Surround Sound Speaker Problem.

CMH1967 · 26-02-2005, 20:48

I recently upgraded my Acoustic Solutions DS533 to the DS1133, i have always been happy with the sound of the DS533 but wanted DTS and a bit more sound power. Well, to say i'm dissapointed with Pro Logic II is an understatement, the amp is connected to my Sky+ box via an optical lead. When listening to spoken dialogue there is constant distortion of the dialogue through surround speakers, centre speaker doesn't suffer. The distortion wasn't evident on the cheaper DS533 system and isn't evident when music put through surrounds or during DVD playback. Am i expexting too much from PL2 or is the unit faulty. I know it isn't top of the range kit, but for twice the money of the DS533 i was expecting much improved sound, which isn't the case. Any advise what can be causing the distortion would be very much appreciated. I would be very pleased to hear from anyone who has a DS1133 which is performing ok, would appreciate advise on how you've got it set up.

Thanks In Advance Chris

phelings · 26-02-2005, 21:03

Whether using PL1 or PL2,your dialogue should not be coming out of the surround speakers at all.Virtually all the time dialogue should be centre speaker only.
Do you have additional sound processing that is incorrectly activated.
PL2 has a "movie" (or cinema)and "music" setting.Ensure its set to "movie"

CMH1967 · 27-02-2005, 09:20

Phelings, Many thanks for taking time to reply. The dialogue is coming through the surround speakers, in what could be best described as a "martian" like distortion of the dialogue. It is worst on the dialogue only channels ie news channels. I have no additional sound processing, the distortion is still evident on the "movie " setting. I have tried adjusting levels, setttings etc with no success. I don't know what to think, the pl2 decoder isn't functioning properly or i am missing something. Regards Chris

clockworks999 · 27-02-2005, 11:26

What happens when you listen to 5.1 material from the Sky+ (Sky movies 1 & 2)? If this still sounds bad, check the setup of the Sky+ and the amp input.

If Sky+ 5.1 is OK, but stereo signals are bad, is there a speaker configuration option on the amp? Maybe a "phantom centre" option (for 4 speaker setups)?

phelings · 27-02-2005, 13:43

Is the amp capable of 6.1.If it is,there must be a speaker config option to tell it whether you have a rear centre.
PL2 in its "movie" and "music" modes also has a selection of "sub modes" for each setting,like "mono movie" etc.It sounds as if one of these is activated

CMH1967 · 28-02-2005, 09:40

The sound via 5.1 Sky and 5.1 and dts via the dvd is spot on. The problem only occurs when listening to pro logic II broadcasts it is most evident on the news channels, the amp has only the very basic settings and doesn't have 6.1 capability. The only speaker options are the sound level settings and the music and movie modes have no sub modes, in fact there is no obvious difference in sound output in either pl2 mode. I have exhausted the various settings without success. I will speak to Acoustic Solutions today before deciding which way to go . Thanks For Advise Chris

phelings · 28-02-2005, 14:12

As DD sound is ok,it does sound as if a PL2 seting is out as I suggested above

clockworks999 · 28-02-2005, 20:39

Have you checked that all your speakers are connected "in phase"?

phelings · 28-02-2005, 21:10

Thats a bit difficult to do without a test disc

CMH1967 · 01-03-2005, 09:40

Quote:

Originally Posted by clockworks999

Have you checked that all your speakers are connected "in phase"?

Excuse my ignorance not sure what "in phase" would mean or how you would check whether speakers are "in phase". The amp does have a speaker test facility and i can verify the speakers are connected correctly.
I have searched the net regarding this issue and found that some amps seem to handle PLII better than others, it does seem that some systems do suffer the "garbled" vocals through the rear speakers.

Dunedin397 · 01-03-2005, 11:12

I've a JVC TV with Pro Logic 2 and it's got the same behaviour with dialogue in the surround speakers that you describe. However, it's only noticable when you are up close to the speaker, you don't hear it in the sitting position. I think that this is a characteristic of Pro Logic 2, as it's simply deciding which sound should go where.

Dunedin

clockworks999 · 01-03-2005, 11:18

Quote:

Originally Posted by CMH1967

Excuse my ignorance not sure what "in phase" would mean or how you would check whether speakers are "in phase". The amp does have a speaker test facility and i can verify the speakers are connected correctly.
I have searched the net regarding this issue and found that some amps seem to handle PLII better than others, it does seem that some systems do suffer the "garbled" vocals through the rear speakers.

Assuming that the amp and speakers were built properly, all you need to do is check that all the speaker +ve terminals are connected to the amplifier +ve terminals.

To check for bad internal wiring, you really need an audio test disk, as phelings said.

