47Hz room mode woes...

[sam_adams]

0 degrees pointed to the midpoint of the speakers

Dolby recommends 45º to the vertical at the console seating position for level setting in a multi-channel studio setting. Pointing the mic forward towards the speaker midpoint at the MLP would require a .cal file for the mic off-axis response.

Dolby 5.1 Channel Music Production Guidelines - Issue 1

See Section 3.4.3.

 

[nvidia_7]

Nope. Eg Neumann MA1, dito Genelec GLM. MIC at 90deg. See also REW instruction. Yes both have their purpose but here I would also measure at 90 deg.

Still doesn’t explain the wavy HF response. My bet. Put the speakers on stands.

This is what I get with them off the desk and sitting on a stand. To my eyes this looks much better, a downward slope as you'd want for in room response.

 

[Daverz]

Nope. Eg Neumann MA1, dito Genelec GLM. MIC at 90deg. See also REW instruction. Yes both have their purpose but here I would also measure at 90 deg.

Still doesn’t explain the wavy HF response. My bet. Put the speakers on stands.

From the REW "Getting Started" guide:

• A tripod to support the mic or meter (hereafter just called "mic"). Small movements of the mic can result in large variations in the measurements, for repeatable results a means of supporting the mic for a prolonged period is essential. For low frequency measurements (below a few hundred Hz) the mic can be set pointing straight up. This avoids having to move it to measure different speakers and makes it easy to read the display on a meter. Use a "90 degree" mic calibration file if pointing the mic upwards. To make measurements at higher frequencies it is best to point the mic directly at the speaker being measured. Use a "0 degree" mic calibration file in that case. In both cases the mic should be placed at ear height in your usual listening position.

 

[HarmonicTHD]

This is what I get with them off the desk and sitting on a stand. To my eyes this looks much better, a downward slope as you'd want for in room response.

Yep. Much much better.

Now EQ out the LF peaks and all is well.

 

[nvidia_7]

From my short time reading, it would appear that putting speakers directly on a hard surface such as a desk causes "comb filtering", as the FR measurements I saw matched mine almost perfectly. That makes the idea of "desk speakers" a non-reality.

 

[MaxwellsEq]

From my short time reading, it would appear that putting speakers directly on a hard surface such as a desk causes "comb filtering", as the FR measurements I saw matched mine almost perfectly. That makes the idea of "desk speakers" a non-reality.

That's always been the case with speakers on a desk, but for some installations it may be the only choice.

 

[AudioJester]

Whats the crossover point with the sub?
First simple step may be turning down the sub and/or moving it.

 

[nvidia_7]

Ok, just want some input on my current progress in getting these lsx ii's dialed in. The top graph in red is the before, and the bottom graph in blue is where im at currently. This is with a KEF Kube 10b, which I have no ability to EQ. My first question is, if I get a sub such as the Arendal 1723 1s which has a 7 band PEQ, would that help me to get rid of the 47.5Hz mountain? Or would it affect too much of the nearby frequencies? And secondly, how is my overall FR looking?

 

[DVDdoug]

which has a 7 band PEQ, would that help me to get rid of the 47.5Hz mountain? Or would it affect too much of the nearby frequencies?

With parametric EQ you should be able to adjust the center-frequency and width of the filters. The width may be listed as "Q", where a higher Q is narrower. You should be able to make a dramatic improvement, although you don't usually get "ruler flat" results.

..And, you might LIKE a little bump-up in the bass! If you listen at low volumes you might "need" a bump in the bass.

 

[Sokel]

One thing I noticed is that the umik-1 shows 15dB less sound than my stand-alone dB meter. Maybe my mic is defective?

So,your sweeps are at 90db?
That may not be nice for those speakers,try (much) lower.

You can also calibrate your mic againt your SPL meter,use REW's SPL tab,is easy.

 

[nvidia_7]

So,your sweeps are at 90db?
That may not be nice for those speakers,try (much) lower.

You can also calibrate your mic againt your SPL meter,use REW's SPL tab,is easy.

I feel that my SPL meter may be off, as my iphone 15 pro max and the umik-1 measure within 1db of eachother. My iphone reads 76dB and the umik-1 reads 75dB. Volume is only at 63 when doing the sweeps to reach what the umik-1 is saying 75dB is.

 

[nerdemoji]

I feel that my SPL meter may be off, as my iphone 15 pro max and the umik-1 measure within 1db of eachother. My iphone reads 76dB and the umik-1 reads 75dB. Volume is only at 63 when doing the sweeps to reach what the umik-1 is saying 75dB is.

might be a db weighting thing. I would trust the umik especially if you calibrated it

 

[Sokel]

I feel that my SPL meter may be off, as my iphone 15 pro max and the umik-1 measure within 1db of eachother. My iphone reads 76dB and the umik-1 reads 75dB. Volume is only at 63 when doing the sweeps to reach what the umik-1 is saying 75dB is.

You're ok then,no need to calibrate.
The way I read it was that you did the sweeps super loud and the iPhone showed 90db and REW showed 75db but I probably got confused.

 

[nvidia_7]

You're ok then,no need to calibrate.
The way I read it was that you did the sweeps super loud and the iPhone showed 90db and REW showed 75db but I probably got confused.

Something else ive noticed though is that listening to music, around 51 on the volume is all I can handle before I think "this is too loud". Using my iphone it shows an average dB of 67 and peaks of 74dB.

 

[nerdemoji]

Something else ive noticed though is that listening to music, around 51 on the volume is all I can handle before I think "this is too loud". Using my iphone it shows an average dB of 67 and peaks of 74dB.

What are you defining as a peak? Is it instant like a drum, or a loud section? At least in my experience iphone doesn't show me peaks (as in a drum) properly

 

[nvidia_7]

What are you defining as a peak? Is it instant like a drum, or a loud section? At least in my experience iphone doesn't show me peaks (as in a drum) properly

Not sure how the app is defining peak, I use the pro version of dB Meter.

 

[Sokel]

Not sure how the app is defining peak, I use the pro version of dB Meter.

There's basically three numbers you must look at.
Average,max and peak.
The first two are usually A or C weighted and peaks are Z weighed.

If you want to take a good look of how they work and see your actual peak,use REW's logger,is under the SPL tab and it looks like this:



Purple is Average (s),yellow is Max and Red is the peak.