# Setting sub level by pink noise makes it too loud?



## lorkp (May 26, 2010)

I'm guessing that we use pink noise to set the speaker level because pink noise acts as an average level for the speaker's entire range? At least that's my understanding.

With my sub, after equalizing to match the target level (75 dB), why use pink noise to readjust the level? Isn't the subwoofer pink noise only try to approximate an average of the lower frequencies?

Besides, I'm finding that leveling to 75 with pink noise for the sub leads the sub to be set way too loud. When I remeasure the sub, some frequencies are hitting 90 dB.

So, assuming the receiver's volume is set so that the mains are at 75 dB (with pink noise), is it okay to leave the sub level where it's at if I didn't have to change the target?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Question: What method did you use to adjust your sub level before you equalized it?

Regards,
Wayne


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## lorkp (May 26, 2010)

I basically turned up the sub to get the response I was looking for. When I had set it using pink noise, there wasn't enough volume in the 25-40 range. So I turned it up to the point where I was satisfied with the lower frequencies and then used the BFD to pull the higher frequencies into line.


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## Wayne A. Pflughaupt (Apr 13, 2006)

I don’t think we’re on the same page here. What you’re describing in your last post is not level setting, it’s _equalizing._ Equalizing has nothing to do with a sub or speaker’s SPL. The equalized curve that’s applied to a speaker or subwoofer will be the same no matter what the volume level is.

In your first post it sounded like you were asking about adjusting the sub level in its proper relation to the main speakers. That’s typically referred to as level setting. So, I’m really not sure what you’re asking - if you’re trying to understand pink noise, equalization, or how to adjust (blend) the sub’s level in relation to the main speakers.

Regards,
Wayne


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## lorkp (May 26, 2010)

Wayne A. Pflughaupt said:


> I don’t think we’re on the same page here. What you’re describing in your last post is not level setting, it’s _equalizing._ Equalizing has nothing to do with a sub or speaker’s SPL. The equalized curve that’s applied to a speaker or subwoofer will be the same no matter what the volume level is.
> 
> In your first post it sounded like you were asking about adjusting the sub level in its proper relation to the main speakers. That’s typically referred to as level setting. So, I’m really not sure what you’re asking - if you’re trying to understand pink noise, equalization, or how to adjust (blend) the sub’s level in relation to the main speakers.
> 
> ...


_Posted via Mobile Device_


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## lorkp (May 26, 2010)

I'm still talking about level setting. When the level is set and the sub is eqed, isn't the goal to measure 75 dBs across its assigned frequencies (assuming no house curve) and for that matter, having the entire speaker system read 75 dBs across all frequencies when the system is set to "reference level"?

I appreciate your help, Wayne.
_Posted via Mobile Device_


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## Wayne A. Pflughaupt (Apr 13, 2006)

Achieving 75 dB (or any other arbitrary value) “across all frequencies” for “the entire speaker system” would amount to picture-perfect, ruler-flat frequency response. That’s theoretically and factually impossible to achieve, from any speaker system in any room.

Even if it were – that’s _equalizing,_ not level-setting. Equalizing means smoothing out the peaks and dips in a speaker’s in-room response to something that’s flatter and smoother. Level-setting, for the purposes of home theater, is adjusting the SPL of the various main speakers in the system so that they’re all the same, then adjusting the subwoofer to a level that’s an appropriate blend with the mains speakers.

Regards,
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

If it helps, I’ll try to answer the questions in your first post.




> I'm guessing that we use pink noise to set the speaker level because pink noise acts as an average level for the speaker's entire range? At least that's my understanding.


Pink noise isn’t an average of anything. In basic terms, it’s a broadband signal with equal energy across the full frequency spectrum. However, for certain purposes and applications, the bandwidth of pink noise might be limited. 

For instance, the signal REW uses for the subwoofer test signal is pink noise, but it is filtered and only includes the bass frequencies. But for the frequencies it does generate, the signal is flat, not an “average” of anything.

You’d have the same thing with the cycling test signals for a home theater receiver’s calibration signals that are used to manually adjust the speaker levels. They’re pink noise, but limited-bandwidth that do not include the bass frequencies or the upper high frequencies.




> With my sub, after equalizing to match the target level (75 dB), why use pink noise to readjust the level? Isn't the subwoofer pink noise only try to approximate an average of the lower frequencies?


After equalizing, the sub’s level will change. For instance, if you had a 10 dB peak at 50 Hz, that peak is what was determining the level you had your sub set at, because it was audibly what you heard the most of. Once you eliminate that peak, it’s going to seem like the sub’s level is too low. So, it after equalization it will have to be re-adjusted.




> Besides, I'm finding that leveling to 75 with pink noise for the sub leads the sub to be set way too loud. When I remeasure the sub, some frequencies are hitting 90 dB.


If you still have some frequencies at a 15 dB peak after equalizing, you didn’t do a good job of equalizing. 




> So, assuming the receiver's volume is set so that the mains are at 75 dB (with pink noise), is it okay to leave the sub level where it's at if I didn't have to change the target?


Sorry, not sure what you mean by that. You don’t have to be concerned with any “target” after equalizing the sub. Just re-adjust its level using the same method you used before equalizing it – e.g. by ear, the receiver’s built-in test tones, a calibration disc, etc.

Regards,
Wayne


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## Drudge (Sep 1, 2008)

The other thing that may affect how you adjust your sub using band limited pink noise,is if you have a null in the area of 40-80Hz.That is where the band limited pink noise used for the sub channel in most AVR/pre-pros is generated and when that area is adjusted to read 75dB on an SPL meter the other bass frequencies in the sub channel are going to be outputing higher levels relative to the 40-80Hz region if the response is not even(flat) with the null.

You may be reading 75db,but the the other frequencies may be hitting 78-80dB or more depending on how deep of a null there is.


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## gdstupak (Jul 13, 2010)

In my experience, no you can not use pink noise to adjust the volume level of the sub. Whenever I tried to use pink noise, the subs volume would end up being way too high also.
Several years ago I discovered equalizers and now have eq's for all my speakers (each of my 2 subs have there own outboard eq's). I also have several test cd's with test tones in the range of 20khz-20hz. 

Here's the method I've used the last several years and don't know how I listened to music before it:
1. set up spl meter at listening area. set all eq sliders to neutral.
2. turn off subs (because I'm going to equalize the main speakers first).
3. to set the avr volume level I run a test tone somewhere in the middle, such as 300hz, and level the avr volume to 80dbls. NOW DO NOT TOUCH THE AVR'S VOLUME CONTROL UNTIL COMPLETELY FINISHED WITH EQ'ING!!!
4. now I run through the test cd and use the eq to level all frequencies to 80hz for my main speakers. My main speakers run 20khz-35hz.
5. now I turn on my 10" sub and set it's volume level. I run a test tone of around 40hz and set the subs volume to match 80dbls. NOW DO NOT TOUCH THE SUB'S VOLUME ANYMORE.
6. run through the test cd and use the eq to level all frequencies to 80hz for the sub. My 10" sub's range is 50hz-30hz.
7. now I turn on my 15" sub and go through the same steps to volume level and then eq it. My 15" sub's range is 40hz-below 20hz.

Buy some good eq's, go through a process like this and you'll think that someone swapped out your old speakers for much better ones. With my set-up, it's like the difference between DVD and Blu-Ray, I'll never go eq-less again.


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