Topic: room correction with ADI-2 eq

Hi,

I have some standing waves round 66Hz and here and there other quirks that I'd like to get rid of via eq-ing.
Normally I would be fully opposed to adjusting via eq, but with ADI this would work like a breeze.

My thought process is:
Play white or pink noise, take a measurement mic and analyze it "live" via spectrum analyzer, then go adjusting ADI 's eq first side L and then side R until the curve is approx flat, or, as linear as reasonably possible.

Would you agree? Would you suggest placing the mic in the listening position or take two mic and place them left and right from the listening position, or even place them in multiple spots?

ADI2, Digiface, ARC

Re: room correction with ADI-2 eq

it sounds like a good idea. I use ADI-2 this way too.

you need to measure multiple spots and take the average.

3 (edited by KaiS 2022-05-13 20:35:54)

Re: room correction with ADI-2 eq

If you have an iPhone get the app AudioTools by Andrew Smith.
https://apps.apple.com/de/app/audiotools/id325307477


This changes the iPhone into a full blown, self content and calibrated Audio Analyzer, using the internal microphone with high precision.
The 1/3 Oct. Real Time Analyzer is free.
So is the FFT Analyser, which can’t be set to a higher resolution.

Most important:
This analyzer is capable of averaging over a time period.
Just slowly move or rotate the iPhone through an area across the listening position(s) during a measurement run.


If you just want to correct the low frequency range only, it’s usually best to use monophonic pink noise (bass is mostly monophonic in the music mix) and correct both speakers at the same time.

This way even the important phase relationship between left and right is taken into the result.


For higher frequencies use L/R uncorrelated Pink Noise.
Different settings of left and right speakers are not desirable.
If those are needed it’s a sign that the speakers are broken.

Keep in mind:
The human ear can differentiate between direct and reflected signals.
The measurement microphone can not.
Therefore corrections in the far field, above 300 Hz, usually don’t have the expected result.

Re: room correction with ADI-2 eq

Thanks KaiS and yes, I was aiming to smoothen out the bass freq upto 200Hz or so.
Did an attempt with uncorrelated pink noise with a measurement mic but I needed to put on ear protection in order to get the spectrum visible in wave lab during recording. Guess there's some background noise (though it is 45dB max) that is disturbing. Therefore I believe your suggestion to use an app dedicated to room correction is better indeed.

Oh I wish I could put the signals into RME, but well, I have a motu smile But still it's a pain in the xxx

ADI2, Digiface, ARC

Re: room correction with ADI-2 eq

I found this tool helpful. You input your room dimensions and it'll show likely problem areas. Then you could hover your mouse over the frequency where modes are likely and it'll play a sine tone at that frequency. Then you can move around your room and see where the tone increases or decreases in volume.

https://amcoustics.com/tools/amroc

For example, I have both a 60hz dip and a 162hz spike. Fixing the spike by EQing it down works very well, and boosting 60hz HELPS but when I play the sine tones around that range I can still hear the dip as I move in and out of my listening spot. I'm hoping that increasing my cloud from 4" to 7" will help.

I also used SonarWorks' very thorough measuring system to get my room response for Left and Right speakers. I only use SonarWorks for their measuring (I don't like how their correction sounds), so I just sign up for a free trial with a new email every few weeks...

Here's a link to images of my room measured before and after EQing:
https://drive.google.com/drive/folders/ … sp=sharing

6 (edited by KaiS 2022-05-13 20:57:18)

Re: room correction with ADI-2 eq

Virtual modeling a room is nice if you’re about to built a room or place speakers or choose a listening position etc.

If the room and speakers and everything already exists, a measurement of the real thing is simpler (takes a minute) and precise.


I even found the correlation between modeling and reality not too good.

In a real room there are too many parameters that cannot easily be determined, like surface elasticity (hinged ceiling, wooden walls and floors, doors and windows etc.), the influence of furniture ...
The speakers themselves are complex systems and hard to model.

Re: room correction with ADI-2 eq

I found this free room-correction application for Windos, MacOS and Linux.
- It can create a list for parametric EQ settings: frequency, dB and Q-factor.
- The short tutorials below are very helpful and tell you what and NOT to do!

https://www.roomeqwizard.com/

German https://www.youtube.com/watch?v=5vL2KdUjqiQ
English https://www.youtube.com/watch?v=Rmd5HgODQDg

I'm now on the point to buy a measuring microphone and digital interface (I have a RME DAC without microphone input). Does anyone have experience with the Behringer ECM8000 microphone with correction file?

8 (edited by unpluggged 2023-12-06 18:21:39)

Re: room correction with ADI-2 eq

wbartels wrote:

I'm now on the point to buy a measuring microphone and digital interface (I have a RME DAC without microphone input). Does anyone have experience with the Behringer ECM8000 microphone with correction file?

Just get a miniDSP UMIK-1. It works with REW and I recently used it to EQ my speakers with the ADI-2 Pro. Its advantage over the Behringer is that it is not only calibrated for frequency response, but also it's a calibrated SPL meter. And it being a USB device, you don't need an interface for it.

Re: room correction with ADI-2 eq

unpluggged wrote:

…  And it being a USB device, you don't need an interface for it.

Might be a problem to access 2 USB audio interfaces at once from REW:
ADI-2 for playing the measurement signal, and the mic for recording it.

I vaguely remember there is a solution to combine both into a single virtual USB device.

Re: room correction with ADI-2 eq

KaiS wrote:
unpluggged wrote:

…  And it being a USB device, you don't need an interface for it.

Might be a problem to access 2 USB audio interfaces at once from REW:
ADI-2 for playing the measurement signal, and the mic for recording it.

I vaguely remember there is a solution to combine both into a single virtual USB device.

PC USB to DAC USB, UMIK-1 to PC USB, works great.

11 (edited by unpluggged 2023-12-07 17:47:48)

Re: room correction with ADI-2 eq

KaiS wrote:
unpluggged wrote:

…  And it being a USB device, you don't need an interface for it.

Might be a problem to access 2 USB audio interfaces at once from REW:
ADI-2 for playing the measurement signal, and the mic for recording it.

I vaguely remember there is a solution to combine both into a single virtual USB device.

It's the other way around: you can't use more than one ASIO device at a time. But when Java API is used you can select different devices for playback and capture. I had almost no problems using them both. Just make sure to set the ADI-2's SR to 48 kHz, as this is the only SR supported by UMIK-1.

12 (edited by wbartels 2023-12-08 22:56:18)

Re: room correction with ADI-2 eq

Thanks all for the feedback, this is very helpful!!

I have done some experiments and can confirm that two devices is possible on MAC mini (M2):
The input and output can be selected separately from different internal and external (for example USB) sources.
This is enough there is no need for two outputs simultaneously, but if you need it add a "Create Multi-Output" in the "Audio MIDI setup" app.

Because my Mac mini is not in the same room as the RME and Main speakers.
I will use a XLR mic for input and toslink for output.
(The RME dac is connect to my TV and Ubuntu server with Music Player Daemon).

I still will do some research for I order.