Waterfall Graph Question - REW

[Darkscience]

Ok so I snipped this waterfall graph from REW. I kind of have an idea how to read this but not 100% sure what to do with it. Is this suggesting I get bass traps designed for the long decay time frequency ranges? Any tips welcome.

 

[HarmonicTHD]

The waterfall shows you how quickly each frequency decays (or inversely how long it „rings“ ie is present).

I think it doesn’t look bad at all. The ringing below 40Hz is some 20dB down. And above 40Hz, hardly extends beyond ca 400ms. Personally I would even leave it as is. If you are happy too, don’t sweat it.

Bass traps, which take care of frequencies below 40Hz are huge unwieldy things (size correlates to the wavelength of the frequency you want to treat). You have to first decide if you want those in your room. And there are also other downsides to their use (no free lunch).

If you can get your hands on Floyd Toole „Sound reproduction“ read the sections on Room Modes, Sub Placement, Room Treatment and Decay Times.

 

[alex-z]

Your response already looks great compared to most rooms.

I would check seat to seat consistency, and if it is good, use EQ to pull 2-3dB out at 40Hz. Then maybe add some 6" absorbers to tidy up the 100-200Hz region.

 

[amirm]

Any tips welcome.

Here is the major one: it doesn't tell you anything frequency response doesn't! It is pretty to be sure but of very limited value. If you look, wherever you have a peak in frequency response, there is also a long "tail" until that dies down. Use EQ and pull those peaks down and the tails reduce with them.

 

[Kvalsvoll]

Here is the major one: it doesn't tell you anything frequency response doesn't! It is pretty to be sure but of very limited value. If you look, wherever you have a peak in frequency response, there is also a long "tail" until that dies down. Use EQ and pull those peaks down and the tails reduce with them.

It does not show much meaningful information, but that is due to the signal processing and the waterfall graph being more nice to look at than good for showing information about the response of the system.

Try reducing rise time to 10ms. With 100ms rise time, all information is lost. Impossible to see resonances and the true decay profile.

Try viewing the Decay graph instead, it is not so nice to look at, but is now possible to see resonances and decay profile, and also compare to other systems or some reference. Start out with 20ms lines, with 20ms rise time, try reducing down to 1ms rise time, observe. You will now be able to see resonances, and then be able to do something about it.

 

[dasdoing]

neither waterfall, nor decay.
use spectogram and check the "normalize to peak each frequency" box.
eq a bluetooth speaker in the bathroom to get rid of the FR shows all myth

 

[Darkscience]

Thanks everyone, going to need a mental break, the system is sounding killer and that is what matters. Need to enjoy the music for a few days and come back to this when I have some free time. I learned quite a bit from the comments.

 

[ernestcarl]

All the graphs can be informative even if being only one-dimensional... still, it helps to compare the different views, filters, and settings to figure out how they might relate to each other (or not so much).

Two different measurements (equalized) taken in rooms with polar opposite damping characteristics:

Which on-axis measured response at the main listening position (MLP) looks better?

IMO, although not having listened to the room highlighted in red, the more uneven (and maybe overly dry) yet extended response (green trace) should be a far "better" room for critical listening.

Wavelet Spectrogram:


RT60 Decay:

*some people argue that it's inappropriate to call it "reverb" time in small rooms, hence "reflection-decay" time seems more apt a descriptor