[errivera]

Today, as I was cleaning and rearranging some things in the house I made an incredible discovery.

Firstly, let me say that I have been searching for a cost effective way to reduce standing waves in the low bass region.

Today I move a 100 lb punching bag into the audio room while I cleaned another room. Well, I forgot that I had left it in the corner and later on began listening to music. To my surprise, the bass in the room was considerably better; tighter, better defined, more control. At first I thought that something was wrong (but pleased). I couldn't figure out what was different until I noticed the punching bag in the corner. I guess the mass of the bag, which is somewhat loosely filled with some type of material does a great job of absorbing some of the standing waves that I was unable to tame before.

I stongly urge that everyone give this a try. Picking up a 100 lb punching bag at your local Sports Authority will only set you back about $90 or so. If you don't like the results, take the bag back for a refund.

Good luck, and please post your findings.

[Red Dragon Audio]

Plus it will be useful when you get angry.  Instead of kicking your speakers in, you can hit the bag...

at the very least in will increase the manliness of the room by a factor of 8-10...

punching bag = manly endeavor.

[Harmon]

What is the brand name of the punching bag? Was it lying on the floor or held up in a stand? LOL

[ooheadsoo]

Do let us know what brand you picked up.  This is great news because I was finding it tough sneaking in a decent bass trap into the house.

[errivera]

I don't remember the brand of the bag. I do remember removing the plasticized brand name from the canvas but not the brand. I don't really know if it would make too much of a difference as long as it is a canvas bag with some sort of 'material' filler. I think more importantly is the weight. Maybe some would like to experiment with 50 lb bags and other weights.

The bag is still standing in the corner, laying slightly against the wall. I am still amazed at the difference in bass. Actually, I think it looks just like a 'Tube Trap' except heavier. Believe it or not, I have actually thought of purchasing one of the punching bag stands available at stores. It probably wouldn't make too much of a difference but it would look pretty cool. The stands I have seen can be had for as little as $50-$75.

I can't wait for some of you guys out there to try this. I really think it is an incredible improvement, especially for the money.

[azryan]

This should be in the 'Acoustics Circle', not the 'Lab' right?

Maybe the mod can move it?

Anyway... Why not just buy compressed fiberglass cylinders?

That's what I did and they're about the same dia. as a punching bag but far lighter.

It's the dia. that's the effective part. Larger the dia. the deeper the bass waves it'll chop up/kill.

You could fill the tubes as packed as a punching bag though if you wanted to. I don't see any need though but the options there anyway.

I left the paper on the tubes (that's how they come), capped the ends and painted them to match the room. Covers floor to ceiling (so you hit the entire corner buildup) yet blends into the walls real well.

Hidden? No, not really, but for huge tubes it is pretty subtle I think.

Much cheaper per foot than a punching bag too.

I don't see how a punching bag is going to be a way to 'sneak' a bass absorber into a room?

Your significant other really won't notice a punching bag in the living room?

Also... being canvas shouldn't matter. Bass waves will be able to get into any bag whether vinyl, canvas, leather, etc...

[ooheadsoo]

I can say that the punching bag is a punching bag, not a "useless frivolous piece of audio junk."  Fiberglass would be best though.

[errivera]

I am sorry for posting in the wrong area. I guess I got caught-up in the moment.

As for the weight not making a difference, I must beg to differ. Mass does have an influence on which bass frequencies are absorbed. This is why sound travels faster through more dense materials as opposed to air and why different wavelengths (think frequencies) excite a mass (think resonance) differently (think amplitude).

Bass waves are readily able to pass through 'light' materials without any effort. 'Heavier' materials however, 'absorbe' (think energy transformation) bass frequencies. That is why certain bass absorbers are tunable by adding or decreasing the mass.

If I am mistaken please inform and educate me (no sarcasm intended at all).

[ooheadsoo]

The main issue here is that lots of massive compressed fiberglass would probably be better than lots of massive compressed generic filler of whatever it may be.  I'm starting to think of buying an empty punching bag and filling it with fiberglass!  I'm not sure I'd want to punch it afterwards though, which would take away half the reason to get one.

[JLM]

I've read in a couple of places where guys I respect have gone the cheap/easy route of just piling rolls of fiberglass batt insulation (still in the plastic bags they came in) in the corners of their rooms and loved the effect so much that they ended up dressing them up and keeping them there.  For about $200 you could have a tall bass traps in all four corners.

