I am in my shop. There is a yoga studio above me and they are very noisy an annoying. I can come back later tonight when it is quieter
I have 14 foot ceilings and its very big. Probably 50' accross and 50' to the back wall
Are you sure the loopback is working correctly?
Do you use a 2 channel measurement setup with ref input?
Edit:
I suppose you went through this website:
https://www.roomeqwizard.com/help/help_en-GB/html/makingmeasurements.html
Do you use a 2 channel measurement setup with ref input?
Edit:
I suppose you went through this website:
https://www.roomeqwizard.com/help/help_en-GB/html/makingmeasurements.html
Last edited:
Your level is very high for a normal frequency response measurement. 86 dB or 2.83 V input is more typical.
As discussed in the other thread, if the background noise is 30 dB below your signal, the influence to the measurement will be trivial. Did you take a measurement of the background noise to see how bad it really is during the day?
1) Your SPL is probably not calibrated correctly which is fine, as it doesn't really matter. But it may help you think through things when you get to your xo work to have it reasonably accurate. If you don't have an SPL meter, download one as a phone app and calibrate the SPL in REW just to keep things close. This will also avoid questions about SPL levels when you aren't really measuring at 129db.
2) Earlier it looked like you were getting reflections in your measurements, although that may be gone with your new delay settings. But...What is your speaker stand and mic stand like? If you have sharp surfaces then you may be getting reflections. If so, you can put some padding/foam on those surfaces. Here is an interesting test by Troels.
3) I try to follow the VituixCAD directions for REW EXACTLY. I know little differences may not matter much, but I'm not as experienced as most of these guys so I don't want to leave anything to chance. Here is a screenshot from the Vituix instructions. I don't know what difference it makes to have the Length 1M instead of 512k, but Kimmo has 1M so I use 1M. (I don't measure tweeters down to 5hz though.) I do notice that he has "Use loopback as cal and timing refernce" set, so that makes me wonder about your issues above. The instructions do have some REW setup steps on pages 3 and 4.
2) Earlier it looked like you were getting reflections in your measurements, although that may be gone with your new delay settings. But...What is your speaker stand and mic stand like? If you have sharp surfaces then you may be getting reflections. If so, you can put some padding/foam on those surfaces. Here is an interesting test by Troels.
3) I try to follow the VituixCAD directions for REW EXACTLY. I know little differences may not matter much, but I'm not as experienced as most of these guys so I don't want to leave anything to chance. Here is a screenshot from the Vituix instructions. I don't know what difference it makes to have the Length 1M instead of 512k, but Kimmo has 1M so I use 1M. (I don't measure tweeters down to 5hz though.) I do notice that he has "Use loopback as cal and timing refernce" set, so that makes me wonder about your issues above. The instructions do have some REW setup steps on pages 3 and 4.
Sometimes it is pretty loud when they walk and then REW will say "distortion is too high". So it reads their footsteps as distortion at lower frequencies.
I have not set the SPL level. I'm really taking measurements at about 60 db
Yeah I didn't bother with calibrating the SPL as it doesn't really matter for my purposes. Yes, it would stop people from commenting about it though. I do have an spl tool on my phone. It is type c rated and is accurate to within 2 db.
It's that timing a reference and cal that cussed the issue. If I set it to just timing allllllll the problems go away
If you take measurements in the 86db range, all of that background noise - which has not increased my 26db - will be 26db down RELATIVE to your new measurement.
If you want to take meaningful distortion measurements in the future, it will also matter more.
The SPL calibration doesn't have to be perfect. Even a ballpark number is much more useful than a random value.
So I need to be playing these sweeps much louder then? When I go louder then REW says it's clipping. So do I turn the mic gain down to play the sweep louder?
I don't REW so I'll let someone else answer the microphone gain part, but without at least a ballpark idea of actual SPL for the signal and noise there's no realistic way to answer whether your sweeps need to be louder to improve accuracy.
Given the poor reproducibility I agree there's something wrong with the measurement. Please post the raw data of your impulse response so we can take a closer look.
Great! that looks perfect!
By the way that's what I was mentioning in your other thread:
Sweeps normally are unpleasantly loud from 1kHz up. Measure amp output with a decent AC coupled (true RMS in the right ranges) Voltmeter; you should have a reading between 2 and 3V, ideally 2,83V.