About to build the traps....

I'm about to build the low bass, high bass, and mid/high traps per Ethan's instructions. But I have a couple of questions I haven't found the answer to from searching: 1. Do these have to go from floor to ceiling (note on my reflected ceiling why this would be a hurdle) 2. Would fabric on the face of the Low and High Bass traps do anything to hamper their effectiveness (I want to finish them in fabric insteaad of painting them)

Is there any body out there?

C'mon guys! I've followed all the rules. :cry:

The images aren't showing up. I think it's because you're trying to use the tags for images that are hosted on MSN, and there's probably programming logic on MSN that prohibits that. Try attaching them instead.

The traps can be what ever size you want, however the longer you make them the more surface area of trap you have. (I know that goes with out saying). As for the second question. Anything touching the front panel of the "low" trap will reduce its effectiveness. You might try using a thin (1/4") piece of wood around the edge. Then attach your fabric so the fabric is not touching any of the middle of the panel.

Sorry for no iamges. They showed up on my screen so I just assumed.... Anyway I fixed it. Let me know if it worked. Or I can just go check on my studio computer. Nevermind. Back to the subject, I'm confused on how important it is to run these panels from floor to ceilng as opposed to say 6' panels. Now that you can see my pictures notice the reflected ceiling. In those corners where the ceiling slopes, if I was to just stick a rectangular Etahn type 8' low bass panel it would not seal at the top, unless I custom fit it to have a peak. And so I was wondering just how much of a difference that gap would make. Did I confuse you guys?

Sorry... They're not fixed. My guess is that the images are cached on your browser, based on them having worked for you at first, viewing them "legally" per se. However, once your session ended at MSN, those images are no longer served from those URLs and/or aren't served to appear on an external site. MSN does this because they want people to visit your MSN photo gallery directly so that the banner ads can be presented to the visitors. When you use their system as an external image host, they incur all the expense of hosting the images without any benefit to them... Hence, their programmatic solution that prohibits that. Download the images and attach them to your post (as long as their width is 700 pixels or narrower, of course).

Thanks for the picture guidance.

We can see 'em now that they're attached. 8) Hopefully you'll start getting some good advice now.

Aloha, Just a few thoughts and observations... Both Ethan's and John's designs use a material facing on their bass traps/absorbers. I would suggest a material that is acoustically transparent, if possible. I've used both burlap and weed cloth before with good results, but the Guilford of Maine line of products give a bit more "professional" look. Very cool. 8) Ethan's Real Mondo Traps stand 4'9". You have according to your diagram...(which I can see! :D ) up to 8'3" of wall height before your sloped ceiling begins. I would think by going up as high as your wall height before the sloped ceiling begins will allow you the most absorption you can get in your case. By the way, how wide/deep are you planning your traps? Lastly, have you considered front and rear absorbers behind the desk and behind the sofa? (12' and 9' 3" walls) Hope this helps. Aloha 8)

1.On Ethans do it yourself low and high bass traps he actually uses ACX plywood to be painted. The cloth he uses on the mid/high traps. Thats why I was asking if using cloth on the bass traps was ok. 2. In regards to the height, I must not be understanding what happens to the bass after it hits the trap because it seems like having it open on top would just send the bass back into the room to be reflected again. Your guidance much appreciated. 3.I do plan on adding absorbers elsewhere as this thread will soon show. I'm starting with low frequencies and working up. So after I feel confident about the direction I'm going with the low traps we're gonna make like Curtis Mayfield and Move On Up!

By the way, which setup is better the one above or ............

I would think the listening position from the sofa (which is obviously not a high priority, I realize) would be worse in the updated. How about putting the sofa along the wall on the right side?

I definitely appreciate the concern for the couch, but as you said Sharward, all this hard work and endlees studying on acoustics is not for the guys sittin on the couch listening to the PA system. Everything on this thread is for the benefit of that person sitting at the mixer........me :wink:

The original drawing has better left to right symmetry for the mix position. For the wooden traps, you can cover with cloth IF you space the cloth 1/2" or so away from the front panel. If you just wrap with cloth, it will damp the front panel somewhat and make it less effective as it will be less free to vibrate at it's target frequency.

Thanks. I'll do that. One more question and I should be ready to make the traps. If I'm going to build the traps per Ethan's plans, he mentions alternating the three types of panels: low bass, high bass, mid-high, high bass, low bass etc. with a low bass and high bass in each corner. Which one of the ways below is better? And is this better than only one in corner @ a 45 degree like John has on his design?

derekdun101 wrote:

1.On Ethans do it yourself low and high bass traps he actually uses ACX plywood to be painted. The cloth he uses on the mid/high traps. Thats why I was asking if using cloth on the bass traps was ok.!

Ethan's Low bass traps (the ones with 1/4" plywood fronts are a sealed system. They work because the plywood spanning the frame vibrates in sympathy with the sound waves and this vibration is absorbed by the system of the box and dissipated as heat (albeit a very small amount of heat!!) They absorb the most sound at their reasonant frequency therefore the size and shape of the box will affect how they work. My guess is that covering them with cloth will probably have only very small, if any effect in their ability to absorb low frequencies..... is it just for aesthetics that you want to cover them as opposed to painting them?

derekdun101 wrote:

2. In regards to the height, I must not be understanding what happens to the bass after it hits the trap because it seems like having it open on top would just send the bass back into the room to be reflected again. Your guidance much appreciated.

There is no right or wrong here on the height issue. Only varying degrees of effectiveness based on practicality. I have probably the worst room you can have (11'x11'x9'). For practical purposes I built my absorbers 8' tall (the length of precut 1x4 lumber) and hang them with a half of foot free at the top and bottom. See here: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4581 the more area you cover the better.

derekdun101 wrote:

3.I do plan on adding absorbers elsewhere as this thread will soon show. I'm starting with low frequencies and working up. So after I feel confident about the direction I'm going with the low traps we're gonna make like Curtis Mayfield and Move On Up!

Sounds like a plan! ... db

derekdun101 wrote:

Thanks. I'll do that. One more question and I should be ready to make the traps. If I'm going to build the traps per Ethan's plans, he mentions alternating the three types of panels: low bass, high bass, mid-high, high bass, low bass etc. with a low bass and high bass in each corner. Which one of the ways below is better? And is this better than only one in corner @ a 45 degree like John has on his design?

I'm still learning, but I would put the plywood covered panels flat on the wall/ceiling and span 4" thick OC-705 panels across the corners. The airspace behind the panels is important. Anyone else??? ...db

I'm still learning, but I would put the plywood covered panels flat on the wall/ceiling and span 4" thick OC-705 panels across the corners. The airspace behind the panels is important.

When you say span the 705, do you mean a trap on a 45 deg. to the corner? If so then wouldn't that make the ones I have jammed into the corner (see picture above) pointless? Thanks for the reply. Was beginning to wonder if I had bad breath or something. :shock: