Sound control...

kharp1

Was noticing that the rooms at the hotel were playing heck on the sound with most of the vendors this past weekend, and, I also noticed that several of them were using the "tube style bass traps" as well. Had a discussion with a few different folks on the "bass traps" and wanted to post this.
Was having this conversation with a couple of folks this weekend. He has many good sound control videos.

https://youtu.be/KtBPsNqPv9E

and start the discussion as to thoughts on the subject. Who uses what to control their bass?

txcoastal1

More balls

http://www.acousticsfirst.com/educational-videos-acoustic-sound-diffusion.htm

kharp1

After this weekend I'm convinced you're fixated on balls.

txcoastal1

kharp1 wrote: »

After this weekend I'm convinced you're fixated on balls.

Not this guy, I was already gone....I did get Guest of the Day though

And jeez, thought I was providing constructive info to the thread

Clipdat

marvda1

I have homemade bass traps. three of the small rolls of pink insulation in one of the collapsible laundry baskets.

tonyb

I have my wife stand in a corner....much better to look at, but harder to concentrate on the music.

Kerry,

If you also noticed, some rooms had none at all. Sonner and JWM come to mind off the top of my head, and they had no problems with sound. Which also may indicate they aren't as picky about placement as some others are.

kharp1

Was noticing that several of the rooms had similar "traps" using tubes with insulation, and, physically it's just an impossibility to stop bass energy with those materials. You end up sucking more mid and upper frequency with all the insulation. That can lead to a perception of even more bass. The actual frequency you want to tame becomes potentially more pronounced because the material you thought was going to trap bass instead sucks out everything but the bass.

tonyb

I hear ya bro, but I believe, and correct me if I'm wrong, that those big bass traps are meant to diffuse the bass energy, not eliminate it, as to keep that boomy sound away.

I do get what your talking about though, sucking out some of the other frequencies. It was fairly evident in a few rooms...but, the alternative might have been worse. In the end, you work with the room you got, do the best ya can to achieve the best sound possible given all the variables.

I think in your own personal space at home, you might have a tad more control over it. Plus....it appears adding some DSP into the mix can also make up for those room anomalies to some degree also. Different ways to skin that same cat, know what I'm sayin' ?

kharp1

I'm not sure Tony, but, they're usually referred to as "bass traps" which is why I posted that link. There's lots of science behind this, which is another reason I posted.
.
Recently there's been several threads about wanting to definitively measure a particular piece, or process, to see if something works. Well, here is one piece and process that you can most certainly measure and quantify.

It's not my opinion, there are laws of physics that dictate this. I understand why they are using them at these shows...the rooms have horrible acoustics and some attempt needs to be made to mitigate those nasty waves. The diaphragm method is heavy and would be difficult for most of the vendors to implement. I posted the link to try and see what kind of ideas surfaced.

I think the tubular "trap" design stuck after the electronic tube traps that were built 30 years ago by Infinity, if I'm not mistaken. Was kind of revolutionary at the time. Not 100%, but I believe they utilized some early system of DSP to eliminate the signal. If DSP isn't utilized to counter the standing wave then you're left with having to physically control it. No amount of cardboard tubes and foam insulation, that you csn fit in a sound room, will stop those waves. Physically impossible.

voltz

you get to fix up my room next year

P.S. since my SUV is so small you may need a trailer next year to bring it all with you to LSAF

But you know I'll be there to help you unload and set it all up.

marvda1

interesting.
https://www.youtube.com/watch?v=pABvTWSxOes

kharp1

I question the testing method, outdoors with no walls. Not sure what impact that has on the results. I also question his choice of "acoustic foam" as it didn't look like any acoustic foam I've ever seen, it just looked like plain foam. I would say you could build those on the cheap and absorb some mid and high frequencies.

The part I've been looking at over the past year or two is the bass waves. Uncontrolled bass can cause all kinds of problems. I've tried experimenting with different things, but, have come to realize that there is a set of physics involved that I can't work around, and, I hate when I this k the experts are scamming me because they can. In reality, there is a cost involved with building something that can control that much energy. Again, naive or me to think it would be easy, or cheap, to control that much power.

tonyb

Personally, I like panels over the towers. Since bass waves are non directional, you'd think having a tower would absorb or diffuse more than just the bass waves in the other frequencies. Maybe that's the purpose anyway, to absorb or tame more than just those lower Freq. Mids and highs can be just as offensive in a wrong room.

We all know the challenge, setting up higher end speakers in a room in your house not dedicated to just audio. A living room/family room....with furniture and do-dads all over. Throw in the WAF and it becomes nearly impossible. You single dudes have one up on us married guys in that respect. You can start from scratch, arrange a room strictly for audio.

