Changing carpet degraded my sound quality - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 6Likes
  • 2 Post By Adamg (Ret-Navy)
  • 1 Post By Buddylee123
  • 1 Post By Buddylee123
  • 1 Post By DaveClement
  • 1 Post By LydMekk
 
Thread Tools
post #1 of 25 Old 09-19-2017, 07:21 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Changing carpet degraded my sound quality

I recently changed the carpet in my room and I think it has had a huge effect on my sound quality. The carpet I had in the room was very fluffy and plush. The new carpet has almost no shag to it and it's not fluffy at all. When the old carpet was in the room the sound was great and dialog was the best that I have ever had with my setup. After the new carpet went in the dialog is not anywhere near as clear, and the room hs a lot of echoes in it. Could the new carpet be causing my dialog problems? My room is on the small side 13x 14 feet.
Buddylee123 is online now  
Sponsored Links
Advertisement
 
post #2 of 25 Old 09-19-2017, 07:38 AM
Ultimate Sound Wave
 
Adamg (Ret-Navy)'s Avatar
 
Join Date: Jul 2009
Location: SW Florida
Posts: 1,356
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 701 Post(s)
Liked: 1275
Quote:
Originally Posted by Buddylee123 View Post
I recently changed the carpet in my room and I think it has had a huge effect on my sound quality. The carpet I had in the room was very fluffy and plush. The new carpet has almost no shag to it and it's not fluffy at all. When the old carpet was in the room the sound was great and dialog was the best that I have ever had with my setup. After the new carpet went in the dialog is not anywhere near as clear, and the room hs a lot of echoes in it. Could the new carpet be causing my dialog problems? My room is on the small side 13x 14 feet.
Absolutely yes! The old carpet as you described was acting as a reflection neutral/absorbent material. The new Carpet has less absorption properties. Several ways to fix this. Re run the Calibration function of your AVR, if it has that. Install some padding under the carpet. This will increase the density of the floor covering and therefore increases the sound absorption properties.

All reflective surfaces in a room can create harsh reverberations, echo's and distortion. The Floor, walls and Celling are three of the most reflective surfaces you have in any room. So your observations and conclusions are spot on! Good thinking.

AdamG, ...out!
The government cannot give to anybody,
anything that the government does not first,
take from somebody else.
Adamg (Ret-Navy) is offline  
post #3 of 25 Old 09-19-2017, 07:53 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by Adamg (Ret-Navy) View Post
Absolutely yes! The old carpet as you described was acting as a reflection neutral/absorbent material. The new Carpet has less absorption properties. Several ways to fix this. Re run the Calibration function of your AVR, if it has that. Install some padding under the carpet. This will increase the density of the floor covering and therefore increases the sound absorption properties.

All reflective surfaces in a room can create harsh reverberations, echo's and distortion. The Floor, walls and Celling are three of the most reflective surfaces you have in any room. So your observations and conclusions are spot on! Good thinking.
Thanks for the info. I did rerun the auto calibration but can't get the good dialog clarity back. I think the room might just be too reflective for the calibration to handle. When I clap my hands the echo is really bad. I have a pad under the carpet so I can't do much more there. I have some treatments on the side walls and a little on the back. I was thinking about adding 3 to 4 GIK 242 panels to the ceiling and one more panel to the back wall.
Buddylee123 is online now  
 
post #4 of 25 Old 09-19-2017, 08:13 AM
Ultimate Sound Wave
 
Adamg (Ret-Navy)'s Avatar
 
Join Date: Jul 2009
Location: SW Florida
Posts: 1,356
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 701 Post(s)
Liked: 1275
Quote:
Originally Posted by Buddylee123 View Post
Thanks for the info. I did rerun the auto calibration but can't get the good dialog clarity back. I think the room might just be too reflective for the calibration to handle. When I clap my hands the echo is really bad. I have a pad under the carpet so I can't do much more there. I have some treatments on the side walls and a little on the back. I was thinking about adding 3 to 4 GIK 242 panels to the ceiling and one more panel to the back wall.
Hi Buddylee,

I took a look at your build thread, but did not see any pictures of the front set up and room in general. It looks like your center speaker is sitting on the floor or very close to it. If that is the case, then you are most definitely suffering from early reflections from the floor. Can you place the center speaker on a stand? Even something temporary that will work for now. Just to see if moving the center speaker away from the floor fixes your problem.

