Question How to get 9.1 from 5.1 decoder

ru555

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Hello fellow geeks :) i need a little advice please...

I'm currently running 7.1 - LCR, 2 x side and 2 x rear. and I want to add another 2 side speakers, as its a long room.

My decoder only has 4 signal outputs for rear channels (rear LR and surround LR) whats the best way to get two more signals from the surround channel to send to my amp?

My anthem d2v does have balanced (XLR) outputs that im not using, could i use the tow surround LR outputs from there? Are there any issues of delay etc with using a mix of balanced XLR and unbalanced RCA outputs to the amps?

thanks in advance

D2v2Rear.jpg
 
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Your processor only supports up to 7.1 speakers, and is processing the sound for that set up. If you want more speakers you would need a different processor that supports it.
 
The usual solution when dealing with long and narrow rooms is to use a dipole surround speaker. The MK 150 series offers the S-150T for this.

Apparently you want to add a second pair of MK S150's to run in parallel with the existing S150's for the surrounds. Since these are 4 Ohm speakers, this basically means you'll need to add an Anthem P2 to get the two extra amplification channels. Assign amplification channels across your 2xP2+P5 to the 7 speakers. Use a splitter cable (RCA, not XLR) to connect the pair of power amp channels to drive the parallel surrounds, then rebalance the D2v's levels.

The questions in your last paragraph concert the D2v, but your problem is with the power amplification; connectivity is as explained above..

As Rambles says, you cannot get more than 7 discreet channels from a 7.1 processor.
 
7.1 is probably adequate for your room IMO... ripe, considering I haven't seen it, I know :)

Experiment with the placement of your sides, bring them forward a bit. As said, invest in dipole speakers. They'll probably sort your problem out perfectly.

Running a second pair in parallel would be horrible.
 
No need to have more than 5 amps to make a 9.1 system with a 5.1 decoder...

You need only to connect correctly your 6 surronds in parallele and series.

Sorry for the french exemple, but it's with the advices of the french THX representative :

«[Guide]Placer ses enceintes Surround en 5.1 / 7.1 voir Page1» - 30067649 - sur le forum «Normes» - 1092 - du site Homecinema-fr.com

Electronique - Bases - Association haut-parleurs

This is a 5.1 installation with 20 surrounds :

«[Guide]Placer ses enceintes Surround en 5.1 / 7.1 voir Page1 - Page 22» - 30067649 - sur le forum «Normes» - 1092 - du site Homecinema-fr.com
 
I think running more 2 speakers off my amps outputs with 4ohm speakers isn’t going to do it any good.

I do have a Yamaha z9 available so I can use his amps.

Ste7en my room is 7.2m x 5.3m (LxW) so can it can easily cope with another side surround speaker...why do you think it would sound horrible?? Majority of commercial cinemas use 7.1 channels with multiple speakers on each channel
 
But the surround effects are going to be wrong if you are sending audio meant for a surround speaker and duplicating it to another surround back speaker, the movement of audio around the room will be out of balance to how it is intended to be.
 
Maybe a misunderstanding from my original post. I want to add two more surround (side) speakers. I will keep the two rears as they are.

So I was planning on splitting the surround signal from my decoder so I would have 4 surrounds and 2 backs
 
You can of course, do that if you want, but my point is the same, that the processor will be sending specific sounds to specific speakers at specific times in order to create a realistic surround audio effect. If you duplicate the audio to two, or four side speakers, it will break the movement and placement of audio within the room.
 
Having said that, I am just reminded of a concept I read of on a different forum, where instead of duplicating audio meant for 2 speakers to 4 speakers, which I think is your intention, you could feed the audio output for a pair of surrounds into another processor and apply an upmixer to it to create further pseudo surround effects for additional speakers. The concept is not for me, but these people seem to like it:

http://www.avsforum.com/forum/90-re...d-7-1-4-multi-avr-set-up-immersive-audio.html
 
In Dolby Digital (TrueHD or not) or Dts (HD or not), surround are not ponctual.

In a theater like that, it's only 5.1 (or 7.1 sometimes) !

679974surroundcinejpl.jpg

Each surround speaker have the same signal than the others.

Bipole speaker use this system but two speakers with the same signal = a bipole
(Dipole speaker = two speakers with the same signal but opposite phase in tweeter/medium)

It's only with Atmos than the Atmos speakers (and not the 5.1 surrounds which are independants) have a ponctual signal (objet) and need a processor to adress the correct signal to the correct speaker.
 
Ste7en my room is 7.2m x 5.3m (LxW) so can it can easily cope with another side surround speaker...why do you think it would sound horrible?? Majority of commercial cinemas use 7.1 channels with multiple speakers on each channel
I find it hard to believe that your existing side-wall speakers are unable to provide sufficient horizontal dispersion in a room of that size, even assuming three rows of seating so that all the children can watch. As a result, I rather wonder if you don't have a very different issue, needing a somewhat different resolution. I have a larger room (42m2, with length 10m and variable width), and do not needed multiple surround speakers to achieve realistic placement.