If one or more speakers is out of phase, you can get some really wierd effects, due to the sound waves arriving at your ears out of sync. The one at a time test tone will not show this, it just allows you to adjust the level of each channel.
These effects may be more noticeable on PLII than on 5.1, since the centre and rear signals are guesstimated from the left and right channels, rather than being discrete signals.

I've had 3 AV amps fitted with PLI and PLII, and I've never noticed any disturbing side effects.

Jim Rae · 03-03-2005, 13:22

ProLogic depends on the decoder picking up a coded signal from the stereo output of a sound source which is then spread around to the rear speakers.

ProLogic 2 splits the rear signal, whereas in ProLogic 1 it's mono.

The Simpsons is a very effective example to test your system.

However if there is no encoding for ProLogic done, then all you are picking up is spurious phase differences between the two stereo channels - which might sound OK or might sound horrible!

The news is broadcast in mono so there is even more chance of sending garbage to the rear speakers from out of phase mono signals!

So the answer is really switch the ProLogic off unless you know the programme is in stereo or ProLogic.

clockworks999 · 03-03-2005, 14:00

Quote:

Originally Posted by Jim Rae

The news is broadcast in mono so there is even more chance of sending garbage to the rear speakers from out of phase mono signals!

Now that you mention it, I have noticed this. The ITV news here (Westcountry) is broadcast in stereo, but the local news is broadcast in mono, which sounds awful. The changeover is very noticeable.

Jim Rae · 03-03-2005, 23:58

Yes but one news reader speaking is not going to give much stereo information to your decoder...

Glawster2002 · 05-03-2005, 15:44

Quote:

Originally Posted by phelings

Thats a bit difficult to do without a test disc

Why?

Good quality speaker cable should be labeled along it's length with a "+" sign for the +ve and "-" for the -ve. The +ve often has a ridge along its length as well. Therefore is should simply be a question of ensuring the +ve cable is connected to the +ve terminal on the amp and also the speaker.

I use QED cables and they are certainly marked in that way.

26-02-2005, 20:48	#1
CMH1967 Forum Member Join Date: Oct 2003 Posts: 94	Surround Sound Speaker Problem. I recently upgraded my Acoustic Solutions DS533 to the DS1133, i have always been happy with the sound of the DS533 but wanted DTS and a bit more sound power. Well, to say i'm dissapointed with Pro Logic II is an understatement, the amp is connected to my Sky+ box via an optical lead. When listening to spoken dialogue there is constant distortion of the dialogue through surround speakers, centre speaker doesn't suffer. The distortion wasn't evident on the cheaper DS533 system and isn't evident when music put through surrounds or during DVD playback. Am i expexting too much from PL2 or is the unit faulty. I know it isn't top of the range kit, but for twice the money of the DS533 i was expecting much improved sound, which isn't the case. Any advise what can be causing the distortion would be very much appreciated. I would be very pleased to hear from anyone who has a DS1133 which is performing ok, would appreciate advise on how you've got it set up. Thanks In Advance Chris

26-02-2005, 21:03	#2
phelings Banned User Join Date: Jul 2003 Location: 2MB NTL Posts: 3,246	Whether using PL1 or PL2,your dialogue should not be coming out of the surround speakers at all.Virtually all the time dialogue should be centre speaker only. Do you have additional sound processing that is incorrectly activated. PL2 has a "movie" (or cinema)and "music" setting.Ensure its set to "movie"

27-02-2005, 09:20	#3
CMH1967 Forum Member Join Date: Oct 2003 Posts: 94	Phelings, Many thanks for taking time to reply. The dialogue is coming through the surround speakers, in what could be best described as a "martian" like distortion of the dialogue. It is worst on the dialogue only channels ie news channels. I have no additional sound processing, the distortion is still evident on the "movie " setting. I have tried adjusting levels, setttings etc with no success. I don't know what to think, the pl2 decoder isn't functioning properly or i am missing something. Regards Chris

27-02-2005, 11:26	#4
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	What happens when you listen to 5.1 material from the Sky+ (Sky movies 1 & 2)? If this still sounds bad, check the setup of the Sky+ and the amp input. If Sky+ 5.1 is OK, but stereo signals are bad, is there a speaker configuration option on the amp? Maybe a "phantom centre" option (for 4 speaker setups)?