You were happy with the sound before right? Then the only thing you changed was the carpet, correct? If this is correct, you may not need to spend money on wall treatments here. It may be just that the new carpet is too reflective for the center speaker. Getting the center up off and away from that first reflection point (floor) may completely fix your problem. Try using a chair or stool, stack of books. Get the center up and away from the floor and demo the change.
rboster and DaveClement like this.

AdamG, ...out!
The government cannot give to anybody,
anything that the government does not first,
take from somebody else.
Adamg (Ret-Navy) is offline  
post #5 of 25 Old 09-19-2017, 08:32 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by Adamg (Ret-Navy) View Post
Hi Buddylee,

I took a look at your build thread, but did not see any pictures of the front set up and room in general. It looks like your center speaker is sitting on the floor or very close to it. If that is the case, then you are most definitely suffering from early reflections from the floor. Can you place the center speaker on a stand? Even something temporary that will work for now. Just to see if moving the center speaker away from the floor fixes your problem.

You were happy with the sound before right? Then the only thing you changed was the carpet, correct? If this is correct, you may not need to spend money on wall treatments here. It may be just that the new carpet is too reflective for the center speaker. Getting the center up off and away from that first reflection point (floor) may completely fix your problem. Try using a chair or stool, stack of books. Get the center up and away from the floor and demo the change.
I should update my build thread. The center in new behind an AT screen.

Adamg (Ret-Navy) likes this.
Buddylee123 is online now  
post #6 of 25 Old 09-19-2017, 08:37 AM
Ultimate Sound Wave
 
Adamg (Ret-Navy)'s Avatar
 
Join Date: Jul 2009
Location: SW Florida
Posts: 1,356
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 701 Post(s)
Liked: 1275
Quote:
Originally Posted by Buddylee123 View Post
I should update my build thread. The center in new behind an AT screen.

I'm sorry but I still can not see the details of how the Center channel speaker is positioned. Is it on a shelf? If so, make sure the speaker is ALL the way forward on the self so there remains no immediate reflective surfaces in front of drivers.

To be able to provide any more detailed advice I need a well light picture of the front 3 (L,C,R) speaker set up. If behind the screen, raise the screen then take a well light pic please. The picture provided is too dark to make out any details. It could be my monitor, but I am viewing the pic on a 4K UHD Laptop.

AdamG, ...out!
The government cannot give to anybody,
anything that the government does not first,
take from somebody else.
Adamg (Ret-Navy) is offline  
post #7 of 25 Old 09-19-2017, 08:49 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by Adamg (Ret-Navy) View Post
I'm sorry but I still can not see the details of how the Center channel speaker is positioned. Is it on a shelf? If so, make sure the speaker is ALL the way forward on the self so there remains no immediate reflective surfaces in front of drivers.



To be able to provide any more detailed advice I need a well light picture of the front 3 (L,C,R) speaker set up. If behind the screen, raise the screen then take a well light pic please. The picture provided is too dark to make out any details. It could be my monitor, but I am viewing the pic on a 4K UHD Laptop.


It is on shelf behind the screen. I will try to move it closer to see if that helps. When I get home I will also try to get some better pictures, the black carpet is making that hard


Sent from my iPhone using Tapatalk
Adamg (Ret-Navy) likes this.
Buddylee123 is online now  
post #8 of 25 Old 09-19-2017, 09:35 AM
Ultimate Sound Wave
 
Adamg (Ret-Navy)'s Avatar
 
Join Date: Jul 2009
Location: SW Florida
Posts: 1,356
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 701 Post(s)
Liked: 1275
Quote:
Originally Posted by Buddylee123 View Post
It is on shelf behind the screen. I will try to move it closer to see if that helps. When I get home I will also try to get some better pictures, the black carpet is making that hard


