Romy the Cat wrote:

unicon wrote: …sealed tube traps can be implemented the way to not absorb LF easy and just in case the pressure gets over high and they can yet to be remain fully customized to absorb and diffuse what you want them for . I do not think that you are corrects. They can be turned to absorb or diffuse FM but they always form for LF. I do not think that there a way to moderate tube traps LF impact besides moving them around and changing the tube diameter. Pussy.

Unicon, can you explain what do you mean and how and what for the acoustic impedance need to be used. I read the articles at tubetrap

http://www.tubetrap.com/

and I do underrated what is the acoustic impedance is.

http://www.phys.unsw.edu.au/jw/z.html

What I do not underrated is way I need to be involved in all of it if I experience no problem with bass and no need for tube traps to intervene with my bass. In my view tube trap for bass is like stomach treating medication after one eats wrong food. No one question that those medications help but also if you do not eat bad food then there is no need for medications.

I do feel hat tube traps are very potent HF observer and here is what I would like to learn to use them effectively and creatively, with respect to what I would like to accomplish.

unicon wrote:

It is right that when you do not have bass problem then why to do any absorption for it ... But how do you know you do not have any problem ?

unicon wrote:

if you think you do not need to go below 150hz then just try to make your tube fiberglasses well structured from within and covered hardly from outside.

I do not know how you feel if you have large glass surface in your listening rooms but in my room if I have any exposed balls then I instantly feel that something is terribly wrong with sound. It is kind of ironic as when I was buying this house I did appreciate the fact that wall behind the speakers will be transparent. However, when I begin to experiment with playback in this new room I concluded that exposed glass is terminal for the why how I hear Sound. I wonder: if is there any way to deal with the problem? I can lift up my blinds but then I have to open the French doors. It works great so far but it will not be an option during cold season. So, is any glass treatment that would make it still visually-transparent and let me to have fan seeing the Massachusetts snow but at the same time to be acoustic-wise not such aggressive?

I was looking around trying to see what people use and to my surprised I did not see people alerted to the glass problem. My glass is many feet behind the loudspeakers line and it does horrors. This guy from Sound Africa:

… has his large glass window right the zone of the first reflection, on the side of the horn mouth. In my view it is absolutely atrocious configuration and it look like the guy spend no effort to deal with this glass. Ah, I forgot, the HF from Goto driver does not reflect… The image is taken from here:

http://audioheritage.csdco.com/vbulletin/showthread.php?20880-Mid-range-driver-advice-needed

I was thinking about some kind of cage or a few inch deep screens that might be hanged before glass on winter to acoustically cure the glass reflections. Did anybody  see anybody work on this problem?

Hi Romy.

Why trying to reinvent the wheel? Everything about room treatment and room accoustics has been said and done. By a guy totally in the know and offering his advice and his tools on his website. Michael Green does NOT damp, diffuse, trap or whatever the "old school" approaches are. He TUNES rooms and audio-gear like instruments are TUNED to make real music come alive...

This should be worth your consideration.

http://tuneland.techno-zone.net/forum.htm

bernie_f wrote:

Hi Romy. Why trying to reinvent the wheel? Everything about room treatment and room accoustics has been said and done. By a guy totally in the know and offering his advice and his tools on his website. Michael Green does NOT damp, diffuse, trap or whatever the "old school" approaches are. He TUNES rooms and audio-gear like instruments are TUNED to make real music come alive... This should be worth your consideration. http://tuneland.techno-zone.net/forum.htm best wishes for your project bernie

In my case I use empirical consequence and empirical demands of my actual Sonic results and if in some cases I do reinvent the wheel then… then I do not care. Why shall be bothered but the fact that reinvent the wheel if I act in according with my own understanding?  If I do reinvent a wheel then it will be my wheel and I will ride on my wheels my own carriage.  I do it not to sell wheels, not to declare ownership of the wheel concept but for no other reasons then make my own carriage to ride smoother. If so, the why do I care who reinvented the wheel?

