Sensitivity mismatch between fronts and surrounds

[bcg27]

I'm looking at rounding out my Towers/Horizon fronts with surrounds for a 5.1 system and am considering a pair of HTM200s or Lunas. Ignoring the cost difference, which is admittedly very large, is there an issue with the 5.5 dB sensitivity difference between the Lunas and the Towers? The HTM200s match the sensitivity much more closely. It also seems like the SE tweeter will have an advantage in vertical dispersion over the Raals, but I'm very enticed by the all Raal surround system :cool:. This would be for home theater only, for music my source material is all stereo.

[racrawford65]

assume your HT processor has room correction which would adjust necessary channels to level match so wouldn't expect any issue with the difference in sensitivity.

[curtis]

assume your HT processor has room correction which would adjust necessary channels to level match so wouldn't expect any issue with the difference in sensitivity.
But they would only be matched at the reference level used by the processor. At any other volume (higher or lower), they wouldn't be matched. The amount of difference would depend on the difference the "volume knob" is from reference.

[bcg27]

assume your HT processor has room correction which would adjust necessary channels to level match so wouldn't expect any issue with the difference in sensitivity.

Yes, I have a Denon with Audyssey XT32. But I'm generally in the less is more camp with room correction. I do run Audyssey but have it apply the correction at 500Hz and below. I'm not sure if that only applies to level matching though.


But they would only be matched at the reference level used by the processor. At any other volume (higher or lower), they wouldn't be matched. The amount of difference would depend on the difference the "volume knob" is from reference.

I would have assumed that the level matching would apply across all volumes, but I could be wrong.

[rsmt2000]

Yes, I have a Denon with Audyssey XT32. But I'm generally in the less is more camp with room correction. I do run Audyssey but have it apply the correction at 500Hz and below. I'm not sure if that only applies to level matching though.



I would have assumed that the level matching would apply across all volumes, but I could be wrong.

I added LUNAs to my front towers and horizons recently. My take is that just for movies, RAAL surrounds are an over kill. But if you are one of those who listen to more music once the speakers are there and start thinking about what ifs, you may get the LUNAS and be done.

[jimb]

Curtis, please say more. I would expect correction to be a gain adjustment and apply at all signal levels, equally.

[racrawford65]

Curtis, please say more. I would expect correction to be a gain adjustment and apply at all signal levels, equally.

As would I as although the gain (or negative gain) is determined at ref level, it's applied to each channel. If not, wouldn't things get out of whack if one listened above or below reference level?

[mikesiskav]

The distance from the speakers to your listening position also matters. The closer the rear speakers are to you, the less power they need.

[jimb]

As would I as although the gain (or negative gain) is determined at ref level, it's applied to each channel. If not, wouldn't things get out of whack if one listened above or below reference level?
Furthermore, the range of signal levels over time varies tremendously with program material, regardless of the volume knob setting. Curtis is a knowledgeable guy. I'm interested in hearing more of what he was addressing in his comment. Perhaps it is to do with relying on room correction versus channel level matching, which is a separate setting. I assume one would use the channel level setting controls for the what the OP asked.

[curtis]

Furthermore, the range of signal levels over time varies tremendously with program material, regardless of the volume knob setting. Curtis is a knowledgeable guy. I'm interested in hearing more of what he was addressing in his comment. Perhaps it is to do with relying on room correction versus channel level matching, which is a separate setting. I assume one would use the channel level setting controls for the what the OP asked.
Hi guys...sorry for chiming in late...

Disregard what I posted and blame it on not it having enough coffee before thinking. I was thinking at reference level, the less sensitive speaker will need more power....but that is not what came out when I typed.

You just need to make sure you have enough amplifier power to cover the less sensitive speaker.

[davef]

I'm looking at rounding out my Towers/Horizon fronts with surrounds for a 5.1 system and am considering a pair of HTM200s or Lunas. Ignoring the cost difference, which is admittedly very large, is there an issue with the 5.5 dB sensitivity difference between the Lunas and the Towers? The HTM200s match the sensitivity much more closely. It also seems like the SE tweeter will have an advantage in vertical dispersion over the Raals, but I'm very enticed by the all Raal surround system :cool:. This would be for home theater only, for music my source material is all stereo.

Your receiver will compensate for sensitivity differences between all the speakers. You room acoustics and distances will also affect overall output for each speaker at your listening position.

For most rooms, the surrounds are located quite a bit closer to the listener. For example, if your surrounds are 5 feet away from the listening position and the fronts are 9 feet away, these differences alone account for the 5.5dB difference in sensitivity.

However, there could be a concern if your surrounds are located at a further distance from the MLP than your fronts and your receiver does not have enough power.

Obvious question:

1. What is the distance from the listening position to the front L/R speakers?
2. What will be the distance from the listening position to the L/R surrounds?

[rsmt2000]

Your receiver will compensate for sensitivity differences between all the speakers. You room acoustics and distances will also affect overall output for each speaker at your listening position.

For most rooms, the surrounds are located quite a bit closer to the listener. For example, if your surrounds are 5 feet away from the listening position and the fronts are 9 feet away, these differences alone account for the 5.5dB difference in sensitivity.

However, there could be a concern if your surrounds are located at a further distance from the MLP than your fronts and your receiver does not have enough power.

Obvious question:

1. What is the distance from the listening position to the front L/R speakers?
2. What will be the distance from the listening position to the L/R surrounds?

This is what separates professionals from the rest. Precise and Thorough.

[bcg27]

Thanks for the replies everyone, I hadn't considered the effect of the closer distance. The L/R mains are positioned about 13 feet away from the MLP and the center about 12 feet. The right surround will be about 6 feet away and the left about 9 feet horizontally. Unfortunately due to some room restrictions they will also be mounted about 4 feet above the ear so will have to be tilted down somewhat and making the straight line distance about 7 and 10 feet.

[davef]

Thanks for the replies everyone, I hadn't considered the effect of the closer distance. The L/R mains are positioned about 13 feet away from the MLP and the center about 12 feet. The right surround will be about 6 feet away and the left about 9 feet horizontally. Unfortunately due to some room restrictions they will also be mounted about 4 feet above the ear so will have to be tilted down somewhat and making the straight line distance about 7 and 10 feet.

At these distances, you should be fine with Luna's as surrounds, but much also depends on the volume levels you would like to achieve combined with how much power your amp / receiver can provide. Please feel free to send me an email directly.