Room Treatment or Speakers? - Page 2

lol, do you have a different language (serious question)?

I posted its crap to deal with and you reply something about calling it crap. Im talking about touching it.....This is common though, you still think I posted < 100Hz somewhere.

Anyways, the OP can choose. I hope you have something more then theory to offer him including some silly link that reads like a lecture with zero application examples. The world does not need another theory, it needs low cost solutions that are blunt and obvious so that people do not need to spend 100 hours figuring it out.

I would choose to follow the guys that have nice custom HT rooms myself but who knows

Gentlemen, gentlemen, gentlemen. *sigh*

I agree with the call for data, and I think the expectations of the device need to be more clear to decide which is "better". I've seen it said before that "Whealy is your friend." I'm not reading the bickering just to determine what you guys are trying to compare; if you want a comparison with a different 703 configuration, let me know. Or give Whealy a spin yourselves - or even the online porous absorber calculator.

OC703 12 inches thick:
Attachment 220984

OC fluffy 12 inches thick:
Attachment 220985

Looks to me like an oc703 'chunk absorbs more at ~30 Hz, but a fluffy 'chunk absorbs more at ~100Hz. Note that I used 45 degree incidence as you'll see for modes with a typical superchunk. Also, note that the calculator doesn't model the resonant effect seen in the studiotips tests for the 703 version, and probably wouldn't happen if you use unfaced fluffy. Solution: use a batt with facing on the outside when building the fluffy version; now these graphs are probably close enough to straight comparisons.

You may perform your own price/performance calculation based on the costs at which you can procure the materials in your own area.

My corner absorbers are ~15-inch cubes composed of nested "corner bass absorbers" from The Foam Factory with a faced fluffy R-13 batt on the outside (and some aesthetic stuff). I posit they should work essentially the same as the same device with solid fluffy. Thumping produces a _very_ low and well-damped note. I can present some before-and-after waterfalls tomorrow if OP is interested.

For the record, my opinion for most anyone (including OP) is if you have a working HT that is better than an HTIB, you should then do acoustical treatment before upgrading equipment. Since I'm cheap, I prefer to learn how to do acoustical measurements (to verify operation of the treatment and double check my perception) and build all treatments myself - and actual monetary outlay in that scenario (including the measuring gear) is almost certain to be well under $2000. Of course it is a large time investment. If I thought the time was too much and didn't think I had the cash to get a known acoustics guy in, I'd get a (free) recommendation from GIK, then buy at least some of my panels and/or supplies there to reward them for their trouble even if I chose to DIY much of it. If, as someone mentioned, one has absolutely no desire to learn about acoustics (and a medium-size budget), I'd bet if you went to GIK with a clear set of goals, a good layout of the room, and a budget of $2k those guys could sell you everything you need to be 80% of the way there without you doing more than reading off a few numbers from a piece of plastic and you'd be done inside of a week.


And now, I've gotta jet. Going to hit the D for those packs of fluffy to try in my room's closet.

Behind the seating meaning rear wall. Not much you can do with the middle of the front wall if you're going to mount the screen directly onto the concrete.
Sounds expensive. Is there a local air conditioning contractor that is willing to sell you some rigid fiberglass material?

These kinds of inquiries almost always go in the toilet when the discussion turns into a lecture. Sanjay (sdurani) gave you some straightforward advice without the idiot savant quasi-scientific mumbo jumbo. He and penngray gave you some simple placement advice, which I'd recommend you try first to see if it helps (but see below).

Since it seems you're currently pleased with your bass, then I'd just get some pre-made 2" thick 2'x4' panels (703, mineral wool, whatever) and experiment with the placement suggestions they gave you. However, the net effect will be to absorb mid and high frequencies, so if you're already thinking they're dull and compressed, you won't want to overdo it. Finding the right spots might clean the MF and HF up, though, so experiment.

I'll repeat here what I write everywhere: Good speakers come first, good placement comes second, and good room treatments come third. My instinct is to answer your original question this way: start with speakers that sound better to you than the ones you've got.

Get some professional help......seriously, if you don't spend the time to really understand this you could (read 'will') do more damage than good

Yes 2K would get you pretty far with us. He can use the following form to give us just about all the info we would need.
http://www.gikacoustics.com/room_setup.php

FWIW, I think the discussion around controlling < 200Hz is not part of this thread at all. I posted already that to handle Low Frequencies properly requires multiple subwoofers around the room including flanking subs that run up to 200Hz.

My posts are mostly about controlling 200Hz to 20KHz. The OP can DIY for under $500 or buy from a site like GIK for $70 each panel (not all that bad of a price).

I say buy....

6 GIK 244 Bass Traps (Thats 3 boxes @ $140 per box)
6 GIK 242 Acoustic Panels (Thats 2 boxes @ $180 per box)

He can DIY buying wraps for $300 and OC703 for $200 but he still has to put it all together and he wont have GIK offering solid advice...Like others posted just email them. Maybe just a PM to myfipie who posted above this post!


To the OP sorry for the tech stuff. I was worried about that and why I posted I was done discussing it.

All you need to know is that the speaker generates sound 360 degrees and that it does not create a very nice soundwave at 90 deg or 180deg. Control those first and you can worry about other room issues later if you want.

No real harm just could waste $$$ and not have the right placement but if he covers the wall behind the speakers and beside the speakers (along with reflection points wrt listening position) he will have a great start.

Honestly, Its really, really hard to screw that up.

How about putting too much absorption at the reflection points and closing down the soundstage? I;d say that'd pretty easy to do and a monumental screw up.

The OP doesn't even know what he wants to achieve

If he listens to it before putting up (too many) treatments and he doesn't like the result after putting them up, then he can take some down. It's a simple process. Experimenting is not screwing up, it's investigating process, application, and result. Don't like the result; don't do that!

Sanjay and penngray already have given simple starting points that any enthusiast can follow. Based on both their experience and understanding of the science behind it, they're helping to shave off unnecessary messing about. They're also avoiding a bombardment of irrelevant data for the first-time, casual experimenter who wants some simple improvement.

OR the OP can take my advice and start with speakers that sound more like he wants. That's a simple preference-based choice, too. (Notice I didn't write "cheap." I'm not confused about the difference.)

i don't understand?
who are you to say at what level of information a particular individual may find irrelevant regarding the introduction to a particular topic?

i for one think it may be wise for any user purchasing absorbers made from porous material to at least take a simple few moments to understand how porous absorbs sonic energy and as such, where it needs to be placed in order to be most effective for a particular issue. why is that met with such resistance on an "audio theory" sub-forum?

People who spend too much time reading opinion, trying to read all the books in the world really know squat about what they will really want if they have zero experience. They need to start doing and figuring it all out. Experience is the only way to really know, listening education is a must in the world audio.

The only way to know what you really want is to starting putting up the basic treatments. There isn't a quality room out there that does not start with the basics some of us have posted. You can not screw up the soundstage period, it does not matter if the first reflection point has 1", 2", 4",6" at since all frequencies above 500Hz reflecting off that panel are absorbed with any of those choices. There is no case of "too thick" other then wasting $$$ on building thicker panels. Remember the suggestions didnt say "fill the room with 2" panels"...back wall and all other points on the side wall are still empty.

Of course if soundstage is the discussion then we should get into proper speaker design choices with better directivity control (neither of his speaker choices are really in that realm either) but again that is another topic.

FWIW, I have 1" OC703 100% on my walls and I have an incredible soundstage but I believe in directivity and I spend a lot more $$$.

My suggestion is worlds of improvement just as a start. There is very, very, very low probability of a downside, 1000+ DIY room builds found online prove that to be a very, very good bet. Now one is asking him to treat more then 1/3 of his room anyways so there is no way it will become a dead room.

oh.....I love your build thread, love the details!!!! I didnt get all the way through it but you seem to also have the "standard" type treatments??

Fair enough penngray. I might humbly suggest you have an ear that is more attuned to that of a sound engineer or professional musician and find certain first reflections distracting - most hacks, myself probably included, would find enjoyment in the ambience from first reflections (assuming good off axis response)

Thanks for the comments re my thread....its a bit of a mess at present, but a good resource I feel. That room hasn't been finished unfortunately due to $$ issues. Nevertheless my previous room had absorbers scattered around the first reflections and when I took them down to move I actually preferred the sound...just my personal preference

My DIY preference is to build a second shell of insulation covered in pegboard and a riser for bass trapping (this is what I'd pay Dennis to tell me how to do). Absorb the entire front wall, middle of the back (as per Toole) and add BADs et al at first reflections (per Erskine). You're pretty much guaranteed of not screwing that up, unless your speakers and positioning and eq of subs is completely screwed

P.S. I love your dedication to DIY, I have admired many of your projects whilst I've been on AVS. It was a comment you'd made somewhere that lead me to my current "diy" sub - in my case "design it yourself" (I had someone make it for me). Its totally awesome and I think I'll struggle to buy an off the shelf sub ever again.

