Already have home made traps should i buy some pre-made now?

I have about 24 4" fibrex panels that I have in ready bags. In my control room, I have 2 stacked in each corner. I have 2 on each side of the console at first reflection points. 2 Mounted on the ceiling. I also have 3 on the back wall. I have been seeing many people talkig about gik and realtraps. I have seen people say that the design is much better than just having the panels in a bag. Should I take down the traps I have now and put some better designed traps up? Or should I do a mixture? GIK bass traps in the cornes, and my current traps for just first reflections and ceiling? What do you guys think? Are realtraps and gik traps that much better?

I guess my basic problem is that I have the 4" thick panels with no frame, no membrane. I really don't know what the specific purpose of the panel is. Meaning is it good for broadband absorbtion, decent at lowend, decent at mids and highs.... So my question really boils down to this, should I: 1) Keep the traps how they are, just don't use so many. IE 2 in each corner, 2 on the ceiling, 2 at reflection points on each side, 2 at the back. And one one each side at the top corner of the walls. 2) Leave the current panels in the corners, and get the premade traps to go at reflection points, on the ceiling, and on the walls 3) Replace the current corner panels with the premade 4" thick traps. So buy new ones and place them in the corners, and leave what I have on at reflection points, ceiling, and walls. It doesn't seem much different to me. But I am no acoustics man. I hope this clarified my question

Mineral fiber panels wrapped in fabric (such as your Ready Traps and GIK's panels) when placed across a corner are an effective solution to the problem of modal resonance down to about 50 Hz. Below that, the best solution is to build a tuned device such as a panel trap with your particular mode's frequency as the trap's design frequency.

I'm not really worried about anything blow 50hz. So, it seems as though a wood/metal frame is purely aesthetic. And the added membrane in gik and realtraps will not provide me with better results than my current bass traps. If that is the case, then I will save myself $2000 on totally new treatment for my control room

I don't think I would retreat the room, but the nice part of our product and the Real traps product is they have a membrane in them so the high end will not be over dampend. As David pointed out our product is pretty effective down to 50hz (as our lab numbers show) but really they shine from 80hz to 500hz best. Glenn

Glenn: I think we all appreciate the fact you recognize that the author of the thread doesn't need to throw away his absorbers and send you and Ethan Winer a big fat check. :D I’d also appreciate it if you would consider a retraction of your specious and negative comparison of our products with the Ethan Winer MiniTrap, both here, and at every other internet forum you have made similar false assertions. Specifically I refer to the idea that the MiniTrap is somehow superior when compared with mineral fiber panels upholstered using our RT424B Bass Trap Bags because “high end will not be over dampend [sic]”. Given that the performance of your GIK 4” panel drops like a rock at 500 Hz I certainly can understand your desire to describe this characteristic as a beneficial “feature” – I don’t agree with you – but I understand. And if you are amenable, I’m willing to just leave that as a disagreement between competitors, as I reckon most folks can ponder the notion that you and I might disagree on that point all that need be without help from me. But, when you start making claims as to the superiority of the MiniTrap to our product, due to variances in their respective absorptive properties I am compelled to present a scientific comparison so that the market and interested professionals are not left with impressions which I regard as a falsehood. To illustrate my point please review the graph below. This graph shows absorption measurements for the Ethan Winer MiniTrap, which he has published at his web site – multiplied by 18 [the reason for the multiplication is explained below]. Alongside are measurements for the RT424 Bass Trap which we recently conducted at Riverbank Acoustical Laboratory [RAL] – multiplied by 12. [A full measurement report containing this data will be available for download on our web site at http://www.readyacoustics.com as soon as we have certified reports in PDF format from RAL – probably next week – let me know if you want me to notify you as soon as it gets posted] The RT424 is a 4” thick panel of Owens Corning 703 upholstered with the same RT424B Bass Trap Bag mention in the original post of this thread. The RT424B is a plush fabric “bag” used by studio and home theater owners seeking to build Do-It-Yourself [DIY] broadband absorbers. The RT424 Bass trap is the assembled version of the device you have, in my view, unfairly, and incorrectly disparaged. Please look at the graph below and take note of the following: i) The RT424 is a superior broadband absorber to the MiniTrap. So much so in fact that in order get the two absorption curves to overlay one must amplify the measurements at a 3/2 ratio in favor of the MiniTrap; ii) Eighteen MiniTraps and Twelve RT424’s yield extraordinarily similar measruements all the way across the band. In fact, the curves are so similar when expressed in a 3/2 ratio as shown, that the two devices exhibit almost EXACTLY THE SAME absorption measurements at the majority of data points [MODERATOR'S NOTE: The image was NOT posted in accordance with forum rules. It was linked off-site, rather than being posted directly to the forum. It has now disappeared from the original location: Therefore, the rest of this thread is pretty useless, due to the poster's blatant disregard for forum rules- The reason why the poster chose to link it (instead of posting it), then remove the original from his lined location, I'll leave to your own imagination...] To put this data in a practical context, consider a studio or home theater that requires broadband absorption treatment on scale equivalent to that depicted in the graph above. To meet his needs a user might either: i) buy 12 RT424’s at a cost of about $1,000 [free delivery]; or, buy 18 MiniTraps for $3,400 [plus delivery costs]. If he opts for the RT424, he gets a set of sharp looking professional grade acoustic panels in the color of his choice, gets to skip hanging the extra 6 panels, and saves at least $2,500 [more if he is on the West coast]. On the other hand, if the +/-3 Sabine per panel variance at 10k bothers him, I would suggest he read up on the absorptive qualities of air at 10k hz, get rid of the throw pillows off the couch and send the band out for a haircut and a shave while he counts his money and bids on a German microphone or some such on eBay. edit: smaller graphic - sorry

