only 0/180?

I don't know if Yamaha does another method of making up for the 10dB difference between mains and LFE content or something like that but don't think so....as its in the wrong direction for something like that. You are using the avr test tones?

 

[ryanosaur]

To be clear, you never want positive trim on the AVR. This means that the AVR is digitally augmenting the signal and is pretty much guaranteed to increase distortion.
You should only need to do the crawl once to identify some of the better performing spots in the room.

What is the gain range on your Subs? Is there any way to set them at 50% and see what SPL you get with just one sub playing a test tone?

 

[ryanosaur]

I just did a quick read on LEO... not a deep dive. I think you have two forms of room correction fighting each other. This is bad.
You want your LPF on the sub set to maximum or off, for example. You then want to keep phase at 0. If you can run YPAO without LEO involved in any way, I think you might have a different experience.

 

[lovinthehd]

I just did a quick read on LEO... not a deep dive. I think you have two forms of room correction fighting each other. This is bad.
You want your LPF on the sub set to maximum or off, for example. You then want to keep phase at 0. If you can run YPAO without LEO involved in any way, I think you might have a different experience.

Sometimes its preferable to have a way to eq/match the subs for integration by the avr, but no idea what LEO (I thought law enforcement officer myself) is either. Does YPAO handle differences in phase for two subs?

 

[ryanosaur]

I just did a quick read on LEO... not a deep dive. I think you have two forms of room correction fighting each other. This is bad.
You want your LPF on the sub set to maximum or off, for example. You then want to keep phase at 0. If you can run YPAO without LEO involved in any way, I think you might have a different experience.

@Jonathan Galea
Can you control the Sub without fully engaging LEO? This is what you should do. Phase can be set afterwards to maximize sound (though only in 90º increments). EQ can be applied separately, it looks like.
Allow YPAO to do the first round of correction. See what happens.
Perhaps run LEO after YPAO just for experimentation. See what happens.
If you note your manual settings, you should be able to return to them with no problem.

I just want to encourage you to experiment and not rely on what MA probably intended to be used with just a Stereo Receiver with no room correction. (Just a suspicion there, but it seems reasonable.

Sometimes its preferable to have a way to eq/match the subs for integration by the avr, but no idea what LEO (I thought law enforcement officer myself) is either. Does YPAO handle differences in phase for two subs?

I know very little about YPAO, but based on what he OP said and the manual, I think doubling up on LPF, for example, as well as fighting over SPL goals. To me, those should come first, then experiment with EQ and Phase on the Subs.

 

[lovinthehd]

@Jonathan Galea
Can you control the Sub without fully engaging LEO? This is what you should do. Phase can be set afterwards to maximize sound (though only in 90º increments). EQ can be applied separately, it looks like.
Allow YPAO to do the first round of correction. See what happens.
Perhaps run LEO after YPAO just for experimentation. See what happens.
If you not your manual settings, you should be able to return to them with no problem.

I just want to encourage you to experiment and not rely on what MA probably intended to be used with just a Stereo Receiver with no room correction. (Just a suspicion there, but it seems reasonable.


I know very little about YPAO, but based on what he OP said and the manual, I think doubling up on LPF, for example, as well as fighting over SPL goals. To me, those should come first, then experiment with EQ and Phase on the Subs.

I still try and do some basic sub setup outside of the eq when it comes to phase depending on positioning (particularly when not equidistant or co-located for much of their range), then check it later as well....it's gone both ways.

 

[ryanosaur]

I still try and do some basic sub setup outside of the eq when it comes to phase depending on positioning (particularly when not equidistant or co-located for much of their range), then check it later as well....it's gone both ways.

I can dig it… just uncertain about how adept our friend is thus far. he knew enough to recognize a problem! hopefully he’ll come back through with some more to share and we can help bring this home for him.

