Acoustic treatment and room measurement

Roust_m

Roust_m

Enthusiast
Hi,
I measured my cinema room before applying acoustic treatment and after using the approach described in this video:
I used this page for my room treatment calculation:
I've put "Quality Level" as Ultra and "Room size" as 300-400 sq. ft.

I measured my room before treatment for the two seats in the front row I use 99% of the time. After treatment I measured all 6 seats.

To my surprise my measurements showed that my acoustics did not get better. They actually got worse.

This is a OneDrive folder with the measurements and the screenshot of acoustic treatment selection:
_cinema

The measurement files do not attached to the post for some reason.

Just to explain a bit the coding of the measurements:

S1, S2, ..., S6 are the seats and I placed microphone where the ear position would be when someone takes the seat. For pre-treatment time I only measured seat 1 and seat 2 (the front row I use 99% of the time)

Next character is "L" or "R" meaning left or right ear.
Next character is "L" or "R" meaning left or right speaker.
So, S1 L R means seat 1, left ear right speaker.

Wondering why this has happened?
Thanks.
 

Attachments

Last edited:
TLS Guy

TLS Guy

Audioholic Jedi
Hi,
I measured my cinema room before applying acoustic treatment and after using the approach described in this video:
I used this page for my room treatment calculation:
I've put "Quality Level" as Ultra and "Room size" as 300-400 sq. ft.

I measured my room before treatment for the two seats in the front row I use 99% of the time. After treatment I measured all 6 seats.

To my surprise my measurements showed that my acoustics did not get better. They actually got worse.

This is a OneDrive folder with the measurements and the screenshot of acoustic treatment selection:
_cinema

The measurement files do not attached to the post for some reason.

Just to explain a bit the coding of the measurements:

S1, S2, ..., S6 are the seats and I placed microphone where the ear position would be when someone takes the seat. For pre-treatment time I only measured seat 1 and seat 2 (the front row I use 99% of the time)

Next character is "L" or "R" meaning left or right ear.
Next character is "L" or "R" meaning left or right speaker.
So, S1 L R means seat 1, left ear right speaker.

Wondering why this has happened?
Thanks.
I suspect you killed beneficial reflections. There is a massive amount of BS and nonsense in this area including from people who should know better.

The problem as always is speakers and aberrant off axis response. I have never used room treatments as such, but the live end (speaker) end and the rear wall, relatively dead end, has some merit. So the architecture of my room is designed to accomplish that without 'funny' wall treatments. My great room and family room have no acoustic treatments at all.

The speakers in my family room were in a live acoustic in our last home, and now in a much deader room, but sounded fine in both spaces. As I have said before if you have a bad room, you must have installed your set up in a public lavatory.

The other dead end is room Eq. It might on occasion help a bass reinforcement or null problem, but more likely will move it from one spot to another. If you are lucky enough to be doing new construction then you choose optimal ratios for room dimensions.

The point I keep hammering home, is that if your family and friends voices sound the same in different rooms, then your speakers should as well, but a lot don't and that's the problem.

So I use no specific room treatments and auto Eq programs are set firmly to off.
 
Eppie

Eppie

Audioholic Ninja
I think room treatments for non-professionals should be restricted to simple situations where it makes sense logically. I have a wall on one side, but it is open on the other side for my HT. It would make sense to place panel on the wall to balance things out. I never did, though, as I find the reflections beneficial in that room.

Another instance is bass traps, when you know that you have a specific issue that can be address by a specific style of treatment.

To do a full room treatment, I think the op has discovered that this really is the realm of professionals. You need to have the proper equipment and knowledge to treat a room for best results. Doing it yourself, even with a good video tutorial, is still a stab in the dark. Rather than do the whole room, I would stick to specific issues; whichever ones will yield the biggest improvement.

And to touch on what TLS Guy has stated, it is important to choose speakers that have an off axis response that matches the on-axis response. Those are speakers that can benefit from EQ. If you watch videos from Erin's Audio Corner, he goes over the directivity index and explains which speakers can benefit from EQ and which ones can't because their off-axis response is so different. Poorly designed speakers can not be made to sound better through room treatments alone. Not to imply the op has bad speakers but it is a factor in getting optimal sound in all locations.
 