Interesting to notice are the very old and countless discussions about the effect of a membrane and the traditional high density advices. Yet unclear is what the difference is between the old original MiniTraps measurements showing a much more enhanced resonant membrane behavior and the current ones. The above measurement is a plain OC 703 in a nice fabric bag one can blow through, without whatever real membrane (it probably/possibly still shows some membrane effect, depending on gas flow resistance of the bag). Hence the above graph, if correct, shows 12 standard 4" OC 703 panels in a bag being +/- equal to 18 MiniTraps with double density fiberglass AND special dual-layer damped membrane. Maybe looking at Bob Golds' absorption page is not such a bad idea after all. http://www.johnlsayers.com/phpBB2/viewt ... ght=#45678 Maybe more accurate comparisons come available in the future, but the above, without discussion, questions some typical net axioms. Anyhow it's nice to see that more and more real data comes available on the net substituting stories.

DNorth wrote:

I have been seeing many people talking about gik and realtraps. I have seen people say that the design is much better than just having the panels in a bag. Should I take down the traps I have now and put some better designed traps up? ........ Are realtraps and gik traps that much better? ...... I guess my basic problem is that I have the 4" thick panels with no frame, no membrane. I really don't know what the specific purpose of the panel is. Meaning is it good for broadband absorption, decent at lowend, decent at mids and highs....

DNorth Without minding what brand or choosing the DIY path, just going to the core of things, the above graph, its included measurements and the idea it represents, put such stories in the context they belong. It's a real pity that people take that over, and spread it further as acoustic facts. Even dedicated Magazine reviewers buy and spread these stories (which I find VERY questionable).

A possible scenario: Unlike suggested here in the Forum, until finding info to the contrary, general knowledge of the typical behavior of corner absorption is relative recent in the studio world (and even for lots of labs). Hence a lot of reviewers are confronted for the first time in their live with corner absorption and it's very specific low frequent behavior. Not really knowing corner absorption, they are amazed about the effect related to the strongly improved definition of the low frequencies, based on relative simple solutions. Comparing that with previous flat to the wall applications, often not even or hardly aimed at, or designed for low frequency treatment, they seem to buy whatever special/magic description, rather than relating the reviewed absorbers and related musical experience to the typical acoustic behavior inherent with corner absorption. And they hardly can go wrong since they are covered by others, hence this phenomenon multiplies, certainly when activitated by interested parties.