Sent from my iPhone using Tapatalk
No problem. Just quote me and I will see the reply and come try to help. No rush, I'm not going anywhere

AdamG, ...out!
The government cannot give to anybody,
anything that the government does not first,
take from somebody else.
Adamg (Ret-Navy) is offline  
post #9 of 25 Old 09-19-2017, 11:05 AM
HOME THEATER CONTRACTOR
 
BIGmouthinDC's Avatar
 
Join Date: Jan 2003
Location: Northern VA
Posts: 28,162
Mentioned: 267 Post(s)
Tagged: 5 Thread(s)
Quoted: 3901 Post(s)
Liked: 3335
If it is behind the screen try raising it up, also try removing that hard reflective surface you put your drinks on (table).
BIGmouthinDC is offline  
post #10 of 25 Old 09-19-2017, 11:11 AM
Advanced Member
 
DaveClement's Avatar
 
Join Date: Aug 2001
Location: Lynnwood, WA USA
Posts: 814
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 185
While recalibrating the receiver is a good idea, there is only so much that calibration can do. It cannot take away reverberation of smearing of the signal due to reflections.

Most of the dialog should be coming from the center speaker, so its position would have the most effect on the dialog clarity, but you might also try raising up your left and right speakers, which are sitting on the floor.

If you can hear the echoes in the room, you have too much reflection. Short of replacing the carpeting, you might look into putting a very thick throw rug on top of the new carpet.

Are you familiar with the trick of temporarily putting a mirror on the floor, walls or ceiling to determine where the first reflection points are? Basically, you hold a mirror against one of the surfaces and you can see the speaker(s) from that location, it is a primary reflection point. In addition to treating the floor with a throw rug, make sure that your treatments on the walls and ceiling are in the proper locations to be effective.

Do you still have the coffee table that is in some of your earlier pictures? Try removing it. It looks to be right in a primary reflection point where you don't want a hard reflective surface.

Last edited by DaveClement; 09-19-2017 at 11:13 AM. Reason: typo
DaveClement is offline  
post #11 of 25 Old 09-19-2017, 03:31 PM
Advanced Member
 
Join Date: Dec 2015
Posts: 825
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked: 198
When a room develops slap echo you can often address that by adding more absorption to the room spread out. 2" or 4" panels would both work fine for the echo but since most rooms could use a bit more Lf absorption, thicker can be nicer.

You can put panels on the floor too. If they are black they may not be noticable. You could also build a sort of stage in front of the screen and speakers in order to absorb. I actually think this is an under-utilized trick.

I think your L and R speakers are way to far apart. I would place them closer to the screen. You are getting a lot more early reflections from the walls with them placed so close. If you want to keep them there I think you need a lot more absorption as your first reflection point is most of the wall near the speaker.

Another trick worth trying would be to add some pictures to the walls. Interior designers sometimes do this to mitigate slap echo problems. They have been known to respond to simply roughening the barrier surfaces with things like bulky picture frames. It's one reason why empty rooms echo but once you fill them with furniture it's gone. Not only is some of the furniture absorptive but all of it is also creating a lack of parallel surfaces. I read this in an acoustic text and have since found it to be true (to a point). In that text they suggested that multiple smaller panels around the walls was better than one large panel.

Keep in mind slap echo is unrelated to first reflections and heavily treating first reflections won't get rid of it. They usually are causes by parallel surfaces near the source of the clapping. In other words if you hear it at your listening position, it's those walls and ceiling that need treating.

If you cover too many surfaces with 4" thick panels you will have a notch in hour midbass RT60. You will want to be careful and use a mix of panel thicknesses as well as other means to reduce the slap echo.


Sent from my iPhone using Tapatalk
Mpoes12 is online now  
post #12 of 25 Old 09-19-2017, 03:59 PM
Advanced Member
 
Join Date: Dec 2015
Posts: 825
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked: 198
When a room develops slap echo you can often address that by adding more absorption to the room spread out. 2" or 4" panels would both work fine for the echo but since most rooms could use a bit more Lf absorption, thicker can be nicer.

You can put panels on the floor too. If they are black they may not be noticable. You could also build a sort of stage in front of the screen and speakers in order to absorb. I actually think this is an under-utilized trick.

