Can rear speakers sound good even when far from the main listening position?

[Tenet]

tl;dr -- can rear speakers in a 7.1.4 system sound good if they're placed around 20 feet behind the main listening position of a home theater?

I'm starting the process to finish our basement. The space is basically 16’ x 32’ with a home theater on one side and a bar/lounge on the other. (See attached picture.) For WAF, one option is placing the rear speakers (Philharmonic Audio ceramic minis) on the built-in bookshelves going into the wall opposite from the TV -- with the speaker cable running through the ceiling and back wall. That'll be about 20' from the main listening/watching position. Has anyone placed rear speakers that far away in their own set ups? Is the sound quality still good, or would you prefer having the speakers directly behind the sofa/listening position instead?

 

[Audio Science Pal]

can rear speakers in a 7.1.4 system sound good if they're placed around 20 feet behind the main listening position of a home theater?

Yes. The surround sound panning effect will be better for the different seating positions than if the speakers were closer.

 

[kyuu]

Think about how far away some of the speakers in a theater can be from the audience.

Only thing to be concerned about is that they will need to get loud enough to overcome the dB loss from the greater distance, but surround channels aren't demanding in the first place so as long as you aren't using really dinky little speakers you should be ok. Something with narrower dispersion might be beneficial also, such as coaxial.

 

[Oddball]

As noted, you will need to make sure you can get loud enough at MLP. The speakers are rated at 84dB sensitivity so 100W of amplification (into your 4ohm rated speaker) would give you roughly 95dB at MLP that is 20 feet away. That would be sufficient for listening at -10dB to reference level at MLP, which is quite loud.

This might cause AVR to add significant gain to the rear surrounds pre-amp output to equalize their distance and potentially lower sensitivity with other channels/speakers. Not sure exactly how would your AVR handle that scenario. Sometimes concern with such positive trim could be be decreased SINAD or in worst case clipping. Getting some speakers that have higher sensitivity might help.

 

[kyuu]

Somehow I managed to not notice that the rear speakers were already specified. I wouldn't normally choose those Philharmonic Ceramic Minis for this application due to their low sensitivity and relatively high distortion/compression at high SPLs. They have nice bass capability for their size, however assuming you're crossing them over to a sub that's of limited value (and you do want to cross them for this application), except that they should handle an 80Hz crossover pretty well. Might want to try 100Hz though if you notice any issues in the mid-bass at elevated volumes.

Since you already have them, can't hurt at all to try and see how well it works. Like I said, surround duty is not super demanding so they might work perfectly fine.

 

[Tenet]

I tend not to listen at super loud volumes. I don't have an external mic, but according to the decibel meter app on my phone, I rarely listen at MLP beyond sustained ~70 dB with peaks around 80 dB (and 90% of the time, I'm not even at those volumes). I use a Sony AZ7000ES for an AVR, so that's 150W per channel at 8 ohms, and the Phils operate at 4 ohms. (Can't easily find Sony's official rating at 4 ohms.) Hopefully that's plenty of power for the rears -- and the overall system. If that doesn't prove to be the case, I'm game for adding supplemental power amps. Crossover with my Arendal 1723 2S is set at 80Hz.

 

[kyuu]

I tend not to listen at super loud volumes. I don't have an external mic, but according to the decibel meter app on my phone, I rarely listen at MLP beyond sustained ~70 dB with peaks around 80 dB (and 90% of the time, I'm not even at those volumes). I use a Sony AZ7000ES for an AVR, so that's 150W per channel at 8 ohms, and the Phils operate at 4 ohms. (Can't easily find Sony's official rating at 4 ohms.) Hopefully that's plenty of power for the rears -- and the overall system. If that doesn't prove to be the case, I'm game for adding supplemental power amps. Crossover with my Arendal 1723 2S is set at 80Hz.

Less concerned about feeding it enough power and more that the speaker will compress/distort when fed enough power to get to the required SPL. However, given normal listening levels and the undemanding nature of surround channels, I suspect it will be fine.

 

[Oddball]

I would hope the same. Throwing more power would not be the answer as Sony should have plenty. Funny enough they did not rate the speakers for RMS and peak power which is usually very helpful to understand their recommended limits.

Please let us know how it works with Sony - interested how it will handle pre-out offsets.

 

[Tenet]

I would hope the same. Throwing more power would not be the answer as Sony should have plenty. Funny enough they did not rate the speakers for RMS and peak power which is usually very helpful to understand their recommended limits.

Please let us know how it works with Sony - interested how it will handle pre-out offsets.

Patience will be required on that front. This project is many months from completion, unfortunately. =)