Need rear speaker help

J-dubb16 · 12-27-06, 12:23 PM

My situation is that I have just finished my HT room. My rear speakers in the 7.1 set-up are located per THX recommendation, not Dolby's. They are about 24" apart on the center of the rear wall. It will be very difficult, expensive and time consumming to move them.

While in the front row, I can barely tell they are there, mainly due to "rear-to-front sound reversal". In the rear seats they sound much better. Is there anything I can do electronically to help the situation? Change delays or volume level slightly so the sound reveresal does not occur?

The speakers are M&K in-walls that match the rest of the system.

Please help me if it is possible.

Thanks

J-dubb16 · 12-28-06, 04:37 PM

Is this problem that bad that there is no solution beside moving the speakers. I was hoping one of the gurus here would a have a little trick I could use to help alleviate the issue.

trekguy · 12-28-06, 07:48 PM

Assuming that everything was balanced useing your AVR auto setup w/mic or by you with an SPL meter, did you try raising the rear surround volume slightly?

Out of curiosity is it equally a problem in all surround modes?

J-dubb16 · 12-29-06, 08:17 AM

I have a Denon 3806 so I completed the Audessey calibration. I then raised the rear levels about 0.8 db. I notice in mainly in my movie mode which is set-up as DD+ or TruHD. For sports I use 7.1 logic surround processing, so I don't notice it.

Any ideas?

trekguy · 12-29-06, 01:21 PM

I have no experience with True HD so all I can do is note that .8dB is not a big change. Detectable with pink noise maybe, but not huge. I would try a larger boost of up to 3dB (a change that most can easily hear).

Perhaps someone else can jump in.

J-dubb16 · 12-29-06, 06:02 PM

I will try that, I was just worried about the back row in which you can tell the speakers are behind you ( because you are coler to them). I do not want to blast them out with rear signals that are too loud.

I will try boosting the rears about 2-4db to see if that works.

Any other suggestions.

Thanks trekguy.

louthewiz · 12-30-06, 02:12 AM

When you ran the auto setup did you run it from the center of the room or from the main listening possition ?
Because to me it sounds like you setup from the center of the room when the ideal place is the "Sweet spot' in the center of the room but in the first row if you have several rows of seating.
And finally get an spl meter to balance everything properly, Here are some links.
http://www.audiophilia.com/hardware/spl.htm
And here is the meter:
http://www.bswusa.com/proditem.asp?item=SLM100

Brian27 · 01-01-07, 04:30 PM

Well, sorry to tell you but I also have the 3806 and unfortunately it is not thx select2 or ultra2 certified so it doesn't have the thx ASA(advanced speaker array). You should have done it by dolby recommends it. In the manual for the 3806 it shows you how you should place them and it is just like dolby does it so I hate to tell you this but you should spread those rear speakers out....alot more work

since they are in-wall but thats what you should do. You could leave them where they are and buy a THX select2 or ultra2 receiver but of course that is more expensive unless you can return the denon etc...

ps...what surround mode do you use for sports on the denon? you said 7.1 logic but what is the actual surround mode called since denon doesn't have a logic7 surround mode?, 7 channel stereo? You shouldn't use the dsp modes that much in my opinion and should stick with the dolby digital+prologic2x for more accurate sound.

take care,
Brian

12-27-06, 12:23 PM	#1 \| Link	<a href='http://rev.avsforum.com/phpAdsNew/adclick.php?n=a4ac4393' target='_blank'><img src='http://rev.avsforum.com/phpAdsNew/adview.php?what=zone:30&n=a4ac4393' border='0' alt=''></a>
J-dubb16 Advanced Member Join Date: Oct 2001 Location: Virginia Beach, Va, USA Posts: 735	Need rear speaker help My situation is that I have just finished my HT room. My rear speakers in the 7.1 set-up are located per THX recommendation, not Dolby's. They are about 24" apart on the center of the rear wall. It will be very difficult, expensive and time consumming to move them. While in the front row, I can barely tell they are there, mainly due to "rear-to-front sound reversal". In the rear seats they sound much better. Is there anything I can do electronically to help the situation? Change delays or volume level slightly so the sound reveresal does not occur? The speakers are M&K in-walls that match the rest of the system. Please help me if it is possible. Thanks __________________ J-dubb HT Photos HT Construction Thread