I think your L and R speakers are way to far apart. I would place them closer to the screen. You are getting a lot more early reflections from the walls with them placed so close. If you want to keep them there I think you need a lot more absorption as your first reflection point is most of the wall near the speaker.

Another trick worth trying would be to add some pictures to the walls. Interior designers sometimes do this to mitigate slap echo problems. They have been known to respond to simply roughening the barrier surfaces with things like bulky picture frames. It's one reason why empty rooms echo but once you fill them with furniture it's gone. Not only is some of the furniture absorptive but all of it is also creating a lack of parallel surfaces. I read this in an acoustic text and have since found it to be true (to a point). In that text they suggested that multiple smaller panels around the walls was better than one large panel.

Keep in mind slap echo is unrelated to first reflections and heavily treating first reflections won't get rid of it. They usually are causes by parallel surfaces near the source of the clapping. In other words if you hear it at your listening position, it's those walls and ceiling that need treating.

If you cover too many surfaces with 4" thick panels you will have a notch in hour midbass RT60. You will want to be careful and use a mix of panel thicknesses as well as other means to reduce the slap echo.


Sent from my iPhone using Tapatalk
Mpoes12 is online now  
post #13 of 25 Old 09-19-2017, 09:33 PM
Senior Member
 
LydMekk's Avatar
 
Join Date: May 2005
Location: Spain
Posts: 273
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 69 Post(s)
Liked: 48
Remember: a decent goal to aim for is 20-25% of the rooms surfaces covered in absorbers, 20-25% more in diffusors.
Ceiling is as important as the floor to treat.
What materials are the walls and floor/ceiling? Concrete, wood or?

"If everything is under control you are just not driving fast enough"

Home Theatre Heaven in Spain - V2.0 - Build thread
LydMekk is offline  
post #14 of 25 Old 09-20-2017, 07:52 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Spoiler!


Thanks Big, I’ll try moving it and I’ll try to get a picture of my center placement this weekend.

Spoiler!


Thanks Dave, I have some treatments on the walls, see photo. Good idea on the mirror trick, will try it this weekend.



Spoiler!


I moved the L and R speakers in last night and can already tell an improvement in sound quality. Just moving those in seems to have helped with the sound from them, and cleared up my dialog from the center some. I’m guessing I was getting a lot of reflections from them. I can’t really place anything on the carpet like rugs so I am limited to treating the wall and ceiling. I did some testing at my MLP last night and it must be my celling that is causing my slap echo because it’s completely untreated, and the wall near it have the panels in the picture above.

Spoiler!


I think you are on to something with the ceiling. My walls and ceiling are drywall and the floor is concrete with the thin carpet and pad. My room is not that big either 14x13 feet so I think the ceiling will be my next area of focus. I’m thinking 4 24”x48” panels attached to the ceiling.

Thanks again for the info everyone. Over the next few weeks I will be adding treatments and making the adjustments that you all suggested. When I just everything worked out I will update this post.
Buddylee123 is online now  
post #15 of 25 Old 09-20-2017, 11:43 AM
Advanced Member
 
DaveClement's Avatar
 
Join Date: Aug 2001
Location: Lynnwood, WA USA
Posts: 814
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 185
You may want to watch this.

And this.

I commented earlier about raising the L and R speakers off the floor to minimize reflections off the floor. Now that I see where your absorption panels are, that's all the more reason to raise the speakers up to the same level as the panels so that the absorbers will be at the first reflection point.

Also, try toeing in the speakers so that they are pointed at your ears in the primary listening position. When you look at the speakers from this position, you should only see the front of the speakers, and not the sides of the cabinet.

If you haven't done it already, make sure that the center speaker is at the same level as the left and right speakers. If it is oriented horizontally, turn it so that it is oriented vertically, like the left and right speakers.
LydMekk likes this.
DaveClement is offline  
post #16 of 25 Old 09-20-2017, 12:27 PM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by DaveClement View Post
You may want to watch this.
https://youtu.be/raAyF5ksbkk

And this.
https://youtu.be/i_DQWB0mAOo

I commented earlier about raising the L and R speakers off the floor to minimize reflections off the floor. Now that I see where your absorption panels are, that's all the more reason to raise the speakers up to the same level as the panels so that the absorbers will be at the first reflection point.

