SPL ...the math hurts my head. - AVS Forum
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post #1 of 7 Old 02-01-2013, 08:15 PM - Thread Starter
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Looking at new speakers but concerned I will have a cascade of upgrades...so I want to make sure I can drive these bad boys...well.

What worries me some is that the are 6 ohm rated and 89 Sensitivity. So I would have LCR and two more rear speakers...

So using my handy dandy SPL calculator and making an assumption that I can try 6 ohm speakers nearly the same as 8 given the variance I appear to be "good"

http://myhometheater.homestead.com/splcalculator.html


I will be driving these with two rear eventually so 5.0 with a 135 watt Onkyo 818.

I should be "ok" right?

Now by "ok" I mean I shouldn't have huge performance gains by going with a seperate amp...at least for the front LR speakers? If I can't drive these and get good sound from my 818...then we are talking a whole lot more dollars down the road.

Sonus faber Venere are the speakers I am looking at...
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post #2 of 7 Old 02-01-2013, 08:36 PM
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+10 db = 10x power requirement.
+20 db = 100x power requirement.

Most AVRs are around 100w, so around +20db from the listed sensitivity of the speaker (at 1m).

If you sit more than 1m away you lose 3-6db every time your distance doubles.

1m = 0db
2m = -3db to -6db
4m = -6db to -12db

If you are worried about 6 ohms (and that's "nominal" or "minimal", not constant, anyway); then take the rated power from your source for 8ohm and 4ohm and presume the worst case.

What will a separate do? On paper that depends on the separate; though there are issues like the voltage limit on the rails which there's no standard reporting of but which is oft better on separates than on AVRs.
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post #3 of 7 Old 02-01-2013, 08:57 PM - Thread Starter
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Off subject: but are those B&W diamons in your avatar shot?

On topic: Is it true that if you push (some speakers) towards the top of their power handle (but not over) that they open up...and you can hear more seperation ..better bass..etc?)
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post #4 of 7 Old 02-01-2013, 09:42 PM
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Quote:
Originally Posted by Newbie01 View Post

Off subject: but are those B&W diamons in your avatar shot?

On topic: Is it true that if you push (some speakers) towards the top of their power handle (but not over) that they open up...and you can hear more seperation ..better bass..etc?)
They are Nautilus 801's (well, it is half of a pair of N801's).

I would say "no"; though as SPL increases your hearing changes. http://hyperphysics.phy-astr.gsu.edu/hbase/sound/maxsens.html
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post #5 of 7 Old 02-01-2013, 10:08 PM - Thread Starter
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Getting more edumecated as I go... I called they were B&W at least smile.gif
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post #6 of 7 Old 02-02-2013, 07:57 AM
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Quote:
Originally Posted by Newbie01 View Post

Is it true that if you push (some speakers) towards the top of their power handle (but not over) that they open up...and you can hear more seperation ..better bass..etc?)

Audiophile myth. If it were true, speakers would only ever sound good very loud and have no dynamic range. Consider that you often listen to music at less than 0.01 Watt, so if it takes 100 Watts to sound good, everyone is in trouble.

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post #7 of 7 Old 02-02-2013, 09:02 AM
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Originally Posted by psgcdn View Post

 Consider that you often listen to music at less than 0.01 Watt, so if it takes 100 Watts to sound good, everyone is in trouble.

 

Whew...

 

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