[bpape]

OK.  That's not huge but decent size.  You're a bit away from the rear wall.  Sitting about 9-10' from the wall will likely give you smoother response.

What specific issues are you trying to address?  Frequency response?  Ringging?  One note bass?

1 pair of absorbers should make some difference but it's certainly not what I'd consider a minimum for a room of that volume.

Bryan

[bmckenney]

OK.  That's not huge but decent size.  You're a bit away from the rear wall.  Sitting about 9-10' from the wall will likely give you smoother response.

What specific issues are you trying to address?  Frequency response?  Ringging?  One note bass?

1 pair of absorbers should make some difference but it's certainly not what I'd consider a minimum for a room of that volume.

Bryan

Bryan, I don't know what my issues are.  I haven't used a RTA or even an SPL meter to see what's going on.  I can't say my ears are telling me what's wrong.  I have used the mode calculations and in theory there should be some issues with the room of course.  There is a vaulted ceiling and a large opening on the side wall near the chair that would skew the mode calculation results too.

What I want to do is fix the things I don't know about.  Like fix the modes in the ranges that bass traps work in.  I want better sound, like everyone else.

[jtwrace]

What I want to do is fix the things I don't know about.  Like fix the modes in the ranges that bass traps work in.  I want better sound, like everyone else.

Very simple then.  Just listen to what Bryan recommends and do it!  You will be very happy...he has done wonders in my room.  I have D1's, Elite Bass Traps and just added 242's.

[bpape]

Can you put a rough sketch of your room in the gallery and link to it so I can better see what's happening?  Maybe a couple of pics, especially the ceiling?

Bryan

[bdiament]

Hi arthurs,

Barry, why do you recommend not stuffing the tubes?

The question could just as easily be "why stuff them?" ;-}

Harry Olsen's original concept as well as the commercial and DIY varieties made today require the space inside the cylinder.  The cylinder wall creates resistance, which drops as the sound passes through the wall into the space inside.

If you try traps both ways, you'll find Olsen's idea works more efficiently.
ASC continues to observe this in their excellent Tube Traps.

Best regards,
Barry
www.soundkeeperrecordings.com
www.barrydiamentaudio.com

[arthurs]

Thanks Barry.  I was curious since Glenn recommended stuffing them earlier in the thread.  When I built mine I was under the impression density was the goal, if there's improvement to be gained by leaving them empty, I'd be interested in knowing about it.  ASC are tuned tubes are they not?  I've always wondered how they tune them, is it in the size and the sealed empty chamber?

My current tubes are not sealed at all, open on top and bottom, when I redo them, I will be taking your cue and capping them with wood.

[bdiament]

Hi arthurs,

...ASC are tuned tubes are they not?  I've always wondered how they tune them, is it in the size and the sealed empty chamber?

My current tubes are not sealed at all, open on top and bottom, when I redo them, I will be taking your cue and capping them with wood.

They are "tuned" as you said, by their size and the fact they are sealed.
If your tubes are not sealed, you are in for some big smiles if/when you seal them.  An important -no, *critical*- part of the design is that the fiberglass walls are the only means of entry into (or exit from) the inside of the cylinder.  Without the seal, they really don't function.

Best regards,
Barry
www.soundkeeperrecordings.com
www.barrydiamentaudio.com

[markC]

Bryan, I don't know what my issues are.  I haven't used a RTA or even an SPL meter to see what's going on.  I can't say my ears are telling me what's wrong.  I have used the mode calculations and in theory there should be some issues with the room of course.  There is a vaulted ceiling and a large opening on the side wall near the chair that would skew the mode calculation results too.

What I want to do is fix the things I don't know about.  Like fix the modes in the ranges that bass traps work in.  I want better sound, like everyone else.
[/quote]

If you don't know what your issues are it will be more than difficult for someone to help you. Could you at least explain what it is about the sound of your system that is bothering you or at least don't like/could be imrovrd.

[TRADERXFAN]

Well, not to speak for the OP, but I suspect the question arose of what bass trapping can do, because over and over you hear "that your room is X % of the equation". "Treat your room to get better sound" and "you can never have too much bass trapping" kinds of comments.

So it leads one to wonder what it could do to enhance one's system. Not that you know what to expect it to do beforehand.  Most people think their system is great, and are surprised to find what treatment can add...

-Tony

[bmckenney]

Thanks Tony, you nailed it.  I would just to add that I was hoping there would be a cheap, easy, but albeit less than stylish way of experiencing what the fuss is all about.

Bryan, we've been in touch before and I have sent pictures of my room via email.  You suggested corner bass traps for starters (pillars, and tri's on the floor).  I was hoping I could try something in my room before taking the plunge on manufactured products.  I should call you to discuss more.

Bryan

[Ethan Winer]

I was under the impression density was the goal

Actually, the goal is gas flow resistance, which often goes hand in hand with density. Up to a point. With "porous" bass traps made from fiberglass or foam, you want as much material, surface area, and thickness as possible. A tube filled solid with fiberglass will absorb more than with only an outer wrap. But the difference is small unless the outer wrap is very thin, such as 1-inch thick 703.

ASC are tuned tubes are they not?  I've always wondered how they tune them, is it in the size and the sealed empty chamber?

ASC tube traps and similar DIY models are not tuned. That's a web myth that somehow refuses to die. Likewise for sealing the ends of the tubes. All that does is reduce absorption a little by preventing sound from getting to the fiberglass through the ends. With the ends open (or covered with fabric), the total absorbing surface area is increased. Again, this is small stuff, but it's important to keep the theory straight.