Thanks, Interesting comments about taking them down but honestly not uncommon.

Everyone spend years and years listening to audio a certain way then we expect to just love any change towards more accuracy. I see this in many discussions.

1. People love peaky subs. EQing them properly flat and people complain about the sound. Offer them a pro audio style sub that peaks 20+ dB from its F3 point and wow people go crazy thinking it has the most output then they tell you that your room gain will make up for it I remember my first DIY creation (IB array). I wonder where was that boomy bass gone.

2. Remember back when we all had EQs and the most popular setting was a "V" shape?? Now we have audyssey and its flat.....yuck, where is our bass!!!

3. Even I like my own "house" curve so even after Audyssey has done its thing I tweak my setup to what I like since I have 100% control over 10Hz to 20KHz using DSPs.

I actually think one of the hardest things to do in this hobby is to train ourselves on what is a truely accurate setup (incl. room). We have very little experience/time/training for our brains to accept what is truely accurate. Our brains will revert back to what is the most familar sound. I can correlate this to sports. Think of a baseball or golf swing or football throw. Ask anyone how its almost impossible to change any of them if you have spent years doing it one way (possible the wrong way). You might be able to create the proper throw/swing most times but when things get crazy/fatigue sets in you will revert back. That is how amazing/annoying our brains are.

specular reflections are attenuated with respect to gain (eg, down -XdB from original signal) - a specular reflection is not broken down in terms of frequency.


broadband porous absorbers (such as rigid fiberglass) have reflection coefficients - especially at high angles of incidence (grazing angles).

if a user is using broadband porous absorption, then they need to determine to what level they wish to attenuate a particular early reflection. thickness, material, air-gap, etc are all variables which are taken into account when determining the solution. angle of incidence plays a key role in absorption coefficient (and reflection coefficient).

if a user believes 1" of OC703 is an effective absorber of a specular reflection, one can always verify with the ETC response to see just how effective their absorber really is - instead of relying on guesswork.

These are very good points.

For whatever reason, if one determines the proper action is to address reflected energy with attenuation, simply placing the treatment and moving forward is only half the story. As you noted, the grazing angles and actual efficacy of the treatment is of paramount importance. I've been experimenting extensively with ASW, lateral mirror points, ceiling attenuation, and actually "catching" the energy physically, and containing the critical MF/HF energy,..and subsequently attenuating it to an acceptable level. This is the point, I'm not entering in the debate of whether the theory of attenuating lateral mirror point energy is correct or not. My contention is if one proceeds down the attenuation path,...execute it properly. Angle of incidence, the actual material covering/encapsulating the absorption panel, mounting methods (i.e. wood backing etc.), boundary spacing, all have significant impact on the effectiveness of the panels attenuation properties.

Although I've competently taken notes, I don't have any documented data that I can share. I merely possess subjective anecdotal interpretation of my experiments and extended listening. This isn't some isolated listening sessions, or weekend experiment,...I've been experimenting extensively for months. It's been humbling, enlightening, and quite fun as well. My wife and kids have been phenomenally patient, as this non-dedicated HT space is our daily driver if you will. Everything from the local news, Sponge Bob, to The Pacific(stellar btw), and full tilt 120db playback of hi rez audio

My goal is to preserve "adequate" spaciousness/envelopment, without entirely adulterating what the engineering team intended.

If I were building a room today, I have no idea what I'd do but one approach would be (after ample bass trapping) having some type of listening height ledger-board, around the perimeter of the room. Perhaps having an adjacent storage space containing various hangable panels to absorb, poly/cyl reflect, diffuse, every potentiality acousticly,... combined with easily hang on the wall and move around to wherever needed type style. Myself (w/OCD), I could never commit to a particular style of acoustic design




Thanks and good luck

solid commentary as always, FOH !


there in lies one particular logic conflict -

it seemssometimes that a user's first and foremost priority regarding their room ( and their participation within a particular thread) is entirely focused on the frequency domain. as if a flat frequency response is a holy grail of 'end state'.

how do we communication that, "by nature", first-order reflections of specular energy are the very source of constructive and destructive interference of which many users go to great lengths (regarding hardware or software "solutions") seek to solve?

if i were to request my room have a particular specular response - inducing 'early reflections' ... how do you suggest i cure specular frequency response issues that are a direct result of first-order reflections in summation with the original response?

i have yet to see a clear dictation or recommendation regarding that very specific request.

regardless of "approach" - there is one static ... and that is that you are likely confined to a being within a "small acoustical space". sound will behave with regards to a 'particular' fashion - and as such, you have very particular constraints of which to design around. ya

http://seanolive.blogspot.com/2009/0...reference.html

Seen this?

