Can I add my REW measurements and please ask if someone can advise me on what they really mean ?

 

I have a really hard time interpreting what they are and I’ve tried dozens of YouTube clips on what to do and what it means.

 

But I’m afraid that I get very overwhelmed at the REW system in general and what all the adjustments and parameters actually do or for that matter what I’m trying to input to get what is being measured in a simple data or charts.

 

I get lost in the system basically…

 

 

@seadog

AFAIK members will want to know your method for obtaining the data also. If you look back through the last previous few pages of this thread you will find a lot of information already.

1. What method?
2. What are you trying to accomplish?
3. What hifi system produces those measurements?

 

Thanks for the advice.

 

1. REW software and measured via a

Mini DSP UMIK-2, stereo RCA and RCA to H/P Mini Jack splitter adaptor via MacBook Pro H/P input to my preamp RCA inputs.

 

I painstakingly set it up as advised on most YouTube advice clips for stereo speakers and no subs. etc

 

2. To see what my room is actually measuring vs what is a good room measurement should be (or thereabouts). I have recently moved house and I’m lost as to what to do room treatment wise.

 

3. My system is: 

 

ATC SCM 100 ASLT active speakers.

@Keith_W might like to speak to that. AFAIK the RT60 is a value of interest.

I tried to pull the RT60 up and this is what I’ve got.

 

Not 100% sure it’s the right graph or graph setting though….

@seadog please upload the .MDAT file to Dropbox or Google Drive and post the link or PM it to me. I also need to know the dimensions of your room including height and where the microphone was positioned. A quick sketch of the room is also helpful. 

Thank you for sending me your measurements. 

 

 

Firstly, you sent me 3 measurements. The one in red is obviously wonky so I am going to ignore it. The green/blue ones look better, so i'll look at those. I applied 1/6 smoothing to all graphs. The other thing you did is measure both speakers together. We normally measure only one speaker at a time - because of that, I am going to avoid commenting on some of the measurements because they will be meaningless (e.g. step response, Energy-Time Curve). 

 

 

Let's compare your measurement with a ATC SCM100 ATSLT review I found online. Your measurement is in blue, the online measurement is in green. I used an image editing program to extract the online measurement then scaled it so that it is the same horizontal and vertical scale, then superimposed the images so that you can see the difference. We can see that there are little differences here and there between the two measurements, probably due to different measurement technique. Where we see the most difference is below 100Hz, which is typical in any room.

 

You have a 14dB suckout at about 50Hz which is obviously room-related cancellation. There are some upper bass issues in your room below 200Hz which means you are hearing about 2-3dB less bass than what that review shows. It would make your loudspeakers sound a little bit lean. But otherwise it does not look too bad. 

 

 

FYI, this is my system post DSP. I adjusted the vertical scale of the graph so that it is directly comparable to yours. You can see that it is noticeably less lumpy. 

 

 

This is your RT60 display. I used the room dimensions you sent me in PM to calculate the RT60 tolerance and then drew in the targets over your actual measurement. What this shows is that you have too much reverb above 300Hz, your T30 reaches as high as 650ms. This is huge.

 

I saw some thin grey panels in one of your pictures, and it was removed in another picture. I am not sure what it is, but if this measurement was taken with those panels in situ, I can tell you they aren't doing anything. It is possible to reach the RT60 target with normal room furnishing alone. From your pictures, it looks as if you have just moved in because the furniture is pretty sparse. I suggest you furnish your room properly and then redo the measurement. Otherwise you might need some foam to tame that reverb. 

 

22 hours ago, seadog said:

To see what my room is actually measuring vs what is a good room measurement should be (or thereabouts). I have recently moved house and I’m lost as to what to do room treatment wise.

 

If you plan on the DIY route you will be in rabbit hole acoustic purgatory forever. If this place (new home) is potentially your endgame home, then spending the money on proper acoustic treatment will be the single best use of your money, no matter what or how your system evolves.

Latency/Delay/Reverb - whatever you want to call it, requires physical solutions to fix - DSP only takes you so far.

I've been fortunate to be involved in some incredible acoustic treatment transformation systems, that all started the same way, filling out this form:-

 

https://www.artnovion.com/project_support_request/new

 

I strongly recommend with this link above to take on the principle of "no such thing as too much information".

Edited March 26, 2025Mar 26 by Hydrology

Help Interpreting REW Measurements – Duntech PCL 25 Setup

 

Hi everyone,

 

This is a post I made over at AV NIRVANA forums but thought I could also add it here for a response, if that's okay?

 

I recently measured my Duntech PCL 25 speakers using REW for the first time and I’d love some insights into my results. I’ve attached three graphs and pics of my room for your reference:

 

L+R Combined Response (Blue)

Left Speaker Only (Red)

Right Speaker Only (Green)

 

Observations:

 

There’s a noticeable bass peak around 40-50 Hz and dips around 100-200 Hz in both individual and combined responses.

The midrange (200 Hz - 2 kHz) shows fluctuations, but I’m not sure if they are room-related or speaker-related.

The high frequencies (2 kHz - 10 kHz) vary slightly between L & R, though they seem fairly consistent overall.

