Positioning of Left and Right Surrounds

[EscapeV3locity]

Hey all,

I have the following 2 issues:

1. I've done some light research on the positioning of Left and Right surround speakers. The Dolby setup guide allows for 90 - 110 degees. Most people suggest not to go with 90 degrees with my bookshelf speakers on a 22" pedestal, due to direct sound waves may sound harsher to the ear. I have mine at 60 degrees which seem to "violate" the Dolby setup guide. I'm I loosing out on any experience by not having these speakers according to Dolby setup guide? - Resolved
2. After MultEQ32 calibration via the Audyssey app. the center channel level is set to -7.5 dB. Pink noise through this center channel during test is indistinguishable in sound volume from L and R. During content playback after calibration the dialogue on most content is very low volume. I had to adjust the center level to +0.5. I have confirmed that the jumpers are on both posts. I have also taken a calibrated UMIK-1 mic. and ran the Test Tone after calibration and measured SPL. The SPL was lower for the Center channel vs. L and R by 2 bD(Z). I then proceeded to make the adjust for the center channel from -7.5 dB to -4.0 dB. At -4.0dB the pink noise volume again was indistinguishable in volume from L and R and most importantly the SPL meter measured LCR at the same bD(z) levels. Even at -4.0dB however dialogue from content was difficult to hear for both my wife and myself. I proceeded to adjust until we both were satisfied and ended up at +0.5 dB level for the center. My speaker is below the projector screen at about chest height which is not ideal, I'm suspecting it could be because of this speaker placement, but cannot be 100% certain. - Opened

Here are specs. of my setup:

• 7.2.4
• Processor: Marantz AV7706
• Floor Speaker Amplifier: Monolith 7x
• Atmos Speaker Amplifier: Outlaw 5x
• Front Left and Right Speaker: Prestige 85F
• Center: Prestiege 55C
• Surround Left/RIght: Prestiege 15B
• Atmos: Paradigm Pro-R 8"
• SVS PB-3000

Location	Distance (ft)	Level (dB)
Font L	9.9	-8.0
Front R	10.2	-8.0
Center	9.9	-7.5
Surround L	5.6	-7.5
Surround R	5.9	-7.5
Surround Back L	6.8	-4.5
Surround Back R	6.9	-5.5
Top Front L	7.6	-8.0
Top Front R	6.4	-8.5
Top Rear L	8.4	-8.5
Top Rear R	7.4	-8.5
Subwoofer 1	12.5	-7.5
Subwoofer 2	13.5	-4.5

PS. I calibrated/tuned the system using MultEQ32. I don't have any treatments in the root yet, which will soon be another thread.

 

[ryanosaur]

In a 5.x.x setup, the surrounds are meant to give you the side and rear info as objects pan through the space. Having them in front of you would cut that effect off.
In the end… it is your system and your ears.
If you haven’t tried to set it up properly, you should. I find that trying to match the recommended setup as close as possible is rewarding.
That said, there are always limitations we have to adapt to. I get it. I have them too! (My Rears are mounted up over a closet on the back wall instead of down just above ear level, which is the recommendation.)

I would urge you, again, to try setting up more properly, if you can.

 

[William Lemmerhirt]

Hey all,

I've done some light research on the positioning of Left and Right surround speakers. The Dolby setup guide allows for 90 - 110 degees. Most people suggest not to go with 90 degrees with my bookshelf speakers on a 22" pedestal, due to direct sound waves may sound harsher to the ear.

I have mine at 60 degrees which seem to "violate" the Dolby setup guide. I'm I loosing out on any experience by not having these speakers according to Dolby setup guide?

Here are specs. of my setup:

• 7.2.4
• Processor: Marantz AV7706
• Floor Speaker Amplifier: Monolith 7x
• Atmos Speaker Amplifier: Outlaw 5x
• Front Left and Right Speaker: Prestige 85F
• Center: Prestiege 55C
• Surround Left/RIght: Prestiege 15B
• Atmos: Paradigm Pro-R 8"
• SVS PB-3000

PS. I calibrated/tuned the system using MultEQ32. I don't have any treatments in the root yet, which will soon be another thread.