Also, try toeing in the speakers so that they are pointed at your ears in the primary listening position. When you look at the speakers from this position, you should only see the front of the speakers, and not the sides of the cabinet.

If you haven't done it already, make sure that the center speaker is at the same level as the left and right speakers. If it is oriented horizontally, turn it so that it is oriented vertically, like the left and right speakers.
Thank's Dave, I watched those videos but it was almost a year ago. I definitely need to rewatch them. I have a question on raising the L and R speaker. The chairs we use in the theater sit lower than most so I am worried about raising the L and R up very much. will my low seating height affect the sound when raising the speakers up? Also great idea with the center, I am going to turn it vertically this weekend and see if that helps. I put a link below to the chairs we use so you can see how low they sit.

http://www.ikea.com/ca/en/images/pro...E107124_S4.JPG
Buddylee123 is online now  
post #17 of 25 Old 09-20-2017, 01:21 PM
Advanced Member
 
DaveClement's Avatar
 
Join Date: Aug 2001
Location: Lynnwood, WA USA
Posts: 814
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 185
All things are relative, so there is no specific right or wrong answer. Often, it takes experimentation to figure out what works best.

Speaker midrange and tweeters should be at or near ear level. Having them at or near the center height of the screen should be perfectly OK and will minimize reflections from the floor and ceiling. Having the speakers centered vertically on the absorbers that are already mounted on the side walls will be more effective. Right now the left and right speakers are centered much lower than the absorbers. If the speakers are significantly higher or lower than ear level, you tilt the speaker up or down to aim at the listener to compensate.

Avoid placing speakers near reflective surfaces such as walls, floor and ceilings. "On the floor", even for floor standing speakers may be lower than ideal. Left and right positioning may take some amount of compromise. You don't want them too close to the walls, but you also want them a certain distance apart for best aural imaging. 30 degrees off center is a good starting point, but in long and/or narrow rooms, this may not work and they may have to be closer together.
DaveClement is offline  
post #18 of 25 Old 09-20-2017, 01:40 PM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by DaveClement View Post
All things are relative, so there is no specific right or wrong answer. Often, it takes experimentation to figure out what works best.

Speaker midrange and tweeters should be at or near ear level. Having them at or near the center height of the screen should be perfectly OK and will minimize reflections from the floor and ceiling. Having the speakers centered vertically on the absorbers that are already mounted on the side walls will be more effective. Right now the left and right speakers are centered much lower than the absorbers. If the speakers are significantly higher or lower than ear level, you tilt the speaker up or down to aim at the listener to compensate.

Avoid placing speakers near reflective surfaces such as walls, floor and ceilings. "On the floor", even for floor standing speakers may be lower than ideal. Left and right positioning may take some amount of compromise. You don't want them too close to the walls, but you also want them a certain distance apart for best aural imaging. 30 degrees off center is a good starting point, but in long and/or narrow rooms, this may not work and they may have to be closer together.
Thank you again, I have a lot of experimenting to do.
Buddylee123 is online now  
post #19 of 25 Old 09-20-2017, 02:25 PM
Advanced Member
 
Join Date: Dec 2015
Posts: 825
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked: 198
I'll echo what Dave is saying and reinforce his point that the speakers should have the tweeter roughly at the same height as your ears. That is very important.

Toeing is also very important. Certainly you should like how your speakers sound. However, a speaker like yours is known to have a flat axial response but often a much less flat and rolled off power response (average of the off-axis). When the speakers are pointing straight at the rear wall then you are hearing the off-axis response. You should really try toeing them in. Additionally it will reduce the amount of early reflected energy.

The Center channel is ideally identical the L and R speakers. If yours isn't then try Daves suggestion and try reorienting it.

Also don't forget that the echo you described is a slap echo and not a first reflection problem. Slap echo is caused by reflections at the seating area and so must be addressed at the seating area. Slap echo is notorious for causing smearing of voices. Fixing the first reflection issues might help some but you will want to address the slap echo problem.

