About to invest in room treatments; GIK, RealTraps, DIY -- what is your experience?
I'm reaching the point soon where I'll invest in some treatments for my two channel listening room. Standmount speakers with tube amps. Room about 28x14ft with low ceilings, 6.5ft. Probably different kinds of treatments are needed. I'm not exactly sure yet what I'll need or how much to spend. This is not my final listening room, but I won't be able to configure another one for a few years.
I've seen many people tout GIK on this forum and I'm already communicating with them a bit. I will also reach out to Real Traps and possibly others. I do not feel bound to go with just one company or solution, so if you've mixed and matched, I'm curious about that, too.
Any recent comparisons between these two, or others? Do you have stories of good or not so good products or service? Any comments about the value of competing products? I'm not super handy or have a lot of free time, but DIY is also considered.
I went through a very similar situation as you presently have. Over the course of a couple of years, I read the books and literature, plus participated on Gearslutz acoustics threads. That was most helpful. It's good that you've done some REW sweeps; it was valuable to be on Gearslutz in order to properly interpret the various sweeps and to know what they indicated in terms of treatment application.
Perhaps I misread your approach, but it did not look like you started treatment with very low/low frequency treatment (which you should). My room is about the same dimensions as your room, except for 9' ceilings. I ended up treating the corners, floor to ceiling, with RealTraps Mega units, as GIK were not as effective as I needed. All along the rear wall (short wall), I use 10" Knauf mounted in skeletal frames behind RealTraps diffuser panels which are sitting atop their 2' x 2' x 6" absorption panels. This will give me pretty much what I need for LF control and diffusion.
I moved my speakers closer to the front/short wall to help speaker boundary/LF issues. I'm testing the first reflection/side wall areas with near diffusers and with combination of diffusion and absorption/range limiting to preserve source content. On the front/short wall, in addition to the 34" wide corner Mega traps, some additional very effective absorption is necessary; I think you'll find the same.
Ceiling area just above and toward the front of listening position is something you can determine with additional sweeps and experimentation.
The reason I used RealTraps corner units in addition to their effectiveness and quality build, is that I just did not want to build those myself; predictive software models weren't what I would want to use to build, etc. However, for non-corners, regular rectangular absorption panels are a piece of cake to build, and pretty cheap. Knauf from Home Depot comes in pieces that fit just right, at less than 20 bucks a panel, and in thicknesses of like 6" (minimum you should even consider) to over 12". Knauf has tested very, very well. A simple skeletal frame is cheap and easy. You'll save yourself around $1,000 or more for the amount of absorption you will need in your room. In order to afford the RealTraps units, I had to save money elsewhere. That said, a few GIK 6" with range limiters was also something I figured in my scheme.
I suggest you consider calling Ethan Winer at RealTraps for advice. You can take it or leave it at the end of the day. He is very nice and quite patient.
Take your time. Address one issue at a time. Keep running/interpreting room sweeps/measurements, then move to the next issue as indicated. Be careful of over absorption or using where not called for. Move your listening position and speaker distance from front wall as necessary.
I've used GIK Acoustics twice for two different homes over the last 12 years. Good advice/service, highly effective products at very reasonable prices. Their business is booming right now, so you may have to wait 8 weeks, like I did, to take delivery.
GIK requires full payment on standard production items, while making you wait 8-10 weeks....even for a several thousand dollar order! The actual production of the product takes about 2 days. No partial deposit allowed. Of course, GIK has required full payment up front for years, but the wait used to be about 2-3 weeks. You'd think with a $54M annual revenue and exceptionally long wait times, they'd modify this policy.
OTH, RealTraps makes a better product with a three-week wait, so there are choices available.
Finally, don't use dense/rigid foam products for early reflections/side wall applications; they do not perform well for that application. Instead, choose a medium weight, medium density, minimum 6" product such as Knauf Ecobatt.
@nolojunko is correct regarding the long lead-times and paying up front with GIK, however, from a value standpoint, GIK's products sell for roughly half the price that RealTraps do... so not necessarily an apples to apples comparison. I've heard nothing but good things about RealTraps products... I just didn't want to pay more (2x) when I know from past experience that GIK's products are effective and a better value for me.
