About to invest in room treatments; GIK, RealTraps, DIY -- what is your experience?

@audio2design Thanks -- I’m trying to correlate the factors you mention. The room is quite irregular in some ways, so it’s lack of closed-ness and rectangularity makes it hard to know what the standards might be. I know there are ways to do it, but I’m quickly getting over my head.

I have one sub dedicated to listening and another in the house I can try out along with the first to do measurements. I am convinced about swarms/arrays but I cannot go there, in this room. I will do it eventually, but for now, I’m optimizing a less-than-perfect room.

Thanks for the info, re: Foley.

This seems like the mortal blow, since this technology is their killer app (if I gleaned their message correctly):

Aside from all that - what do you all think about using activated carbon in bass traps? For me it of itself makes some sense

Activated carbon actually does have some useful acoustic absorption properties. That much is true. Somewhere I have a couple of papers and some research on that. It is even used in some types of "ear defender" headsets, for industrial hearing protection. It's better than foam for that. However, in studios, it does not perform better than more traditional bass traps, and doesn't even get to the same level of efficiency. Then there's the cost, and the weight... it would have to be much, much better than other types of bass trap to be justifiable.

Comparing my local prices for materials it would be ca. 10x more expensive

And there you have it! It mostly certainly will not be ten times better, nor five times, nor even twice... To justify an increase of ten times in the cost, one would expect to have a rather substantial increase in performance. That isn't the case. There are already very good bass traps that can do the same job for a fraction of the price, and at a fraction of the weight: panel traps, limp membrane traps, Helmholtz resonators, even plain old porous absorption. All are proven to work at low frequencies, and to work effectively, at lower cost and lower weight. So there's no real benefit here... except to the pocket of the manufacturer!

@hilde45 :   With respect to your bass issues you are presently seeing on your room sweeps, I guess I'd just say two things:

First, any data must be quite specific (frequency, +-db, left speaker or right speaker, mic placement, listening position in relation to speakers and in relation to room length, and show graphs/waterfall).  Also, I'm assuming you have no corner or front-wall bass traps in place yet?  If you have traps in place, what are they and where they are helps to answer specific questions.  You won't get much good advice with such a general question.  The second thing is partially addressed above: where is the listening position in relation to the front wall (and to the speakers).  At 6.5' from the front wall, I'd assume you are likely 13-15 feet from the front wall.  That would position you at half-way between the front and rear(?).  Or, are you already at the standard 38% recommended to avoid nulls.  No modes on your sweeps?

If what you are seeing on the sweeps before treating is just a couple of nulls, that's exceptional.   Treating is easy at that point.

Are you measuring each speaker separately?  Do they some very close graphs/issues?

Just a general response to a general issue is, bass traps/corner traps can be the product of known specific concerns.  It is pretty straight forward.  However, generally, a corner unit should be 34" wide for effectiveness, and maybe floor to ceiling, maybe not.  They usually won't cure the problems by themselves.   

You can reach out to the acoustics thread at Gearslutz forum if you provide pretty specific data - only then would you get good advice, including type and placement of LF treatment.  You can also tap into some great guys who have tested, built, installed treatment professionally.  But, you have to have all your data (room dimensions, speaker/listening locations, room sweep data).

This might help some.

https://www.acoustic.ua/forms/calculator4.en.html

Thanks, djones! Looks good.

@nolojunko

Thank you for your detailed and probing reply. A few answers/comments.

I am realizing that I need to do more left/right speaker sweeps. With help, I've built a spreadsheet to record db changes at key frequency points along with various positionings.

Yes, I have no corner or front-wall bass traps in place yet.

I am about 14 ft from the front wall, but the room is odd. It's 27 ft long in the rectangle I'm in, but there is an additional 8' x 5' hallway entering into it. This listening position was chosen because of the way it both sounded and measured. It's very hard to know where the standard 38% position is, given the irregular shape.

And yes, what I'm seeing on the sweeps before treating is just a couple of nulls; the member here helping me said it was one of the best untreated scans he's seen in a long time.

Are you measuring each speaker separately? Answer: no, but I will.

I will reach out to the acoustics thread at Gearslutz forum. I have a lot of the data ready to go. And if I stare at it any longer, I'll lose my mind.

Thanks again!