Just compare measurements if you can find them, and preferably official measurement data if possible. And be very careful to interpret values below 80 Hz, because the inaccuracies can be significant (too extensive here to explain). As one will notice you hardly will ever see the statistical values of these numbers which are automatically calculated by labs.

Scott, > the author of the thread doesn't need to throw away his absorbers and send you and Ethan Weiner a big fat check. I’d also appreciate it if you would consider a retraction of your specious and negative comparison of our products with the Ethan Weiner MiniTrap < Yikes - that's some first post you made there. That you haven't learned how to spell my name after all these years says a lot too. :roll: > I am compelled to present a scientific comparison < Where? What I see are bogus comparisons of product measurements made in different labs. If your aim is to be scientific, I suggest you start by buying the ASTM C423 document where you'll learn about the very large variance among labs, especially at low frequencies. > The RT424 is a superior broadband absorber to the MiniTrap. < Groan. > To meet his needs a user might either: i) buy 12 RT424’s at a cost of about $1,000 [free delivery]; or, buy 18 MiniTraps for $3,400 [plus delivery costs]. < I didn't realize manufacturer spam was allowed in this forum. Scott, this fine forum really isn't the place for such posturing. I invite you to call me any time on the phone and we can have a nice discussion about acoustic products, marketing, scientific testing and comparisons, and especially about appropriate public behavor. Please. I'll be around Saturday early morning and late afternoon, and all day Sunday. Thanks. --Ethan

:wink: When useful: http://www.realtraps.com/art_measure.htm

RealTraps / Ethan Winer wrote:

US labs that perform acoustic tests are certified by NVLAP, a department of the US Government's National Institute of Standards and Technology. Testing of acoustic materials is defined by ASTM, an international organization that establishes standards and practices used by acousticians and their companies. By ensuring that its members follow exactly the same rules and guidelines, materials tested to ASTM standards in different facilities can be compared with confidence.

When annoying:

Ethan Winer wrote:

> I am compelled to present a scientific comparison < Where? What I see are bogus comparisons of product measurements made in different labs.

No more words needed here: The above graph, if correct, is clear, and I expect, as told, will be confirmed by an official lab report, which nobody ever saw from RealTraps. The difference is there, being explicit and present over the whole spectrum range. Calling this bogus is the same as calling 'Official Accredited US Laboratories', ASTM and NVLAB bogus. Maybe the notion stories I emphasized falls more in place here (neither responsibility, nor ethics, nor the interest of, or respect for Forum or Site visitors). Possibly a range of detailed, hardly in context, pseudo-arguments will follow to divert from what this Graph clearly shows.

Scott I have ever said anything bad about your "bags" as far as I can remember. I have pointed out you do not have testing as you did point out about our product before testing, but that is not saying anything bad. Hell I am glad guys like Rod pointed it out. I wish you luck with the company you just bought. Hope we can all get along online and not just bitch at each other. Cheers, Glenn

EW: I corrected the spelling of your last name... I apologize, no slight was intended. The balance of the post is correct and scientifically valid. And it belongs here because a response is appropriate to the false of claims made as to the attriubutes of our products and the Minitrap. As to your desire to bring your emotional needs into the discussion - I have no interest - you will need to work that out some other way. Good Luck!

> The balance of the post is correct and scientifically valid. < Look Scott, I'm not going to get into a pissing contest with you. If you don't understand why your data comparing corner testing in unknown corners in different labs is not valid, you have a long learning curve ahead of you. Likewise, if you really believe you have invented a magical bass trap that surpasses MiniTraps by 50 percent, nothing I say here will educate you. The same goes for Eric pretending he doesn't understand the difference between official ASTM C423 tests and uncertified tests in corners. But please listen to Glenn, because when you bitch and snipe at your competitors' products you come off as immature and jealous. --Ethan

I let Ethan speak (he does it much better than I can, yet it's confusing if one doesn't see the strategy, but I can't help that):

1) Ethan Winer in this thread wrote:

> The balance of the post is correct and scientifically valid. < If you don't understand why your data comparing corner testing in unknown corners in different labs is not valid, you have a long learning curve ahead of you.