@audio2design I have had a mic and REW for 7 months and have done hundreds of measurements. I thought I mentioned that, but I agree with you that this is an absolutely necessary prerequisite to spending money on the room.
@pdreher Thanks for the head's up about wait times for GIK. Will probably try to confirm about wait times. Others have suggested others, here, too, such as ATS Acoustics. That may be a good solution, too
@rbstehno good rec's. thanks.
@midareff1 thanks for your experience report. nice room!
@martinb Glad to hear of good experiences with GIK. I will send them a scan, I'm sure.
@hornps Good to hear from someone with a similar ceiling height. Dennis Foley said to me, "Worst ceiling height I've ever encountered in 20 years. Find another room." Good to hear about GIK.
@nagel Good to hear your story, too. Thank you.
@nolojunko I have not started treatment at all. I have been doing analysis for 6 months (learning) especially focused on 20hz-300hz only, because bass is most important to figure out, first. I've optimized LP and Speakers. Working on scans with sub(s). I've heard good reports about RealTraps, too, and they're on my list. I had not heard of Knauf; not against simple building project, and agree about complicated corner traps -- too much for my schedule/abilities. I suppose you're not warning against OC 703 in your comment about "dense/rigid foam" or are you? Now sure what they're best called.
+1 on ASC tunable traps. Movable, tunable available in multiple colors and if you want to resell, you’ll do fine. I have 4 and also had room analyzed and treated with Artnovion panels - absorption and diffusion. They are absolutely beautiful, if that’s a consideration for you. Definitely treat ceiling to eliminate slap echo. Good luck
Regarding first reflection/first order/side wall reflection treatment: Don't use anything less than 6". Some of the best engineers will recommend 8" to 12" for better performance. Reason: angle of incidence at 30 degrees, or so, plus low frequency considerations. Yes, you will get "some" benefit from 2" or 4", but that's not the objective in terms of desired results. The comment on rigid insulation is only an example of flow resistivity; a common error is to think more density is better. Products like Knauf or Safe 'n Sound, etc., work well. So would a product like GIK 6" Alpha, with an air gap behind the panel.
One important consideration with side wall/first reflection treatment to note is how wide the treated surface area must be. Each side wall reflections are generated by both left and right speakers at different locations. A single 24" panel does not seem to cover the affected area. I prefer to cover an area 48" x 48" instead.
Finally, budget is a major factor in prioritizing treatment options. Diffusion is expensive, as is corner bass treatment. Corner bass was my single most expensive challenge for proper treatment. You just can't get around it. Even GIK focused low frequency units are super expensive, just like RealTraps. Highly effective bass corner traps are just plain expensive from any company. Even the GIK soffit traps, when used in sufficient number as "some" sort of alternative scheme, are very expensive as a part of the low frequency component.
When I did my project, I had to accept my budget just did not allow for all the treatment I needed. Low frequency treatment ate up about 75 percent of my budget, when I first thought it would be about half. It was over $3,000. The reality is this: full treatment of a typical room costs more than most people can afford (at first - or even ultimately, when treated in stages over time). Thus, people who are serious about it make adjustment and/or compromises they can live with. Deciding what acceptable compromises are is the key. The adjustments are commonly to build some acoustic panels, rather than buy them. These would be the panels which are the easiest to build and which are known effective: 24" x 48" panels. So, aside from the complex corner panels, the rest can be simple absorption made from readily available material. In my room, I needed at least 15 panels (after corners - the main priority - were treated): 4 ea. for the side walls, 4 ea. for the rear wall (minimum) 4 ea. for the front wall behind the speakers, and 3 ea. on the ceiling between listening position and front wall. This scheme treated less than 50 percent of the room, which is what I wanted for a more lively room. I could have easily used more panels on the rear wall. And, I could have used a cheaper, but effective diffusion treatment on the remaining area of the front wall, and on the ceiling. I could have used 3 panels on each side wall instead of 2 panels. And, treating side wall - ceiling intersections was a non-starter in terms of priorities and budget.
I wouldn't listen to much of anything Dennis Foley says. Period. That's not just my opinion.
