• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

REW Measurement Review

cfiliz

New Member
Joined
Jul 5, 2022
Messages
3
Likes
0
Hi all,

Just a newbie here - so maybe I'm asking stupid things..

Read the FAQ page and user manuals of REW and tried to complete a measurement.

First of all, the equipment in use:
Acer laptop - HDMI output used, feeding into Yamaha RX-V477 5.1 receiver. STRAIGHT mode used.
Mic - using the own calibration mic of the receiver, Yamaha / no model defined. Placed on top of tripod, approx at listening level.
Completed the mic SPL calibration (78 dB) using iphone Decibel app - I know it's far from perfect :/

Finally, do I get it right? The RT60 calculation mostly shows around 850ms. Is it somewhere acceptable or should I bring it down using acoustic panels etc? My main use is movies and some music - but want some quality sound setup.

Any ideas are more than welcome.
Thanks
 

Attachments

  • left RT60 decay.jpg
    left RT60 decay.jpg
    135.2 KB · Views: 77
  • right v2 waterfall.jpg
    right v2 waterfall.jpg
    124.8 KB · Views: 80
  • right v2 RT60.jpg
    right v2 RT60.jpg
    84.7 KB · Views: 79
  • right v2 SPL.jpg
    right v2 SPL.jpg
    74.1 KB · Views: 79
  • left v2 SPL.jpg
    left v2 SPL.jpg
    75.2 KB · Views: 67
  • left RT60 v2.jpg
    left RT60 v2.jpg
    84.6 KB · Views: 69
  • left v2 waterfall.jpg
    left v2 waterfall.jpg
    127.2 KB · Views: 74

dc655321

Major Contributor
Joined
Mar 4, 2018
Messages
1,564
Likes
2,142
Welcome to ASR.

Can you provide more details?
Speakers?
Gate width?
Smoothing factors?

The rt60 seems high, but not outlandish.
 
OP
C

cfiliz

New Member
Joined
Jul 5, 2022
Messages
3
Likes
0
Welcome to ASR.

Can you provide more details?
Speakers?
Gate width?
Smoothing factors?

The rt60 seems high, but not outlandish.
Thanks for the welcome :)

Sure.

The speakers are JBL Cinema 510 Pack :/ the satellites have 3" drivers and and the sub is downfiring 6.5". The satellites are wall-mounted in this case. I'm actually planning to invest in some proper bookshelf speakers, but wanted to confirm the room acoustics are in good shape.

No idea about the term gate width :/

Smooting factors: pseneuacoustics smoothing applied for SPL graph and the waterfall graphs, it should be the default value of 1/48.
 

Attachments

  • jbl.jpg
    jbl.jpg
    4.6 KB · Views: 16

dc655321

Major Contributor
Joined
Mar 4, 2018
Messages
1,564
Likes
2,142
Thx.
Distance between mic and speaker?

It may be a good idea to focus on the sweep (?) data to start with. It’s diagnostically helpful to zoom in on the vertical (SPL) axis - limiting to a range of about 50 dB is typical.

I figured your measurements were sans gating, but thought it best to ask. Gating is a technique employed to remove the effect of the room from an acoustic measurement (focus on the speaker, alone). Since you’re interested in room effects, this may not apply.

Still, the upper freqs of your l/r speaker plots are quite flat, leading me to ask:
Mic very close to speakers, or very lively, reflective room? Hardwood floors, concrete walls, that sort of thing?


Also, I assume you meant psychoacoustic smoothing?
 
OP
C

cfiliz

New Member
Joined
Jul 5, 2022
Messages
3
Likes
0
Thx.
Distance between mic and speaker?

It may be a good idea to focus on the sweep (?) data to start with. It’s diagnostically helpful to zoom in on the vertical (SPL) axis - limiting to a range of about 50 dB is typical.

I figured your measurements were sans gating, but thought it best to ask. Gating is a technique employed to remove the effect of the room from an acoustic measurement (focus on the speaker, alone). Since you’re interested in room effects, this may not apply.

Still, the upper freqs of your l/r speaker plots are quite flat, leading me to ask:
Mic very close to speakers, or very lively, reflective room? Hardwood floors, concrete walls, that sort of thing?


Also, I assume you meant psychoacoustic smoothing?

The distance between the mic and the speaker is approx 3.5 meters. The thing I've noticed with the measurement is, although using STRAIGHT mode in receiver, it still uses the room correction. I guess this might be a reason the flat upper freqs. There's also a mode called "DIRECT", although the words sound similar, that is a mode without any room correction etc. I'll try to re-measure using that mode.

Also, I assume you meant psychoacoustic smoothing?

Yep :) English is not my native language as you can guess, and did not cheched spelling before posting.
 
Top Bottom