Roust_m

Roust_m

Enthusiast
This is the setup I have BTW:
I currently have a dedicated cinema room with 7.2.4 Monitor Audio Silver range speakers and Yamaha A8A AVR and 5-channel Rotel 1585 power amp dedicated to front and side speaker:
2 x Monitor Audio Silver 500 (front)
1 x Monitor Audio Silver c250 (centre)
2 x RXW12 (sub)
2 x RXFX (side)
2 x RX1 (back)
4 x Monitor Audio CP-CT380 8" In Ceiling Speaker

And attached is my room layout.
 

Attachments

lovinthehd

lovinthehd

Audioholic Jedi
What did measurements look like originally? What were you trying to resolve particularly?
 
Roust_m

Roust_m

Enthusiast
What did measurements look like originally? What were you trying to resolve particularly?
I put the before and after treatment measurements in this one drive folder:

I decided to put acoustic panels into the room to improve the sound quality, smooth out variations in frequencies, reduce decay. I went with the top package from that link in my first post and expected significant improvements compared to untreated room.
 
lovinthehd

lovinthehd

Audioholic Jedi
Was room furnished same on both measurements?

ps Don't have a one drive account
 
Roust_m

Roust_m

Enthusiast
Was room furnished same on both measurements?

ps Don't have a one drive account
Yes, same. You don't need One Drive account to access the link. I just accessed it in another browser without signing into my one drive account.
 
lovinthehd

lovinthehd

Audioholic Jedi
Yes, same. You don't need One Drive account to access the link. I just accessed it in another browser without signing into my one drive account.
Oh, it asked for a login....I'll look again in a bit....
 
TLS Guy

TLS Guy

Audioholic Jedi
I put the before and after treatment measurements in this one drive folder:

I decided to put acoustic panels into the room to improve the sound quality, smooth out variations in frequencies, reduce decay. I went with the top package from that link in my first post and expected significant improvements compared to untreated room.
Does not work, sign in code was sent, but does not work.
 
TLS Guy

TLS Guy

Audioholic Jedi
This is the setup I have BTW:
I currently have a dedicated cinema room with 7.2.4 Monitor Audio Silver range speakers and Yamaha A8A AVR and 5-channel Rotel 1585 power amp dedicated to front and side speaker:
2 x Monitor Audio Silver 500 (front)
1 x Monitor Audio Silver c250 (centre)
2 x RXW12 (sub)
2 x RXFX (side)
2 x RX1 (back)
4 x Monitor Audio CP-CT380 8" In Ceiling Speaker

And attached is my room layout.
Your problem is that the room suddenly widens at the listening area, that is bad.
 
Roust_m

Roust_m

Enthusiast
Your problem is that the room suddenly widens at the listening area, that is bad.
It was built like this intentionally, as the book I read about designing a home theatre was saying it is actually good for sound. We can debate about this, however the question in this topic is not about this. It is about why in the same room I don't see improvement after installing acoustic treatment.
 
TLS Guy

TLS Guy

Audioholic Jedi
I shared the files separately, as it is some glitch/feature of one drive when you share a folder you may need to sign in, but for separate files you don't.

Before treatment:
After treatment:
Stop posting it that way. You can attach your files to your posts on AH. Not going to bother to look at your data if you post it that way. I'm not fussing about with codes.
 
TLS Guy

TLS Guy

Audioholic Jedi
It was built like this intentionally, as the book I read about designing a home theatre was saying it is actually good for sound. We can debate about this, however the question in this topic is not about this. It is about why in the same room I don't see improvement after installing acoustic treatment.
It didn't because room treatments have a 50/50 chance of improving or making it worse and not even that good.

Where did you get that bogus idea about your room shape? If you re going to do that then you should have sloped the walls starting near the speakers, not that abrupt transition.

An even bigger mistake was picking those speakers. We have been round the houses with those before. The 3" midrange drivers are far too small for the power they have to handle. They cross at 800 Hz, and there is a huge amount of power above 800 hz to 2,700 Hz. So a big reason I suspect for your poor result is that the acoustic treatments absorbed a lot of sound that would have been reflected and stressed the speakers even more.

You have to choose speakers with huge care, as there are far more lousy ones than good ones.
 
Trell

Trell

Audioholic Spartan
Stop posting it that way. You can attach your files to your posts on AH. Not going to bother to look at your data if you post it that way. I'm not fussing about with codes.
There are size limits to attachments in a post, though. He for sure should compress them, and even them he might have to export measurements to multiple files before posting.
 