My current tubes are not sealed at all, open on top and bottom, when I redo them, I will be taking your cue and capping them with wood.

Don't bother. But if you have REW or other software that can measure your room's response and ringing, and you're curious, go ahead and try that as an experiment. Then post Before and After waterfalls here. Just be very careful not to move the traps even half an inch when you cap the tops with wood. For a valid test, it's critical that nothing change except the addition of a cap.

--Ethan

[bpape]

Bryan, I don't know what my issues are.  I haven't used a RTA or even an SPL meter to see what's going on.  I can't say my ears are telling me what's wrong.  I have used the mode calculations and in theory there should be some issues with the room of course.  There is a vaulted ceiling and a large opening on the side wall near the chair that would skew the mode calculation results too.

What I want to do is fix the things I don't know about.  Like fix the modes in the ranges that bass traps work in.  I want better sound, like everyone else.

If you don't know what your issues are it will be more than difficult for someone to help you. Could you at least explain what it is about the sound of your system that is bothering you or at least don't like/could be imrovrd.
[/quote]

Most likely, there is a masking of small details, a potential additional chestiness in the mid to upper bass/lower mids caused by extended decay times in the bottom end.  After that, we deal with reflections which can skew/muddy imaging.  Most rooms have similar problems - it's just a matter of how specifically to treat them based on speakers, room size, room layout, construction, etc.

Bryan

[arthurs]

Actually, the goal is gas flow resistance, which often goes hand in hand with density. Up to a point. With "porous" bass traps made from fiberglass or foam, you want as much material, surface area, and thickness as possible. A tube filled solid with fiberglass will absorb more than with only an outer wrap. But the difference is small unless the outer wrap is very thin, such as 1-inch thick 703.

--Ethan

So Ethan, if I'm using rigid fiberglass pipe wrap with 2" wall thickness and 15" total diameter, is there performance improvement by filling it with mineral wool or something like UltraTouch?

[bpape]

Thanks Tony, you nailed it.  I would just to add that I was hoping there would be a cheap, easy, but albeit less than stylish way of experiencing what the fuss is all about.

Bryan, we've been in touch before and I have sent pictures of my room via email.  You suggested corner bass traps for starters (pillars, and tri's on the floor).  I was hoping I could try something in my room before taking the plunge on manufactured products.  I should call you to discuss more.

Bryan

You're welcome to call me any time to discuss.  A similar experiment to the OP's could be in order.

Bryan

[TRADERXFAN]

   "bmckenney" was the op....

Thanks Tony, you nailed it.  I would just to add that I was hoping there would be a cheap, easy, but albeit less than stylish way of experiencing what the fuss is all about.

Bryan, we've been in touch before and I have sent pictures of my room via email.  You suggested corner bass traps for starters (pillars, and tri's on the floor).  I was hoping I could try something in my room before taking the plunge on manufactured products.  I should call you to discuss more.

Bryan

You're welcome to call me any time to discuss.  A similar experiment to the OP's could be in order.

Bryan

[bdiament]

Leaving the ends of a cylindrical trap open defeats the trap and creates a decorative cylinder, nothing more.

I would suggest anyone interesting in this type of trap not take my (or anyone else's) word for this but instead to try it both ways and draw their own conclusions.  The difference between fully functional and not is far from subtle and the listener will know for themselves in short order.

Similarly, the cylinder's size will determine the frequencies at which it will be effective.  Whether one calls this "tuning" or not doesn't matter.  A given size cylinder of this design will have a given native resonance frequency.    This is no more a "web myth" that saying different size rooms will have different resonant modes.  Again, please don't take my word for this.  Try 16" cylinders, then try 9" cylinders in the same spots, play music with lots of low bass and see whether there you hear a difference or not. 

Anything, even a flat panel, can be "tuned" by its mass and dimensions, particularly its thickness.  Try it and hear for yourself.

Best regards,
Barry
www.soundkeeperrecordings.com
www.barrydiamentaudio.com

[bpape]

  "bmckenney" was the op....

Thanks Tony, you nailed it.  I would just to add that I was hoping there would be a cheap, easy, but albeit less than stylish way of experiencing what the fuss is all about.

Bryan, we've been in touch before and I have sent pictures of my room via email.  You suggested corner bass traps for starters (pillars, and tri's on the floor).  I was hoping I could try something in my room before taking the plunge on manufactured products.  I should call you to discuss more.

Bryan

You're welcome to call me any time to discuss.  A similar experiment to the OP's could be in order.

Bryan

My bad    Misread Marc C's post.

[arthurs]

At worst it doesn't sound like wood caps on the ends will hurt anything, at best it may be a nice improvement...I'm planning on adding them when I refinish my tubes, so I'll try to do a before and after and report back on it....

Now, stuffing or no stuffing? 

[TRADERXFAN]

At worst it doesn't sound like wood caps on the ends will hurt anything, at best it may be a nice improvement...

Well, one argument was that the wood cap would decrease performance, because you are taking away surface area of the trap.

Similarly to why they do not suggest framing the panel traps, as the side surface area is significant relative to the front.

[arthurs]

Likewise for sealing the ends of the tubes. All that does is reduce absorption a little by preventing sound from getting to the fiberglass through the ends. With the ends open (or covered with fabric), the total absorbing surface area is increased. Again, this is small stuff, but it's important to keep the theory straight.

I guess this is what I was quoting..."reduces by a little"..."small stuff"....don't seem like major dealbreakers one way or the other and I could actually use the wood caps to finish out where you have to stack them (not an open area anyway) so it looks like the only open end that would be capped is at the top.  My room uses three of the 3' stacked so the only exposed opening is the top...