I think the bottom line here Kerry is the old saying.......right tool for the right job. Panels come in all shapes and sizes, you can make your own too fairly cheap, and will accommodate any sized room. Of course everything starts with the speakers in a given sized room . Too big a room+ too small speakers. too large speakers in too small a room and panels will not cure that problem. Right tool for the right job, every step of the way. Your not being naïve, to want good sound, just takes some trial and error + your ears. Maybe a sprinkle of being realistic too on what can be accomplished in the room your working with. You'll get there bro....

txcoastal1

For DIY material, this it what I have used that works well with bass nodes

I have cut, stacked and wrapped with whatever material suits your fancy.

https://www.acoustimac.com/ecoinsul422

Joey_V

Have not watched the videos, so pardon me if I'm wrong.

Those tube traps or cylindrical tubes do not diffuse the bass if there is no solid material along the perimeter of the tube, they act as sinks and absorb the bass. The more material (or a certain type of material) is in that that cylinder, the lower in frequency it can absorb which is why panels work to absorb a higher frequency spectrum while tube or pillar type traps absorb lower (and higher). However, given that they are set in corners (they absorb bass waves that bounce around in corner areas moreso than absorb high frequency information) they function primarily as bass sinks.

Bass when absorbed appropriately takes away boominess and in many instances act to tighten and increase the perception of bass?

Why?

It removes a good portion of destructive interference headed your way in the listening position.

SCompRacer

As Ethan Winer says, reflections are the root of all evil.

I prefer the GIK triangular corner bass traps to reduce peaks and nulls. I have two stacked in one corner, singles in opposite corners.

GIK has a Range Limiter option that absorbs even lower frequencies with less effect of absorbing upper frequencies. They also do lab testing on their products.

Bass is controlled so that you get it at the listening position in my room. Move toward center of room toward opposite wall and bass will begin to null then return.

Joey_V

SCompRacer wrote: »

As Ethan Winer says, reflections are the root of all evil.

I prefer the GIK triangular corner bass traps to reduce peaks and nulls. I have two stacked in one corner, singles in opposite corners.

GIK has a Range Limiter option that absorbs even lower frequencies with less effect of absorbing upper frequencies. They also do lab testing on their products.

Bass is controlled so that you get it at the listening position in my room. Move toward center of room toward opposite wall and bass will begin to null then return.

Gik tritraps do not absorb as much bass as gik soffits, I believe to the tune of 2:1. It all depends on application and aesthetic

tonyb

Good to know on the GIK, and range limiter.

I think sometimes though, we audiophiles tend to pick apart things instead of just simply enjoying the tunes. I find myself doing just that all the time and have to force myself to chill and enjoy....unless something is really offensive.

I refer back to our younger days, playing music on very modest systems, no room treatments to speak of, and we enjoyed the crap out of them. Obviously we didn't know better back then, and that might be for the better if you ask your wallet.

Knowledge .....double edged sword I tell ya.

SCompRacer

Joey_V wrote: »

Gik tritraps do not absorb as much bass as gik soffits, I believe to the tune of 2:1. It all depends on application and aesthetic

The GIK Soffits are only 50% more effective on the lows. The Soffits also absorb the upper mid-band frequencies, up to 5,000Hz. I had a mids dropout issue in my room with my Salk SoundScape 8's that I solved with placement, so the Soffits would hurt what acoustic results I have achieved so far.

And I have WAF, as she selected the fabric color.

SCompRacer

tonyb wrote: »

Good to know on the GIK, and range limiter.

I think sometimes though, we audiophiles tend to pick apart things instead of just simply enjoying the tunes. I find myself doing just that all the time and have to force myself to chill and enjoy....unless something is really offensive.

I refer back to our younger days, playing music on very modest systems, no room treatments to speak of, and we enjoyed the crap out of them. Obviously we didn't know better back then, and that might be for the better if you ask your wallet.

Knowledge .....double edged sword I tell ya.

Well....we get what we accept. Some things are worth fixing, then we can enjoy the fruits of our labors. I find I don't crave gear changes when I can hear all the audio frequencies that I play.

kharp1

Joey_V wrote: »

Have not watched the videos, so pardon me if I'm wrong.

Those tube traps or cylindrical tubes do not diffuse the bass if there is no solid material along the perimeter of the tube, they act as sinks and absorb the bass. The more material (or a certain type of material) is in that that cylinder, the lower in frequency it can absorb which is why panels work to absorb a higher frequency spectrum while tube or pillar type traps absorb lower (and higher). However, given that they are set in corners (they absorb bass waves that bounce around in corner areas moreso than absorb high frequency information) they function primarily as bass sinks.

Bass when absorbed appropriately takes away boominess and in many instances act to tighten and increase the perception of bass?

Why?

It removes a good portion of destructive interference headed your way in the listening position.

