[dmestan]

Is it necessary that speaker sensitivities are close? I currently have 89db surround speakers and want to get new LCR. I'm considering BIC Acoustech HT-75/65 that are rated at 96db. Is it just a matter of offsetting the level at the receiver, or is there more to it than that?


thx, Don

 

[psgcdn]

Nothing more to it.


Keep in mind that on some (rare) material (maybe multichannel music), the power going to the surrounds will be the limiting factor on how loud you can push the front speakers. But in general this isn't a problem since little power is usually sent to surrounds so they should be able to keep up.

 

[RazorX]

Sorry for resurrecting such an old thread. I couldn't decide whether it would be better to bring this one back from the dead or start a whole new one on pretty much the same topic. I decided the former was the lesser of the two...

I had a very similar question but the inverse of the OP. I am currently running Paradigm speakers all the way around in my 7.1 setup. I am using Monitor 7 v4 for my mains, a CC-370 center, ADP-370's for my surround and a pair of AMA-250's for my rears. All of these speakers have a sensitivity rating of between 90 - 94 dB. I am seriously considering replacing my L/R/C with Ascend Sierra-1's. The Sierra's have a rating only 86dB.


I'm not familiar enough with the impact of running speakers with different sensitivity ratings to know if this will be an issue. I know I can level set all of the speakers with test tones but I'm not sure how the different sensitivity ratings will manifest at various volume levels and/or content. Does the lower sensitivity rating create a situation where the higher sensitivity speakers will play louder under some circumstances? If yes; what would be some conditions that would cause this to occur?


Thanks,

 

[Kal Rubinson]

Most AVRs have channel level corrections that run +/-10 or 12dB (a 20-24dB range). So, unless there is something glaringly different in the acoustical situation of the fronts vs. the surrounds, the differences in sensitivity (94 minus 86 = 8dB) should easily be compensated.

 

[RazorX]

Thanks Karl. That's what I assumed but I wasn't sure if the more efficient speakers would play louder than the less efficient speakers at certain volume levels (e.g. more pronounced at lower volume levels).


It sounds like I should have nothing to worry about.

 

[PsychoM3]

Not really an issue for you however for someone that might be searching the thread later the only other issue might be with some speakers that are very low sensitivity (84-84) paired with much more sensitive one they may not be able to reach reference level in a given room this could lead to unexpected clipping when the other more sensitive speakers may be loafing along sucking 10-20 watts.

 

[Kal Rubinson]



Quote:
Originally Posted by RazorX /forum/post/15770887


Thanks Karl. That's what I assumed but I wasn't sure if the more efficient speakers would play louder than the less efficient speakers at certain volume levels (e.g. more pronounced at lower volume levels).

Why? Within reasonable domestic limits, most speakers respond linearly to input levels.

Quote:
It sounds like I should have nothing to worry about.

Yup.

 

[RazorX]



Quote:
Originally Posted by Kal Rubinson /forum/post/15772216


Why? Within reasonable domestic limits, most speakers respond linearly to input levels.

That's the part I wasn't sure about. I suspected that was the case but I wasn't sure. I'm not familiar enough with the science behind electronic sound reproduction to come up with much more than a guess.

Quote:
Originally Posted by Kal Rubinson /forum/post/15772216


Yup.

Thanks again.

 

[Paul Scarpelli]

The potential problem will be with headroom in the channels with the low-sensitivity speakers. At comfy levels for your fronts, you could run out of speaker headroom and/or amplifier power. Remember, it would take four times the power to drive 86 dB speakers to the same level as 92 dB speakers. What will probably save you is surrounds don't get as much information sent to them, and they aren't tasked as hard.

 

[Kal Rubinson]



Quote:
Originally Posted by Paul Scarpelli /forum/post/15772572


The potential problem will be with headroom in the channels with the low-sensitivity speakers. At comfy levels for your fronts, you could run out of speaker headroom and/or amplifier power. Remember, it would take four times the power to drive 86 dB speakers to the same level as 92 dB speakers. What will probably save you is surrounds don't get as much information sent to them, and they aren't tasked as hard.

Good point(s).

