Question regarding 7.1 surround

StinkyDog

I am just starting to venture into the realm of 7.1 surround sound after living with 5.1 for the last 15 years or so, and I have a couple of questions regarding the rear speakers.

I've been reading over some posts recently and have seen people referring to speakers as 'Rear Surround' and '7.1 Surround'. Are the rear surrounds the ones on the back wall and the 7.1 surrounds the ones on the sides? Or do I have it backwards? Also, can you have all four on the back wall (ala 6.1) or would that just sound stupid?

One other question is regarding speaker sizes. Should all four rear speakers be the same size, if possible? If they are different sizes which ones should be bigger, the ones on the sides or the ones on the back wall?

Thanks!!

Sean

cnjvh

StinkyDog wrote:

I am just starting to venture into the realm of 7.1 surround sound after living with 5.1 for the last 15 years or so, and I have a couple of questions regarding the rear speakers.

I've been reading over some posts recently and have seen people referring to speakers as 'Rear Surround' and '7.1 Surround'. Are the rear surrounds the ones on the back wall and the 7.1 surrounds the ones on the sides? Or do I have it backwards? Also, can you have all four on the back wall (ala 6.1) or would that just sound stupid?

One other question is regarding speaker sizes. Should all four rear speakers be the same size, if possible? If they are different sizes which ones should be bigger, the ones on the sides or the ones on the back wall?

Thanks!!

Sean

http://www.dolby.com/consumer/home_entertainment/roomlayout.html

Click the Dolby Pro Logic IIx button to see the correct layout for 7.1.

The speakers to the sides are the surround left and right speakers.

The speakers behind you are the surround back left and surround back right speakers.

7.1 is not a recorded format. It is created by a Pro Logic IIx capable receiver from stereo, 5.1 or 6.1 sources. The receiver takes the 1, 2, or 3 surround channels that are actually present on the DVD and steers them across the 4 rear speakers.

Good luck!!

cnjvh

StinkyDog wrote:

One other question is regarding speaker sizes. Should all four rear speakers be the same size, if possible? If they are different sizes which ones should be bigger, the ones on the sides or the ones on the back wall?
Sean

They should not only be the same size, they should be identical if possible. If your speakers of different types they have a different inherent sound and pans across the rear sound stage are disrupted.

StinkyDog

Thanks for your help! Very useful link you provided.

dorokusai

The main issue is that they be timbre matched, to the rest of the lineup, actual physical size and or model, is not neccesary. Is it ideal? Perhaps, but that depends on what marketing idea to which you subscribe.

The Dolby site is useful for information, but it doesn't set the bar....it's a suggestion.

cnjvh

StinkyDog wrote:

Thanks for your help! Very useful link you provided.

No problem. Unfortunatley, alot of people (like me) don't have the right shape/size room to make the layout work perfectly, but it's a nice starting point and you work with what you have. As mentioned above, it's not "do it this way and no other". Even if your room isn't perfectly suited to the Dolby layout, you'll still be able to get a nice sound with a little patience.

I'm not sure I totally subscribe to the idea that having 4 identical rear speakers just marketing...its simply the easiest way to get the timbre matching which is so critical. If you already have two speakers and can't find exact matches, I wouldn't go out and buy 4 new speakers just to have matching ones. Just try to keep the manufacturer the same and match them as close as possible.

dorokusai

Excellent response.

StinkyDog

cnjvh wrote:

No problem. Unfortunatley, alot of people (like me) don't have the right shape/size room to make the layout work perfectly, but it's a nice starting point and you work with what you have. As mentioned above, it's not "do it this way and no other". Even if your room isn't perfectly suited to the Dolby layout, you'll still be able to get a nice sound with a little patience.

I'm not sure I totally subscribe to the idea that having 4 identical rear speakers just marketing...its simply the easiest way to get the timbre matching which is so critical. If you already have two speakers and can't find exact matches, I wouldn't go out and buy 4 new speakers just to have matching ones. Just try to keep the manufacturer the same and match them as close as possible.

Thanks for your help. I'll do my best to get the same speakers the the rears. However, if the speakers ended up not being the same ones, or the same sizes, does it matter which ones go where? In other words, would the larger ones be the side surrounds or the rear surrounds, or would it not make a difference?

cnjvh

Well, the back surrounds will likely have the least work to do so I'd make the speakers that sound best to you the left and right surrounds. However, in all honesty it's really not going to matter. Just make sure to calibrate all 7 speakers to be at equal output. General accepted practice is to calibrate them to 80db with your master volume at 0 using test tracks from some test DVD (DVE or Avia). DVE would be better in your case as Avia only includes test for 5.1 systems. You receiver may be able to generate these tones as well but I've found using a DVD yields better results since that way your bass management is in effect when you run the tests (which is the real world setup in which it will be used).

StinkyDog

Great info! Thanks again for your help!