The original post was about "traps" that are nothing more than carboard cylinders filled with insulation and wrapped in cloth. Those will pretty much do nothing but eat up mids and highs. Those cause more problems than they solve. How will a cardboard tube filled with insulation stop bass waves? The same waves that you can hear outside of a nightclub penetrating the people inside, the inner drywall, insulation, studs and outer cement (or cinderblock or whatever building material) and exterior sheathing? The science isn't there. Most insulation material gets very marginal at around 250hz, almost to the point of being nothing.

txcoastal1

That's why I like the material density of the post I put up above. It's better suited for for 100hz and below

I played with a lot of materials a couple years ago. Biggest reason was LSAF and rear ported speakers with the rooms all concrete walls

Thorton

SCompRacer wrote: »

tonyb wrote: »

Good to know on the GIK, and range limiter.

I think sometimes though, we audiophiles tend to pick apart things instead of just simply enjoying the tunes. I find myself doing just that all the time and have to force myself to chill and enjoy....unless something is really offensive.

I refer back to our younger days, playing music on very modest systems, no room treatments to speak of, and we enjoyed the crap out of them. Obviously we didn't know better back then, and that might be for the better if you ask your wallet.

Knowledge .....double edged sword I tell ya.

Well....we get what we accept. Some things are worth fixing, then we can enjoy the fruits of our labors. I find I don't crave gear changes when I can hear all the audio frequencies that I play.

Very true Rich. I use the GIK soffits in both front corners and they do an amazing job. They really assist with reducing decay times or eliminating that boomy or ringing sound that can be produced in the lower frequencies.

Improving/controlling or whatever you want to call it bass control can be heard and identified instrumentally. A REW waterfall graph shows what's happening in the lower frequencies via decay times or basically the time domain. The improvements (both instrumentally and being heard) are easy to identify before and after the bass traps are placed.

Room acoustic software and treatments can be key parts to getting the most out of your system to get your toes tapping on a regular basis.

To the OP, if not already known, you can send GIK frequency plots, waterfall graphs and room layout diagrams and they will assist with selection and placement to optimize your system.

kharp1

I've been using a source other than GIK. I'm currently not in need of treatments, was just making observations at the show and throwing it out for discussion.

tonyb

Room treatments certainly hold their value/worth, as a means to fine tune your system. We all know the room plays a big part itself.

At LSAF, we had rooms treated to the 9's, and some not treated at all. From my own personal observations, some of the best sounds came from rooms not treated at all.

How do you quantify that in your head ? Is it the speakers fault ? Room acoustics, Maybe something else in the system not jiving or lack of synergy one is trying to tame ? Maybe all of the above ?

Throw in individual preferences as to what dictates "good sound", and your all over the map. I guess my point is....or question, are we using traps to cover up other defects in our system, or just fine tuning ? Sort of a fine line there. I guess if you've been around the block a few times in this audio thing you know that difference but I think some are unwilling to accept their new 23k integrated may not jive with everything else , or their new 15k speakers won't work in the room they have for them. Know what I'm sayin' ?

Msabot1

I never have used a trap on bass...I find that a black motor oil worm with weedless hooks cranked super slow on the bottom works wonders though....

txcoastal1

Speakers like my Dyn C1's (pic from LSAF 2013) needed to come out from the wall a little more, but the room and foot traffic wouldn't allow it...so add panels to keep the boom off the walls

Speakers fault....no

tonyb

Those are some snazzy panels Ron, did ya steal that material from a cab driver ? I would have loved to have heard those C1's.

SCompRacer

tonyb wrote: »

How do you quantify that in your head ? Is it the speakers fault ? Room acoustics, Maybe something else in the system not jiving or lack of synergy one is trying to tame ? Maybe all of the above ?

I hear you Tony. I go by room sweeps to see where the frequencies are in dB at listening position. I can't imagine trying to add acoustic treatments without sweeps. Moving speakers, subs, adding/moving treatments while measuring the results guarantees progress. Keeping notes to refer to eliminates trying something that didn't work again.

Eventually you arrive at a compromise. You've achieved the best results and flattest room response you can get. It may not be ruler flat, but severe nulls and peaks are addressed. You record measurements of gear placement and put a copy in your safe deposit box. You move stuff to clean, it can be returned to the correct spot. Inches can make a difference. Well worth the effort IMO.

tonyb

Yeah Rich, I get all that, just wondering how some do it without sweeps. The ear is one thing, but sweeps are more exact for sure.

Plus, getting everything to be ruler flat or close to it, may or may not tickle ones fancy. Different strokes and all that. The tools are available, and products, to take one down that exact path should one be so inclined. I'm guessing many aren't though, and the ear is their best tool. If your system sounds good to you, does anything else really matter ? Open a cold one and enjoy the tunes. I think we as audiophiles.....sometimes....spend more time fretting over the little things than we actually do listening to music. Just my opinion there obviously.