 

[Mark E. Long]

YPAO will set the sub eq’s automatically as well as phase I believe . If it was me I’d turn off the auto setup in the subs and raise the gain up and rerun the ypao. Iam not familiar with his subs but I agree he’s got two auto setups doing crazy things to his subs eq and levels . I recently upgraded my subs to SVS Pb 1000 pros and after setting them to what SVS recommended on gain I got no room to play with on sub levels it set them at 0 db I then turned the gain on the subs up 4 db on the subs and rerun ypao and got -6 on the auto setup which give me room to add a little boost if I needed it . His subs auto setup is definitely fighting the ypao I’d turn it off and raise the gain on the subs and go from there let ypao handle the auto setup and eq .

 

[Jonathan Galea]

Are you using the avr's test tones for all the spl meter measurements? Or? How consistent is your placement of spl meter?

The gain on your subs could simply have been set too low for your avr's pre-out level, but not sure what the built in dsp could do to properly set level with the avr's output particularly without running the avr. Keep in mind you generally simply start with a suggested gain setting on the sub as there's such a wide variety of output levels on pre-amps as well as sub amp sensitivity levels....and it is indeed possible two subs of the same make may not have identical gain even with the same "number" on the controls showing (altho digital ones I'd hope would be more accurate and aligned than older just dial-type).

YPAO will set the sub eq’s automatically as well as phase I believe . If it was me I’d turn off the auto setup in the subs and raise the gain up and rerun the ypao. Iam not familiar with his subs but I agree he’s got two auto setups doing crazy things to his subs eq and levels . I recently upgraded my subs to SVS Pb 1000 pros and after setting them to what SVS recommended on gain I got no room to play with on sub levels it set them at 0 db I then turned the gain on the subs up 4 db on the subs and rerun ypao and got -6 on the auto setup which give me room to add a little boost if I needed it . His subs auto setup is definitely fighting the ypao I’d turn it off and raise the gain on the subs and go from there let ypao handle the auto setup and eq .

Sorry for my lack of knowledge but when you say raise the gain on subs does it mean that i raise the volume on sub from 0 to example +5 before running ypao? The maximum on sub is +10!

 

[Jonathan Galea]

Crawl, and raise gains on your subs and re-run YPAO is a good start I think. Phase may need to be adjusted....do you have variable phase or only 0/180?

I don't know if Yamaha does another method of making up for the 10dB difference between mains and LFE content or something like that but don't think so....as its in the wrong direction for something like that. You are using the avr test tones?

Yes i am using the avr test tones. The spl meter that i am using has a frequency range from 30 hz upwards on C weighting could it be that it is not reading the low frequencies properly and thus the poor results since funnily enough to my ears they punch a lot in both movies and music.

 

[Mark E. Long]

Sorry for my lack of knowledge but when you say raise the gain on subs does it mean that i raise the volume on sub from 0 to example +5 before running ypao? The maximum on sub is +10!

I’d start with that and not run it’s auto setup you can always turn it up or down from there .

 

[Jonathan Galea]

In the coming days i will try to experiment a bit using your suggestions and will let you know the outcome perhaps I will manage to solve the issue.

 

[ryanosaur]

Yes i am using the avr test tones. The spl meter that i am using has a frequency range from 30 hz upwards on C weighting could it be that it is not reading the low frequencies properly and thus the poor results since funnily enough to my ears they punch a lot in both movies and music.

Correct, handheld SPL meters are better than phone apps, but the are still not great. Perhaps the OSHA approved ones for workplace safety are better, but I’m not going to spend that kind of coin!

 

[ryanosaur]

In the coming days i will try to experiment a bit using your suggestions and will let you know the outcome perhaps I will manage to solve the issue.

I think trying this without LEO in the way will be a big step toward solving the problem.
If you are open to moving the Subs to different locations, you may be surprised at what proper placement can add in the equation!

Please keep us posted!

 

[lovinthehd]

Sorry for my lack of knowledge but when you say raise the gain on subs does it mean that i raise the volume on sub from 0 to example +5 before running ypao? The maximum on sub is +10!

Yes the volume adjustment on the sub amp is a gain adjustment. The purpose of the gain adjustment is for the sub amp to be able to use all its power with the pre-out level provided by the pre-amp/avr (as they are not all equal nor are sub amps of the same sensitivity). It's a matter of getting max use out of the amp with the signal provided. Maybe this article can help https://www.audioholics.com/audio-amplifier/amplifier-voltage-gain