 

[Paul Scarpelli]



Quote:
Originally Posted by Kal Rubinson /forum/post/15772666


Good point(s).

Do NOT patronize me.

 

[Kal Rubinson]



Quote:
Originally Posted by Paul Scarpelli /forum/post/15772757


Do NOT patronize me.

Why would I do that? I was subtly admitting that I should have said that.

 

[RazorX]



Quote:
Originally Posted by Paul Scarpelli /forum/post/15772572


The potential problem will be with headroom in the channels with the low-sensitivity speakers. At comfy levels for your fronts, you could run out of speaker headroom and/or amplifier power. Remember, it would take four times the power to drive 86 dB speakers to the same level as 92 dB speakers. What will probably save you is surrounds don't get as much information sent to them, and they aren't tasked as hard.

Quote:
Originally Posted by Kal Rubinson /forum/post/15772666


Good point(s).

Now I'm worried. Not really. OK, maybe a little.

I will be driving the L/R/C (86dB) speakers with a Emotiva XPA-3 amp rated at 200 watts/channel. I will be using the amplifier section of an Onkyo TX-SR705 AVR rated at 100 watts/channel to power the surround (94dB) and rear (93dB) speakers.


Based on what I gather from Paul's statements - it sounds like I have the potential to have greater volume generated from the surround and rear speakers (as they are more efficient) than the front L/R/C speakers (due to them being less efficient) during more dynamic passages but...it likely will not manifest into a significant or common problem due to the very nature of the content that is sent to the surround channels. Correct so far?


I would also assume the fact I am using a separate/dedicated and more powerful (although not 4x) amp to power the fronts and the less powerful AVR amp to power the surround and rear speakers will help out somewhat. Is this a correct assumption?


It may (or may not) be worth noting I have my system in a relatively small room (11'6" x 16' x 8') and never feel the need to play movies above -20 - -15 (with all of the channels calibrated to 75dB at 0).

 

[Paul Scarpelli]



Quote:
Originally Posted by Kal Rubinson /forum/post/15772779


Why would I do that? I was subtly admitting that I should have said that.

Obviously, you posted in a hurry, or you would have included that info as well. I defer to your wisdom.

 

[Kal Rubinson]



Quote:
Originally Posted by RazorX /forum/post/15772818


Now I'm worried. Not really. OK, maybe a little.

I will be driving the L/R/C (86dB) speakers with a Emotiva XPA-3 amp rated at 200 watts/channel. I will be using the amplifier section of an Onkyo TX-SR705 AVR rated at 100 watts/channel to power the surround (94dB) and rear (93dB) speakers.


Based on what I gather from Paul's statements - it sounds like I have the potential to have greater volume generated from the surround and rear speakers (as they are more efficient) than the front L/R/C speakers (due to them being less efficient) during more dynamic passages but...it likely will not manifest into a significant or common problem due to the very nature of the content that is sent to the surround channels. Correct so far?


I would also assume the fact I am using a separate/dedicated and more powerful (although not 4x) amp to power the fronts and the less powerful AVR amp to power the surround and rear speakers will help out somewhat. Is this a correct assumption?


It may (or may not) be worth noting I have my system in a relatively small room (11'6" x 16' x 8') and never feel the need to play movies above -20 - -15 (with all of the channels calibrated to 75dB at 0).

Since you have 3dB more power from the 200wpc amp than from the 100wpc amp (assuming all are honest and comparable ratings), that leaves only a 3-4dB discrepancy between front and back. Very likely not going to be a problem.

 

[Kal Rubinson]



Quote:
Originally Posted by Paul Scarpelli /forum/post/15772891


Obviously, you posted in a hurry, or you would have included that info as well. I defer to your wisdom.

Don't you dare.

 

[RazorX]

Thanks guys. I really appreciate the input.

 

[Filby1]

Can i just add, how does say adding a sub crossing over at 80Hz effect things given that an AV reciver will make the speaker small and therefor not full range eliminating most of the deep base a full range speaker would need to do in a 2 ch setup?

 

[Kal Rubinson]

Adding a sub will increase the headroom for all the bass-managed channels.