2) http://www.realtraps.com/data.htm - Ethan Winer wrote:

Both data formats are shown so you can easily compare MiniTraps to other products not listed here, regardless of how their performance is stated.

Both data formats refer to the 'sabins' and 'absorption coefficients' tables, method which BTW is NOT allowed by the ASTM standard and relates to the locked "edge effect" threads (having more depth than realized here). To prevent confusion: quote 2) is valid for everything inferior, and quote 1) for everything superior. Truth and physics should have some flexibility. I didn't knew I pretended whatever in this thread, just analyzed. (even don't understand the context of that sentence ..., but please don't explain ....)

From Ready Acoustics site:

What is a BASS TRAP? Why haven't I heard of a Bass Trap or High Frequency Panel and what is the difference between the two? A BASS trap is simply a device designed to absorb low frequency sound and enhance your overall sound experience. Ready Traps use mineral fiber to capture sound waves. The core of a Ready Trap is a panel of compressed fiberglass that is made of inert fibers [glass - which is of course made of sand]. These panels are an assembly of such fibers formed into a dense mat. The panel is riddled throughout with many little gaps and holes [interstices]. The air that fills these little gaps and holes has a vibrational connection to the air in the room - but this connection is attenuated by the matrix of fibers that makes up the panel. When a sound hits the Ready Trap, the air inside the panel is caused to vibrate - like a spring - and all this wiggling around turns the vibrational energy of the sound into a small amount of heat. If the panel is of proper size and density - and properly placed in your room - it will absorb sound at all frequencies. This is called a broadband absorber because it is effective on all frequencies in the audible range. Broadband absorbers such as the RT424 are called BASS Traps because they are big enough [4" thick] and made of a material of proper density and structure such that if mounted near a room boundary [a wall, floor, or ceiling] they will provide absorption of low frequencies [bass]. Thinner panels such as the RT422 at 2" thick are not thick enough to have a significant effect at lower frequencies. Thus these are called High Frequency Panels because their absorptive properties are limited to higher frequencies. Use of the 4" RT424 Ready Trap is appropriate when you want to include low frequencies in the sound absorbed by the device - and the 2" RT422 panel is for when you don't want to capture low frequencies. Many rooms and applications will benefit from the exclusive use of the thicker RT424 panel for all of the treatment locations, but there are special cases where the 2" RT422 are all that is desired. Some of those places may involve voice over booths, voice only studios or places where light acoustic instrumentation is being played or recorded.

That's the most ridiculous description of a bass trap I've ever read. I'll sell you a cloth bag, 4 x plastic corners and two sheets of cardboard that will wrapup a sheet of 703 or rcokwool or what ever you have and we'll call it a bass trap!! This is a bass trap: You will notice that the corners where the ceiling and walls meet are in fact ports where the bass buildup in the corners can escape into the cavity above the timber ceiling where acoustic hangers trap and absorb the bass frequencies. That is a bass trap. A sheet of 703 placed across a corner of a room is NOT a bass trap IMO. It's just standard utilisation of the corner effect of a sheet of 703. Suggesting that adding a fancy bag around it makes it a bass trap is really stretching the concept of a bass trap IMHO. - it's just a sheet of 703 wrapped in a bag. cheers john

Hi John: What does a bass trap do?

Scott R. Foster wrote:

Hi John: What does a bass trap do?

it absorbs the low frequencies at the high SPLs typically generated in a control room.

