# 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:** 10
**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 11, 2024, 3:07pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/181 "2024-02-11T15:07:41Z")
> [@Baldy](#): > > You could also use a MiniDSP SHD which has both XLR and RCA in / out an can go between the preamp and power amp. It can be bypassed via remote control at any time so easy A/B comparisons could be made. Thanks, Baldy. As for the connection, it should suit my needs, placing the MiniDSP SHD between the XLR OUT of the MSB DAC and the XLR IN of the MSB amplifier. As for the perfectly matched impedance and sound quality within the MSB chain, I hope it doesn’t alter anything from my current setup. In your experience (even if you haven’t used it in your system yet - or never will) could these things alter the sound in any way? Let me explain: before using any type of filter for room correction, I am a little perplexed about the real neutrality of this unit (and the additional XLR cables required) inserted in the analog signal path. I don’t want the solution to a problem to become another problem (even potentially more serious than the original one). ---
**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 11, 2024, 3:46pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/182 "2024-02-11T15:46:00Z")
> [@luca.pelliccioli](#): > > I don’t want the solution to a problem to become another problem (even potentially more serious than the original one). I agree completely. Every solution has a whole new set of problems for sure. That stuff we deal with every day at work. I dont have personal experience yet but the general consensus is that when bypassed it does not add to or take away from the signal. Many “audiophiles” seem to shy away from it for some unknown reason (probably doesn’t cost enough for the possible benefits) although lots of small recording studios use one for taming down the space so it is in the recording. If you were interested in pursuing the test you would be out the cost of another pair of XLR’s (maybe you could borrow a set) but the unit itself usually sells for $1000 USD on the used market including a mic and $1300 or so new. Not much money for the test all things considered. And only if you were interested in the technology and testing it out in your space. ---
**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 11, 2024, 4:13pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/183 "2024-02-11T16:13:02Z")
Thanks, Baldy. I need to discuss this matter with my dealer, who may be paid for consulting him and testing the unit at home. It should be a possible solution to try these things, letting an experienced person take measurements, set configurations and everything else. Once I have proof of the listening benefits I will be able to decide whether to buy it or just pay for the dealer’s time. Curiosity often guides my life, it doesn’t matter if the results are good or bad, the experience is worth it because in the end we can come out enriched (not financially of course). Meanwhile I’m liking a lot what I’ve already learned and what I’m hearing. Now back to music and relaxing! ---
**Author:** ![dchang05](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/dchang05/32/294697_2.png) [@dchang05](https://forum.psaudio.com/u/dchang05)\ **Post date:** [February 11, 2024, 4:36pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/184 "2024-02-11T16:36:43Z")
Your experience tells me Subs may not be the best solution, and BB or C214 may be a better approach for some systems. Interestingly both devices seem to improve other aspects (midrange, soundstage, etc) more than just bass. My speakers have built-in subs, so I do not know if adding subs will add more, but AVAA C214 may be the way to go (BB just do not look attractive to me in comparison). ---
**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 11, 2024, 5:01pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/185 "2024-02-11T17:01:34Z")
> [@dchang05](#): > > Interestingly both devices seem to improve other aspects (midrange, soundstage, etc) more than just bass. FWIW, IME, properly integrated LF (via room tuning, subwoofer placement, speaker placement, seating placement, etc.), which ultimately leads toward optimizing bass response directly improves the clarity and “hearability” of mid- and upper mid-level frequecies. This “de-muddying” if you will uncovers the sweetness and details otherwise offered in a system. It should be everyone’s goal to work on continuously improving the low-level performance of the room/system. The ultimate impact to fidelity and performance is across the board - not nearly as bass-centric as I first thought when I started on this path. Cheers. ---
