Advice for getting started with REW

[cyclecamper]

New/old house; I'm starting with room treatment, and setting up my family room (half-vaulted ceiling) as a multi-purpose audio room mostly for listening, practice (bass guitar mostly) and eventually perhaps a little bit of recording. It's going to be less than ideal because there's a kitchen at one end and things will rattle no doubt. But it has some cubic volume space to it, and I live alone so I can do whatever I please. My first steps were based on what's expedient and affordable.

 

I've started by making 30 2'X4' absorption panels based on the GIK Acoustics DIY frames, 4" thick Roxul, with perforated pegboard on the back.

 

A few have an additional staggered-wall extension frame sistered on, and another 6" of Roxul behind the pegboard and then a closed Masonite back. A few have a thick stack of acoustic ceiling tiles in that back chamber instead of more Roxul.

 

I've got a little used Auralex I bought for cheap, but it isn't very effective except at high frequencies.

 

Admittedly, I didn't do the math, I'm hoping for relatively broadband absorption and can rearrange their placements many ways if I need to adjust what bands are absorbed. If it gets too dead there are connecting hallways and rooms that can use absorptive treatment and some panels might end up in other rooms. I'm probably also making some very large convex curved diffusers, and some fractal diffusers. I don't know whether I'll get around to any RPGs or skyline diffusers. First I'm doing the broadband absorption every LEDE room needs. Absorption to address the reflections from the speakers to the walls and the early reflection points to the listening area and near all corners. Some diffusion to the sides and behind. Some ceiling treatment and some overhead clouds since the room has the height to accommodate them.

 

But then, halfway thru hanging absorption and diffusion (if not sooner), I need to take baseline measurements and determine where I am and what I still need to deal with. If additional bass traps or diffusion are required, they will need to be tuned properly.

 

I'm a programmer by profession, but new to actually doing any room measurement myself. I imagine I'm going to want to know, at the least, room frequency response and what the reverberation times are in various frequency bands.

 

So, what hardware / software do I need to start gathering in order to use REW for room measurements? I have:

- A Behringer RTA / EQ.

- Inexpensive Behringer measurement mic, and many other mics.

- Various inexpensive mic preamps with phantom power.

- Cables etc.

- Alienware laptop.

- I think I'm getting an iFi micro DSD???

What I don't have:

- any way to connect the mic pre to the laptop besides the built-in sound card.

 

So do I need some kind of A/D to take the output of the mic preamp into the laptop's USB? Is it practical to attempt using the laptop's built-in sound card for measurement purposes?

 

What additional hardware should I accumulate in order to use REW?

[Ralf11]

I don't know what REW is, but a PC sound card should be adequate for room EQ measurements - you just need either a "flat" freq. response, or a stable one that can be compensated.

[Jud]

https://www.minidsp.com/applications/acoustic-measurements/umik-1-setup-with-rew

[cyclecamper]

Thanks Jud I'll check it out.

 

Ralf11, I'm not looking for room EQ measurements, or I would use my RTA. Room EQ cannot correct early reflections or standing waves. The RTA or the equivalent via a soundcard gives some useful data for room treatment, but I'm hoping for a lot more, maybe ideally some impulse time/frequency waterfall plots like MLSSA produces...I might be expecting too much, I've never used REW yet myself!

[cyclecamper]

Jud, I was hoping not to buy a USB mic, but use my existing Behringer mic and my existing mic preamp, and purchase some kind of A/D that might be repurposed later for recording perhaps? The miniDSP UMIK-1 might be cheaper, but would it be very useful repurposed for anything else after I'm done?

[cyclecamper]

http://www.roomeqwizard.com/REWhelp.pdf

 

Sounds like I can use my Radio Shack SPL meter, with or without my Behringer measurement mic / preamp combination, and just use my laptop's built-in sound card.

[Ralf11]

DEQX High Definition Audio

 

??

[cyclecamper]

Cool. But of course though it can correct timing deficiencies in the speakers, and can achieve some room EQ at one listening location or an averaged response, no electronic correction can remove the room's extra reflections and their timing problems, nor can it remove the standing waves that cause frequency response to vary wildly from one location to another only centimeters away. Only altering the room's characteristics can, which is why that must be the first step.

[tboooe]

Cool. But of course though it can correct timing deficiencies in the speakers, and can achieve some room EQ at one listening location or an averaged response, no electronic correction can remove the room's extra reflections and their timing problems, nor can it remove the standing waves that cause frequency response to vary wildly from one location to another only centimeters away. Only altering the room's characteristics can, which is why that must be the first step.

 

I agree 100%. Room EQ is not a magic bullet. I've been spending a lot time recently adjusting my speaker position and experimenting with room treatments. I use REW to test the result of my changes. Unfortunately for those of us without a dedicated listening room, its a compromise. Now that I have more or less optimized my room response, I use REW (I am moving to Acourate) to make the final adjustments. The results have been stunning!