How do I finalize speaker levels?

[aaharvel]

i have an H/K 235 as a pre amp and for my front L & R speakers (Polk rti-4). I have a 2ch. Adcom 5300 amp at 80watts per ch. For my Center (csi-3), Sides and Rears (F/X 300i) I have a 5ch. Adcom 7300 amp at 60 watts per ch. All speakers are 8ohm and have identical sensitivity at 89db.

I did the math and considering that +3 db doubles the power or volume: on the 60 watt amp +3 db. would be 120 watts, +2db would be 100watts, +1db would be 80watts (this would match my 80watt amp for my front L&R) and 0db would be 60watts.

My question is: Do I set Center, Side and Rear Surround levels on the H/K at +1db so that the power from the 60 watt amp equals that of the 80 watt amp or should I keep all channels set at 0 db on the H/K regardless?

(EDIT) i'm not needing advice on measuring volume via an SPL meter- this is merely a theoretical question regarding power delivery between 2 amps working together with a set of 7 speakers. Regardless if set at 0db or +1db everything seems to sound similar.

[Dennis Gardner]

Forget the math, sensitivity, and power levels. 10 watts from any amp will make the same sound levels as each other.

To setup properly, you need a spl meter to set them at the same levels in your listening spot. Amp power should have nothing to do with the settings at normal levels. The power comes into play only when you reach that power output level as the higher power amps will allow louder levels, but the difference can't be heard when they are all putting out 10 watts into similar speakers. This is really true if the amps from the same maker.

The settings will probably only be 1db difference with speakers as similar as you are using. This may mostly be due to distance from your seating.

Not to be flippant, but 1 watt into your speakers from a 1 watt amp will be exactly as loud as 1 watt into your speakers from a 1000 watt amp. It only matters when you want 2 watts.

I hope this helps,

DG

[Dennis Gardner]

Originally posted by aaharvel
Regardless if set at 0db or +1db everything seems to sound similar.

Most humans take 3db changes to notice a difference in volume.



When using the SPL meter, the setting of speakers is made around the normal listening levels of 70-85db to eliminate the small differences that may exist between amps.

[unc2701]

One thing to add- not all amps have the same gain... Since you're using Adcom's from the same product line, the gain on each is similiar, however some amps will produce somewhat higher or lower wattage for the same input voltage (which you can iron out with an SPL meter).

[aaharvel]

sounds good to me.

as i've said before i've already gotten the speaker levels within 1-2 db. with the spl meter- i was just wondering about the 60watt vs. 80 watt performance, that's all.

i've decided to simply leave all levels at 0 db.

thanks again for the feedback- everyone.

[aaharvel]

Hello?!?
Problem solved guys.

Let's kill my thread now. =)