John: I know you design and build some pretty spiffy stuff, but I think you are getting a bit over the top to claim title to a well known and long used generic word for absorption systems that work on low frequencies. Are you are suggesting a mineral fiber panel wrapped in fabric and mounted in a corner will not serve precisely the function you use to define what a bass trap is? If so, I beg to differ. What about a mineral fiber panel in a steel frame, or an acoustic foam wedge, or a tuned and ported vessel with a mineral fiber lining of a dimension such that it is tuned to a bass note? Aren't all these contructs also "bass traps"? Or, does a "bass trap" in your semantic universe require a "fancy" bit of timber hung on a string in a secret chamber above the ceiling to merit the noble title? :lol: [just teasin' ya]

Somehow I thought that's what you'd say Scott :D. look, maybe I'm old fashioned but to me for a product to be called a bass trap I should be able to stick it on the wall and it absorb bass, not in the corner specifically. A straight panel absorber will absorb bass, but it's called a panel absorber, not a trap and it's design goes back over 50 years.. The term Bass Trap originated with the dead studio construction of the 70s and it referred to a hanging trap system as invented and utilised by Tom Hidley of Eastlake Audio where he was trying to contain the extreme SPLs reached by the 70s rock bands where existing acoustic treatment of the time, aka BBC, couldn't cut it. the broadband effect of these traps gives you low end response and reverb times like these pics below If you compare your absorption peaks to these results you will plainly see the difference between a Bass Trap and a piece of 703 hanging across a corner. cheers john

John, Can you show me comparable threads where you responded comparable against the use of the word "Bass Trap". Checking Google for "Bass Trap" gives me 75,500 hits. I haven't checked them, but I assume only extremely tiny fraction will relate to Tom Hidley and the hanger principle. A wild non-checked guess: <= 0.5%? The notions "Bass Trap" and "bass trapping" has became a generic notion for trapping/absorbing bass. A Google check about Panel Traps also delivers numerous hits (couldn't split them to correct number of hits since it seems to be used for other things too). Is this all about semantics?

John Sayers wrote:

A straight panel absorber will absorb bass, but it's called a panel absorber

Definition used by the Arizona State University http://www.asu.edu :

http://www.asu.edu/hc/electrics/Sound_Terms/sound_terms.html wrote:

diaphragmatic absorber: A flexible panel mounted over an air space that resonates at a frequency (or frequencies) determined by the stiffness of the panel and the size of the air space. Also called bass trap.

You certainly can point to numerous comparable messages of you, where you disputed the same with Ethan where Real Traps covers the whole company under the name Traps. And his DIY Panel absorbers are referred to as Panel Traps as well. But I'm really glad you point to this resonant peak in the absorption as indeed one of the strange things related to corner absorption. That problem or question mark, I discuss alread for 5 years on the net. But you know yourself VERY well, that you can not relate ANYTHING from your room entered response measurements with this absorption behavior of that device. The peaks and dips in RT and Room response (which is the result of a complete room, not one single device of series of) point to much larger anomalies than the difference in absorption shown by those measurements. In a strict diffuse field a difference of - 3 dB should point to a difference in + 100% absorption (a doubling). The anomalies in your room response are larger. And this piek does not increase absorption with 100%, far from. I know this comparison is nonsense, but so do you. What I see happening here is that you attack a company on semantics, which delivers a "most to core stripped" piece of acoustic device, giving honest information about the content of the device, meaning that DIYers can compare such a DIY solution with others. The original post in this very thread starts here with a guy wondering:

"do I have to replace my simple devices by special designed ones, which people say are much better".

The company who delivered those DIY bags, proves with measurements that this DIY solution is FAR from inferior versus the "SPECIAL DESIGNED TRAPS". Shouldn't it be nice that the Forum should welcome such information, whether people buy from that company or not? That company delivers that bag on its own for a low price for semi-DIY purposes, but you even don't need to buy it, and use the info as a 100% DIY solution. NO magic involved, with references to vague mysterious membranes and expensive high densities. But I repeat, I'm glad you noticed and discussed that resonant absorption peak, which is typical for the principle. I possibly will quote you on that in the future.