Its not a conflict, its purely a choice.

If you want accuracy you have to remove all inaccurate off axis response curves a speaker creates. If the tweeter is not in an horn or a waveguide it generates inaccurate off axis response. Its as simple as that, there are thousands of measurements for you to look at if you want too. If you really cared about all this theory then you should have measurement equipment, if you have that then you can measure your speakers 90deg and 180Deg response. You can compared them against the 0 deg response (on axis response) to see how much they differ.

The first goal is to remove the nasty response curves that exist because of flawed speaker designs.

Think of it this way, what do you think the measured response of a paino is at all angles? Take a measurement of a paino at any angle. Now compared that vs that piano playing on your speaker.

You can easily see how the speaker can not recreate the real response of the paino. You can see where the speaker breakdown. Those off axis where the response breaks down the most need to completely absorbed in room so that they never even get a chance to have a first reflection.

Again, this is all a choice, this is about controlling the response in room and its a choice of having accurate playback.

The difference here is that you think the reflection of 90deg or 180deg speaker response curves is okay and I do not. I want them controlled so that they are removed from the end result. People have to start somewhere and throughout this debate you have never once posted a real life solution for the OP. Theory is fine but with out real solutions posted theory is kind of useless for those looking for answers instead of write a paper on acoustics. I have posted viable solutions backed by 100s of threads with measurements. Is the solution I posted a perfect solution?? Never posted that I said its a start only. There is much more to creating a perfect room but is this the thread for that discussion?? Nope!

why do i care? the only thing i care about is the boundary that incident off-axis energy reflects off of, and to what gain (in dB) that reflection is - and to what gain (-dB) i wish to attenuate that signal to.

i shouldn't need to measure polar response for my speakers - that should come with the brochure. and even then, i only care about geometric reflection points that induce specular energy to the listening position. the actual boundaries (reflection points) are the primary concern here. polar response really doesn't dictate anything for me. the only measurement i care about (within this context) is the ETC such that an early specular reflection's gain is measured --- and then remeasured once treatments have been put in place to very the reflection has been attenuated.

it's that simple.



they most certainly do not need to be "completely absorbed". attenuated, yes...but absorption is not the preferred method to attenuate early reflections - as stated many many times.


what tool do you use to measure the 'response' you are discussing? i hope it is not with respect to the frequency domain?

what tool do you use to measure that you have properly attenuated (absorbed) your early reflections?


you mind quoting me where i insist such? or have you resorted to fabricating claims...


did you miss the 3rd post of this thread?



could you maybe quote my specific theory that you in fact have concerns with?


then quote me where i insist anything of the sort.

line by line debating is bad form, I really wish you would realize it. There is no reason to have more then a couple of quotes in any post 7 quotes is simply a sign that someone just likes to argue which Im not remotely interested in going back and forth on every word (overall 30+ quotes in two page....very detailed in arguing) Next you will be debating what the word "absorption" means or something similar.

Anyways, I have concluded that you are not very familar with how speakers create a response and you have never experimented with treatments including never have done a measurement with/without treatments so the discussion really can not go anywhere until you have real life experience. As much as you tell the OP (or even some of us) to go read more I would recommend getting some real life experimentation under your belt. Your post #3 was as about as far from a real life helping solution as possible too, you think anyone understood what to do after reading it??

Many of us already have real life results with PROPER measurements to back up those results. To question if I know how to measures is absolutely foolish too considering how much I do in terms of measurements, speaker design, etc.

Im definitely okay with us disagreeing on how to treat a room although I think the end result is even you putting up similar panels like we do, if you end up doing almost exactly what we recommend then why all the debate....hmmm.

just so we're on the same page, what specific tool or measurement should i be using when testing the effectiveness of my broadband porous absorbers for attenuating early reflections?


asking someone if they know what their final destination is before giving them directions is not 'disagreeing' with you...

Yes

Yes

Yes

Yes

Yes

Someone's on my ignore list so I can't read the original post; nonetheless, my "experience" tells me you're spot on. (Thanks for not quoting BTW.)