Regarding Michael Green.  Bernie, can you explain in a few words what he is saying and what he is doing? I have read this character before and since you mention him I read a few his posts again. I truly do not get what he is doing and even what is trying to do. It looks like he does very rudimental and banal things and then and them with fancy names “tuning”, “optimization”, “harmonization” etc…  His posts that promised practical steps offer no tangible practicality, no methodology but rather very basic and very simplistic things. Perhaps I did not read what I need to read but from what I read I did not detect any “wheels” in what Michael Green saying.  Would question the notion of tuning audio-gear “until real music come alive” but I did not see that Michael Green saying anything practical or original on the subject. My Cat rolls from one side to another and by doing it she can fee that she creates a world economical crisis, bit I do not think she does. I do not day that Michael Green is a buffoon but in what I have seen/read I did not detect any  substance in his comments that would make me feel that he “tunes” anything or offer any “new school" approach. I might be mistaken, please show me that I am wrong.

zanon wrote:

I know that because of your new mid bass horn, the speaker position is mostly fixed. So you move chair. I am wondering -- to those of us who can move both chair and speaker, how do you go about getting system to play the room? Do you place speaker where you think it may be best and then move chair around? Or do you sit where you want and then move speaker?

Actually in my case the speakers position is not fixed. The mid bass horn is fine and this is the only one element that can’t be moved. The Macondo islands and the chair are perfectly can move.

There are however some constrains. For instance I would like to keep Macondo islands as far as possible from back wall. I would like to have the Macondo islands to be spread as wide as possible but without deformation of center image. I would like the chair to be equidistant between crossover altered midbass and the rest MF channels. There are many other constrains and wishes. Sure putting up room treatment and by other means the critical listening position might be adjusted and it will be adjusted but the main skeleton will be pretty much remain.

For those who both chair and speaker I would advise to find one stationary objects. For me in most of the case it is the back wall of the speaker when I know how far my speaker needs to be from there. This would give to you the base line for the speaker. Everything comes from there. You know your base line, you know your spread of the R/L channels, so you know more or less your listening distance. In many way it is back and forth ceremony….
The Cat

I think my new room and new midbass horn will give me an opportunity to play at the NEW LEVEL with a notion that I have been chasing for years. I am taking about perceptual shrinking of frequency response. I need to admit that most of the ugliest character of most of the loudspeakers out there is that they are not that full range acoustic system but each not then produce then try to spread it in a widest possible range. That artificial virtual extension of range, combined with dymick deficiency and tonal restrain is very unpleasant to my ears. Year back I call it Porcupine Sound but very few understood what it meant.

What I am trying to do is sort of reverse the situation and to make a truly wide range he plays to play mostly midrange. Partially I was able to accomplish in my old room and there are some reference about it in the following thread

http://www.romythecat.com/Forums/ShowPost.aspx?PostID=13585

.. but I think the new room will take it further as the longer reverberation time in my new room is such a power tool to keep lower MF longer! I would need to think about all of it when I will put the acoustic treatment on the wall and when I will set up the new Macondo balance.

What I listen live orchestra from the sites where orchestra (that is certainly is able for stupendous wide range) is more or less properly balanced, I mostly do not hear audio extremes but rather IMPLICATION OF EXTREMES.  Yes, I do understand that most of the recordings are unfortunately done with microphones located much closer than any sane listening distance for live listening. However, I to advocate the Morons who record music to use “dummy head” approach is too long and the people who do recording it too spoiled with wrong ideas about recordings. What however they do not have fortunately control is how sound done in my room. This anti-porcupinenees or the anti-Magico/Kharma Sound is perfectly achievable by balancing sound on playback level.  I think my new room will give to me more options to do it then my old room.

Romy the Cat wrote:

A few days back I unpacked my last moving box, which was good. Today for a first day in the new room when I have my playback system back, namely I time-aligned Macondo. Sine I find the right listing position there was no reason not to do it. It took 3 hours and what I did it then foe a first time since April I hear my Macondo as I accustom to hear it. The magnitude of changes in Sound with aliened channels is truly huge and I wish the prejudicial time-aliment was a norm rather a refuge of a few dissidents.

Romy the Cat wrote:

Tomorrow a cleaning lady will de-dust and clean the house and the acoustic treatment will go to the walls.

