Help with REW and Room Treatment

Hey, LPH! I'm looking at moving spaces soon, and I've been experimenting with REW so that I can test my room and figure out the best place for the listening position and treatment.

 

I read the manual for REW, but it was fairly confusing. I have spent about 20 hours trying to figure out a lot of this stuff, and I'm looking for a couple of different answers that I can't seem to figure out. I'm not afraid of shying away from the work of figuring this stuff out, but I'm also not trying to become an acoustician.

 

I was hoping someone on here could either help answer these questions or help direct me to a thread that answers them. (I know that there is a LOT of information on this topic out there, but I can't seem to find clear and consise answers to these questions):

 

Should I measure each speaker individually or the accumulation each?

 

How should I measure my sub in correlation to my nearfields? Currently, my sub has a built-in crossover, so both my nearfields are running through it.

 

I saw some people doing a spacial average using pink noise - should I use this method, or use a sine wave sweep with a the single measurement at the listening position method?

 

Thanks so much for your help. I know that there is a lot of information out there on this topic, but I truly appreciate the direction.

What's REW?

 

This is a good article on the topic of listening position and speaker positions: https://realtraps.com/art_room-setup.htm

REW is for Room EQ Wizard, an application for room acoustic measurements, corrective equalization and room simulation.

Oh ok thanks. I don't really believe in room EQ correction for home studios. Better to treat the room with bass traps that are precisely positioned and find the optimal listening position.

I agree with you David about room treatment instead of eq. REW gives you all the tools for room acoustics and it’s not for amateurs. It’s free by the way (donations are accepted)

 

Please forward any helpful REW tutorials you find. Last time I checked, my favorite one from last year had all of its image links broken.

 

Hey Mark! I apologize, I must have somehow turned off notifications for my posts on here, so I missed all of these replies... Although I wish I would have seen your reply earlier, because I have gone down quite the rabbit hold of room setup. I've spent almost the entire last two weeks solely devoting my time to it.

 

I'm actually in the middle of creating a comprehensive room setup guide which will include everything from taking measurements with REW, to speaker placement, to phase aligning a sub, to acoustic treatment placement, etc. I'm mainly creating this as a guide for myself, but I plan on forwarding it along to anyone whom it could help. I'll be sure to forward it to this thread and maybe it will help you in some way. If you're already up and running then it probably won't help you too much, but who knows. (Also a lot of it is copy pasted, paraphrased, or summarized versions of things I've found on the web, so I in no way claim for it to be my own work, or be an expert on the topic.)

 

From my reading, video watching and discussions directly with GIK acoustics, I've found the following to be true in regards to my previous questions:

 

Single mic measurements are best for calculating things like time alignment, checking polarity, and room setup (this being the only one that I claimed to have tried). You want to use spacial averaging when getting results for corrective room EQ. The reason for this is that with SPM (Single point method), the slightest change of the microphone impacts the readings in dramatic and unrepeatable ways (usually in the high end). This makes the results unverifiable - the reason being that we don't hear sound at a single point the way that a calibrated microphone does. However, it still gives us a pretty good idea of where things are sitting in the frequency spectrum, which allows us to make general decisions about room setup without getting into the nitty gritty. It also allows us to do time alignment and check polarity since these are 1 or 0 operations that are either right or wrong. However, since we don't hear sound like a single mic in one position, you want to use the MMM (Moving mic method) in order to get an average of the space around the listening position. This allows us to get an idea of how our ears are actually perceiving the sound to make appropriate EQ moves. This can also be done by taking a number of SPM's around the listening position and averaging them, but the MMM using spacial averaging is a lot more time efficient.

 

I also agree with you that using the RTA method with pink noise playing is best to get an idea for placement of the monitors and listening position. This allows you to get real time feedback. I would then begin to take a variety of SPM's in and around the listening position to get an idea for how things are sitting and tweak from there.

 

Generally, its fine to measure Left alone, Right alone, Sub alone, all combined. That's plenty to get an idea of the room.

 

Thanks for your help. I hope this helped in some way. I'll post that comprehensive guide as soon as it's finished.

 

-alex

Oh ok thanks. I don't really believe in room EQ correction for home studios. Better to treat the room with bass traps that are precisely positioned and find the optimal listening position.

 

Thanks for your reply David! You've helped me on a number of topics on here!

 

REW is used in some professional circumstances to correct the room's EQ, but most people use it to get an accurate view of their room's coloration on the sound. This is generally useful information to have as it allows you to find the best listening position, monitor positions, acoustic treatment, and acoustic treatment positions while having verifiable results.

 

This allows you to hopefully properly treat the main three problems with any room (frequency response, decay time, and RT60) using the best analogue, tried and true methods possible.

 

Personally, from here, I like to use sonarworks to gently smooth out the phase issues between the left and right speaker as well as gently smooth out the frequency spectrum, but this is personal taste. I believe that it gives a near-flat and somewhat unifying listening experience across all control rooms, allows mixes to translate better; however I realize this is a personal opinion, and that many prefer to mix on non EQ-corrected systems. I realize that our ears are colored so perfect neutrality is impossible when it comes to frequency response, but I believe that things like sonarworks give somewhat of a unifying and trustworthy experience when moving from room to room. Also, to be clear, the makers of sonarworks (as well as hopefully all other room correction services) state that room correction should be one of the last pieces to the puzzle after great monitoring, positioning and room treatment. They do not claim it to be a cure-all. It's also important to note that the only real cure for room nodes and decay time is acoustic treatment - EQ correction obviously only operates on the frequency domain and not the time domain.

 

-alex

Does anyone know if REW is still actively developed? Latest Mac version is for 10.3. on their site.

 

Otherwise, any other suggestions for cheap room calibration software for Mac (Big Sur, M1)? Ideally something that can provide an average from a number of samples. I used SysTune previously, but I just want something simple that can be used with a cheap test mic to get studio frequency response for the purpose of informing room treatment decisions.

 

Thanks!