# Room Acoustic Measurements (REW) Rabbit Hole **URL:** \ **Category:** Accessories and Tweaks\ **Created:** [January 31, 2024, 6:31am UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553 "2024-01-31T06:31:24Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![jvvita](https://avatars.discourse-cdn.com/v4/letter/j/e56c9b/32.png) [@jvvita](https://forum.psaudio.com/u/jvvita)\ **Post date:** [February 3, 2024, 12:47pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/101 "2024-02-03T12:47:25Z")
You know that on these matters there are a lot of conflicting opinions. Many sound engineers I know and have worked with do not care about rt60 for small rooms. They look at the attack-sustain-decay combo (that is similar to the spectrogram), and control (not eliminate) reflections, using them to add more realism to the sound stage and ease the pain on the amplifiers. But as I said, it is a matter of preference. This article from Dr. Toole is very interesting. > **[Room Reflections & Human Adaptation for Small Room Acoustics](https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation)** > > Dealing with acoustics in small rooms is no trivial matter. This article focuses on how to treat early reflections based on listening habits, your loudspeaker choice. Absorb, diffuse, reflect; decide. The most important thing is to have fun! ---
**Author:** ![Baldy](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/baldy/32/223847_2.png) [@Baldy](https://forum.psaudio.com/u/Baldy)\ **Post date:** [February 3, 2024, 12:52pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/102 "2024-02-03T12:52:24Z")
I agree on all points. Most important is to have fun and enjoy what you have been able to achieve and or accomplish with your rig. I am still amazed by what a really good stereo can sound like even in a less than optimum room. It just makes you smile and forget about everything else. As it should. 😄 ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 3, 2024, 1:26pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/103 "2024-02-03T13:26:04Z")
> [@jvvita](#): > > Many sound engineers I know and have worked with do not care about rt60 for small rooms. They look at the attack-sustain-decay combo (that is similar to the spectrogram), and control (not eliminate) reflections, Fully agreed. Luca, if you read the REW tutorials you’ll see the difference between the RT60 and what the RT60 Decay provides (time domain vs frequency domain). The latter can provide some useful assessment in a regular sized room, but in general I also feel the spectrogram is preferred. ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 3, 2024, 1:31pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/104 "2024-02-03T13:31:21Z")
That’s it. Just to the upper right corner of that box on the top, there is a small gear shaped icon. It will pop up a panel. From there click on the Calculate RT60 Model. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [February 3, 2024, 1:41pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/105 "2024-02-03T13:41:54Z")
Great stuff…very educational. TY. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [February 3, 2024, 1:42pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/106 "2024-02-03T13:42:58Z")
More good stuff… TY. ---
**Author:** ![scotte1](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/scotte1/32/147_2.png) [@scotte1](https://forum.psaudio.com/u/scotte1)\ **Post date:** [February 3, 2024, 1:45pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/107 "2024-02-03T13:45:14Z")
Hey REW mavins, let’s give @ErVikingo some love too. 😀 ---
**Author:** ![luca.pelliccioli](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/luca.pelliccioli/32/93681_2.png) [@luca.pelliccioli](https://forum.psaudio.com/u/luca.pelliccioli)\ **Post date:** [February 3, 2024, 2:32pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/108 "2024-02-03T14:32:41Z")
Got it! ![jjj](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/d/5/d5cebbd68c2eb11310a6ed6c22aa08da4f20c9fb.png) ---
**Author:** ![Baldy](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/baldy/32/223847_2.png) [@Baldy](https://forum.psaudio.com/u/Baldy)\ **Post date:** [February 3, 2024, 3:53pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/109 "2024-02-03T15:53:37Z")
The hot spots at 40hz, 80-100hz and the null at 150hz are most likely all room issues as they are below the Schroeder frequency. They will require a listening position (or speaker) move to fix. REW can also generate filters to trim the tops off the peaks but a null cant be fixed by software. If you try the end result wont be pleasing to hear. The hot spot between 1k and 2k is most likely a reflection and some sort of diffuser or absorber in the first reflection area might fix it. It could also be off the ceiling or floor. A heavy carpet or rug will fix the floor if you dont already have something there. Usually the room doesn’t sound as bad as the graph looks as we have the ability to fill in the blanks (some) and ignore the peaks (some). One thing to try is simply moving the microphone to a new spot a few inches one way or the other and see if there is a tendency to fix room issues just by moving your seat. Let us know what you find out! ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 3, 2024, 4:28pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/110 "2024-02-03T16:28:04Z")
Luca, sorry! I forgot to mention the results on this chart are frequency sensitive. On the lower waterfall place your cursor over the 100Hz position and click there. Please repost the result. ---
**Author:** ![Baldy](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/baldy/32/223847_2.png) [@Baldy](https://forum.psaudio.com/u/Baldy)\ **Post date:** [February 3, 2024, 5:53pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/111 "2024-02-03T17:53:36Z")
It also helps to take 2 or 3 sweeps of each speaker each time and average them or toss out the oddball. One other method is to measure the left speaker where your left ear would be and the right speaker where your right ear would be. This method is most accurate but also the hardest to repeat as you need to be within 5/8" (16mm) in all 3 planes to get repeatable results. ---