27-02-2005, 13:43	#5
phelings Banned User Join Date: Jul 2003 Location: 2MB NTL Posts: 3,246	Is the amp capable of 6.1.If it is,there must be a speaker config option to tell it whether you have a rear centre. PL2 in its "movie" and "music" modes also has a selection of "sub modes" for each setting,like "mono movie" etc.It sounds as if one of these is activated

28-02-2005, 09:40	#6
CMH1967 Forum Member Join Date: Oct 2003 Posts: 94	The sound via 5.1 Sky and 5.1 and dts via the dvd is spot on. The problem only occurs when listening to pro logic II broadcasts it is most evident on the news channels, the amp has only the very basic settings and doesn't have 6.1 capability. The only speaker options are the sound level settings and the music and movie modes have no sub modes, in fact there is no obvious difference in sound output in either pl2 mode. I have exhausted the various settings without success. I will speak to Acoustic Solutions today before deciding which way to go . Thanks For Advise Chris

28-02-2005, 14:12	#7
phelings Banned User Join Date: Jul 2003 Location: 2MB NTL Posts: 3,246	As DD sound is ok,it does sound as if a PL2 seting is out as I suggested above

28-02-2005, 20:39	#8
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Have you checked that all your speakers are connected "in phase"?

28-02-2005, 21:10	#9
phelings Banned User Join Date: Jul 2003 Location: 2MB NTL Posts: 3,246	Thats a bit difficult to do without a test disc

01-03-2005, 09:40	#10
CMH1967 Forum Member Join Date: Oct 2003 Posts: 94	Quote: Originally Posted by clockworks999 Have you checked that all your speakers are connected "in phase"? Excuse my ignorance not sure what "in phase" would mean or how you would check whether speakers are "in phase". The amp does have a speaker test facility and i can verify the speakers are connected correctly. I have searched the net regarding this issue and found that some amps seem to handle PLII better than others, it does seem that some systems do suffer the "garbled" vocals through the rear speakers.

01-03-2005, 11:12	#11
Dunedin397 Forum Member Join Date: Aug 2003 Posts: 182	I've a JVC TV with Pro Logic 2 and it's got the same behaviour with dialogue in the surround speakers that you describe. However, it's only noticable when you are up close to the speaker, you don't hear it in the sitting position. I think that this is a characteristic of Pro Logic 2, as it's simply deciding which sound should go where. Dunedin

01-03-2005, 11:18	#12
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Quote: Originally Posted by CMH1967 Excuse my ignorance not sure what "in phase" would mean or how you would check whether speakers are "in phase". The amp does have a speaker test facility and i can verify the speakers are connected correctly. I have searched the net regarding this issue and found that some amps seem to handle PLII better than others, it does seem that some systems do suffer the "garbled" vocals through the rear speakers. Assuming that the amp and speakers were built properly, all you need to do is check that all the speaker +ve terminals are connected to the amplifier +ve terminals. To check for bad internal wiring, you really need an audio test disk, as phelings said. If one or more speakers is out of phase, you can get some really wierd effects, due to the sound waves arriving at your ears out of sync. The one at a time test tone will not show this, it just allows you to adjust the level of each channel. These effects may be more noticeable on PLII than on 5.1, since the centre and rear signals are guesstimated from the left and right channels, rather than being discrete signals. I've had 3 AV amps fitted with PLI and PLII, and I've never noticed any disturbing side effects.

03-03-2005, 13:22	#13
Jim Rae Forum Member Join Date: Mar 2002 Location: Ayrshire Posts: 4,125	ProLogic depends on the decoder picking up a coded signal from the stereo output of a sound source which is then spread around to the rear speakers. ProLogic 2 splits the rear signal, whereas in ProLogic 1 it's mono. The Simpsons is a very effective example to test your system. However if there is no encoding for ProLogic done, then all you are picking up is spurious phase differences between the two stereo channels - which might sound OK or might sound horrible! The news is broadcast in mono so there is even more chance of sending garbage to the rear speakers from out of phase mono signals! So the answer is really switch the ProLogic off unless you know the programme is in stereo or ProLogic.

03-03-2005, 14:00	#14
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Quote: Originally Posted by Jim Rae The news is broadcast in mono so there is even more chance of sending garbage to the rear speakers from out of phase mono signals! Now that you mention it, I have noticed this. The ITV news here (Westcountry) is broadcast in stereo, but the local news is broadcast in mono, which sounds awful. The changeover is very noticeable.

03-03-2005, 23:58	#15
Jim Rae Forum Member Join Date: Mar 2002 Location: Ayrshire Posts: 4,125	Yes but one news reader speaking is not going to give much stereo information to your decoder...

05-03-2005, 15:44	#16
Glawster2002 Forum Member Join Date: Nov 2003 Location: Nailsworth, Gloucestershire Posts: 10,404	Quote: Originally Posted by phelings Thats a bit difficult to do without a test disc Why? Good quality speaker cable should be labeled along it's length with a "+" sign for the +ve and "-" for the -ve. The +ve often has a ridge along its length as well. Therefore is should simply be a question of ensuring the +ve cable is connected to the +ve terminal on the amp and also the speaker. I use QED cables and they are certainly marked in that way.

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Surround Sound Speaker Problem.