Have I Over Treated My Room?

[DanDan]

"All this RT60 & ETC's is brand new to me so you will have to bear with me.

I am guess that due to the amount of absorption in my room the RT60 readings are very low? I have been told that this is an issue as the room will sound dead? So my room is over damped?

I have no clue what ETC's are so I will need to do some more research on that one."

No worries. RT60 and it's more sophisticated cousin are measures of decay of room tone. Your, apart from in the sub range, is almost ruler flat and quite dead at 100mS. BBC used to reckon their listeners fully furnished living rooms at around 500mS.
So yes, your room tone is very minimal and very uncoloured. But as you are listening in surround, perhaps this is a good thing?
I would guess that most movies these days have significant information most of the time in the surround channels. If you listen to a lot of music in there, or would like to try a livelier acoustic you could try including a Lexicon or such. Take a look over at DeadSlutz, jim1961 did massive research into this dead, neutral, plus whatever....... He ended up with a Lexicon......and a Target Curve very close to the Bruel and Kjaer, Harman, etc. etc.
ETC is, can't remember exactly, but let's call it an EchoGraph. If you play a single speaker it will show every individual surface bounce, particularly in the early field. Most Control Room designs strive for no reflections above -20dBFS during the first 20mS. 20/20. Many designs do way better than that. Hidley and Newell's Non Environment and even many of our Prosumer CRs would be below -30 and for longer. Virtually Anechoic. My puzzle with yours is that you have a nicely tight RT60 but a lot of scattery reflections in your first 20mS. Bad Panels perhaps, but still puzzling.

 

[Bpape]

sorry for not being around. So, I didn't see a recent measurement with the 80Hz xover and the mains set to small and along with the sub. Am I just missing it?

 

[AdamA]

So here is L, C ,R including subs all with an 80Hz crossover & all EQ enabled.

The other file is the L, C, R individually & the subs individually all with an with 80Hz crossover NO EQ.

All these measurements are at my seating location.

If I have missed any requests for other measurements please let me know.

"All this RT60 & ETC's is brand new to me so you will have to bear with me.

I am guess that due to the amount of absorption in my room the RT60 readings are very low? I have been told that this is an issue as the room will sound dead? So my room is over damped?

I have no clue what ETC's are so I will need to do some more research on that one."

No worries. RT60 and it's more sophisticated cousin are measures of decay of room tone. Your, apart from in the sub range, is almost ruler flat and quite dead at 100mS. BBC used to reckon their listeners fully furnished living rooms at around 500mS.
So yes, your room tone is very minimal and very uncoloured. But as you are listening in surround, perhaps this is a good thing?
I would guess that most movies these days have significant information most of the time in the surround channels. If you listen to a lot of music in there, or would like to try a livelier acoustic you could try including a Lexicon or such. Take a look over at DeadSlutz, jim1961 did massive research into this dead, neutral, plus whatever....... He ended up with a Lexicon......and a Target Curve very close to the Bruel and Kjaer, Harman, etc. etc.
ETC is, can't remember exactly, but let's call it an EchoGraph. If you play a single speaker it will show every individual surface bounce, particularly in the early field. Most Control Room designs strive for no reflections above -20dBFS during the first 20mS. 20/20. Many designs do way better than that. Hidley and Newell's Non Environment and even many of our Prosumer CRs would be below -30 and for longer. Virtually Anechoic. My puzzle with yours is that you have a nicely tight RT60 but a lot of scattery reflections in your first 20mS. Bad Panels perhaps, but still puzzling.

When you say "Bad panels" are you referring to the BAD diffusers or my crappy DIY panels

I read that an RT60 around 300ms is good for home theatre so my room does seem on the low side. I was thinking of removing all the panels covering the windows other than the ones covering the first reflection points.

I did read a while ago now that glass absorbs low frequencies & reflects high frequencies. I was told to cover it at all costs but I am unsure if this is a good idea or not.

sorry for not being around. So, I didn't see a recent measurement with the 80Hz xover and the mains set to small and along with the sub. Am I just missing it?

I have attached those measurements to this post.

L, C, R With Subs & Subs Alone - Seat 1 - Full EQ - 80Hz Crossover

L, C, R Only & Subs Alone- Seat 1 - No EQ - 80Hz Crossover

Also what do you guys think of these on and off axis measurements of my front left speaker.

I took them with the microphone pointing at the speaker using my 0 degree calibration file. The microphone was 2 meters away from the speaker.

I took the measurements at 0, 15, 30, 45 & 60 degrees level with the tweeter.

Are my mains just total junk?

 

[AdamA]

Can REW perform short tone bursts for speaker measurements?

