making a 5.1 a 7.1

K-daugh

currently running a 5.1 set up .....thinking about adding two speakers(monitor 4's) but have a problem finding a good spot to put them ......also do i make the monitor 30's the back surrounds and the monitor 4's the side surrounds or vica versa......what are some good placement options for a 7.1 system.....

tonyb

Kind of hard to say without any room dimensions or pics. Looking at your gear though,I would say that in 7 channel surround,your receiver may only put out 30 watts or so. You may have to upgrade or add an amp to the front 3 to take some work off the receiver. Also keep in mind most Blu-ray disc are 5.1.

kuntasensei

tonyb wrote: »

Kind of hard to say without any room dimensions or pics. Looking at your gear though,I would say that in 7 channel surround,your receiver may only put out 30 watts or so. You may have to upgrade or add an amp to the front 3 to take some work off the receiver. Also keep in mind most Blu-ray disc are 5.1.

The surrounds take very little power, so his AVR will be fine. People get hung up on total power, but the fact is that most soundtracks rarely require 60w to reproduce near reference level from the mains in a home space, and surrounds typically don't take near that much... even less so if you're handing off bass duties to a powered subwoofer with a crossover of about 80Hz. Besides that, H/K tends to be pretty honest and often downright conservative with their power ratings. That AVR should have no problems driving 7 channels.

Also keep in mind that despite what people say about most Blu-ray discs being 5.1, the mixes are done for EX-enabled theaters and the vast majority of recent movies will have material meant to be in the rear surrounds via matrixing. DPL-IIx processing can recreate the sound of the theatrical mix in your smaller space IF you can properly place the rear and side surrounds per Dolby's specs, and is actually Dolby's preference over DD-EX in the home space. If you can't place them at the angles that Dolby dictates, it may well be better to stick with 5.1... but a properly configured 7.1 setup is the only way to properly recreate the effect of a theatrical Dolby EX array in the home space, and it will work well with damn near every 5.1 mix out there, on Blu-ray or DVD.

To the OP, hit Dolby.com and look at their speaker placement guide for 7.1. If you can make those angles work in your room, you're good to go. If you have any other placement issues, post some pics and we'll see what we can do to help.

K-daugh

Yes I am investing in an external amp before I set up the 7.1 and yes ill have to check out the dolby specs for speaker placement.......my room is 16x18 with 8' ceilings
Ill post some pics tomorrow

tonyb

K-daugh wrote: »

Yes I am investing in an external amp before I set up the 7.1 and yes ill have to check out the dolby specs for speaker placement.......my room is 16x18 with 8' ceilings
Ill post some pics tomorrow

Cool,just make sure your avr has pre outs to do that. The spec on your receiver I think is 50 watts in surround mode, 65 watts in 2 channel. My point earlier,is that some receivers in surround mode rob peter to pay paul so to speak. I would say your on the brink of not having enough power and if you ever want to upgrade your speaks in the future, you'll be hard pressed to make due with what you have.

K-daugh

tonyb wrote: »

Cool,just make sure your avr has pre outs to do that. The spec on your receiver I think is 50 watts in surround mode, 65 watts in 2 channel. My point earlier,is that some receivers in surround mode rob peter to pay paul so to speak. I would say your on the brink of not having enough power and if you ever want to upgrade your speaks in the future, you'll be hard pressed to make due with what you have.

Your absolutely right about the specs although because I'm only in 5.1 instaed of 7.1 I'm probably running somewhere in between fifty and sixty five watts.......I got my eye on a 3-5 channel amp 100 plus watts looking to spend like four five hundred......that should open my monitors right up ....and allow me to possibly add two more speakers if I can find a home for them.....

kuntasensei

K-daugh wrote: »

Your absolutely right about the specs although because I'm only in 5.1 instaed of 7.1 I'm probably running somewhere in between fifty and sixty five watts.......I got my eye on a 3-5 channel amp 100 plus watts looking to spend like four five hundred......that should open my monitors right up ....and allow me to possibly add two more speakers if I can find a home for them.....

If you're running your speakers crossed to your sub, I can guarantee you that you're not using 50w/ch sustained (and your AVR has enough dynamic power for transient bursts beyond its rated specs). Polk speakers are very efficient on their own, and with bass duties offloaded to a sub, you likely aren't using more than 30w/ch at any given time (and less from the surrounds).

I get the whole "robbing Peter to pay Paul" thing, because each channel typically draws from a common power store in AVRs (with the odd exception of designs that use multiple power rails)... but a 90dB efficiency speaker like the Monitor 60, at about 14 ft. distance, can produce 94dB of sound with 50 watts. If you have them within 2 feet or so of a wall, that ends up closer to 98dB. When you offload the bass below 80Hz to a powered sub, the power requirements are even lower, giving you additional headroom from your AVR.

Let's just assume that with all channels going, your H/K can produce 250w max. That yields you 112.8dB peak, NOT counting the subwoofer. When you figure that the subwoofer is handling the bass, that potential goes up.

I'm not saying that external amplification isn't a good thing... but don't feel like adding 2 speakers to your AVR is going to significantly rob power from the mains such that it will noticeably alter their output.

K-daugh

good input..... thanks