Acoustical Treatments Master Thread - Page 301

Understood. My point about multiple subs was not for increasing bass levels, but as an alternative to using passive bass traps, presumably to reduce bass lumpiness caused by room modes. If the system is not plagued by such uneven response, then no need.
If there's some significant energy returning from that portal, then yes, killing it would be useful. Best to determine the spectrum of that before deciding on the solution.
Yes, the pix show standard walls. Undoubtedly sound would benefit from some appropriate diffusion and absorption. I realize you are trying to minimize visual impact, but a large percentage of the surface will need coverage, more than the wicker baskets will address. I have found the standard GOM covered panels, in the right colors to blend with the walls (or ceiling), are not visually overbearing at all, and can be very effective in taming a live room.

Thanks Roger, I appreciate your thoughts. They're actually not too far off from my own, but I doubt I'll be able to do anything but subtle treatments, maybe the artwork covered panels at best.
I don't plan on just plunking wicker baskets around the room willy-nilly, I'm actually thinking of using them as material to build architectural columns, perhaps with lighting incorporated into them, or as plant holders etc... I'm just in the infancy of thinking this through and just have loose concepts right now.
So I still would like to know how small a circular corner bass trap can be to have a degree of effectiveness.
Edited by rnrgagne - 7/30/12 at 8:12am

Roger, I know what you're saying, however I want to clarify for those that may think otherwise; just because one's freq response may be smooth, doesn't necessarily mean that bass traps aren't warranted.

LF damping in general, and more specifically bass traps, can be effective in both the frequency domain, as you stated, but also in the time domain.

Both, examining waterfall graphs before and after bass traps, and listening to the subjective "tightness" in bass quality, typically reveals that bass traps add appreciably to the overall quality of the bass. So yes, the frequency response can be smoothed w/bass traps, but the decay characteristic of the room is also tightened up and is quite significant.



Thanks

I have paradigm studio 100 speakers. To avoid speaker distraction while watching movie, it would help if they are as close to side wall as possible. I have 17x17x24 bass trap on the back of speaker. Here is the picture. Do you think any other absorption panel side of speaker helps SBIR?

Not what you are asking, but have you considered an acoustically transparent screen with the speaker behind it?

Jeff

Unfortunately, I am using Dalite high gain screen to handle brighness needed for 3d and it is not AT. I am not considering yet to replace screen.

That certainly was my experience in the previous well treated room I had. It had considerable bass trapping and that was despite the room's dimensions being built to have the fewest problems in the bass region. The combination led to probably the best bass I've yet experienced out of a system.

But in this new room I've got to be creative as I'm not starting from scratch. I need to know what the parameters are I'm working with for reasonably effective circular bass traps and if there's anything negative to using wicker as a frame.

So your question about the speakers being nearly touching the side wall is a good one that I will follow for an answer. If the proximity is not harmful, or can be mitigated with treatments and/or room correction, then you are OK.

Jeff

I am trying to balance video experience vs audio. Based on feedback from the forum, I got highest possible size screen (142 inch). So, I was left with 1 and 1/2 feet on each side. (may wall is 13 feet 6 inch for around 8 feet and then changes to 16 feet).

I read that minimum distance is 20cm from either wall for speaker placement. I have bass trap (17x17x24) behind it. I can add 2 or 4 inch absorber (OC 703) on the side.

My understanding is 2 inch oc 703 with 2 inch gap is equivalent to 4 inch OC 703 without airgap. Is it right? Is 2 inch OC 703 with 2 inch gap can handle reflections (I guess above 500hz)? I am going to make absorbers this week.

I already have corner 4 bass traps from floor to ceiling and front and back wall bass traps from side to side. I am trying to find if 4 inch really makes sense even for reflections.

Do you have a way to measure your room? REW and related gear or maybe Omnimic or XTZ? If not, that is really the only way you will know. A general "rule of thumb" might work for you, but you wouldn't know w/o measuring.

Jeff

1.  Those panels will not do squat for bass.

2.  If you want to know what the issues are so that you can attack them, think about getting a measurement system, like REW.  Consider, also, a good book to inform you on acoustics.

Jeff,

I already bought Tascam 144, ECM 8000 microphone and learning REW. There is steep learning curve, but I am getting better day by day. I will use it to test.