The on & off axis measurements above are apparently in accurate as I was using continuous tones instead of short tone bursts.

This means that the room is a factor in the measurements which is obviously not what I wanted.

I just want to be able to measure my speakers to see what there response is without the room.

My theory is that if my speakers are junk I can do all the in room measurements in the world but if the speaker is trash I will never fix my issues?

Probably a flawed theory but it makes sense in my head.

 

[DanDan]

REW is, has grown into, a very well equipped Acoustical Laboratory. There is a fascinating learning curve, a brilliantly written manual. That said, as a Professional Acoustician, I use only a fraction of it, and there are many aspects I have never visited. Fwiw I have a growing opinion that it might well benefit from splitting into several apps in the future.
I hope you enjoy your particular journey, but probably best not to fill up the forum with data hungry images without specific questions.
You could research gating and other techniques which attempt to separate the speaker from the room. But IMO, none of this would yield any useful data. It is likely that the manufacturers data is reasonably accurate. Or you could try your own DIY version by measuring a single speaker in your garden up on a pole.

Trying to get unlost here, where were we? Those Early Reflections...... Is your ceiling treated?

 

[AdamA]

REW is, has grown into, a very well equipped Acoustical Laboratory. There is a fascinating learning curve, a brilliantly written manual. That said, as a Professional Acoustician, I use only a fraction of it, and there are many aspects I have never visited. Fwiw I have a growing opinion that it might well benefit from splitting into several apps in the future.
I hope you enjoy your particular journey, but probably best not to fill up the forum with data hungry images without specific questions.
You could research gating and other techniques which attempt to separate the speaker from the room. But IMO, none of this would yield any useful data. It is likely that the manufacturers data is reasonably accurate. Or you could try your own DIY version by measuring a single speaker in your garden up on a pole.

Trying to get unlost here, where were we? Those Early Reflections...... Is your ceiling treated?

Apologies for the images, I though instead of just posting the .mdat files like I did last time I would upload the images to as I was receiving requests for measurements that were contained within the .mdat files. I thought it would be easier for people to see the data right here instead of downloading it & having to use a program to view it.

My ceiling is treated but for the front row only, these measurments are from the rear row where I sit.

Treating the ceiling for the rear row is next to impossible as the first reflection points for the rear row fall directly on top of the RSJ that spans the width of the room so placing a panel there is not practical.

Can you show me in the data these early reflections? Maybe if I know what to look for I can experiment & try to eliminate them?

 

[DanDan]

I need to update this everywhere it was posted to include the pics, but take a read and note particularly the What to Expect section.

Measuring Room Acoustics - Gearspace.com

Measuring Room Acoustics Intro Acoustic Measuring Software of decent quality has become very affordable. This has led to many attempting to use it to e

www.gearslutz.com

No worries about your exploration, my point is too much wood, can't see the trees. REW and science are of course fascinating and amazing, but what is it you want here? The title question? No, it is not possible to over treat relatively small rooms. The treatment would take up too much space. Pro spaces can have up to say 60% of the volume occupied by treatment.

Here's a well written piece on the 20/20 thing ZWER..... Zone Without Early Reflections....

 

[AdamA]

I need to update this everywhere it was posted to include the pics, but take a read and note particularly the What to Expect section.

Measuring Room Acoustics - Gearspace.com

Measuring Room Acoustics Intro Acoustic Measuring Software of decent quality has become very affordable. This has led to many attempting to use it to e

www.gearslutz.com

No worries about your exploration, my point is too much wood, can't see the trees. REW and science are of course fascinating and amazing, but what is it you want here? The title question? No, it is not possible to over treat relatively small rooms. The treatment would take up too much space. Pro spaces can have up to say 60% of the volume occupied by treatment.

Here's a well written piece on the 20/20 thing ZWER..... Zone Without Early Reflections....

Well I though my issue was to much treatment which I thought was causing the issues I describe in my initial post such as poor integration of the mains & surrounds with thin/lean bass.

That is when I was asked to provide measurements & we started down this road of looking else where to find the issue.

I started to read the post you linked to but all the images are no longer visible.

 

[DanDan]

"Well I though my issue was to much treatment which I thought was causing the issues I describe in my initial post such as poor integration of the mains & surrounds with thin/lean bass."
Has this been answered satisfactorily?

"That is when I was asked to provide measurements & we started down this road of looking else where to find the issue. "
Indeed and they do tell a story. But nothing like as powerful as your human descriptions and details.
I now gather your are sitting at the back and there is no ceiling treatment back there? I would assume that the sound quality, immersion etc. would be much better closer to Front Speakers.

