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Share your in-room measurements?

MaxRockbin

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Stupid question from me: why do we measure L and R separately, rather than LR together? When I measure them both together (post-EQ), I get very different results than an average of the two. In particular, there are often large cancellations evident that I can only get rid of by smoothing the response even more. :cool:
Amir prepared this video explaining why he tests mono instead of stereo if you would like a detailed (very) answer:
 
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abdo123

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Amir prepared this video explaining why he tests mono instead of stereo if you would like a detailed (very) answer:

This has nothing to do with what you're replying to?

Stupid question from me: why do we measure L and R separately, rather than LR together? When I measure them both together (post-EQ), I get very different results than an average of the two. In particular, there are often large cancellations evident that I can only get rid of by smoothing the response even more. :cool:

in most mixes bass is 'mono' below 200Hz, so it might be insightful to look at the response of both below 200Hz.

otherwise both responses should be managed independently as they receive two different signals.
 
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aac

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Stupid question from me: why do we measure L and R separately, rather than LR together? When I measure them both together (post-EQ), I get very different results than an average of the two. In particular, there are often large cancellations evident that I can only get rid of by smoothing the response even more. :cool:
If you measure them together comb filtering (interference) can affect your results (often quite strong).
So always measure separately.
The only area you can measure them together is bass (as it's mono in the recording as rule).
 
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GDK

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Thanks for the above responses which all make sense, For some reason (likely user error) I was getting a 25dB cancellation in the sub-bass that wasn’t appearing when the channels were measured separately. However, magically it has disappeared now and so all is good.
 

Chromatischism

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Thanks for the above responses which all make sense, For some reason (likely user error) I was getting a 25dB cancellation in the sub-bass that wasn’t appearing when the channels were measured separately. However, magically it has disappeared now and so all is good.
It is a useful test though, if you are not using a subwoofer or a center channel speaker, you will have that phase cancellation in real use.
 

SAC_2

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I got my system somewhat tuned, but I'm looking to start tailoring the target curve to taste. From what I'm seeing nobody uses something like the equal loudness curve, particularly in the mid/high range. Seems like people generally roll off the high end, which REW allows for by default. Why?
 

Chromatischism

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I got my system somewhat tuned, but I'm looking to start tailoring the target curve to taste. From what I'm seeing nobody uses something like the equal loudness curve, particularly in the mid/high range. Seems like people generally roll off the high end, which REW allows for by default. Why?
Be careful when looking at the high frequency in-room "roll off". Much of that result depends on how wide or narrow the tweeter disperses its sound, how close the walls are, and how far away the listening chair and microphone are. The speakers themselves could measure flat but show a "roll off" in-room.
 

SAC_2

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Be careful when looking at the high frequency in-room "roll off". Much of that result depends on how wide or narrow the tweeter disperses its sound, how close the walls are, and how far away the listening chair and microphone are. The speakers themselves could measure flat but show a "roll off" in-room.
I think people are making their measurements at listening positions in this thread. That's what makes the high frequency roll off seem strange. Speakers should be angled on axis etc.

My room is different (speakers are on the ceiling) so I am going to have to compromise... but I'm just looking for some ideas on how to subjectively tailor the sound.
 

Chromatischism

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I think people are making their measurements at listening positions in this thread. That's what makes the high frequency roll off seem strange. Speakers should be angled on axis etc.

My room is different (speakers are on the ceiling) so I am going to have to compromise... but I'm just looking for some ideas on how to subjectively tailor the sound.
Many box speakers don't sound their best on-axis. It's actually an issue I have with many reviews - they assume on-axis is best and don't always consider that it may not be.

Your situation with on ceiling speakers is different. I have no idea how those measurements should look.
 

radix

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I'm a REW newbie. I've measured L and R separately. If I want to look at the average response, do you go raw - avg - smooth, or smooth - avg?

Here's my old Beolab 4500s, which are an active wall mount. They are supposed to be 54 - 20k, with a crossover at 3500 Hz. They are driven by a RoPieee to SHD to speaker via line level RCA right now. I cannot find the wall mount for them, so they are literally sitting on a hardwood floor a bit under a piece of furniture. So, it's pretty bad positioning and they are about 45* off alignment from my listening position where the umik-2 was. But with all of that, DRC isn't too bad.

Orange is raw-avg-smooth, and green is smooth-avg. Both are psy avg.


beolab-4500-avg.jpg
 

Zedly

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I decided to play around with Multi-Sub Optimizer (MSO) and got some very good results from my dual SVS SB12-NSD with miniDSP 2x4 HD. I optimized for 85 dB from 20 Hz to 120 Hz and told MSO to minimize seat-to-seat variations between the seats on my couch and a chair. Here are the before and after graphs.