Eric - I said - maybe I'm old fashioned. I was just pointing out what I mean by the term Bass Trap - you are welcome to use the term any way you like. I checked the Arizona University chart and they do say a diaphragmatic absorber is a bass trap. Mind you, I clicked on the other links and they don't say much else - it's the only page in their sound area which appears to be part of a lighting project of some kind - I wonder where they copied that list from. So what we have here is a diaphragmatic absorber is a bass trap, a construction like I refered to is a bass trap and a piece of 703 across a corner is a bass trap. Doesn't appear very scientific to me, but hey - you are the scientist.

"do I have to replace my simple devices by special designed ones, which people say are much better". The company who delivered those DIY bags, proves with measurements that this DIY solution is FAR from inferior versus the "SPECIAL DESIGNED TRAPS".

I suppose it's what you call special design traps. I showed what I call a special design trap and I believe it's superior to the DIY version. If you believe you can get a room reverb response like I showed, note the top end verbtime compared to the low end, with DIY cloth bag Traps - go for it. cheers john

John, I don't discuss whether the use of the word Bass Traps is right or wrong, My related document uploaded here by you shows, that I called those things "diagonal absorption" when I measured them. Is that the correct term? I've no idea. It was just a logical term for me to distinguish the principle from my other measurements. For me, even "corner absorption" wasn't that evident, since I measured also flat applications in corners, also showing a specific behavior. But now people seem to understand "corner absorption" almost automatically as this "diagonal absorption" (... straddling the corners). It's the studio world itself who uses the name "Bass Traps" for anything specifically used to trap or absorb bass. Hence they link it more functionally. Here (locally in my surroundings) I still refer to "diagonal absorption" and also "corner absorption" (term I also use on the net), since all my old data and docs are using these notions. On the net I also use bass traps, not because the notion should be right or wrong, but because the studio world itself made it a generic term (including here at the Forum), which Google proves beyond any doubt. I don't refer to SPECIAL DESIGNS with all the magic involved, people do, triggered by commercial interests pushing that through. My use of the notion here is derived from the related uncertainties expressed by the original poster. But you knew exactly in which context I used all this. I humbly admire real developments and designs as the one you showed, but I can't accept your close to systematic degeneration of corner absorption as the logical path to go, known by anyone for ages, knowing the surprise of labs when they see their first related measurements and how Dr. Peter D'Antonio and Prof. Dr. Trevor Cox referred to corner behavior and absorption in the most recent and most extensive $ 175 book designated to diffusion and absorption and related devices (Acoustic Diffusers and Absorbers; Theory, Design and Application - 2004). I also remember my related discussions with a Prof. specialized in Room and Building acoustics, where an acoustic lab assistant (all graduated academics) was involved trying to find mathematical relations to explain this behavior. BTW: Also RPG managed by Dr. Peter D'Antonio uses the notion Bass Trap for several types of devices, none related to Hidley and hangers. And to be honest, if these measurements entered by Ready Acoustics are confirmed by an official report, then it proves that the "ALSO SO LOGICAL" higher density advised anywhere as an axiom is wrong or at least EXTREMELY questionable. And that advice has cost MANY people lots of money already. I'm not comparing commercial products here, just the principle. Because I gladly admit that GIK delivers commercial products with very high density on very interesting prices, compared to other products. I fought and/or questioned this axiom for years also, but it gives me the bad name, since I'm not a populist. But I also know that there are people who do read, analyze and see.

I hope I will not help start any flame wars here... But this is as good a place as any to ask this question, since Ethan, Glenn, John and Scott are all here... :) I'm looking for some acoustic treatment for a home studio, but it has to be very portable, so any kind of acoustic pannels make sense... There is a big difference in price betwen the RealTraps, GIK and ReadyTraps... Let's just say i'm a buyer and want to know the difference betwen them... As I'm shure, any potential buyer of absorbers... With my very limited knowladge in acoustics, as far as I understand, The main difference is that ReadyTraps don't have a membrane. So they absorb higher freqs and could make a room more dead sounding. Am I correct? I don't think any of the panels are tuned (or they wouldn't be universally "fitting" to all the rooms)(I could be wrong... please correct me if I am...) I'm not after any business secrets here, but what do you think makes your product outstanding? If you would just say it in words and not use graphs, since one of the three manufacturers clearly disagrees with the other two when it comes to testing...