@pdreher:
With respect to GIK vs RealTraps, I was particularly concerned with corner bass traps, not with side wall or ceiling, or even rear wall. I did not find GIK corner units to achieve the effectiveness needed when calculating for my application. Otherwise, I find their non-corner units (minimum 6") to suffice for most applications. Like many engineers, I prefer a high quality diffusion on the rear wall. However, bass treatment is also necessary on the rear wall. Thus, I chose to have 6" absorption behind the diffusion panels, as diffusion frequency cut off is rarely lower than 750. Plus, absorption is cheaper for the added benefit.
I used ATS panels with the coffee bean bag covering in my current room, prior to replacing them with GIK 244, Alpha 4 and Tritraps. While the ATS https://www.atsacoustics.com/item--ATS-Acoustics-Coffee-Bag-Acoustic-Panel--3001.html satisfied my wife from a WAF standpoint, their performance from an acoustics standpoint was lacking. The difference in sound quality with the GIK vs. ATS was night and day in my experience.
I have 3 art panels rear walls look good too as well as curved bass absorber diffusers in rear corners. Diffuser and bass tritraps on first reflection points and some in front corners too. Large leather g plan sofa. Thick carpets... And other furniture cushions used to further clean image. Should have something on ceiling 3.7m up... But cornicing too pretty to mess us.
@hilde45, stubborn nulls or deep partial nulls just need more bass traps and in the right place which are the corners. All corners can be considered, This means the wall to ceiling corner and the wall/wall corners. And unfortunately they must be BIG.
Superchunk corner bass traps that go from floor to ceiling are very effective and easy to DIY cheaply. Mine have turned out well and look great. A 2’ x 4’ OC703 or similar panel is cut in half giving 2 x 2’ square sections that are then cut on the diagonal providing you with 4 triangular pieces that are then stacked one above the other until they reach from floor to ceiling. This is what it takes to absorb bass frequencies which as we all know are long wavelengths. Google for easy DIY plans. In previous posts I have provided links to programs that will analyse the modal region of your room.
They all show bass build up in corners.
@corelli, nice clean layout you have. Am I mistaken and you referred to bass traps on your rear wall. If so I am afraid that they will not be true bass traps and wonder what professional said they were. They will provide broad-band absorption but for bass will need to be in some corner and a whole lot deeper. Ignore this If I misunderstood you.
I have noticed some suspect advice from Foley at Acoustic Fields.
Thank you Lemonhaze. I have seen some instructional videos on how to make corner traps. They look easy-ish. (I’m not that handy but this seems doable.)
When dealing with bass peaks or nulls, the corners are the obvious places, but you also look at the frequency of those nulls/peaks and consider your room dimension and where those nodes are for each null/peak.
Are you just using two main full range speakers @hilde45, or do you have subs? When you look at the cost and complexity and esthetics of bass control, sub-arrays make a lot of sense. I personally would still want acoustic control in addition, but it does make for a far more controllable problem.
@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).
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.
It’s very hard to know where the standard 38% position is, given the irregular shape.
This location is indeed very good....
this is the golden ratio....
My 2 locations are good and the 2 are at this same ratio, one from my front wall (near listening) the other regular position from the rear wall at the same ratio...My room is irregular but permit this....
Try to discover a location in your room inplying this ratio....
1.618 is the magic number of nature....
62 divide by 38 : 1.63
My Helmholtz-Fibonacci silent pipes organ, a room tuner has all three sets of three pipes cut with this ratio....
Your objection is a tautology beside my observation and you dont even realize it....
The golden mean is precisely a ratio which relation can be inscribed in a SPIRAL and the relation between the cosx and sinx exhibit then precisely this 1.6 ratio then this rule 38 and 62 % whichi is only an empirical illustration of this universal fact in traditional architecture and acoustic.... 62//38 which is a gross approximation....55/30 and 89/49 are Fibonnacci number, 2 fractions on an infinite series convergent to 6.1803....38/62 being an approximation itself of 2 terms of these series....
You are definitely intelligent, way more less tough that you think you are...
You make me laugh, go on....
If you try to contradict me, try a real argument AGAINST, not in favor, of what i argue for and not repeating my observation under another wording....You trashed turntables lover with partial fact, you trash E-Mats customers with suppositions without any experience of their products for the pleasure to hurt them with no reason other than your stubbornness...No shame...