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WaynePflughaupt

WaynePflughaupt

Audioholic Samurai
I shared the files separately, as it is some glitch/feature of one drive when you share a folder you may need to sign in, but for separate files you don't.
There's an icon on the REW screen that lets you save a the measurement screen as a .jpg. Looks like an old floppy disc. You can do that an upload the picture here.

Regards,
Wayne A. Pflughaupt
 
H

highfigh

Seriously, I have no life.
Hi,
I measured my cinema room before applying acoustic treatment and after using the approach described in this video:
I used this page for my room treatment calculation:
I've put "Quality Level" as Ultra and "Room size" as 300-400 sq. ft.

I measured my room before treatment for the two seats in the front row I use 99% of the time. After treatment I measured all 6 seats.

To my surprise my measurements showed that my acoustics did not get better. They actually got worse.

This is a OneDrive folder with the measurements and the screenshot of acoustic treatment selection:
_cinema

The measurement files do not attached to the post for some reason.

Just to explain a bit the coding of the measurements:

S1, S2, ..., S6 are the seats and I placed microphone where the ear position would be when someone takes the seat. For pre-treatment time I only measured seat 1 and seat 2 (the front row I use 99% of the time)

Next character is "L" or "R" meaning left or right ear.
Next character is "L" or "R" meaning left or right speaker.
So, S1 L R means seat 1, left ear right speaker.

Wondering why this has happened?
Thanks.
I put the before and after treatment measurements in this one drive folder:

I decided to put acoustic panels into the room to improve the sound quality, smooth out variations in frequencies, reduce decay. I went with the top package from that link in my first post and expected significant improvements compared to untreated room.
Treatment is like the Einstein quote- "Make everything as simple as possible and no simpler".

Since you don't seem to be happy with the results of the installation of your treatments,

If you used REW, remove the treatments and run it again, placing treatments at one first reflection point relative to your primary listening position. Watch the response change. Add one to the other first reflection point that's as close to symmetrical to the first and check the response. Make notes of what changed, how much and above all, listen after each panel has been added.

My room had a deep trough in the 80Hz-110Hz range and by placing/watching/moving the panels, that problem is gone. I have changed nothing in the past ten years, including tone controls, which I don't use.

SIB-KIS: See It Big-Keep It Simple
 
Roust_m

Roust_m

Enthusiast
Let me try again
It didn't because room treatments have a 50/50 chance of improving or making it worse and not even that good.

Where did you get that bogus idea about your room shape? If you re going to do that then you should have sloped the walls starting near the speakers, not that abrupt transition.

An even bigger mistake was picking those speakers. We have been round the houses with those before. The 3" midrange drivers are far too small for the power they have to handle. They cross at 800 Hz, and there is a huge amount of power above 800 hz to 2,700 Hz. So a big reason I suspect for your poor result is that the acoustic treatments absorbed a lot of sound that would have been reflected and stressed the speakers even more.

You have to choose speakers with huge care, as there are far more lousy ones than good ones.
I read an e-book (cover attached) which describes a design of a home theatre in very fine detail (almost 400 pages) and took the dimensions from there. You can be right about that shape being not good or that guy may be right, but this topic is not about the room as I can't change it now. It is about the acoustic treatment. In defense of the shape of the room, it sounded quite good before acoustic treatment. I just was hoping if I throw in some good acoustic treatment, it will start sounding fantastic.

The idea of 50% chance of improving (improvements can also be minimal) and 50% chance making it worse is quite daunting. Could have spent these money on decorations better.

Once again, we can debate if Monitor Audio Silver 500 are good or not, as different people have different standards. For some a 10K pair of speakers may be mediocre. My question was all about how to make sound better with acoustic treatment given the existing room and existing speakers.
 

Attachments

Last edited:
Roust_m

Roust_m

Enthusiast
Stop posting it that way. You can attach your files to your posts on AH. Not going to bother to look at your data if you post it that way. I'm not fussing about with codes.
I tried compressing both files with maximum compression and the server did not accept it. Attaching it as images would not allow the viewer to look at different tabs of the measurements, so putting it on something like onedrive was the only way for me to post those files.
I've also put them on Google drive, in case it is easier for someone to access it:
Before:
After:
 
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