While slap echo is caused by any parallel surfaces in your case you know the change in floor absorption caused it to come out. That means it's caused by reflections between the ceiling and floor. I suspect that adding absorption to the walls would also help, but it probably means you need some absorption on the ceiling. It doesn't need to be thick because slap echo is typically focused in the dialogue range. This is why relatively thin carpet fixes the problem so well.

I keep bringing this up because I feel like the two have been a bit conflated in this exchange and I don't want you to be frustrated.

And just one quick pet peeve with those acoustics videos. The claim you should not sit in the peaks or valleys is contrary to the goal of a multisub approach and would only apply if using a single sub location. The entire point of the multisub approach is mode exacerbation, not mode cancellation (as some experts have mistakenly stated). You actually excite all modes evenly and then can sit wherever as the peaks are eqed out. In my opinion you shouldn't do what they say you should just use multiple subs and open up more seating options.


Sent from my iPhone using Tapatalk
Mpoes12 is online now  
post #20 of 25 Old 09-20-2017, 03:38 PM
Senior Member
 
LydMekk's Avatar
 
Join Date: May 2005
Location: Spain
Posts: 273
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 69 Post(s)
Liked: 48
Recommending to take the time to rewatch the Anthony Grimani clips. He really knows what hes talking about.
Buddylee123 likes this.

"If everything is under control you are just not driving fast enough"

Home Theatre Heaven in Spain - V2.0 - Build thread
LydMekk is offline  
post #21 of 25 Old 09-21-2017, 07:07 AM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by Mpoes12 View Post
I'll echo what Dave is saying and reinforce his point that the speakers should have the tweeter roughly at the same height as your ears. That is very important.

Toeing is also very important. Certainly you should like how your speakers sound. However, a speaker like yours is known to have a flat axial response but often a much less flat and rolled off power response (average of the off-axis). When the speakers are pointing straight at the rear wall then you are hearing the off-axis response. You should really try toeing them in. Additionally it will reduce the amount of early reflected energy.

The Center channel is ideally identical the L and R speakers. If yours isn't then try Daves suggestion and try reorienting it.

Also don't forget that the echo you described is a slap echo and not a first reflection problem. Slap echo is caused by reflections at the seating area and so must be addressed at the seating area. Slap echo is notorious for causing smearing of voices. Fixing the first reflection issues might help some but you will want to address the slap echo problem.

While slap echo is caused by any parallel surfaces in your case you know the change in floor absorption caused it to come out. That means it's caused by reflections between the ceiling and floor. I suspect that adding absorption to the walls would also help, but it probably means you need some absorption on the ceiling. It doesn't need to be thick because slap echo is typically focused in the dialogue range. This is why relatively thin carpet fixes the problem so well.

I keep bringing this up because I feel like the two have been a bit conflated in this exchange and I don't want you to be frustrated.

And just one quick pet peeve with those acoustics videos. The claim you should not sit in the peaks or valleys is contrary to the goal of a multisub approach and would only apply if using a single sub location. The entire point of the multisub approach is mode exacerbation, not mode cancellation (as some experts have mistakenly stated). You actually excite all modes evenly and then can sit wherever as the peaks are eqed out. In my opinion you shouldn't do what they say you should just use multiple subs and open up more seating options.


Sent from my iPhone using Tapatalk
Quote:
Originally Posted by DaveClement View Post
All things are relative, so there is no specific right or wrong answer. Often, it takes experimentation to figure out what works best.

Speaker midrange and tweeters should be at or near ear level. Having them at or near the center height of the screen should be perfectly OK and will minimize reflections from the floor and ceiling. Having the speakers centered vertically on the absorbers that are already mounted on the side walls will be more effective. Right now the left and right speakers are centered much lower than the absorbers. If the speakers are significantly higher or lower than ear level, you tilt the speaker up or down to aim at the listener to compensate.

