You indeed have a very damped room. 0.2 reverberation time qualifies as a dead room regarding resonances. Your measurements look great. Only thing I can spot is a bit excess energy on the 100hz frequency.
It should be an easy fix, assuming you are satisfied with the overall tonal balance of your system (not to bright, not too far etc).
But here is what you can do to tame that excess in 100hz region. You don’t even need to use rew automated EQ design.
Select left channel measurement, and go to the EQ section in REW. Click filter, and dial one PK filter, on 110hz, -3dB gain, Q=2. Make sure the checkbox is selected.
Then, exit the EQ, click on overlays, and predicted frequency response. REW will simulate the filter effect. You should see a smoothing of that 100hz peak. Should it be too broad (many frequencies affected), go up with the Q number. It should be easy peasy.
Remember that most people prefer the bass and mid-bass stronger, so don’t sim for a flat response (it may find the result to be too thin or too bright).
Finally, put your eq filter in roon, sit back and relax.
If you want more details about rew filter design, just ask.
I don’t use roon anymore, just Sense App. I’ll try experimenting with passive stuff and speaker set up next days, I’m curious to find out how things can change.
What I learned is that subs are causing a dip around 40 Hz, it could explain why I’m liking the sound without them.
I’m going to focus on the other dip around 60 Hz (more pronounced from one speaker) and the 100 Hz reinforcement.
I can’t move my listening position, so it’s quite difficult fighting dips, while about peaks at specific frequencies (100 Hz) I need to figure out how solve them in some way. It might be funny and educative.
It is a very nasty peak around 100hz. Logitech media server, that is the motor behind innuos, has just launched a very easy EQ plugin (I believe it is called squeeze-DSP. I will look for you ina couple of hours). Maybe innuos support can help you installing.
One of rew’s features is to simulate room response regarding positioning. You can play with the module. It is fun and quite accurate.
Hmm, my take is not quite as positive, Luca. Your room might be too dead. While RT60 is a questionable measurement for most home listening rooms, having reverb times below about 300ms, depending on who you believe, is not ideal. If you like what you’re hearing, of course, then what I say doesn’t matter. A more useful view is the RT60 Decay Tab, if you want to post it. If you do, be sure to run the Calculate RT60 Model from the widget control panel.
Running amazingly flat out to 20KHz, which most people would perceive as too bright. Studies over time have shown people tend to feel either something looking like the Harman curve, or the B&K curve (which I prefer) is felt to sound more natural. But again, it’s ultimately personal preference.
As for the lumpiness between 20 and 100 Hz or so, after all the work you’ve done probably the best way to deal with it is via DSP room correction. Moving the subs will only move the location of that dip, so not sure how much that will help you. If you want to you could try moving the listening position or the speakers around to see if the FR can be further optimized. Ah, I see you already addressed the difficulties with listening position.
You know, I agree with you. I just think it is best to divide the subjects:
1- the “deadness” of the room. It also seems to me like a “too dead room”. It even meets rigorous studio settings as per reverberation times. But no EQ will address this matter
2- the peak around 100hz. This one should be addressed. It seems to have 3 to 4 dB excess energy, even considering a non-flat response (for flatness, it would be near 10dB). This couldake the sound too bass heavy, in one of the most important regions of frequency response
3- the valleys between 60 and 100hz. This could be a result of the room geometry, or even out-of-phase bass response in the listening position. It would demand more investigation and experimentation.
The only thing we differ is that I could never get accustomed to the B&K curve. It sounds too little bass for me. I use a modified version of the Harman curve.
I think Luca has the ability to add reflectors of some sort to his room treatment solution. Might bring the reverb times up, assuming no other ill effects.
I can’t say I understand the program but reading @luca.pelliccioli rabbithole, here are some of my own. I assume i have the UMIK and program parameters setup correctly.
I appreciate feedback before I start moving stuff around!
Dead room. Since my first sketch when I was planning the room refurbishment I was well aware about this risk due to the type of solutions and acoustic treatments I adopted. I discussed a lot this matter with the acoustic engineer who was following me in the design process.
Being a small basement with open doors and glass windows, we had to fight serious bass issues like boominess and distortion. This the main reason of the side wall panels. The heavy rug, the couch, the amount of books, the furniture behind the listening position and other stuff in the room are certainly playing a role, dampening further more the environment.
