# What frequencies peaks and dips aren't significant?



## JimP (May 18, 2006)

I've read post from time to time where someone would post a REW graph with a pretty large dip or peak and comment that they don't seem to hear it. The response was that it apparantly wasn't at a fundamental.

My question is what are these frequencies?


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## thewire (Jun 28, 2007)

There are many other factors that can be mistaken for having to do with the rooms dips or peaks. There are dynamics, noise, phase, timing, distortion, impedence, crossovers, filters, and the list goes on. There are many other things that contribute to percieved flat response before the signal even reaches the speaker, then leaves into the room. It could also be that they don't have broadband absorption and they percieve only those sounds that arrive at the listening position that are even in decay, and everything else is just the room's resonance which might seem to add a reverberation effect rather than hearing some kind of note.


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## no. 5 (Jul 4, 2007)

JimP said:


> I've read post from time to time where someone would post a REW graph with a pretty large dip or peak and comment that they don't seem to hear it. The response was that it apparantly wasn't at a fundamental.
> 
> My question is what are these frequencies?


Well, there has to be musical energy where the peak or dip is for it to be detectable, so a 24dB peak at 60Hz will go unnoticed when listening to a violin solo. Energy distribution depends entirely on the instruments' being played.

The other thing is that those variations in response are very likely audible when energized, but they don't bother the listener in question, and our hearing's ability to adapt is remarkable, so there is a good possibility that if given the opportunity to compare with and with out the peak/dip it may be found more objectionable.


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## fredk (May 14, 2008)

> and our hearing's ability to adapt is remarkable


Along with room treatements, I think this is one of the most overlooked things in audio.

I have read a number of times that if a peak or dip is very narrow, it is less likely to be noticed.


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## thewire (Jun 28, 2007)

I wonder if they mean fundamental frequencies involving Intermodulation or the length of the sound wave. :scratch: Pink Noise can reveal dips or peaks in a room. According to the Master Handbook of Acoustics so does classical music. :huh:


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