I have started testing REW , but still learning to interpret ate. My friend helped to create bass traps shown here. We need to build one more in the back. I did not take photos yet for front wall bass traps. I will ask him to help to build one with 2 inch and one with 4 inch to test. I am using thin galvanized metal as frame. Appreciate if anybody has suggestions on how it can be attached to wall with gap.

https://plus.google.com/u/0/photos/107811778043676490320/albums/5771003652663651985

Hi,

I have a question about treating my room.



I picked up 6 panels, and i setup 2 of them behind the speakers (on each side of the screen) 2 at the first reflection, which happened to be right past that hanging movie poster, and i have 2 left.

the center channel is a X-voce (partial open baffle) and i am not sure if i would be better off putting treatment behind it, under the screen, or using the leftover treatments on the back wall(or possibly a better location?). my couch is about 4 foot off the back wall

any ideas would be appreciated

sukumar - woo HOO! Congratulations on stepping up with the preamp, mic and REW as well as the really nice traps!!

Jeff

Thanks Jeff. It is interesting to learn REW and what does graphs really means. I am getting lot of help from hometheatershack. It is matter of time to fully exploit the tool..

Yes, HTS is the home of REW and *the* source for support. The really cool thing I like about it is you measure one time, save the measurement file and use it to produce all of the different graphs.

If you are starting out with REW read this article that I co-authored with Ethan from RealTraps, if you are more advanced take a look at this white paper which I co-authored with Jeff of HdAcoustics.

Thanks for the links, Nyal!

Jeff

Thanks for the link. I read this article few months back when I did not know anything about REW. Now, I am understanding better.

I already placed corner super chunk bass traps and front wall floor from side to side bass trap. It really look cool like stage. I did use OC 703. Now I plan to do in the back wall for around 15 feet long. I thought I could use pink stuff that I read has better GFR ( flow).

If I go to Home depot, what exactly I need to ask them to buy the product and approximately how much do you think I can buy it. I have 3 feet space that I can fill. I intend to put in plastic and wrap with cloth. I will make 7 1/2 feet two pieces. This will complete 6 corners out of 12.

Have you noticed improvements in the sound? Typically reducing room ringing at the bottom cleans up the sound from bottom to top. Delicate sounds are especially more audible.

Jeff

So nobody knows if wicker could be a suitable frame to contain a circular bass trap?

I watched briefly dishnetwork and felt good about the sound. However, I need to test with blu-ray content. We are going to make absorpton panels this week end. Our back wall is close to seating as shown here.


we will plan to use 2 oc 703 with 1 1/2 inch gap panels. I am waiting to complete and start enjoying. I also liked video picture very well with black velvet surrounding the screen except ceiling. It is worth the effort.. We also need to cover back basstraps with velvet.

I'd recommend music with a prominent bass guitar, tight bass drum and larger floor toms. For this, my "go to" song is Fourplay's "Chant" from the "Between The Sheets" album. It is only a stereo CD, but with the first large floor tom slam I can hear what my system and room are doing from bottom to top. (Any initial strike of percussion, even LF ones, will have mid- and HF-frequency content.) Try it! For me, and the others in our small home theater group, when this one song sounds good, everything does.

We attended a Fourplay concert recently and got a chance to meet the band during a CD signing session and I told Bob James what I just posted and he commented that the engineer had spent a lot of time getting the mic'ing just right. That made perfect sense.

Jeff
Edited by pepar - 8/3/12 at 11:30am

5 years later...


I've seen one-legged turtles move faster than you.

I'd say experiment between putting the last two at the first reflection of the center channel, or on the back wall. Or maybe at the first reflection of each opposite speaker. What I mean by that is for the left speaker, find the first reflection on the right wall. Same goes for the right speaker.

As I understand, for home theater with multiple seating positions, it's best to treat the side walls entirely with treatments going a little above ear height, and back to the listening position. This way it covers all the reflections for all the speakers and all the listening positions. But if you aren't doing DIY treatments, it gets expensive quick. Especially if you go ahead and make the entire front wall dead, which I have also seen suggested. Treatments on the back wall are a good finishing touch. As I understand, if your speakers are "bright", that can help smooth them out.

The above are some guidelines I've gleaned if you want to make a theater with no bad seats, but no great seat. If you are only concerned about one individual listening position, and want to create a "seat of excellence", then just find each reflection for each speaker and treat those areas.

Thanks Jeff for providing the material. I will get it and test.

Play it loud!