Soulfood Reasonable question, but I'll stay out of it. I will in the future compare those thing on a site, where I will compare them analytically. Too much personal things are involved here. But you'll get your answer here. Hope you can figure it out.

John: OMG Semantic Debate - I Surrender! FWIW I'll grant you the right to hold strong beliefs on semantics in this venue - you certainly have earned the juice to have firm opinions on the correct jargon for the field. Also FWIW, I have no aspiration in that regard. You can be in charge of the naming of names as far as I am concerned - to the extent any choices arise. To that end, IMO, you need to find a different target for fighting the good fight to get the "right" name into common usage. This horse done left the barn. I would [if I thought it mattered] respectfully disagree with the notion that constructs which are not explicitly designed to use the tuned resonance of a wooden panel to absorb LF shouldn't be called bass traps - as that strikes me as counter intuitive to the simple meaning of the words "bass" and "trap"and the idea that devices that grab bass and don't let it go fit the bill. But let's face it - it doesn't matter - history and the vox populi have obviously surpassed your view point. Dirty as it may be, the deed is done. The term "bass trap" covers a broad range in common usage no matter what you or I think. Thus, IMO, to be well understood by a broad audience you need to use a more specific term for that which you hold to be a "real" bass trap - otherwise I fear others are going to assume a larger set of items than you wish to describe. You have lots of interesting things to say on the topic.. it'd be a shame if so many misunderstood you. My $0.02