**Author:** ![jvvita](https://avatars.discourse-cdn.com/v4/letter/j/e56c9b/32.png) [@jvvita](https://forum.psaudio.com/u/jvvita)\ **Post date:** [February 3, 2024, 6:55pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/112 "2024-02-03T18:55:17Z")
Yep. Just waiting for him to clarify some doubts and we can jump right in. ---
**Author:** ![luca.pelliccioli](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/luca.pelliccioli/32/93681_2.png) [@luca.pelliccioli](https://forum.psaudio.com/u/luca.pelliccioli)\ **Post date:** [February 3, 2024, 7:07pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/113 "2024-02-03T19:07:51Z")
It was a long afternoon “sweeping” and moving diffusors, moving diffusor and “sweeping” again. I stopped all now in order to relax and enjoy music. Tomorrow I’ll continue the experiments. Last charts after a few changes: ![l+r rt60 decay new diffusor](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/8/e/8e10db038bbeaf04cb274b129255b1422f6a95be.png) ![l+r all spectrogram new diffusor](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/0/1/01ce104245cab73122c4b1cc13bae4addeb81c8e.png) ![l+r waterfall new diffusor](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/c/0/c07c636116705bb47d6ff431552ae8f6f0227b5b.png) ![l+r all spl new diffusor](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/e/4/e42fa4e6cb2b05305be08f82c0660327e9a73547.png) ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 3, 2024, 7:49pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/114 "2024-02-03T19:49:27Z")
Excellent results, Luca! Short of using DSP to tame that 90-140Hz range, that’s about as good as I’ve ever seen a room done without electronic help. I’m not really sure that trough between 30 and 80 Hz is that big a deal. If you like what you’re hearing - leave it alone for a while and enjoy! ---
**Author:** ![luca.pelliccioli](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/luca.pelliccioli/32/93681_2.png) [@luca.pelliccioli](https://forum.psaudio.com/u/luca.pelliccioli)\ **Post date:** [February 3, 2024, 7:51pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/115 "2024-02-03T19:51:05Z")
> [@tony22](#): > > Luca, sorry! I forgot to mention the results on this chart are frequency sensitive. On the lower waterfall place your cursor over the 100Hz position and click there. Please repost the result. Here you can see the last measurements taken today ![L+R RT60 Decay New Diffusor](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/4/1/4166c79aa25fcf4d2a6862c0d30472c408a7ad07.png) ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 3, 2024, 7:57pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/116 "2024-02-03T19:57:11Z")
Hmm, did you press the Calculate RT60 Model button, as seen here? ![image](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/0/f/0f202503619d29e180393946ee10e6cb2f6b5a17.jpeg) Those N/As should be numbers. You also have to make sure you ran the Classical RT60 on the other tab. ---
**Author:** ![luca.pelliccioli](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/luca.pelliccioli/32/93681_2.png) [@luca.pelliccioli](https://forum.psaudio.com/u/luca.pelliccioli)\ **Post date:** [February 3, 2024, 8:06pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/117 "2024-02-03T20:06:22Z")
Sorry, Tony. I’ve done it again to be sure and yes, I pressed the button “Calculate the RT model but N/A values don’t appear… just the ones on the left half of the window. ---
**Author:** ![ErVikingo](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/ervikingo/32/251111_2.png) [@ErVikingo](https://forum.psaudio.com/u/ErVikingo)\ **Post date:** [February 3, 2024, 8:22pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/118 "2024-02-03T20:22:45Z")
Thanks for the feedback. FYI, I have already placed bass traps on all corners, have abfussers on the sides and ceiling, difussers in the rear wall and a couple of ASC Tube traps currently behind the the bass towers. Room is 14Wx27Lx11H. Very large down sofa. Speakers are Infinity IRS Beta. Speakers are located: Woofer towers 21 inches from side walls and 53 inches from front wall 132 inches (11 ft) woofer to woofer Mid/High towers 39 inches from side walls and 60 inches from front wall 8 ft mid range to mid range I performed the measurements from the sofa which is at 12 ft from the Mid/High wings (drivers) and 13 feet from the woofers. My secondary position is an equilateral triangle from the Mid/highs; sounds better to my me. Following are measurements at that position. ![Equilateral Spectrogram](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/9/a/9a4f54452a4433d1466fa07177c04d9f9fad5d7b.jpeg) ![Equilateral SPL](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/f/e/fe8876a60f6a7fe3d7efca1f45bdea9f8b88bb5c.jpeg) ![Equilateral Waterfall](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/5/b/5b78500ca89150348361b3eeded9d766589d5315.jpeg) ---
**Author:** ![luca.pelliccioli](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/luca.pelliccioli/32/93681_2.png) [@luca.pelliccioli](https://forum.psaudio.com/u/luca.pelliccioli)\ **Post date:** [February 3, 2024, 8:31pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/119 "2024-02-03T20:31:32Z")
> [@tony22](#): > > Excellent results, Luca! Short of using DSP to tame that 90-140Hz range, that’s about as good as I’ve ever seen a room done without electronic help. Thanks, I deployed the heavy artillery ![IMG_1029](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/7/8/78ec05781bbd56d973a3630be1db7d147e5772ac.jpeg) ![IMG_1030](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/4/6/464d84e0332bb5ea1129351e4958ca78a46ef515.jpeg) These MagnetoFusor diffusers seem to do their job and it’s a very flexible solution, you can apply them at your choice in infinite combinations to the panels on the side walls. ---
**Author:** ![ErVikingo](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/ervikingo/32/251111_2.png) [@ErVikingo](https://forum.psaudio.com/u/ErVikingo)\ **Post date:** [February 3, 2024, 8:33pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/120 "2024-02-03T20:33:14Z")
@jvvita here are each speaker and also both at 1/6th smoothing ![UP Close SPL all one sixth](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/a/f/af428264d3d620abc42e6b338ef7b58d4cebe8ba.jpeg) [Previous page](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553.md?page=5) [Next page](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553.md?page=7)