Subwoofers - No EQ.png

MLP - MSO.png

All Seats - MSO.png
 

Le Concombre

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Parsing through the thread, I'm pretty amazed by the quality in room responses some of you get even prior to eQ and I even wonder if I would eQ at all in some instances. I'm also amazed by the bass level of desktop or bookshelf speakers presented here, wondering once more how far from the territory is the map. BTW these are quick and dirty MMM and sweeps done prior to eQ show HF roll offs while MMM are flatter above 10K. I don't bother since I have not applied any correction above 280 Hz. The better "target" fit is obtained with the attached iteration of Harman of which I would be a bit bass shy but it's been done with the top priority of interfering the least : 5 eQ points for L and 7 for R are involved in the making : it's more about being in the right ball park with little intervention than being good looking. This year I purchased a Meyer CP 10 to eQ my vinyl gear and there are only 4 useful knobs per channel : excellent results obtained paved the way for this minimalist approach even when digital offer infinite eQ points. Speakers are large active and play 92 dB forte of a Beethoven's symphony easy and 96 dB C at LP is comfy and rewarding with some pop and jazz
 

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sigbergaudio

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Here's the curve I mentioned earlier. Is there anything wrong with using the "trained listeners" line as a house curve in REW, but with a slight boost in bass to match my personal preference? That's the purple line in my previous post. I also thought that you should never EQ to a completely horizontal line in a typical reflective room (i.e. not an anechoic chamber), but I see some people doing that in this thread. @Chromatischism has mentioned that as well so maybe I'm not alone.

View attachment 148998

Note that the "trained listeners" curve has negative treble as opposed to "all listeners", so the bass level is almost identical. The main difference between all listeners and trained listeners is a more even decline through the mid-bass area. So the trained listeners curve has more energy in the mid-bass/lower midrange area (~100-500hz).
 

sigbergaudio

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Two different loudspeaker setups (same dual subs) in the same room. EQ is applied below 3-400hz.
1637657312342.png
 

Ata

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Parsing through the thread, I'm pretty amazed by the quality in room responses some of you get even prior to eQ and I even wonder if I would eQ at all in some instances. I'm also amazed by the bass level of desktop or bookshelf speakers presented here, wondering once more how far from the territory is the map. BTW these are quick and dirty MMM and sweeps done prior to eQ show HF roll offs while MMM are flatter above 10K.

I can't think of a good reason for more than a couple of db difference between MMM and point sample above the room transition frequency, apart from SBIR which should not be a huge issue at 10KHz and above.

Did you use a timing reference signal with the sweeps? If there is any delay in the chain, there could be impact on the HF curve. Long time ago I measure an AVR via its Airplay input and say -20db at 8KHz, which was clearly wrong. Adding the timing reference sorted that out.
 

Le Concombre

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I can't think of a good reason for more than a couple of db difference between MMM and point sample above the room transition frequency, apart from SBIR which should not be a huge issue at 10KHz and above.

Did you use a timing reference signal with the sweeps? If there is any delay in the chain, there could be impact on the HF curve. Long time ago I measure an AVR via its Airplay input and say -20db at 8KHz, which was clearly wrong. Adding the timing reference sorted that out.yes timing reference signal was used with the
Thank you, yes timing reference signal was used with the sweeps since I cared about fooling with time domain (via RePhase) back then. Actually I did MMM back then which did not show those HF differences. Nowadays my Umik stays put behind and above LP for SPL measurements and craziness, it's pointed towards the ceiling and calib file is 90° : think that's the cause for discrepancy rather than SBIR. Anyway I don't really care for more and more I don't believe in nice looking graphs and maps telling anything about territory but rather privilege right ball park obtained with fewer interferences and none above Schroeder. Anyway here is to compare sweep's and MMM's HF. Scale is 5 dB between horizontal lines
 

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soundwave

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My measurements with an Umik-1, in my badly treated room.
First speakers Adam T5V
Second speakers Dynaudio XD 600


adam.png
dyna.png
 

thewas

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Vintage57

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My best to date, REW with Umik-1 mike.
KH420 running through KH805 high pass at 80 Hz.
It took 3 KH805 in daisy chain to smooth out the bass in my room.
The best sound I’ve heard in my home.

PS
No EQ and no DSP ‍:)
 

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pozz

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My best to date, REW with Umik-1 mike.
KH420 running through KH805 high pass at 80 Hz.
It took 3 KH805 in daisy chain to smooth out the bass in my room.
The best sound I’ve heard in my home.
Could you please share the mdat?

In general, if everyone posts their mdats we could do a pretty good study. Not very controlled of course.
 
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