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Discussion Starter #81
Here is the corresponding waterfall for these changes (medium green) plus the one from Feb 20th (the one with the overlays) without the ceiling treatment. Surprising improvement across a much wider freq range than expected, especially in the 20-40 Hz range. The improvement in the 40-80Hz range was expected, but not that at the lowest freqs. Based on this, the ceiling treatment is worth continuing.

Subjectively in last night's viewing there was less audible difference than the plots suggest. It could have been the program material we chose.
 

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Subjectively in last night's viewing there was less audible difference than the plots suggest. It could have been the program material we chose.
These are some examples of some scenes and an intro where I hear a difference in my HT that treating the ceiling has helped.


Master And Commander 1:09:18


Master And Commander 1:11:57


Star Wars Episode2 50:26


Star Wars Episode3 20:42


Saving Private Ryan 2:33:58


Indiana Jones and the Kingdom Of The Crsytal Scull 21:36


20th Century Fox Intro
 

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Discussion Starter #83
Yeah, I threw more at it last night and there is definately an improvement in bass transient response. I had "Celtic Woman" DVD on and the kettle drum really had a lot of snap. I hope to do more rows next weekend, although there is another house repair that I also need to do.

Did you get your new projector up and running?
 

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Yeah, I threw more at it last night and there is definately an improvement in bass transient response. I had "Celtic Woman" DVD on and the kettle drum really had a lot of snap. I hope to do more rows next weekend, although there is another house repair that I also need to do.

Did you get your new projector up and running?
I have got the mount, the subsonic filter, and the projector shipped yesterday. I am building the screen wall today.
 

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Discussion Starter #85
You know, I was just wondering if the sheetrock panels in the grid themselves are rattling at low bass freqs. and, therefore, are emulating additional time decay in the room. Looking at the two waterfalls above, it is hard to believe that the R30 itself is making that much difference (although there is 88 sq. feet of it in the room now.)

By the way, with the fabric wrapped around the ceilng tiles the fit into the grid is tighter, so hopefully I will have fewer rattles when I am done.
 

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You know, I was just wondering if the sheetrock panels in the grid themselves are rattling at low bass freqs. and, therefore, are emulating additional time decay in the room. Looking at the two waterfalls above, it is hard to believe that the R30 itself is making that much difference (although there is 88 sq. feet of it in the room now.)

By the way, with the fabric wrapped around the ceilng tiles the fit into the grid is tighter, so hopefully I will have fewer rattles when I am done.
It's difficult to know just how much a rattle is a problem when it might be down so far in the range of human hearing. If I can find one I stand under it and try and fix it until it is gone. That is why if I am checking for a problem rattle I fixed I go back to the scene and listen to it on repeat. If it doesn't sound the same each time there is a rattle, which sounds more like a distortion than a rattle. There is a certain point where it takes a louder subwoofer signal regardless if mains or on or not that it is masked out. There is also the higher frequencies in the subwoofer which might cause one so I check with the mains also. The grid that holds my tiles are an interlocking direct ceiling mount system using PVC. When I press on it the two peices go in and out in areas like it is sagging. I'm not sure if it would make any difference to a rattle. The rattles I find are usually tiles that are not sitting on a peice of the shorter grid laying between the other grid after I have been working in the ceiling. It doesn't ever seem to be right the first time I put them in.
 

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I absolutely think that the R30 is really making that much difference. That's a lot of square footage with an effective 12" thickness.

Bryan
 

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Discussion Starter #88
That's a lot of square footage with an effective 12" thickness.
R30 is labeled as 9-1/2". Does "effective" mean acoustically? Glad it is not 12" - it is a snug fit for me as it is.

5 more tiles and 40 more sq. ft. of R30 put up this afternoon. This puts me about half way into the room from the front. No measurements for today's additions; I likely will wait until I put up more.

Bryan: Should I really expect much from putting the R30 above the tiles where the Monster traps are in the back? Reason I ask is that it will take part of a fourth package of R30 to do them. I guess I will go ahead - I suppose I could stuff the remaining R30 behind the Monsters that don't have it now.
 

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My mistake. Not sure why I was thinking 12".

You can probably skip the rear as you already have plenty of bass control in the rear of the room.

Bryan
 

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Discussion Starter #90
I just played a few bass heavy scenes from Iron Man. BIG WIDE GRIN! Uncanny bass transient response now, and I am still not thru with the room treatments. I wish someone had hit me up side the head years ago to get me to put traps in.