The left and right speaker responses are not identical, which makes me wonder if positioning is a factor.

 

Measurement Setup:

 

Microphone: Calibrated USB UMIK-1 connected to a laptop

Signal Chain: ME Audio ME25 preamp (RCA to 3.5mm headphone/mic jack of laptop) → ME850 amplifier

 

My Room & Setup:

 

Room dimensions: 6.11m x 4.46m x 2.4m (20'1" x 14'8" x 7'10")

Listening position: 0.8m (2'7") from the back wall

Distance from speakers: 2.7m (8'10")

Speaker spacing: 2.58m (8'6") apart

Distance from speakers to front wall: 65 cm (2'2")

Distance from left speaker to left wall: 1.8m (5'11")

Distance from right speaker to right wall/cabinet: 1.4m (4'7")

Seating position is on the long side of the room

Ceiling: Timber

Floor: Carpeted with a floor rug

Current system: 2.0 setup, but considering adding a subwoofer for a 2.1 or 2.2 setup

Preference: I don’t want to introduce a MiniDSP or EQ—looking for placement or acoustic treatment solutions instead

 

Questions:

 

Do my bass response dips indicate room mode issues, placement problems, or something else?

Is the midrange fluctuation concerning, or does this look typical?

The left and right responses are slightly different—could this be due to speaker placement, boundary effects, or phase alignment?

Any suggestions for placement tweaks, room treatment, or integrating a subwoofer naturally without DSP?

 

I’d love to hear any thoughts, interpretations, or advice from those with experience tuning their rooms. Thanks in advance!

 

I had help writing this with AI.

Edited March 29, 2025Mar 29 by woopwoop360

11 hours ago, woopwoop360 said:

Do my bass response dips indicate room mode issues, placement problems, or something else?

Is the midrange fluctuation concerning, or does this look typical?

The left and right responses are slightly different—could this be due to speaker placement, boundary effects, or phase alignment?

Any suggestions for placement tweaks, room treatment, or integrating a subwoofer naturally without DSP?

 

1. Your bass and midrange issues are typical of every room. ALL speakers in ALL listening rooms have these issues. 

2. Left/right asymmetry in measurements is due to asymmetrical left/right loudspeaker placement or asymmetrical room (including room openings) or asymmetric furniture setup. It can sometimes be due to defects in loudspeakers, particularly old loudspeakers or speakers with manufacturing defects. 

3. You have no hope of properly integrating a subwoofer without DSP. 

 

I've seen some discussion of RT60 limits above, but there's no mention of which standard these limits are for.

 

A max of 650ms may not be absurdly out of bounds , for say the DIN 18041 Music specification.

 

My ears are quite happy with this standard and < 600ms has never been hard for me to achieve (for my room dimensions obviously), not even needing to use acoustic treatment. But this can be a bit of luck obviously.

Edited April 1, 2025Apr 1 by rand129678
typo

On 30/03/2025 at 1:07 PM, Keith_W said:

 

1. Your bass and midrange issues are typical of every room. ALL speakers in ALL listening rooms have these issues. 

2. Left/right asymmetry in measurements is due to asymmetrical left/right loudspeaker placement or asymmetrical room (including room openings) or asymmetric furniture setup. It can sometimes be due to defects in loudspeakers, particularly old loudspeakers or speakers with manufacturing defects. 

3. You have no hope of properly integrating a subwoofer without DSP. 

 

Thanks

G'day Folks.
I've been tinkering with speakers for a while, and reluctant to dive into measuring as maths ain't my strong point.
I've had a few sessions with REW and Umik-1, and have done quite a few, successful sweeps, near and far field.

I'm about to begin 2 separate speaker builds, and it's time to get stuck into measurements, however I'm starting with my last DIY speaker build/mods. It's a 4 way speaker, consisting of 2 cabinets per side. 1 sealed cabinet housing a 15" woofer, and 1 sealed, dual enclosure cabinet housing an 8" woofer (lower), and tweeter & 6" mid (upper).
Yes, I know it's a complicated way to start, but I can ignore the 15" cabinet for simplicity.

I'm measuring in room, near field at 2cm, and far field at the listening position 2.4m at 90cm height.
For the initial stereo sweep of all drivers, I was using a 'by ear' xover, and I know there are issues there.

I then did near field sweeps of all 4 individual drivers, with no xover.

My current stumbling block comes with measuring all individual drivers at the listening position.
I've done a sweep on the tweeter, and attempted to set an Impulse Response Window, which I did in the Impulse Response tab. It highlighted the window on the IR graph, but after I applied it to the All SPL, it didn't alter that graph.

I'm stuck on this problem.

Any suggestions.

On the impulse trace, top left, change the scale from dBfs to %.

You mix of drivers is a bit of a hodge-podge😀 and integrating them all together will probably do your head in. Is any specs/documentation available for them? In particular you don’t need both a 6” and an 8” between the 15” woofer and the tweeter. Choose one only, I would say.

Plus the time scale on the Impulse trace should be much smaller, say -5 msec to 15 msec to determine gates for individual driver measurements.

Edited February 27Feb 27 by RoHo
Extra info