[MaxCast]

azryan, how did you finish your traps?  What is on the outside?
Thanks,

[ooheadsoo]

Yeah, Jon Risch and his Q&D bass traps.  No doubt it works, I just doubt my ability to dress them up!

[azryan]

I've read in a couple of places where guys I respect have gone the cheap/easy route of just piling rolls of fiberglass batt insulation (still in the plastic bags they came in)-.

Yeah. That should be good too. I'd think that'd be FAR cheaper than $200 though? Fiberglass batting is almost free it's so cheap.

The lumpy shape of it and stacking them up might make it tougher to look nice. I'd guess you might have to drap a long cloth over it which depending on the material might add a lot to the final cost.

I'd think you'd have to jam something down the center of the bags to string the stacks together too -like a long wood or metal dowel/rod?

For the compressed fiberglass tubes I used...

They are about 2" thick and 18" dia. (matching my sonotube sub dia. which you can see in the pic by my name) and rigid enough that you can move them around like a fairly solid/stiff object.

They come wrapped in white paper that has a metalized/plasticy (?) film under the paper. It's meant to help insulate large pipe (what the tubes are made for before audiogeeks got their hands on them heh).

So if the paint ain't too wet, you won't rip or ruin the paper surface putting on whatever paint you want. You can of course wrap them in cloth if you want to but I think for trying to fit into a room, matching the paint of the walls will work the best.

You could cover them like I coverd my subs-with 1/16" wood veneer. The only point of corner tube traps is really going to be bass and bass waves will easily get into the tubes even with the veneer so should not be a problem but I figure most would want to just paint them.

Also you can cut off half the paper/film and cover with cloth so you can turn them to be diffusers or absorbers of higher freqs. if you use them at first reflection points instead of just in corners but I prefer flat panels at the reflection points -looks-wise.

Anyway.. I rag painted my walls 2 shades of reddish brown and my ceiling the next 2 shades lighter.

I used the two middle shades of these 4 to rag paint my tube traps so they're in-between the wall and ceiling shade.
If I really wanted to hide them to the walls though I could have just used the two wall shades.

A lot of people have white walls too so you'd already start with almost the right shade without painting.

I capped the ends with 1/2" particle board and liquid nails. As far as I read... you just need the ends sealed so no need to use thick/heavy MDF or anything.

And like I said.... if someone thinks this fiberglass isn't good enough.... all you'd have to do is fill the inside with whatever you want before you cap the top.
Doing this certainly wouldn't hurt that's for sure, but I do think it's not needed and would make moving them turn from childishly easy to possibly a real bitch?

[JLM]

Az,

I was referring to buying 12 bags of fiberglass batts and stacking 3 in each corner.  I believe the bags run about $13 each.  One of examples that comes to mind was from a guy that just kept buying more bags as the sound kept improving.

[errivera]

Yes, I think that we have strayed a little from the original post however, that's OK. Although I agree with many of the posts thusfar, I think that fiberglass is somewhat less practical. Now I see a post of someone wanting to purchase 12 bats of fiberglass! Let's be real.

I do understand from a physics point of view that compressed hard panels of fiberglass would be a great absorber when used properly; but is it safe? I do know that this topic has been circulated before. I do know that there are no 'proven' or confessions from fiberglass manufactures regarding the safety (or lack of safety) regarding the material.

There have been those that have expressed personal concern in using fiberglass in their homes, possibly because of children or pets... . I know that there are various was to construct absorbers. Could someone just give a punching bag a try and post their findings.

If using a punching bag can yeild results similar to using 4, 6, or whatever number of fiberglass don't you think this would be a viable option? Isn't that what tweaks are about? If some of you could achieve good results from using canvas bags, especially since they are not too expensive, don't you think it's worth a try? Shish! Stay focused people.

I will be heading out to Sports Authority to purchase another 100 lb bag this weekend. I will post my findings, if anyone is interested. Otherwise, we can continue talking about the benefits of fiberglass and how inexpensive it is.

No offense guys.

[ooheadsoo]

If you could figure out what kind of stuffing your bags are using, that would be great!  Thanks

[errivera]

I don't know what the innards of the bag is made of. I opened the outer cover and found another inner bag (more of a thick cotton cover) which has the filling. There was no zipper or opening to view the contents. It does feel like some sort of material.

If I build up the courage to disfigure the bag I'll post what I find here.

BTW, I removed the bag from the room to make sure that I was not hallucinating and sure enough, the low end boom was back. I quickly put the bag where it was. Ahhh!

Any other takers out there?