**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 11, 2024, 5:08pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/186 "2024-02-11T17:08:39Z")
> [@dchang05](#): > > My speakers have built-in subs, so I do not know if adding subs will add more, One very important point to remember about getting a smooth frequency response that you enjoy is that the full-range capabilities of the main speakers are, depending on the room and their placement therein, somewhat limited in importance to getting the best room bass response. By necessity, you will have to (or at lease most folks choose to) place your main speakers (full-range or not) in a manner that allows them to present a great stereo image and a clarity or sweetness in the upper (not LF) frequencies. Much of the time, this placement will be inconsistent with an optimum bass response (again, no matter how low the speakers go). Which is a reason why many experienced audiophiles recommend the use of subwoofers with great, full-range speakers. Cheers. ---
**Author:** ![dchang05](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/dchang05/32/294697_2.png) [@dchang05](https://forum.psaudio.com/u/dchang05)\ **Post date:** [February 11, 2024, 5:20pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/187 "2024-02-11T17:20:26Z")
That’s one reason I want to try devices such as AVAA C214, and I believe it will help. But I probably will downsize my main speakers first; following the seemly popular downsizing trend here. ---
**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 11, 2024, 5:25pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/188 "2024-02-11T17:25:25Z")
One more piece of food-for-thought – Full-range is good and when you get things integrated, you get better use of that LF power from your main speakers. There is no replacement for displacement. But great bass response is all bout the long LF waves created by the drivers in your room and where these waves augment and cancel each other in relation to your seating position. I think the AVAA C214 looks very promising. Interested in what you will be hearing… Have fun. ---
**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 11, 2024, 5:32pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/189 "2024-02-11T17:32:22Z")
> [@dchang05](#): > > following the seemly popular downsizing trend here. All in good time and an important goal depending on the circumstances. Personally, I like to think you can’t have too much speaker or too much amplification (within reason, of course). Convenience and form-factor of sources and accoutrements (smaller, more integrated, less of, etc.)…that’s all good. I am biased toward upsizing when it comes to amplifiers and speakers though. They are the heart and soul of a system. ---
**Author:** ![dchang05](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/dchang05/32/294697_2.png) [@dchang05](https://forum.psaudio.com/u/dchang05)\ **Post date:** [February 11, 2024, 5:41pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/190 "2024-02-11T17:41:47Z")
Since most of my gears are PSA products now, I figure a pair of FR30 could be a good match. I like their two-box design that I can still move them around by myself. These speakers are more than 100 lbs. less in weight each than my current speakers, and I am sure they will produce as big soundstage as mine too. So, the downsizing is on weight only, not on quality and quantity in sound (I hope). 😆 ---
**Author:** ![allan.thunes](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@allan.thunes](https://forum.psaudio.com/u/allan.thunes)\ **Post date:** [February 11, 2024, 8:11pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/191 "2024-02-11T20:11:45Z")
To eliminate analog to digital to analog conversions I run coax out of my BlueSound Vault into the SHD and coax out to the DAC. ---
**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 11, 2024, 11:47pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/192 "2024-02-11T23:47:46Z")
[![](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/e/1/e1e2f9bf9e8c09616c779c53d4c63c5612c2bc77.jpeg "Phase Match Your Speakers with AllPass Filters") ](https://www.youtube.com/watch?v=ChPu0u3nZxc) This guy will make your head spin while explaining the power of REW. He has a great series of videos that is very hard to follow for casual users but does show what is possible using REW and DSP. ---