Also, I have been playing around a little bit with the Aura Bass Shaker Pro from Parts Express. Verdict: fun if used in moderation. It is very easy to get a most unnatural feeling. But, with the level set properly there is a nice kick in the bottom when bombs go off, etc. My wife hates it, but I may use it to wake her up during movies (swift kick in the ...:bigsmile:) I really bought them to use with new Berklines on order from Roman, but decided to start playing around with them on the old chairs.
 

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Discussion Starter #91
For Blu Ray playback, I use the analog outputs from my Panny BD-55 into a 7.1 analog input on the Denon 5805 receiver. This allows DTS-MA and Dolby HD playback via the player's decoding, since the Denon does not process the newer codecs. I still get bass management and distance correction by the receiver using this connection (DSP switched ON on the Denon for the analog ins.) When making REW measurements, I disconnect the sub cable from the back of the Panny and patch in the output of the sound card.

As I was powering the system down last night, I made a startling discovery. After my measurements on Saturday, I had failed to plug the sub cable back into the Panny. So, the bass I heard on Iron Man was coming only from the K'horns:unbelievable:. (I must have left the crossover on them set at 40Hz from Saturday's tests). That certainly explains the superb bass transient response that I heard, but does not explain the bass extension, since the K'horn bass horn's cutoff is 35Hz. I obviously am still getting significant output below that in my room now.

I did not notice that the sub was not working after playing the Blu Ray disc, since the rest of the evening's watching was from the DVR, which has a digital connection to the Denon.

Wow, I must be getting far more benefit from the ceiling trapping than I thought.
 

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I guess then without a weight to the soundfield then the transient response of the other speakers will then be more audible because these sounds that are usually 6dB - 10dB or more down in response from the subwoofer will be more audible than felt. Dependent on your rooms treatment it may be right around the reflections that are also 10dB down from the fundamental sounds, or also 15dB down also sometimes depending on the room. Anyone feel free to correct me on this.
 

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Discussion Starter #94
I haven't done any more since Sunday afternoon. I plan to pick up the rest of the tiles this afternoon. It is supposed to be a rainy weekend, so I should be able to get most of the rest of the work done.

Transient response from the sub is really getting good now. I especially noticed it on the bass drum during American Idol last night. The good thing about using the posterboard is that I am not noticing a drop in mids and highs.
 

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Discussion Starter #95
I forgot to answer your question about how the installation is going. With the fabric wrapped around the tiles, it is a tight fit into the grid. So much so that on most of them I have to bump them from the top to get them to go in - makes me nervous about breaking them but so far so good. When I ran the sweep Saturday I still had a couple of rattles, but I did not take the time to figure out where they were coming from.

I will run out of burlap by the weekend and will order a few more yards from Joanns'. I knew up front that the one bolt would not be enough, plus I have had to cut out a couple of really bad spots. I won't buy another bolt this time, but rather only order a little more than needed to finish.

I haven't decided if I will extend the R30 fully to the back of the room, since that is where 5 of the Monster traps are. I will run a waterfall after this weekend's work and see where I am. If I decide to leave a few of the sheetrock "tiles" in, I can cover them with burlap so that everything matches.

Thanks for your interest in my project - it truly has been a learning experience for me.
 

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Discussion Starter #96
Bryan: One thing that I have noticed as I add more trapping is that rumbling LFE sound effects seem to have lese "rumble." I know that the SPL and FR are there and transient response is much better now. I suppose what I was hearing before was ringing, right?
 

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To a point - yes. You're getting that and also some acoustic doubling like you'd get when a woofer starts to motorboat. You've put in a lot of bass control in the room. You might want to recheck your level balance between mains and subs.

Bryan
 

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Discussion Starter #98
More progress made this weekend. 176 sq. ft. of ceiling treated now; about the front 2/3 of the room is done. I could have finished the whole thing today, but ran out of burlap - more on the way.

Now for the results. The lighter green waterfall is from when I had 48 sq. ft. done (front four rows of tiles). The darker green waterfall is from today. Significant difference in decay time. I am finally seeing results in the 30-40 Hz range. No significant change in sub FR.

I probably will go ahead and do the rest of the room, even tho I have a lot of absorption in the rear already with the Monsters. I have the ceiling tiles, the posterboard and the R30. The extra fabric should be in time to finish next weekend.
 

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Discussion Starter #99
Forgot to mention that the overall room noise floor has gone down noticeably - now reading 40-41 db after calibrating against my RS meter at 75 db, and that is with hard drives in 3 DVRs running about 6 feet from the mic. Wish that I had measured it before the treatments for comparison.
 
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