"Architectual" (man-made) joists have some decided advantages over natural lumber, including excellent unit-to-unit consistency.  Most residential "TJI" joists (as opposed to beams) are made straight and installed without an initial "crown" (manufactured beams often start with a pre-load crown), and TJIs are designed to stay flat under design loads once the subfloor diaphragm is glued and nailed or screwed down to schedule.  In this case, your hi-fi equipment probably exceeds the floor's design loads, so the use of shores in this case is at least pre-emptive structural reinforcement.  As I described earlier in the thread, the usual course is to shore up beams that run perpendicular to and in turn support the floor joists, to divide the floor load, as opposed to using jacks helter-skelter under individual joists.  In any case, the jacks are only truly effective if they are "grounded" to something appropriately solid and stable, and a 4" basement slab is generally considered inadequate for this purpose.  One way around this is to increase the number of jacks and so distribute the load(s).  Another is to use "sleepers" (basically, beams lying on the floor).

I can't think of a structural reason to use the jacks to crank a "crown" into the floor at this point.  You can buy or rent a spinning laser level to check the floor height at any number of "stations"; just do not assume it will in any case be truly "level", nor would one expect it to be.

If you want to "tune" the floor, then you will simply have to use your ears and gut to determine how you like it.  You have probably noticed by now that multiple jacks in various locations can be used to change the "feel" of the room as much as it can alter the "sound", and this "sense" of the room seems to carry up into frequencies that one might say are "not affected" by the treatment.  Don't forget the "wide bowl of water" trick.

All bets are off until you factor in true, strong (U)LF information.

Best regards,
Paul S

Romy the Cat wrote:

I figure out that it is time and put some acoustic treatment on the walls and at some spot of ceiling. The 2” pyramids in white, 24” by 24” look very nice; in fact they almost work like abstract yuppie-ornamentation popular in some Manhattan lofts - not exactly my style but I care less. All together I put 11 sheets of the foam over the entire room and removed all fiberglass traps. I left only 8 ACS fiberglass panel on the ridge of cathedral ceiling. The result was as expected: the room becomes much quitter, sound got less zippy and with less harsh noise, the high amplitude of paling does not overload the room, I might run tweeters harder and the HF ringing on the room not there anymore. That all is fine and they all very positive moments, however I would not say that I this new the Sound all together. I have very difficult time to define what I do like. This new sound got some upper MF efforts in itself that I did not have before when the room was “live”. That effect of heavy laboring in upper range a bit annoying and also it makes wonderful and impressive audio but this is not the result that I am interested in. I very much like the control over HF but I would like do not prevent them to be as they are, I do not want to over manage them. It is not that my room is over-damped now. I think it is OK balance as I cover very few spots with foam- 11 sheet of 24” by 24” is nothing for this room. Still, the contribution of the foam is very profound and not only positive. There is also a sense of artificial hyper-resolution that I very much do not like and it came with the use of foam. The fiberglass on tube traps gave me thin sound, foam gave me flawed resolution. Both are wrong in my view. Surely it is too early to make any conclusion as I only started to play with it. In my old room the “acoustic treatment” was made stuck of record shelves – that worked phenomenally well and it was in a way a natural a natural treatment. Now I use artificial treatment that does not exist in nature. Might it be one of the reasons? If so, then will I have better sound if I order green panels? Anyhow, I look forward to experiment more with acoustic treatment. The result I got now I find not acceptable.

Today I was thinking all day long what the hell is happening in my room and why the 2” pyramids do the job to subdue HF in my room but still create problem and kill Sound. The ease and spontaneity of Sound the I had just two day back is gone and replaced with labored pressure and not at the high frequency but in upper mid range.  I was thinking listening, changing a lot today in acoustic treatment, even put the large black panels back – nothing worked – the right sound has gone. I played good 5 hours with it and twice fallen from my step ladder – the only think the work properly in my room was gravity…

I do not want to give an impression that I love to do all of it too much but I was very pissed as there was some kind of hidden reason WHY it happened and I knew that until I get control over this reason I will not get my Sound in my room. If it was 2 years back then I would blame electricity but now I PP2000 my entire system and I am accustomed that sound does not changed from day to day.

I said that I give up and started to do absolutely idiotic think – I began to move the thing into my room exactly as it was 3 days back, when I make my post “I’m drinking from the grail of glory.” Then I turn the CD. From the very first note I know that I have my sound back, I was laughing like a meshugana!