Avoid placing speakers near reflective surfaces such as walls, floor and ceilings. "On the floor", even for floor standing speakers may be lower than ideal. Left and right positioning may take some amount of compromise. You don't want them too close to the walls, but you also want them a certain distance apart for best aural imaging. 30 degrees off center is a good starting point, but in long and/or narrow rooms, this may not work and they may have to be closer together.
Thanks again for all the help. Took both of yours advice and toed the speakers in last night, I had already moved them closed to the screen the night before. Just doing these two things has greatly improved my overall sound quality and has really helped with the dialog. While sitting in my seat last night I paid close attention to my tweeter height in rearguards to my ear height and they are almost dead on. This weekend I am going to make more changes as listed below.

1. Ordering 3 or 4 of these for the ceiling http://www.gikacoustics.com/product/...coustic-panel/

2. Rotate and align my center to match my L and R speakers.

3. Lower my panels on my left and right walls so they perform better with my L and R speakers.

I do have a question about the back wall. GIK Acoustics originally suggested 6A Alpha Panels for my back wall to add diffusion and address bass issues. After changing the carpet they suggest using monster bass trapes with no diffusion. Would you recommend going back to the 6A Alpha Panels if the panels on the ceiling solve my echo problem? Just thinking that I should add some diffusion at this point.
Buddylee123 is online now  
post #22 of 25 Old 09-21-2017, 11:26 AM
Senior Member
 
LydMekk's Avatar
 
Join Date: May 2005
Location: Spain
Posts: 273
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
Quoted: 69 Post(s)
Liked: 48
3 - Lets say your walls are 8 feet tall for sake of argument. Place the 4 foot high GIK's in the center of the wall height. So 2 foot air on the bottom, the 4 foot GIK, another 2 foot of air before the ceiling.
That should do it.

Normally I would have a mix of diffusion and absorb on the back wall. But, as your room is small I would consider going with more absorbs than diffusors than normal.
I have 2 of the 5-6 inch Monster bass traps but with an added "scatterplate", you can add that to the product on their website when you are ordering the Monster bass traps. Then you get both absorb and diffuse in the same product.

http://www.gikacoustics.com/product/...scatter-plate/

"If everything is under control you are just not driving fast enough"

Home Theatre Heaven in Spain - V2.0 - Build thread
LydMekk is offline  
post #23 of 25 Old 09-21-2017, 11:45 AM
Advanced Member
 
Join Date: Dec 2015
Posts: 825
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked: 198
These sound like great steps, I look forward to hearing what you came up with. It's always nice to get confirmation that acoustic theory met reality. I can tell that your screen and panels were placed so that they visually look right, but relative to the speakers are both too high, which creates these challenges.


As Dave mentioned, you could raise the speakers a bit, and then tilt them down toward the listener. The advantage of that is that you reduce reflections off the ceiling as the carpet is still more absorptive than the floor. I am not a fan of raising the speakers too high. Changing the speaker height does change the soundstage height, regardless of how you tilt them. Tilting them just ensures good even tonality by ensuring you are listening on-axis. For me there is a limit to how high the image should be before it starts to become unrealistic. For me that tends to be roughly at the 1/3 wall height range, but a little higher is ok and even sometimes desirable. 1/2 the wall height is, for me, too high, but some people like that effect. I think it makes the soundstage sound larger than life with music and to some extent, movies.


If you have the ability to take measurements and could share your response, waterfall, and RT60 graph, that would make a world of difference in giving you targeted advice. For example, you ask about bass traps, but I really can't answer that without measurements. I make decisions around adding diffusion or not based on room size and evenness of the RT60. If you have a rising LF RT60 starting at 400-500hz, then I would suggest a full range bass trap. If you have an RT60 that is flat down to 200hz, but need more absorption below that, I would suggest something range limited. If your overall RT60 is very low already, I would suggest adding diffusion and being very careful about adding more absorption. Where you place it also depends on how the room sounds and certain measurement issues. If you have a higher RT60 value but no real evidence of modal problems, then you need to absorb excess energy, but you don't need to target reflections. That means placing traps around the room generally. If you have evidence of reflection problems like a cancelation in the bass range, then you need a trap on one or both of those walls. The most common reason for a bass trap on the rear wall is to absorb some of the LF energy that is reflecting off the rear wall and causing a cancelation. If you have followed the posts on SBR (Single Bass Array) that highlights the effect in isolation.
Mpoes12 is online now  
post #24 of 25 Old 09-21-2017, 04:31 PM - Thread Starter
Advanced Member
 