[azryan]

Yes, I think that we have strayed a little from the original post however, that's OK.-

Sorry, guess that was my fault. I thought the topic was basically about improving room bass with corner loaded bass absorbers and thought I had a better option for people than to use a punching bag and stated why I thought it was better.

Then others were interested in more details about that. Including you since I'm answering some questions/comments you have about fiberglass.

Although I agree with many of the posts thusfar, I think that fiberglass is somewhat less practical. Now I see a post of someone wanting to purchase 12 bats of fiberglass! Let's be real.

If you want to make a real point you'll need to state why you think this option is not 'real'. Just saying so isn't good enough.

Also my option is compressed fiberglass tubes which is very diff. from using bags of loose fiberglass.

But clearly there are more option than punching bags.

I do understand from a physics point of view that compressed hard panels of fiberglass would be a great absorber when used properly; but is it safe?-

Yes. You only need to make sure that you do not lick or eat the fiberglass and you should be fine. You may have heard that some homes use fiberglass in the walls and very few people die from this.

Seriously...

The 'bags of fiberglass' option mentioned means that the fiberglass is in bags. The poster should have made that more clear for you. This means that it's in plastic which means it can't get into the air and can't cause any harm unless you have a kid/dog/cat who wants to tear it open and eat it or something and if that's the case... well there's all kinds of dangers like that in most homes already that parents have to be careful about.

The compressed fiberglass tubes I mentioned are fully wrapped in paper  and capped at the ends with particle board (but I said this already).

There's no health risk at all that I can see here in using them. You tell us if you can say what the risk would be -since you guess there is one.

If using a punching bag can yeild results similar to using 4, 6, or whatever number of fiberglass don't you think this would be a viable option?

Yes. I totally do.

My point though is that I  'don't'  think one little punching bag will do what floor to ceiling fibgerglass tube traps will do.

Note... the tubes I'm talking about come in 4' tall sections so you can buy one and see what happens, then another, etc...

You said you're going to buy more punching bags and stated how others have said that more and more is better so clearly you think that your one bag isn't enough.

Pretty much ruins your point about how one is as good as 4 corner 7' tall fiberglass tube traps that cost me about what two punching bags would have. And they look far better IMO.

If some of you could achieve good results from using canvas bags, especially since they are not too expensive, don't you think it's worth a try? Shish! Stay focused people.

Don't get bitter dude. Your option isn't shown to be cheaper, work better, or look better (when many can't get away with room treatments) IMO and I stated why specifically and gave people another option.

No one's stoppng anyone from using punching bags. People are free to choose any option and we can debate why this or that option is better.

You made comments about fiberglass not being safe and that's fine. I replied why I think that's wrong. All part of forum discussion.

[azryan]

Also note.... you don't even know what's inside these bags you're buying.

Chances are you could just buy whatever 'material' it is and make your own corner traps that aren't meant to be hung up and punched. I'm guessing for a lot cheaper than the price you mentioned you're buying these bags for.

Any 'mass' in a corner is going to help bass. Some people have couches in the corners of a room and don't even know it happens to be improving their bass quality.

You could buy a bean bag chair at a flea mart and pack it with fiberglass or whatever and there's another bass trap for the corner of a room and one a kid or pet could jump/play on even.

[Red Dragon Audio]

AZ,

Did you get your 'Pipe Insulators' from a Knauf retailer?  How much did you pay for them?

Yes. You only need to make sure that you do not lick or eat the fiberglass and you should be fine. You may have heard that some homes use fiberglass in the walls and very few people die from this.

Actually I have never heard of homes that don't use fiberglass insulation in the walls.  It's cheap, easy to install and highly effective.  I'ver never heard of anyone dying from fiberglass 'poinsoning' or 'exposure'; you get itchy at worst but that is if you are cutting it really.  Of course if you work with fiberglass all the time you should wear a mask so it doesn't get into your lungs and plug them up.  Kind of like you shouldn't smoke or something.

You're a million times more likely to get killed while driving to work or the grocery store than by the wildly ferocious fiberglass lurking in your walls

Deaths from Automobile accidents injury: 42,443 deaths in USA 2001 (CDC); 42,401 deaths reported in USA 1999 for "motor vehicle accidents" (NVSR Sep 2001)

Let me get back to the topic though;'BASS ABSORBERS'; I just bought a box of 2" thick 6.00PCF Insulation Board from Knauf Fiberglass and it will be here in a week or so.  I get six sheets, 48sqft, for $110.  It has the FSK foil on one side and should work well to make some easy corner traps.  Plus I can hang them in the middle of the walls for bass absorbtion there too.