Your note says 7.2.4 so I’m not sure which you have. It looks like 5.1.2. Still not sure what you’ve got.
If this is where your surrounds are, then yes. You are missing out on a LOT. That’s where you might place a front wide speaker, or even mains actually.

Curious why you chose that spot.
In a 7.x.x you CAN place sides at 80° to good effect as the separation from the rears is good and it can fill in between the mains and sides, but I don’t think your room will support that without distraction. So 95°-105° would be what I’d try for. Especially after looking at the seats.
The room looks to have potential so I would definitely get those in a better spot.
Again, why there?

 

[Trebdp83]

Perhaps surround speakers placement was confused with atmos speakers placement when looking at a 7.1.4 speaker setup?

 

[EscapeV3locity]

I made the adjustment and the speaker is now sitting 90 degrees to center seat. After re-running the mic. setup on my AV7706 and making the necessary adjustments through the Audyssey app. I gave the system a test. My first impression is that I'm more pleased with the surround sound from both left and right speakers. I can pick out sound that is coming from those speakers more precisely and match to the video content on the screen. I used Avengers End Game's final battle sequence as the test.

Now that this issue is resolved, I have a 2nd issue which I'll document in my another thread. It has to do with very low center channel sound making majority of the dialogue impossible to hear. I had to boost the center channel almost 12 db, which is significant. I though the reason for this could be because my room is not acoustically treated, however the center channel volume is soo low I doubt its because of that.

 

[ryanosaur]

I had to boost the center channel almost 12 db, which is significant

!!!!!


This is a recipe for blowing some equipment!

 

[Trebdp83]

Reminds me of another thread around here recently. Check the wiring on that center channel speaker.

 

[EscapeV3locity]

This is a recipe for blowing some equipment!

The pink noise test which I belive runs at 75 db sounds to have the same SPL from LCR. I'm thinking about using a UMIK (pre-calibrated) MIC to check if indeed the SPL is the same. However after calibration all LCRs are dialed -12DB by the processor. When I playback content the dialogue almost cannot be heard and I have to boost just the center +12 DB.

 

[EscapeV3locity]

Check the wiring on that center channel speaker.

That was the first thing I checked and its good. Even the pink noise test confirms the LCR sound equivalent, the issue is content when played back as weak center channel playback.

 

[Trebdp83]

Jumpers in place?

 

[William Lemmerhirt]

The pink noise test which I belive runs at 75 db sounds to have the same SPL from LCR. I'm thinking about using a UMIK (pre-calibrated) MIC to check if indeed the SPL is the same. However after calibration all LCRs are dialed -12DB by the processor. When I playback content the dialogue almost cannot be heard and I have to boost just the center +12 DB.

Wow. That’s really odd. I don’t think those speakers are sensitive enough for the AVR to trim to -12. That’s bottomed out. Seems like the gain on the amp is too high.

 

[EscapeV3locity]

I ran the test again a 2nd time, but this time I ran with all 8 positions and here is the LCR results:

Location	Distance (ft)	Level (dB)
Font L	9.9	-8.0
Front R	10.2	-8.0
Center	9.9	-7.5
Surround L	5.6	-7.5
Surround R	5.9	-7.5
Surround Back L	6.8	-4.5
Surround Back R	6.9	-5.5
Top Front L	7.6	-8.0
Top Front R	6.4	-8.5
Top Rear L	8.4	-8.5
Top Rear R	7.4	-8.5
Subwoofer 1	12.5	-7.5
Subwoofer 2	13.5	-4.5

 

[ryanosaur]

The pink noise test which I belive runs at 75 db sounds to have the same SPL from LCR. I'm thinking about using a UMIK (pre-calibrated) MIC to check if indeed the SPL is the same. However after calibration all LCRs are dialed -12DB by the processor. When I playback content the dialogue almost cannot be heard and I have to boost just the center +12 DB.