Buddylee123's Avatar
 
Join Date: Jun 2014
Location: Las Vegas
Posts: 780
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked: 220
Quote:
Originally Posted by LydMekk View Post
3 - Lets say your walls are 8 feet tall for sake of argument. Place the 4 foot high GIK's in the center of the wall height. So 2 foot air on the bottom, the 4 foot GIK, another 2 foot of air before the ceiling.
That should do it.

Normally I would have a mix of diffusion and absorb on the back wall. But, as your room is small I would consider going with more absorbs than diffusors than normal.
I have 2 of the 5-6 inch Monster bass traps but with an added "scatterplate", you can add that to the product on their website when you are ordering the Monster bass traps. Then you get both absorb and diffuse in the same product.

http://www.gikacoustics.com/product/...scatter-plate/
I like the idea of the monster bass traps with the scatter plate. I will probably do something like that.

Quote:
Originally Posted by Mpoes12 View Post
These sound like great steps, I look forward to hearing what you came up with. It's always nice to get confirmation that acoustic theory met reality. I can tell that your screen and panels were placed so that they visually look right, but relative to the speakers are both too high, which creates these challenges.


As Dave mentioned, you could raise the speakers a bit, and then tilt them down toward the listener. The advantage of that is that you reduce reflections off the ceiling as the carpet is still more absorptive than the floor. I am not a fan of raising the speakers too high. Changing the speaker height does change the soundstage height, regardless of how you tilt them. Tilting them just ensures good even tonality by ensuring you are listening on-axis. For me there is a limit to how high the image should be before it starts to become unrealistic. For me that tends to be roughly at the 1/3 wall height range, but a little higher is ok and even sometimes desirable. 1/2 the wall height is, for me, too high, but some people like that effect. I think it makes the soundstage sound larger than life with music and to some extent, movies.
I will have to give this one some thought, not sure how I can raise the speakers and keep the room looking ok. Maybe I will build some small stands.


Quote:
Originally Posted by Mpoes12 View Post
If you have the ability to take measurements and could share your response, waterfall, and RT60 graph, that would make a world of difference in giving you targeted advice. For example, you ask about bass traps, but I really can't answer that without measurements. I make decisions around adding diffusion or not based on room size and evenness of the RT60. If you have a rising LF RT60 starting at 400-500hz, then I would suggest a full range bass trap. If you have an RT60 that is flat down to 200hz, but need more absorption below that, I would suggest something range limited. If your overall RT60 is very low already, I would suggest adding diffusion and being very careful about adding more absorption. Where you place it also depends on how the room sounds and certain measurement issues. If you have a higher RT60 value but no real evidence of modal problems, then you need to absorb excess energy, but you don't need to target reflections. That means placing traps around the room generally. If you have evidence of reflection problems like a cancelation in the bass range, then you need a trap on one or both of those walls. The most common reason for a bass trap on the rear wall is to absorb some of the LF energy that is reflecting off the rear wall and causing a cancelation. If you have followed the posts on SBR (Single Bass Array) that highlights the effect in isolation.
I really wish I could take some measurements but I don't have the equipment or the knowledge to do that right now. I plan on getting there at some point but it will be next year before I have time to learn how or to buy the equipment. I will definitely keep this thread updated as I make changes. If you know of anyone in the Las Vegas area that can run these test I would definitely pay for it and throw in some free beer
Buddylee123 is online now  
post #25 of 25 Old 09-21-2017, 05:09 PM
Advanced Member
 
Join Date: Dec 2015
Posts: 825
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked: 198
I'm in the Chicago suburbs and unfortunately don't have any connections in your neck of the woods.


Sent from my iPhone using Tapatalk
Mpoes12 is online now  
Sponsored Links
Advertisement
 
Reply Dedicated Theater Design & Construction

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off