I perused this forum looking for an answer, but to no avail. Seems this would be a well covered subject.

Will I notice a difference if I hook up another surround back speaker and place it beside or within + or - 2ft of it? I'm battling this because of the WAF (Wife Acceptance Factor) and of course the work in running another wire and hanging another speaker.

I'm skeptical. It's a mono channel, no (DD EX and DTS EX)? Are the new formats' (TrueHD etc.) SBL and SBR separate channels? I can't support those new surround formats now anyway (not many can, I believe), so for the time being, isn't one enough?

I do, BTW, have an extra amp channel and another matching speaker just sitting there, so that is certainly not an issue. I'm looking for REAL SONIC BENEFIT.

Thanks for the advice.
Keith

you definitely should use two. 7.1 array preferred over 6.1 array.

Actually the topic has been discussed very often. 2 SB speakers are usually recommended because there is a phenomenon where one speaker directly behind you can sound as if it's in front of you. So 2 are better even if it's mono : eg DD EX or DTS ES. But if you apply Dolby PL IIx or Logic 7 to 2.0, 5.1 or even 6.1 sources, you will get stereo rears.

Ed

Thanks for the replies gents. I tried to find those posts with no luck. I believe my search methods are flawed....

I will take this advice and add the other speaker. When my wife sees me tucking another cable under the carpet and give me the look, I'll just shrug and blame you guys.

While I'm here, can anyone recommend any movies (SD DVD) for evaluating the SB channel?

Keith

While I'm here, can anyone recommend any movies (SD DVD) for evaluating the SB channel?

Keith

Check here, http://http://dts.com/consumer/hometheater/dvd-titles.php and here, http://imdb.com/List?tv=on&&sound-mix=Dolby+Digital+EX

My personal favorite is the entire opening of Master and Commander, the noises of the ship and sea and then the battle are all around you. That movie is a rare delight, a good movie in its own right, based on two good books, and with a terrific Dolby sound track. The cannons in the fog will raise the hair on your neck. If you've not seen it before, you are a better man than I, Gunga Din, if you don't flinch.

Check here, http://http://dts.com/consumer/hometheater/dvd-titles.php and here, http://imdb.com/List?tv=on&&sound-mix=Dolby+Digital+EX

My personal favorite is the entire opening of Master and Commander, the noises of the ship and sea and then the battle are all around you. That movie is a rare delight, a good movie in its own right, based on two good books, and with a terrific Dolby sound track. The cannons in the fog will raise the hair on your neck. If you've not seen it before, you are a better man than I, Gunga Din, if you don't flinch.

I did some searching, and will continue, but cannot find an EX encoded disc of Master and Commander. I'll keep searching though.

By way of follow up, I found this on a website called "time for DVD". Seems to shut the book on the subject.

THX Surround EX, also known as Dolby Digital EX, refers to the Dolby Digital version of the new "6.1"-channel surround sound format that extends the 5.1-channel surround sound format with one (or two) additional speaker(s) located in the back of the audience (i.e., back surround channel). THX Surround EX is actually a 5.1-channel format with the back surround audio channel matrixed into those of the right and left surround. The back surround channel is matrixed in similar fashion as the front center channel is matrixed into the front right and left channels in the Dolby Surround Pro-Logic format. As such, the back surround channel is not discrete and therefore THX Surround EX is not a true "6.1" format.

What about the extended surround "7.1" format? Well, "7.1" is not a true surround sound format. Rather it refers to home theater equipment manufacturers' proprietary implementation of two back surround channels using the same back surround audio signal that was discussed above. Usually, the audio signal fed to the two back surround channels are identical, but some manufacturers may choose to mix some information from the left and right surrounds. Again, these are proprietary implementations that vary across manufacturers and are not industry standards. The use of two back surround speakers fills in the sound better from the rear of the audience than single back surround speaker implementations.

I will take this advice and add the other speaker.Try to place them at least 30 degrees away from the centre line. This will minimize the imaging reversal problem that Ed mentioned, it will improve rear envelopment, and it will allow you to hear left-vs-right separation behind you. Unlike EX and ES decoding, which extract a mono surround-back channel, Dolby Pro Logic IIx processing extracts stereo surround-back channels. Since our human hearing is not very good behind us, it helps to have the rear speakers spread well apart in order to hear stereo imaging back there.

Sanjay

I did find this (http://www.dvdmoviecentral.com/ReviewsText/master_and_commander.htm). BTW, I have seen the movie, but I believe it ws in the theater. I do remember it being very though. I will get the DVD. You must have your SB speaker(s) set to "On" for it to be active.

My personal favorite is the entire opening of Master and Commander, the noises of the ship and sea and then the battle are all around you.That movie has such a well done soundtrack. Rather than getting all gimmicky with the surround channels, they're instead used to re-inforce the environment seen on the screen. With four surround speakers you really feel like you're there. At times I could have sworn I heard wood planks creeking above me (where I have no speakers).

Keith: a thorough and well updated list of SD DVDs, broken down by all three surround-back formats (DD EX, DTS ES, DTS ES Discrete 6.1), can be found here (http://www.hometheaterforum.com/htf/showthread.php?t=17262). Worth bookmarking for future reference.

My favourite examples of rear vs side directionality in the surround field are chapter 16 of 'Blade II' (listen to the whole chapter) and chapter 11 of 'Mission to Mars' (the first couple of minutes of the chapter).

Keep in mind that you can apply EX/ES and PLIIx to any 5.1-channel soundtrack with good results.

Sanjay