Truth be told, I've not taken any measurements on the subject of line-by-line debating; I just got tired of the lectura gravis tone of the incessant braying of Balaam's ass, so it was simply personal preference rather than science that made the decision for me. (If you get that Gunsmoke reference you're as old as I am.)

lmao

I watched it as a young kid

I bet you have a better ear then you think. Listen to the following video of before and after treatment and I am sure you would agree you can hear a huge improvement in quality. The audio before and after starts about 3:30 into the video.
http://www.gikacoustics.com/treated_video.html

I have really no idea what that means. Please clarify.

The OP asked for SIMPLE and LOW COST treatment suggestions. He later posted that all this discussion is just too confusing for him (which I agree with him). You still think many like the OP need to complete a first year acoustical training course to treat their rooms. The OP like 99% of the population do not have the time or the passion to learn about acoustics they would rather trust someone with experience to tell them....

1. Buy 6 2'x4' 4" panels" and place them behind and beside the speakers

2. Buy 4 2'x4' 2" or 1" panels and place them on the side wall around the first reflection points".

They can decide if that will work in their room, they can put them on the wall, listen and or measure. Then take them down listen and measure. They will know the differences and there is a very, very, very high probability that they will love the difference it makes. Because there is a long, long, long list of success stories.

Heck almost every acoustical site has a picture of some room with treatments EXACTLY like we have explained.

GIK rep just posts a video showing pretty much what we have recommended too. Feel free to tell him that room is just "Guessing" at the refections like you have been posting/telling me.

I really believe you do not understand the audience. The audience is trying to buy a battery at Walmart and you are trying to teach him about cold fusion. Take a step back and realize the goals of the thread.

Precisely why (after some reflection) I privately provided a referral to a well known, trustworthy, knowledgeable acoustics pro located more in his part of the world. Not only does OP not want to learn acoustics (imagine, someone who just wants to enjoy the movie/music), I'd bet that none of us have a clue what hardware or acoustical devices are readily available and cost-effective in his part of the world. I know I don't.

I just hope that, through the melee, I hear back somehow on how well it all works out for him.

yes, and i gave a solution for a cheaper and more effective porous bass trap than what you offered. you ignored it.

again, thank you for taking this to polar extremes. taking 20minutes or a few hours to gather an understanding of basic problems (fundamental issues) in small room acoustics before spending money blindly on 'treatments' is not the same as a "complete a first year of acoustical training". you exaggerate to make some sort of point. my preference is not to blindly offer solutions to buy if the user doesn't even know what issues those solutions are there to solve. if the user doesn't want to take a few moments to read why they are applying treatments, then they can ignore the text and blindly whip out their credit card to purchase solutions. this is why manufactures of such products exist - as they provide a service to the customer to explain the issues and what recommendations for a user's room.



penngray, one more time ... what measuring tool will one be using to determine the effectiveness of early reflection absorbers? you keep saying you're measuring or doing "proper measurements". what tool are you using?? how does one verify that their absorbers are effective in attenuating an early reflection (eg., how does one know whether their panel needs to be made thicker or with a larger air-gap?)


the funny part is, you seem to think that i am against attenuating early reflections. if only you could find a single quote where i state otherwise... post 3 of this thread makes a pretty heavy claim for the attenuation of early reflections.

the difference is, absorption is only one way to attenuate an early reflection. some room models require as much sonic energy as possible for the termination of the ISD --- and absorption at early reflection points defeats this purpose. absorption is not a requirement to attenuate early reflections, as stated again in post #52. this may not be relevant to this particular user, but it in no way makes the claim false!


one minute you say measurements are required - the next minute you insist that placement based on what everyone else is doing is good enough.

as i've stated too many times to count, the mirror-trick is guesswork for approximate physical location of a geometric reflection point for specular energy. the mirror-trick does not tell the user if the reflection has been attenuated to a particular gain based on user design requirements. do you understand the difference between placement and measuring the effectiveness of a panel? they are two entirely different concepts. the mirror trick doesn't tell you anything about how effective a panel is.

GIK's customers probably aren't measuring - so the mirror-trick is a good approximation.

however, you keep insisting on taking measurements. so tell me - if you already love to take measurements and have the equipment, then why on earth would you refuse to actually take measurements for your specular absorbers to make sure they are placed in the proper location to be effective for the entire listening position, and to also make sure the panel is effectively attenuating the reflection to a required gain?

you seem to pride yourself on measurements except for absolute refusal to measure regarding this one very aspect!


then they can ignore the commentary and move on. what's the difficulty in that?

it isn't "cold fusion" to understand how porous absorption works and where it is to be placed in order to be most effective.