**Author:** ![tony22](https://avatars.discourse-cdn.com/v4/letter/t/f04885/32.png) [@tony22](https://forum.psaudio.com/u/tony22)\ **Post date:** [February 12, 2024, 12:21am UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/193 "2024-02-12T00:21:45Z")
Yeah. His stuff is not for the faint of heart. But it’s a great bunch of videos. ---
**Author:** ![Jdee](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@Jdee](https://forum.psaudio.com/u/Jdee)\ **Post date:** [February 12, 2024, 7:53am UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/194 "2024-02-12T07:53:42Z")
Going the DSP route will be an eye or let’s say ear opener 🙂 Acoustic treatment to rooms is great and will provide immediate advantages, though there are limits which can only be solved by DSP. If you go for a testdrive I would advice to try HQPlayer - as this not only does the DSP calculation provided (via a convolution filter generated by REW or better FocusFidelity Designer) but you can also use the most advanced upsampling options. ---
**Author:** ![minnesotafats](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/minnesotafats/32/1696_2.png) [@minnesotafats](https://forum.psaudio.com/u/minnesotafats)\ **Post date:** [February 14, 2024, 12:42am UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/195 "2024-02-14T00:42:29Z")
Actually with the 101s I had the rels set at 28hz. With the MBL 120s the Rels are at 32. I think @Paul once said error on a lower crossover with a larger volume versus a lower volume and higher crossover. ---
**Author:** ![paul172](https://sea1.discourse-cdn.com/flex015/user_avatar/forum.psaudio.com/paul172/32/290439_2.png) [@paul172](https://forum.psaudio.com/u/paul172)\ **Post date:** [February 14, 2024, 3:37am UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/196 "2024-02-14T03:37:26Z")
> [@Baldy](#): > > I dont think that high level (speaker input) is needed for powered subs as they take the input signal and run it through another amp and DSP anyway. The high level is used to precisely match the bass to the sound of the speaker. My rel hi level cables are connected directly to my ML CLX and work fantastic. The crossover on the sub is set at 65hz but ML states the crossover should me set at 57hz. I prefer what I hear at 65 personally but I have tried both. Yes it’s true my speakers don’t output much bass but the Rel no. 25’s do a fine job handling the low end! ---
**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 15, 2024, 8:52pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/197 "2024-02-15T20:52:32Z")
Here I am again. Working on the front wall corners with acoustic panels (not traps), I got better result around the 120-150 Hz area. This seems to be the place to work harder: front corners. After that I need to fight the dips at 60 Hz and 300 Hz. One step at a time. Moving around the Black Box I found that positioning it in the null area of the room (middle of the room close to the left wall) it can bring positive improvements (by ears) in bass. Not subtle differences. REW is a great tool to learn and discover the effects that different treatments can bring. I want to dive deeper into passive solutions. It’s really educational and funny! ![L+R TRAP L-R](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/7/9/79ec205ae4263ff46f705df4e82fa15e3e55cdc0.jpeg) ![L+R TRAP L-R SPECTROGRAM](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/b/5/b572eb67179282e88aeac61081fe477bc75ce93f.jpeg) ![L+R TRAP L-R WATERFALL](https://us1.discourse-cdn.com/flex015/uploads/psaudio/original/3X/c/1/c1ee5b92ac496fbe125604ee669bfeae79cfcbef.jpeg) ---
**Author:** ![allan.thunes](https://avatars.discourse-cdn.com/v4/letter/a/f17d59/32.png) [@allan.thunes](https://forum.psaudio.com/u/allan.thunes)\ **Post date:** [February 15, 2024, 9:48pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/198 "2024-02-15T21:48:27Z")
Please let me know if you come to understand group delay. I’m having a tough time with this topic. ---
**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 15, 2024, 10:03pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/199 "2024-02-15T22:03:43Z")
Mmm sorry, can’t help you. ---
**Author:** ![Jdee](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@Jdee](https://forum.psaudio.com/u/Jdee)\ **Post date:** [February 15, 2024, 10:54pm UTC](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553/200 "2024-02-15T22:54:36Z")
Have a look at > **[Understanding\_the\_SOTA\_of\_DRC.pdf](https://accuratesound.blob.core.windows.net/sotadrc/Understanding_the_SOTA_of_DRC.pdf)** > > 12.44 MB Which others will find valuable too. [Previous page](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553.md?page=9) [Next page](https://forum.psaudio.com/t/room-acoustic-measurements-rew-rabbit-hole/36553.md?page=11)