G3P Elevated BM & LFE Issue

[ttocs]

Here is a graphic which should help to understand better what is going on. It should also help to show what is responsible for providing BM, and/or LFE.
Attachment Deleted

[davidl81]

Jul 13, 2021 13:53:26 GMT -5 ttocs said:

Here is a graphic which should help to understand better what is going on. It should also help to show what is responsible for providing BM, and/or LFE.
View Attachment

10dB is huge! I’m surprised more people on here are not complaining about it as it seems pretty consistent with the G3 platform with the newer firmware.

[JKCashin]

Just reading this thread now, but have to say thanks to ttocs for testing and documenting this so thoroughly. Your work and the work of marcl have helped me remain sane!

Now I must go read...

[marcl]

Jul 13, 2021 15:47:21 GMT -5 davidl81 said:

Jul 13, 2021 13:53:26 GMT -5 ttocs said:

Here is a graphic which should help to understand better what is going on. It should also help to show what is responsible for providing BM, and/or LFE.
View Attachment

10dB is huge! I’m surprised more people on here are not complaining about it as it seems pretty consistent with the G3 platform with the newer firmware.

It was basically the same in 2.2, but not with 2.1.  2.1 only had the issue with Center Sub=LFE and Fronts=Large, then bass management goes to large fronts and it would be +3.  But few people do this.

A lot of people noticed something with the bass when 2.2 released but it wasn't as precisely characterized as ttocs has done now.

[ttocs]

Jul 13, 2021 15:47:21 GMT -5 davidl81 said:

Jul 13, 2021 13:53:26 GMT -5 ttocs said:

Here is a graphic which should help to understand better what is going on. It should also help to show what is responsible for providing BM, and/or LFE.
View Attachment

10dB is huge! I’m surprised more people on here are not complaining about it as it seems pretty consistent with the G3 platform with the newer firmware.

I just want to be sure which 10dB you are looking at. Across the board, LFE should be +10dB above the Front channels. And above the crossover the level for the Small channels are -10dB to the LFE, so this is all perfect.

The problem is that the BM is +3dB for most configurations in my system, and gets really whacky when the Fronts Large are used for the BM.

If the ENTIRE group of channels were to float up and down together but with the proper orientation, which is all sound at baseline and LFE at +10dB, then it would just be like the volume increasing and decreasing. But no, it's mainly Bass Management that is too high and gets worse when the Fronts channels are setup as Large and the only subwoofer channel is the Center setup as LFE which will cause the BM to be sent to the Large Fronts because there is no subwoofer for BM in a system setup like this. When I level the Large Fronts down, the BM is then raised +4.5dB above the Fronts due to summing.

Unfortunately, I'm not going to have the time to test a bunch of sound fields this week, but will early next week. I'll probably test some of the setups I know will cause more of an issue and post tomorrow night or Thursday.

[JKCashin]

SO... maybe I missed it.. but if I set ALL my speakers to small, and use BM, will this still happen? That is, will there still be elevated bass going to my speakers, or will it be properly crossed-over to the subs?

[JKCashin]

And.. what if I have All speakers set to small, except the front L+R set to large, and NO subs?

I'm willing to test this myself if there is some set of instructions....

[muslhead]

Thank god someone was kind enough to direct me to this. I have been pulling my hair out measuring and remeasuring with nothing working to fix the problem.
I thought it was me. I find the excessive bass in my 2.2 setup more so than my 5.2. Music is bloated but the additional boost in the low end during movies can hide themselves much easier.
I am concerned this boost will blow my front speakers out now. So my only solution is to turn down the volume?
I am going to watch this thread closely as i am very interested and appreciative of all the work that is being done.
IF there is some way i can help or contribute please let me know.
I have REW and can do some measuring if needed. While, i am not quite as proficient as most (just got it) The only way to get better is practice.
Thanks for everyone's efforts (excluding emo, of course).

[marcl]

Jul 13, 2021 16:09:30 GMT -5 JKCashin said:

SO... maybe I missed it.. but if I set ALL my speakers to small, and use BM, will this still happen? That is, will there still be elevated bass going to my speakers, or will it be properly crossed-over to the subs?

If you set all speakers to small the only place the bass can go is to subs.  If you do that, the small speaker bass will be elevated as ttocs shows in his graphic.  

[marcl]

Jul 13, 2021 16:13:09 GMT -5 JKCashin said:

And.. what if I have All speakers set to small, except the front L+R set to large, and NO subs?

I'm willing to test this myself if there is some set of instructions....

That is the worst case scenario.  The bass sent to the fronts from the small speakers will be +8db at least.  LFE will be sent to fronts also and will be only 1-2db higher than the small speaker bass.