Here and elsewhere there are myriad advices on sub integration, but you will need to move stuff to see if you can get improvement.
Keep a fully open mind, subs may end up anywhere, e.g. half height.

"I started to read the post you linked to but all the images are no longer visible."
Yup, that picture hosting site vanished. You can generate images of all those in REW yourself though.

 

[AdamA]

"Well I though my issue was to much treatment which I thought was causing the issues I describe in my initial post such as poor integration of the mains & surrounds with thin/lean bass."
Has this been answered satisfactorily?

Well, sort of. I guess you have answered my question into if the room is over treated. I do still wonder if treating a home theatre has a different approach to treating a home studio.

I still have my poor integration of the mains & surrounds with thin/lean bass issue.

"That is when I was asked to provide measurements & we started down this road of looking else where to find the issue. "
Indeed and they do tell a story. But nothing like as powerful as your human descriptions and details.
I now gather your are sitting at the back and there is no ceiling treatment back there? I would assume that the sound quality, immersion etc. would be much better closer to Front Speakers.

Here and elsewhere there are myriad advices on sub integration, but you will need to move stuff to see if you can get improvement.
Keep a fully open mind, subs may end up anywhere, e.g. half height.

I spent two days measuring with REW & moving my two subwoofers into every possible location & orientation.

I measured them on their own & once I gathered around 400 measurements I used the trace arithmetic feature in REW to combined each response from each subwoofer at each seating location.

This allowed me to the combined responses of both subs for each seating position to find the best location for the subs for all four seating locations. This took many hours to work through all the possible combinations.

So I am fairly confident I have the correct placement for my subwoofers, the mains I am very limited on where I can place them & a large majority of that is due to the Dolby specifications on speaker placement.

I mean they need to be up front & other than moving them further forward or backwards I am extremely limited in what I can do.

I guess that leaves seating placement, I have wanted for a while to move both rows further back but I read that being near the back wall is really bad for room modes & is generally advised against. I am currently 120cm from the back wall.

 

[DanDan]

When you were optimising the location of your subs, where was the microphone?

 

[AdamA]

When you were optimising the location of your subs, where was the microphone?

As I said I measured at each of the four seating positions which is one of the reasons why I took so many measurements.

I then painstakingly tried all the different combinations of subwoofer placements & orientations to find the one that gave me the best response for all four seats.

All taken at ear height at each seating position.

 

[DanDan]

Perhaps I asked the wrong question. Have you tested to find an optimum listening position. This can change with different sub locations, or if you are very lucky it can 'stick' to the one spot or an area. It strikes me that an awful lot of effort is going into testing and trying to optimise a probably non optimal listening location. Have you tried listening in the front zone, say at 38% L distance from the front wall?
Many don't so I will also ask, have you tried half height sub locations?

 

[AdamA]

Perhaps I asked the wrong question. Have you tested to find an optimum listening position. This can change with different sub locations, or if you are very lucky it can 'stick' to the one spot or an area. It strikes me that an awful lot of effort is going into testing and trying to optimise a probably non optimal listening location. Have you tried listening in the front zone, say at 38% L distance from the front wall?
Many don't so I will also ask, have you tried half height sub locations?

From my testing to find the best subwoofer location I found that the rear row has a better subwoofer response than the front row due to the rear sub being near field to the rear row.

In regard to the mid & upper frequencies I have not tested to see which seating position is the best out of the box so to speak.

I know a lot of people say you should just prioritize one seat & forget the rest but its important to me that I get good performance at all the seating positions.

Otherwise you are sitting there with a big smile on your face at what you are hearing & the person sitting next to you has no clue what your so happy about.

I will be honest I am not sure what 38% L is.

I have not tried half height sub locations, main reason being that my subs weight 80kg each so getting them up off the floor would require a serious structure to support them.

 

[DanDan]

I would recommend finding the optimum listening and sub and sub positions, which are interactive. I guess the Front Speakers are kinda determined by the Listener position, but again some to and fro is possible.
I think it was Bob Hodas, anyway I concur, who said Location is 70% of the job at hand. And generally free....

 

[AdamA]

Had another experiment today, first up was moving the front left up against the front wall to see if that improves the response but no such luck as it made very little difference.

I next tried many different things with the centre channel including moving it up against the front wall, moving it further forward & raising it up to ear level all which made little to no difference either.

So I guess where my rear row is place in the room just sucks & is probably in a room mode? The front row measures much better ask expected.

I did measure in front & behind the rear row to see what response I would get if I did decide to move the rear row to another location but more bad news as both options made the response even worse

So I do believe I have no other options to improve the response at the rear row.

The area that looks the worse is between 100Hz to 400Hz.