This ratio is the FACT......He was probably discovered by accident in room tuning with EARS or by someone who knows the importance in all field of this historical proportion in art and science....
No golden rule, just math rule.
Golden rule IS math....😁 Just this affirmation make you a recipient of the donkey prize!
Try this book written by a Russian mathematician ( the best on the subject ) :
This ratio is the FACT......He was probably discovered by accident in
room tuning with EARS or by someone who knows the importance in all
field of this historical proportion in art and science....
There is no accident in using 38% (really 37.5% of 3/8th, or 6/8th). The room node lengths of any two walls is a complete waveform and multiples of that. 37.5% is simply where the originating waveform and its reflection cancel or reinforce each other out the least.
The golden ratio, unfortunately, is not purely math as you are no doubt aware. It is far too the proverbial square peg that people try to put into a round hole. In this case it is 1.67, and just happens to be close to 1.62. If it was 1.7 or 1.55, people would still try to equate it to the so called golden ratio.
You see this what I consider sillyness applied to 16:9 aspect ratio for TV (movie) but this is again another false analogy. 16:9 was a technical trade-off. No more, no less. Our vision limit is 1.4:1 for black and white, about 2-2.2:1 for color discrimination (hence why widescreen movies are like this), and close to 1:1 for central vision.
There is no accident in using 38% (really 37.5% of 3/8th, or 6/8th).
The golden ratio IS not a human creation...It is a natural and mathematical fact ....
Then it is not an accident or an arbirary choice of a deluded man who want to peg it....
And seriously do you think that a general article pick on the net can ridiculized the work of a Russian mathematician (800 pages) I read it by the way....
You read too much internet articles and not enough serious books....
It was the reason why do dont even know what "timbre" is except a useless addition of colors according to tastes
My profession was counselling books to students and not only in litterature but in science also ..... By the way.... 😁
These are the last paragraph of this very impôrtant works:
«The eighth conclusion touches on the general role of the Mathematics of Harmony in the progress of contemporary mathematics. We affirm that the Mathematics of Harmony can overcome a contemporary crisis in the devel� opment of the 20th century mathematics what resulted in the severance of the relationship between mathematics and theoretical natural sciences [6]. The Mathematics of Harmony is a true “Mathematics of Nature” incarnated in many wonderful structures and phenomena of the Universe (pine cones, pine� apples, cacti, heads of sunflowers, quasi�crystals, fullerenes, genetic code, Uni� verse evolution and so on) and it can give birth to new scientific discoveries. »
Um Mahgister, no offense, but you do this in a lot of threads. Take a question and relatively focused discussion and drag it into your interesting but somewhat hard to follow and tangential directions. At great length.
Clearly you want or need to talk about these issues. That's fine. But may I politely suggest you start a thread with the things you want to discuss (however abstract they are) rather than injecting them into focused threads seeking to solve a problem? It would keep this thread open for more focused or useful contributions (to my question).
@maghister Yes you have the "right" to go on and on. I was only making a request. Forget it. I'll just skip past your posts if they're off topic and everyone else who is interested in the main theme of the thread can do the same.
Here are two links you can use to enhance your ability to use REW; one like is for speaker and listening position placement in real-time, while the other is an REW tutorial by John L. Sayers. Enjoy!
I have used ASC products in my last room. In my current room I went with Real Traps. I get much better results with the Real Traps. The soundstage is enormous and the depth is just better. Both rooms are similar in shape and size. The Real Traps were definitely a lot more effective.
@jdal I've heard similar good reports from others about RealTraps. It's going to be a balancing act between predicted efficacy of the kind of unit and cost. I will probably mix and match companies and go with things I can eventually use in other rooms, should I be able to do a new room, down the road.
bernardo, I have 3 Mondo Traps along the wall behind the speakers, an RFZ panel on each side wall which I put on stands so I can experiment with placement. Behind my chair I have a diffuser on top of a mini 2’x 2’ Mondo Trap.
Spoke with GIK yesterday. They’ve a new CEO (~1 year). He’s extending reassuring messages. Customer service confirmed that there shipping costs have greatly increased, which is based on location > weight.
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