My Cinema Sounds Great BUT RT60 decay, Spectrogram and Waterfall graphs look horrible

[socbutter]

I have used Obsessive Compulsive Audiophile excellent tutorial to calibrate my home cinema. My cinema sounds great. but the graphs look horrible.
I do not know how to evaluate the graphs, but from Audioholic's video How to Measure Good Room Acoustics my RT60 decay graphs do not look good.

My room consists of RealTraps "MondoTrap in each of the four wall-to-wall corners" and "the top of each wall where it meets the ceiling",
GIK Acoustics FreeStand Bass Traps (4" x 24″ x 60”) on the side walls and
Sonitus Bigfuser II Acoustical Diffuser are on the rear wall and rear ceiling.

The side wall treatments placements are based on page 5 Sonitus Standard 150 asymmetrical plan
There are no spaces between panels and not placed 24 inches above the floor.

Room dimensions and speaker placements are provided in the Room Simulation tab.

I like to have good looking graphs with great sound. Any help you could offer would be appreciated! Thank you.

 

[thothsong]

Look at the Distortion tab; all of your measurements show extreme THD. Are you sure your mic is good?

 

[sam_adams]

Something has gone horribly wrong with those measurements.

Filtered Impulse:

RT60 (note the scale on the left is set to 3.5 seconds):

It's almost as if there was some additional processing or monitoring going on during the measurement. Also, you had a Frequency Dependent Window set for these. You don't need that when measuring the room response as it's going to limit the lowest frequency. Turn that off and double check your signal chain before measuring again.

 

[socbutter]

Thank you for your help.

I when ahead and ordered a New

Dayton Audio UMM-6 USB Measurement Microphone​

A new HDMI cable and 16ft usb extension cable. All from amazon for easy returns. Will arrive by Friday 9/29​

@sam_adams
uncheck Frequency Dependent Window in Preferences--> Analysis tab?

I connected the umm-6 mic directly to my laptop, eliminating the 16ft usb cable, REW ran without any error messages! Unfortunately, the cable is too short with the mic at the rear door. Also unchecked Frequency Dependent Window.

I"ll wait until Friday to report back.

Thank you, thank you and thank you

 

[socbutter]

I replaced both USB extension cable and the umm-6 USB-A TO USB-B 2.0 cable. I also tried a different USB connection on my laptop.
This is the result>

As soon as the new Dayton Audio UMM-6 USB Microphone arrives later today I'll give that a try.

 

[sam_adams]

I replaced both USB extension cable and the umm-6 USB-A TO USB-B 2.0 cable. I also tried a different USB connection on my laptop.
This is the result>

As soon as the new Dayton Audio UMM-6 USB Microphone arrives later today I'll give that a try.

When you say 'extension cable', do you mean one like this:

or a repeater cable like this?:

If you are using an extension cable that doesn't have a signal boosting repeater built into the cable, you may run into the issue you are experiencing.

 

[socbutter]

@sam_adams

I've used non-active USB cable always, but I'm will try an active USB cable tomorrow.

 

[sam_adams]

@sam_adams

I've used non-active USB cable always, but I'm will try an active USB cable tomorrow.

You should limit any passive cable to fifteen feet or less. If you need a longer cable, consider using an active one that is as short as is practical to maintain signal integrity.

 

[ddude003]

I'm pretty sure that the generic spec for USB is 10 ft and the UMM6 comes with a 10 ft USB cable... And there are some exceptions... Best to figure out exactly what your computer USB spec is and exactly what your Mic USB spec is and go with the conservative of the two spec(s)... Google is your frenemy... Heck, the new high speed USB spec is 4ft...

 

[sam_adams]

As long as the USB cable meets the correct AWG requirements for both power and signal conductors, the recommended length is five meters (16.5 ft). The actual spec allows for greater length for USB 2.0, but reliability can be compromised as long user experience has shown.

 

[Johnnie]

Your room seems small and if it is, you’re sitting too close to your diffusers. Try removing “all” of your diffusers, leaving only your bass absorbers and retest. Room otherwise looks good though.

 

[socbutter]

I switched out all the cables non-active USB extension, active USB extension, new and old umm-6 USB-A TO USB-B 2.0 cable, no extension cable, new HDMI cable, my wife's Laptop and a new umm-6 Microphone.

I'm now getting the Clock adjustment too large and High Measurement Distortion windows when measuring my speakers.

What can I show you guys? My WIN10 settings {are set per the document
Getting Started with REW: A Step-by-Step Guide (Rev 6.5, Dec 31, 2022)}

The only thing I have not tried is switch the front HMDI input(AUX) in my DENON AVR to one in the rear of the AVR.

All I want to do is confirm the calibrations added to Audyssey.

 

[ddude003]

You might try reinstalling REW, unticking hardware acceleration when installing...

 

[sam_adams]

I'm now getting the Clock adjustment too large and High Measurement Distortion windows when measuring my speakers.

The clock adjustment error may be an indication that REW is having an issue detecting the timing chirps at the start and end of the sweep. This could also indicate that there is some latency issue in the system itself. Increasing the ASIO buffer to the maximum value might solve this.

The only thing I have not tried is switch the front HMDI input(AUX) in my DENON AVR to one in the rear of the AVR.

That is an option—as is using a shorter HDMI cable. Another thing to try to fix the clock adjustment error is to reinstall REW with the hardware acceleration option in the installer unchecked.

 

[socbutter]

1. Increased ASIO buffer to maximum, Ran REW v5.20.14. This did not work,
2. Uninstall REW V5.20.14 and installed REW V5.20.13
3. Ran REW but microphone volume too low
4. Increased UMM-6 Volume level to 100% in WIN10
5. RAN REW SUCCESSFULLY
6. I think everything is good, but I would like someone with more experience to tell so or not.

THANK YOU THANK YOU!

P.S. How do I mark this SOLVED?