REW Rookie Question

[PresbyByrd]

I dig this site, but about 80% passes right over my head. I recently decided I want to measure my small room to optimize my gear. To do that, I will have to learn how to implement REW. This won’t be as easy for me as it is for you engineer types . And since it will take some effort, I wanted to ask: Is REW worthwhile in a odd-shaped (non-rectangular) room? I will put in the time to learn the software if it will be helpful. Thanks in advance for any sugestions.

Chip

 

[Krunok]

I dig this site, but about 80% passes right over my head. I recently decided I want to measure my small room to optimize my gear. To do that, I will have to learn how to implement REW. This won’t be as easy for me as it is for you engineer types . And since it will take some effort, I wanted to ask: Is REW worthwhile in a odd-shaped (non-rectangular) room? I will put in the time to learn the software if it will be helpful. Thanks in advance for any sugestions.

Chip

No worries M8, REW can measure any room. I recommend using UMIK-1 mic, it's cheap and reasonably precise. Try to find online tutorails and give it a go. Folks here would help in case you'll need assistance.

 

[dshreter]

I'd second the suggestion to start with a UMIK-1 mic. It's pretty affordable, and won't require any additional interface other than plugging directly into your computer via USB. The miniDSP tutorial on how to use it is good enough to get you started with very specific instructions, and you can start making measurements at your listening position.

There are many layers of the onion to peel back, but measuring and understanding the frequency response and the Impulse Response will go a long way to helping you sort out your speaker placement and subwoofer integration.

 

[GD Fan]

I've just started down the same path. The following has been enormously helpful:

https://www.audiosciencereview.com/...om-measurement-tutorial-for-dummies-part-1.4/

 

[Sancus]

I have a VERY weirdly shaped room and REW works great.

 

[PresbyByrd]

Thanks guys! This is exactly what I needed to know. I will order the UMIK-1 as advised. I will be traveling for 5 weeks, so it will likely be March before I get to this. I will read Amir’s link as well as other sources. I will probably (almost certainly) be calling on the expertise of this forum. Again, thanks.

 

[GD Fan]

FYI the UMIK-1 is more expensive on Amazon than on the miniDSP website directly. No need for you to make the same mistake I made!

 

[Martin]

So I thought I'd piggyback on this thread rather than start a new one. I completed my first measurements using REW today.

The blue line is both speakers, the red is the right speaker and the green is the left. I have some obvious problems.

I have an odd shaped room:

The piece of furniture in front of the window is an IKEA Expedit and it sits just off the front side corner of my right speaker. There is a Kurzweil Baby Grand on the angled wall. The wall ebhind my chair is kneewall that is just slightly higher than the chair. The opening next to my chair is into a good sized living room and the open doorway is the kitchen. The room is currently untreated but I have six 2'x4' 2" thick rockwool panels I can use.

Placing a rockwool panel at an angle against the Expedit on the side of the right speaker decreased the 100Hz suckout by about 5dB bringing it up even with the left speaker. I don't know what the peaks in the right speaker are at about 32 and 55Hz. I think the giant hole between about 65 and 400Hz is the biggest problem.

FYI - Te speakers are Von Schweikert VR-4 Gen III HSE with a claimed frequency response of 20-30 kHz, +/- 2 dB, 16 Hz-40 kHz –6 dB, (+/- 1dB at midband).

Any thoughts or recommendations?

Thanks,
Martin

 

[RayDunzl]

FYI the UMIK-1 is more expensive on Amazon than on the miniDSP website directly.

MiniDSP - $75 + $22 FedEx shipping from Hong Kong = $97
Amazon US - $91.50 and free shipping, likely from US stock. No tax added.

I ordered mine from miniDSP...

Got a quick tracking number.

Tracking data updated within about an hour.

Watched FlightRadar24 for the FedEx flight from Hong Kong.

Arrived in New York, made the next flight to Memphis, made the next flight to Tampa, early enough to be "out for delivery" that day.

Arrived in like 48 hours from order (maybe it was less, I don't remember exactly, but there were like no delays).

Another item from them took a week, delay at each connection, and across a weekend, so, good luck.

 

[sfdoddsy]

So I thought I'd piggyback on this thread rather than start a new one. I completed my first measurements using REW today.
View attachment 51300

The blue line is both speakers, the red is the right speaker and the green is the left. I have some obvious problems.

I have an odd shaped room:

View attachment 51304

The piece of furniture in front of the window is an IKEA Expedit and it sits just off the front side corner of my right speaker. There is a Kurzweil Baby Grand on the angled wall. The wall ebhind my chair is kneewall that is just slightly higher than the chair. The opening next to my chair is into a good sized living room and the open doorway is the kitchen. The room is currently untreated but I have six 2'x4' 2" thick rockwool panels I can use.

Placing a rockwool panel at an angle against the Expedit on the side of the right speaker decreased the 100Hz suckout by about 5dB bringing it up even with the left speaker. I don't know what the peaks in the right speaker are at about 32 and 55Hz. I think the giant hole between about 65 and 400Hz is the biggest problem.

FYI - Te speakers are Von Schweikert VR-4 Gen III HSE with a claimed frequency response of 20-30 kHz, +/- 2 dB, 16 Hz-40 kHz –6 dB, (+/- 1dB at midband).

Any thoughts or recommendations?

Thanks,
Martin

You have classic boundary issues. Do a search for SBIR and the Allison effect.

Your initial solution would be to move the speakers.

I'd start with a non-parrallel positioning to see if you can get at least one of them to fill in the dip.

REW has a room mode calculator in which you can insert your room dimensions. Even though your room seems to be an odd shape, it isn't that far off rectangular. The problematic dimensions would be front to back and most likely ceiling height.

The VR4s are giving you the full range response you paid for. You're just losing most of it due to the suckout.

If that doesn't work, try putting them right up against the wall. If that fills in the dip you can use something like a MiniDSP or Dirac to flatten the response.

If that doesn't work, pull them as close to you as possible and try nearfield. Might be tricky with all those drivers.

If all that fails, I'd treat them like a mini monitor.. Pull them into the room to get the flattest response down to the dip, then get a sub or two in the corners and cross the VRs high.

You'll feel you've wasted your money, but it may work.

 

[Matias]

This video was all I needed to get confident and finally start. I can't recommended it enough. It is that good.