12-28-06, 04:37 PM	#2 \| Link
J-dubb16 Advanced Member Join Date: Oct 2001 Location: Virginia Beach, Va, USA Posts: 735	Is this problem that bad that there is no solution beside moving the speakers. I was hoping one of the gurus here would a have a little trick I could use to help alleviate the issue. __________________ J-dubb HT Photos HT Construction Thread

12-28-06, 07:48 PM	#3 \| Link
trekguy AVS Special Member Join Date: Nov 2005 Location: Near Mt Diablo--SF Bay Area Posts: 2,132	Assuming that everything was balanced useing your AVR auto setup w/mic or by you with an SPL meter, did you try raising the rear surround volume slightly? Out of curiosity is it equally a problem in all surround modes? __________________ The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd. -Bertrand Russell

12-29-06, 08:17 AM	#4 \| Link
J-dubb16 Advanced Member Join Date: Oct 2001 Location: Virginia Beach, Va, USA Posts: 735	I have a Denon 3806 so I completed the Audessey calibration. I then raised the rear levels about 0.8 db. I notice in mainly in my movie mode which is set-up as DD+ or TruHD. For sports I use 7.1 logic surround processing, so I don't notice it. Any ideas? __________________ J-dubb HT Photos HT Construction Thread

12-29-06, 01:21 PM	#5 \| Link	<a href='http://rev.avsforum.com/phpAdsNew/adclick.php?n=a591f81a' target='_blank'><img src='http://rev.avsforum.com/phpAdsNew/adview.php?what=zone:36&n=a591f81a' border='0' alt=''></a>
trekguy AVS Special Member Join Date: Nov 2005 Location: Near Mt Diablo--SF Bay Area Posts: 2,132	I have no experience with True HD so all I can do is note that .8dB is not a big change. Detectable with pink noise maybe, but not huge. I would try a larger boost of up to 3dB (a change that most can easily hear). Perhaps someone else can jump in. __________________ The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd. -Bertrand Russell

12-29-06, 06:02 PM	#6 \| Link
J-dubb16 Advanced Member Join Date: Oct 2001 Location: Virginia Beach, Va, USA Posts: 735	I will try that, I was just worried about the back row in which you can tell the speakers are behind you ( because you are coler to them). I do not want to blast them out with rear signals that are too loud. I will try boosting the rears about 2-4db to see if that works. Any other suggestions. Thanks trekguy. __________________ J-dubb HT Photos HT Construction Thread

01-01-07, 04:30 PM	#8 \| Link
Brian27 Advanced Member Join Date: May 2005 Location: Northern Virginia Posts: 566	Well, sorry to tell you but I also have the 3806 and unfortunately it is not thx select2 or ultra2 certified so it doesn't have the thx ASA(advanced speaker array). You should have done it by dolby recommends it. In the manual for the 3806 it shows you how you should place them and it is just like dolby does it so I hate to tell you this but you should spread those rear speakers out....alot more work since they are in-wall but thats what you should do. You could leave them where they are and buy a THX select2 or ultra2 receiver but of course that is more expensive unless you can return the denon etc... ps...what surround mode do you use for sports on the denon? you said 7.1 logic but what is the actual surround mode called since denon doesn't have a logic7 surround mode?, 7 channel stereo? You shouldn't use the dsp modes that much in my opinion and should stick with the dolby digital+prologic2x for more accurate sound. take care, Brian Last edited by Brian27; 01-01-07 at 04:46 PM..