My over-simplified view on this discussion: the term "bass trap" should almost be abolished, because it's been bandied about to the point that it means NOTHING any more. Similar to the term "vehicle" when referring to transportation - if you need to move large quantities or weights of material, a VW Jetta isn't your "vehicle" - but a van or semi-truck might be. Likewise, if you want to get there fast (and the roads are good) then forget the van, go for a Lamborghini or Porsche or similar. To my mind, "bass trap" SHOULD mean "only traps BASS", not "traps everything". True, a BROADBAND trap such as a corner absorber, or even 4" MW spaced off a wall, will ALSO trap bass; but it will, in the process, further lower the RT in OTHER frequency bands; this may or may NOT be a good thing. You can build a "low mid trap" using either helmholtz or resonant panel methods, and including enough absorbent inside to broaden the response, or you can build a "surgical" trap by leaving out most or all the inner absorbent (careful about adding resonances BACK to the room though) - this might be necessary if you've NOT been careful about room ratios, etc - when you end up with more than one mode contributing to an excess of one specific frequency needing to be reduced. This is not for the faint of heart, since it would require knowing WHERE to put the trap as well as how to build, tune, etc. I think we need to address the (mostly ignored) concept of EVEN reverb times more than we do; it seems to me that most posters on these forums either "get there" ACCIDENTALLY, or not at all. And a room with wildly differing reverb times at different frequencies is NOT a room you want to listen to music in; it's ESPECIALLY not one you should MAKE or RECORD music in. In one of Newell's books (probably more than one) he stresses the point that an unbalanced room isn't a place to make multi-track recordings, because every track you add to the mix from such a room, ALSO adds that IMBALANCE and after a few such tracks you can't even BEGIN to "fix it in the mix" - to me that's a powerful argument for choosing proper dimensions in the first place, and then treating any "leftovers" once the room's built and tested, so you have a NEUTRAL environment to record in/mix in. Speaking of which, we also don't (usually) stress the differing RT requirements between CR and recording spaces; I know that smaller rooms (including a lot of CR's) can't officially HAVE a real RT60, but a CR should still be deader than almost all recording spaces or you'll think you have enough reverb in the mix when it's really your listening space talking... As a "responsibility" thing, I'd like to see more reference to BROADBAND trap/absorption when talking about non-resonant traps; it just seems more honest and USEFUL when trying for a balanced RT environment. I think we've ALL been guilty of too much "genericism" here, so that most people who are just "discovering" acoustics call any and ALL acoustic treatments a "bass trap". My idea of a SIMPLE but USEFUL method of constructing usable recording space (at least partially due to Eric's help in slightly understanding multi-leaf problems) is to 1 - figure out how loud YOU are, and how loud your outside ENVIRONMENT is, and build your containment to be at least a few dB BETTER than you ever think you'll need, at ALL frequencies. This ain't usually cheap, or even possible, but it's the GOAL. One main reason for building BETTER than you think you need, is that virtually ANY acoustic treatment you add inside will WEAKEN the containment due to multi-leaf problems; in a way, even broadband absorption can do this because you will often play LOUDER when the room's more balanced, so more gets OUT. 1a - don't build squares, or :shock: cubes - and whether you build a full RFZ environment for Stereo mixes or a more absorbed surround CR, at least splay walls/ceilings enough so that you don't have to use inordinate amounts of broadband absorption just to tame flutter - just because you can't HEAR flutter when you clap in a room, doesn't mean it's GONE - it just means that the components are likely too FAST for your ear to discern between your CLAP and the flutter. Your multi-track recordings, however, WILL add these artifacts and they WILL color your mix. Choose average dimensions that give as balanced modal responses as possible; not everyone believes in Bonello but I think it's a good start. Messr's Bolt, Sepmeyer, etc, were pioneers but they didn't have computers; I believe there are far more "golden" room ratios than the ones they calculated. In fact, if you use Jeff Szymanski's VERY helpful sheet ModesV2, found in the file section at Studiotips, you can find more balanced combinations of dimensions than some of the well-known (1:1.6:2.33, for example) ratios. Point being, you do NOT want to choose BAD ratios, whether you go with Bolt, Sepmeyer, Louden, Bonello, or whatever. I equate the above with its electronic counterpart - "The best way to get rid of noise, is to not generate it in the first place" - acoustically, this might translate to "the best way to treat a room, is to size it so it doesn't NEED (as much) treatment"... Once the room is built (hopefully with enough foresight to make it a bit larger than you think you'll need), it's time for testing; if you've done enough homework in the earlier stages, your main treatment needs might be limited to balancing out the reverb times - and this brings me right back to my objection to the GENERIC term, "bass trap". If we continue to call everything that ALSO traps bass, instead of ONLY traps bass, a "bass trap", we do any who ask for advice a DIS-SERVICE. Let's say that we have this room, and it's down to only needing a bit of low end at one or two specific frequencies, reduced by a few dB; the top end is already "dull" enough, the mids are at the same/close RT, and we then add 3 or 4 fully absorptive "bass" traps; now, we just helped the bottom (probably) but now the mids and highs are too dead. If we aren't aware that this (actually BROADBAND) "bass" trap is really absorbing a MUCH WIDER band than we were led to believe, we (meaning the person I referred to earlier, new to acoustics) will probably sit there wondering what happened to our sound, and why "that idiot" told me his products would SOLVE my problems when they really just CHANGED my problems... At this point, I doubt seriously whether my ramblings could be compared to a logical thought process but I wanted to voice my concerns - I absolutely HATE reading posts from people who've taken the advice on these forums only to be frustrated and unhappy with the results, and I think this "genericism" in terms is largely responsible for that. Now I gotta go fix the brakes on my van (wife needed the car for some "hippie fair" and I work nights tonight) - there are times when I wish I didn't know shit about anything other than our favorite subject, so I wouldn't even be TEMPTED to do all this other crap; still, I guess it's better to be somewhat versatile in life. (maybe :? ) Just a "reality" check from one who prefers to keep his $.02 SIMPLE... Steve