Note;  ttocs and I see slightly different numbers but the basic magnitude is the same.  I'm testing with Dirac enables with flat target curves; ttocs is testing with a User slot and no EQ.

[ttocs]

Jul 13, 2021 16:09:30 GMT -5 JKCashin said:

SO... maybe I missed it.. but if I set ALL my speakers to small, and use BM, will this still happen? That is, will there still be elevated bass going to my speakers, or will it be properly crossed-over to the subs?

Look at #1 in the graphics. The bass will be elevated below the XO.

[ttocs]

Jul 13, 2021 16:13:09 GMT -5 JKCashin said:

And.. what if I have All speakers set to small, except the front L+R set to large, and NO subs?

I'm willing to test this myself if there is some set of instructions....

Look at #9. 

The BM will be sent to the Large Fronts and be even more elevated due to summing. Plus, with no subs the Large Fronts will be sent the LFE.

Setting the Center Sub for LFE will have no effect on the level of BM no matter where the BM is sent.

[JKCashin]

Jul 13, 2021 16:14:40 GMT -5 marcl said:

Jul 13, 2021 16:09:30 GMT -5 JKCashin said:

SO... maybe I missed it.. but if I set ALL my speakers to small, and use BM, will this still happen? That is, will there still be elevated bass going to my speakers, or will it be properly crossed-over to the subs?

If you set all speakers to small the only place the bass can go is to subs.  If you do that, the small speaker bass will be elevated as ttocs shows in his graphic.  

Uggh.... not what I wanted to hear
But you're the messenger.... so I will forgive you

[ttocs]

Jul 13, 2021 16:16:57 GMT -5 marcl said:

Jul 13, 2021 16:13:09 GMT -5 JKCashin said:

And.. what if I have All speakers set to small, except the front L+R set to large, and NO subs?

I'm willing to test this myself if there is some set of instructions....

That is the worst case scenario.  The bass sent to the fronts from the small speakers will be +8db at least.  LFE will be sent to fronts also and will be only 1-2db higher than the small speaker bass.

Note;  ttocs and I see slightly different numbers but the basic magnitude is the same.  I'm testing with Dirac enables with flat target curves; ttocs is testing with a User slot and no EQ.

The reason the results posted - so far - show minimal elevation of BM to the Large Fronts is that I'm only using the USER EQ and most of the testing is with simple Levels of the channels with no "fine tuning" to make the levels of the errant channels fall in line.

Next week I'll be posting other combinations which will alter what is evident so far in this thread.

[JKCashin]

So... what's the "safest" arrangement then? I'm now worried about sending too much energy to my small speakers.

(I have three subs, currently disconnected)

[JKCashin]

And thanks gents for investigating this.

[marcl]

Jul 13, 2021 16:24:34 GMT -5 JKCashin said:

So... what's the "safest" arrangement then? I'm now worried about sending too much energy to my small speakers.

(I have three subs, currently disconnected)

ttocs check my math 

If you have three subs, set center sub=LFE, L/R subs Dual Mono, then go to the level controls on the L/R subs and lower them about 5db.   In any case your small speakers are safe, set to small.

[ttocs]

Jul 13, 2021 16:24:34 GMT -5 JKCashin said:

So... what's the "safest" arrangement then? I'm now worried about sending too much energy to my small speakers.

(I have three subs, currently disconnected)

#1 and #3 are simple single sub channel configs and have the least possible rise in elevated BM, but there is no adjustment you could make to alter the offset between BM and LFE levels, none.

#4 would give you more adjustability by using one sub channel for BM and the other for LFE. This gives the user the ability to adjust the Mono Sub for BM down the correct amount, and if needed, adjust the LFE level, and both are independent of the speaker levels above the crossover. This requires the use of REW to measure and adjust per the measurements, which is how I set my channel levels.

BUT! This adjustability will not SOLVE the problem entirely. It will only solve the issue for the measured sound field. The sound field I've used so far in this thread is SURROUND. Things change with different sound fields.

[ttocs]

Jul 13, 2021 16:28:17 GMT -5 marcl said:

Jul 13, 2021 16:24:34 GMT -5 JKCashin said:

So... what's the "safest" arrangement then? I'm now worried about sending too much energy to my small speakers.

(I have three subs, currently disconnected)

ttocs check my math 

If you have three subs, set center sub=LFE, L/R subs Dual Mono, then go to the level controls on the L/R subs and lower them about 5db.   In any case your small speakers are safe, set to small.

Yuuup. I just said kind of the same thing but with more words because I don't know when to quit.

[jbrunwa]

IMHO, having previously managed software development, what ttocs has done is representative of testing that should be done when developing software, enumerating through all the bass management options.