The comparison with a cinema is misleading as they are dealing with directional speakers in a large theatre having multiple rows of seating. Speaker arrays are used to deal with such a setup, but should not be required in 7.2m x 5.3m.
 
Each surround speaker have the same signal than the others.
This cannot be correct. When I am listening to a Dolby True HD soundtrack I can hear sounds moving around the rear speakers, eg as someone is walking around the back, and the audio jumps from each speaker in turn. There is no way that the same audio is being played from the surround speaker at the same time.

Not to menation that the room correction will be applied to each speaker based on it's type, size and interaction with the room. If you are duplicating audio to 4 speakers that are meant for 2, the room correction will be messed up.

Having said all of that, if the OP wants to try it, he might find he likes the effect, but it is not the correct way to go about things and could do more harm than good. Getting 7.1 to work better in the room by changing speakers or placement would be a better solution.
 
I'm confused o_O

I'm pretty sure that 60 speaker system isn't being run by a 7.1 processor.
 
It's possible, not only with a 7.1 processor but also with a 7 channels power amplifier.

The only thing to respect is the impedance of the (group of) speakers.

If your 10 speakers of the left surround channel are connected in such a way that your mono amplifier sees only one speaker (8 ohm for exemple), it's ok.
 
Yes it may be possible to get sound coming out of the speakers, but it wouldn't be the correct sound, as per my previous comments.
 
Yes it may be possible to get sound coming out of the speakers, but it wouldn't be the correct sound, as per my previous comments.
it's not that hard. everywhere you have 1 speaker now, put 3, close together, but seperated a little. hook them all to the same amp channel, without dropping the parallel resistance below what the amp can handle, and you have more than 1 speaker giving the correct sound, coming from the right place. do that for all channels, and you get exactly what has been described above. you already have multiple drivers in each speaker, it's not that different


it's a moot point anyway. i'm with @Mark.Yudkin , the op does not need this. i've a bigger room as well and you don't need multiple speakers, it's not an auditorium you are trying to fill
 
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it's not that hard. everywhere you have 1 speaker now, put 3, close together, but seperated a little. hook them all to the same amp channel, without dropping the parallel resistance below what the amp can handle, and you have more than 1 speaker giving the correct sound, coming from the right place. do that for all channels, and you get exactly what has been described above. you already have multiple drivers in each speaker, it's not that different

Absolutely correct and well explained.
 
it's not that hard. everywhere you have 1 speaker now, put 3, close together, but seperated a little. hook them all to the same amp channel, without dropping the parallel resistance below what the amp can handle, and you have more than 1 speaker giving the correct sound, coming from the right place. do that for all channels, and you get exactly what has been described above. you already have multiple drivers in each speaker, it's not that different


it's a mute point anyway. i'm with @Mark.Yudkin , the op does not need this. i've a bigger room as well and you don't need multiple speakers, it's not an auditorium you are trying to fill
Thats true I guess, if you were doing it evenly around the room but that is not what the OP is planning. He is planning on duplicating just 2 of the current 7 speakers I think, so it would be unbalanced. And mess up the room correction, which I thought was the main attraction of buying Anthem gear in the first place?

As others have said, tweaking speaker placement and / or swapping in dipole or tripole speakers would be a more elegant solution.

But I'm all for creative thinking and saving money so wouldn't want to rain on anyone's parade. It's worth a try but might not sound as good as some of the other options.
 
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Why would it be unbalanced? You'd match the speaker levels.

And why do you think you'd mess up room eq?
 
it's not that hard. everywhere you have 1 speaker now, put 3, close together, but seperated a little. hook them all to the same amp channel, without dropping the parallel resistance below what the amp can handle, and you have more than 1 speaker giving the correct sound, coming from the right place. do that for all channels, and you get exactly what has been described above. you already have multiple drivers in each speaker, it's not that different

That is a very good example of what could be done with extra speakers on each channel. It can and will work.
 
Why would it be unbalanced? You'd match the speaker levels.

And why do you think you'd mess up room eq?
Because if a noise was panning around the room it would be repeated in two speakers at the same time so the precise placement of that sound would be wrong and sound less convincing.

The processor will only be able to correct 7 of the 9 attached speakers. When it is sending the room correction tones out to do the measurements it will repeat the tones to 2 speakers at the same time, that were meant for one. This will mean a poor measurement and hence correction of the room effect on that speaker as it will be two speakers in different locations in the room instead of the one speaker in the one location that the software is expecting and attempting to measure and correct.
 
Room eq measures response at the listening position. Not the output of a speaker. It will have no idea if it is coming from 1,2 or more speakers. People have been eq'ing 2 subs using this method for years . It's easier with subs as you don't have the directionality but the principle is the same. In fact, having two speakers could improve things, room eq is good at killing peaks, raising nulls is dangerous, multiple speakers could fill in the troughs that eq cannot manage and the eq is able to adjust the peaks.

There are arguments why the op shouldn't do this, but they are more related to why bother.
 

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