I'm not going to presume to know what is wrong, but having a +12 dB boost to a single channel means you are digitally boosting that signal which is almost guaranteed to introduce distortions. Likewise, if you were to clip the Amp with that much extra juice going to the speaker... well, this is why I say it's a recipe for blowing something. Every 3dB of boost to SPL requires a doubling of power. That you have effectively a 24dB swing is highly concerning.
All of these speakers are on the Monolith Amp?
Have you tried changing Amp channels? Interconnect Cable?
Anything in the signal chain that could possibly be causing the signal to attenuate so dramatically? (Even a speaker wire that could have gone bad due to overbending? (Just spitballing, here. )

 

[ryanosaur]

I ran the test again a 2nd time, but this time I ran with all 8 positions and here is the LCR results:

Location	Distance (ft)	Level (dB)
Font L	9.9	-8.0
Front R	10.2	-8.0
Center	9.9	-7.5

Those numbers look completely reasonable.
What are the rest of the channels set to, please?

 

[EscapeV3locity]

All of these speakers are on the Monolith Amp?
Have you tried changing Amp channels? Interconnect Cable?
Anything in the signal chain that could possibly be causing the signal to attenuate so dramatically?

These are all valid points, however consider that the pink noise test produces sound from LCR that is equivalent in volume to my ears. The issue is not the pink test, its really the content that I playback. When playing content the Center channel produces dialogue that almost cannot be heard. The only way to hear dialogue is to boost the center channel. I could boost it only +6 dB and this will be sufficient, but I find that the detailed sounds the speaker produces only come out when boosting by +12 dB.

 

[EscapeV3locity]

What are the rest of the channels set to, please?

I updated the original table, have a look.

 

[EscapeV3locity]

I currently have the Center at 1.0 dB so the delta is large vs. the L and R, but to me it sounds better, maybe my ears can't pickup dialogue as well as they use too.

During movies like Endgame I am seeing an SPL of up to 105 bD(Z) during the last fight scene but generally doesn't go over high 90s. I wonder if that is too high and may cause long term damage to my ears .

 

[lovinthehd]

I made the adjustment and the speaker is now sitting 90 degrees to center seat. After re-running the mic. setup on my AV7706 and making the necessary adjustments through the Audyssey app. I gave the system a test. My first impression is that I'm more pleased with the surround sound from both left and right speakers. I can pick out sound that is coming from those speakers more precisely and match to the video content on the screen. I used Avengers End Game's final battle sequence as the test.

Now that this issue is resolved, I have a 2nd issue which I'll document in my another thread. It has to do with very low center channel sound making majority of the dialogue impossible to hear. I had to boost the center channel almost 12 db, which is significant. I though the reason for this could be because my room is not acoustically treated, however the center channel volume is soo low I doubt its because of that.

By low center you mean maybe poorly positioned low to the floor rather than relevant to ear height or something? 12dB boost is nuts with a decent calibration for levels/delays at your MLP, tho....need more details. We did have someone who didn't have the jumpers connected so essentially had only part of the speaker working. Confirmation of connection and how you set up all levels/delays initially might help along with sensitivity of center vs other speakers....

 

[EscapeV3locity]

Thanks for the tips, I updated the original thread to discuss center channel position as well now.

I had my wife also watch some content with me and we both ended up liking a +0.5 dB level for the center channel so this is a delta of 8.0 dB from the original calibration which is still significant. I included some pics. of the speaker showing that the jumpers are connected to the post and I ensured both post a tightened and making good contact with the jumpers. In addition, I included pics. of the center channel height which is at chest level vs. the ideal ear level. The height of the speaker could be introducing sub-optimal performance but not sure if it merits a 8.0 dB adjustment as I'm not a sound engineer, only know physics of sound from by grade 13 class (I'm old and we use to have 13 grades in Ontario back in Highschool).

 

[Trebdp83]

That is a nice, clean room. I like it.