Then I begin to analyze what was change. The biggest thing was that I put the fiberglass tube traps back into the room. They are very powerful at HF but NOT so powerful to moderate the MF pressure. Then it came to! As anything else it was ridicules simple and surprisingly you.

A couple, years back a site reader from Swaziland contacted me and share an interesting idea of shaping sound with reflective panels. We spoke over the phone and I made some experiments building his panels. It was interesting but no more than that. Suddenly during my straggling with Acoustic Treatment I felt that I experience the same “MF pressure” and my Swaziland managed with his reflectors. I looked at the well-treated with foam 24” wide wall behind my listening chair  that cover the load-caring beams - now it was covered with 20” fiberglass half-tubes. It stroked me that it is not about the fiberglass vs. foam but about the shape of this wall. Even covering with foam the wall is not reflective at HF but at MF it acts as the Swaziland reflector. Since the wall is very much stand alone and has my listening position has no back reelections (something that I was craving for years!!!!) the harrow wall was acting like a lens, focusing the only back reflection to my chair. Looking at the size of the wall 22” and the double distance from the wall to the chair it was obvious where the MF pressure came from.  In case of the fiberglass half-tubes the wall was converted into a sphere with no ability to focus the reflection back to me.

That explained everything, including why I felt that the fiberglass tubes had so powerful effect in my room. I immediately took aluminum foil and warped it around the half-tubes behind the chair. The great sound did not despair. So, it was NOT about absorption rate about reflective shape! I am a fucking genius!

Now I had good sound and full control over it.  I was inspired. I took my foam back but kept the half-tubes behind the chair’s wall. I realized that I do not want to kill HF anymore and want to randomize HF making room live but controlled live. I left the foam only on the very few strategic locations and took the rest foam away. Then I took 6” spikes and covered with them the top of the back wall, still keeping the half-tubes on the back wall behind the chair. The Sound was very nice, room feel very nice and I feel that it is it about acoustic treatment. The only thing I need now is to get my custom made 30 pounds air-condition ducts and to replace the 20” fiberglass half-tubes with 24” half-tubes (will less extend into room), covering the half-tubes with nice fabric. Below are a few pictures how the acoustic treatment is use in my room as now.

fulcrum wrote:

Romy, very interesting stuff.That was exactly the kind of info I was seeking with my post on curved corners below that your readers took such exception to.Granted I had the idea ass backwards as a great number of people who contacted me privately pointed out.A couple of the people who did contact me asked to produce 1/4 tubes to fill in corners, partial tubes to diffuse sound from side walls and curved panels that can be wall mounted with tilt and swivel brackets to allow them to be adjusted for the best sound.

Fulcrum, I did see that you have thread but I hardly understood what you are trying to do or to say. Your illustrations are very inadequate and your idea about the application of curvature walls is NOT very clearly expressed. If you are a maker of curved walls and trying to soloist some business at this site then it is fine. I never had any attitude ageist proprietors fishing for clients but I always demand it to be in context of the advancement of sound reproduction techniques. I did not see a lot of it in your posts and I did not pay any attention to them.

To my knowledge the addressing of wide size reflections is not something that people too worry or care.  If you have a large wall behind let say 10 feet back then the mass reflection from the wall create a permanent contra-pressure and people do not acknowledge it and it is virtually imposable to tune ourselves off from it. The reason why I was able to catch it, besides my extraordinary anal retentiveness, is become in my case reflective panel is very distinct and located in something that I would describe as “reflective vacuum”. So, if you wish to advance what you do from a perspective that it be interesting for the people like me then you need to come up with a set of measurements of front vs. back pressure or with an elegantly expressed speculation that curved surface address the back-pressure subject and how to learn the benefit of it.

Generally if you were in my disposal next town over then I would heir you to make the wall under the midbass horn completely wavy – 10-15 horizontal crooked waves under the edge of the horn - in the Salvador Dali style.. However, if you make any acoustic claims then you need to do it not from sheetrock but from acoustically effective material, the compress fiberglass appears fine to me. Anyhow, you need to work on the presentation of your idea and to compile it into a complete product and deliverable package.  The way how you present it in your thread did not attract my attention. I would expect the people like you were able to foresee the reflective pressure of non-curved walls and depends of the reflector size and distance of reflection to find out what frequencies are in play and what rate of wave absorption material would make sense to use for the given reflective situation.