Needless to say, I like the way the room sounds, so I’m happy but I definitely have room for improvement. The Italian importer MSB who often comes to visit my room and also sold me the speakers, always says that in fact it doesn’t sound too dead, even if it is close to the limit. He says it’s a very pleasant room and suggests not to worry about it (he also sells acoustic treatments on request).
The sliding panels on the side walls are very flexible because I can apply all the magnetic diffusers I want on them. Playing with them it’s my primary concern.
Removing stuff from the room (different rug and couch/chair) will be the following step. While changing the furniture behind the listening position (that implies also positioning the rack there) would require spousal approval and I’m afraid it won’t be applicable anytime soon.
60 Hz dips and 100 Hz peaks These are interesting questions to study and investigate. My attention is focused first and foremost on them. Using REW should help me tackle this problem with some experiments with passive solutions. If possible. DSP plugins could possibly be my next frontier, but I’m not sure. Many thanks for your help and possible suggestions to improve the room, any ideas will be greatly appreciated. Life is always a compromise and I would like to enjoy this process, er, this new rabbit hole. Until the new cables I ordered are here!
The green and red curves are the frequency response of each speaker? If so, can you post a graph with the 2 of them together, with 1/6 smoothing (from the all spl tab)? It makes it easier. Also, a spectrogram of each speaker helps.
The most important is to have fun. For the 60hz issue, post the phase response measured with subs, ina graph that shows each channel, zoomed in the region of 20-200hz. You can easily do this in the overlay section. There you will see if there are phase misalignments in your listening position.
Regarding the 100hz, see the plugin as a free trial. Before investing in more treatment. Reducing the energy will pretty much change the way your room sounds. You can try and see if you like it. In roon is a piece of cake, if you are willing to reinstall it dor this test (you could put the core in your MacBook and use the innuos as endpoint only. It should be easy).
There are a lot of people who would love to have the room as quiet as yours (me included) and there is a lot of data that shows the RT60 decay time (which is the time it takes for a sound to decay by 60db) is not a reliable test for small room acoustics.
The standard accepted RT60 time for rooms varies with the size (volume) of the room. The smaller room needs a shorter decay time to sound “right”. Too long and there is too much ringing or echo in the room.
As the room gets larger the RT60 time should go up as it naturally takes longer for the reverberated sounds to make it back to your ears. A concert hall might have an RT60 time of 1.5 seconds instead of the 0.20-0.30 seconds you have. The “normal” target for a “small” room is 0.40 seconds or less.
There is a calculator online somewhere if you would like to calculate the normal RT60 time for the volume of your particular room but it probably isn’t worth the effort.
Again if you like the sound of your room this exercise may just be for info an a fun project to find out what makes a difference and what does not make a difference. REW is also good at blending subs into the mix.
The bump at ~25hz and ~125hz are probably room modes and would be easily cut (if they bother you) by creating a filter in REW.
It is easy to cut peaks (remove energy) but in my experience you never want to boost any frequency. I have never been able to make it sound good.
It is also best if you only EQ frequencies below the Schroeder frequency which varies by room volume but is usually under 400 hz.
I wouldn’t be too concerned that the room is “too quiet”. It certainly lets you hear everything in the recordings above that threshold and there is a lot of information in recordings that is below 50db that we never hear due to the background noise.
If someone has a 50db hiss coming from their tweeters that is only noticeable with their ear next to the tweeter they would throw a fit even though they could not hear it when seated at the listening position as it would be equal to background noise.
In your room that 50db hiss would be easily heard from the listening position…
Keep us posted on your progress. We are enjoying your trip.
It could also explain why I’m preferring solid state vs tubes gear sound, a certain amount of hiss from speakers is always audible in my room as much as it was that subtle buzz from components transformers that convinced me to sell the P20 and P15.
Steps on the floor and piano pedals are always fascinating to hear during live performances indeed, you are right. I like that sense of realism.
Thank you! I will try moving the treatments currently in use to different locations to see what happens and also some changes in the speaker setup. Then I’ll share the REW charts.
It’s fun to monitor in real time how these changes may impact the big picture (even if ultimately only my ears can judge). I consider this experience a sort of educational opportunity.
If I were ever to consider a DSP filter, I would need a lot of help with the software. It requires a lot more effort for a non-tech guy like me. A step at a time!
A more useful view is the RT60 Decay Tab, if you want to post it. If you do, be sure to run the Calculate RT60 Model from the widget control panel.
