Welcome, Guest. Please Login or Register
Decware Audio Forums
11/01/14 at 10:10:06


Pages: 1 2 3 
Send Topic Print
Current listening_evaluation room acoustics (Read 18392 times)
Azul Shiva
Senior Member
***


Visit
www.ambiophonics.org
for a better sound!

Posts: 76
Re: Current listening_evaluation room acoustics
Reply #30 - 01/29/09 at 08:49:04
 
Hi Everyone,

Thank you John for the calculator. It sure will be useful.
I'm just gonna step out of topic for a while and ask; about how much would the wood (MDF) cost for a diffuser 4' x 2' feet large and about 1.5' feet deep? All I need is a guess.

Wolfgang,
Back to top
 
« Last Edit: 01/29/09 at 08:51:19 by Azul Shiva »  

Visit www.ambiophonics.org for a better sound!
  IP Logged
Azul Shiva
Senior Member
***


Visit
www.ambiophonics.org
for a better sound!

Posts: 76
Re: Current listening_evaluation room acoustics
Reply #31 - 01/29/09 at 14:47:56
 
Dear Paul,

About the diffusors: What do you think of the Skyline diffusor? I always thought it's not a good one, but at rpginc.com they say it's the best one they can offer.
http://www.rpginc.com/products/skyline/index.htm

On the same site I found a bass trap with a membrane which turns the sound energy into kinetic which is easier to stop. I don't have a lot of place for bass traps because of a door, so would this one do it instead, and can I build it by myself?
http://www.rpginc.com/products/modexcorner/index.htm


Kindest Regards,
Wolfgang
Back to top
 
« Last Edit: 01/29/09 at 14:49:48 by Azul Shiva »  

Visit www.ambiophonics.org for a better sound!
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #32 - 01/30/09 at 05:50:07
 
You've seen the photo's of the assembled quad prime 23 unit previously in this thread.

Here is how it looks stripped down to the basic frame work.



Here's another view with some of the parts which make up the sequences only within the TOP horizontal sections. This shows about 75% of the parts layout used just in the upper sections. What is seen is mostly the Celetex well sections and a portion of the MDF 1/8th" divider sections. This does not show any of the parts required to assemble the large lower sections.



The use of the Celetex material as shown is optional. This option is reserved for dual purpose absorption properties built in conjunction with the diffuser elements as a hybrid design. †When you want to push the limits of design, this is where it takes you. The wells of this unit actually become diaphragmatic by nature. That is a great bonus when absorption factors come into play for a dual purpose design.
Back to top
 
 
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #33 - 01/30/09 at 07:47:57
 
Quote:
About the diffusers: What do you think of the Skyline diffuser? I always thought it's not a good one, but at rpginc.com they say it's the best one they can offer.
http://www.rpginc.com/products/skyline/index.htm


From what I observe and understand about this design, as with just about any of the RPG products, I would highly recommend them for what they are designed to do. This makes for an excellent product to place within a ceiling grid. It is two-dimensional based upon the primitive root system. The benefit to this is the fact that divider sections are not so critical within a design such as this with the added fact that periodic lobing will not be so much of an issue. I believe that one would be hard pressed to surpass the performance ratios of this design with current designs offered for use in a ceiling grid. That is not to say that something close or even better can not be designed by alternate methods. This does indeed work beyond a shadow of doubt.



Quote:
On the same site I found a bass trap with a membrane which turns the sound energy into kinetic which is easier to stop. I don't have a lot of place for bass traps because of a door, so would this one do it instead, and can I build it by myself?
http://www.rpginc.com/products/modexcorner/index.htm


I absolutely am on board with this concept!! The principle behind this design is very impressive. It is not hard to understand why this type of unit provides such great acoustical coefficients across the audio spectrum.

Absorption techniques are just as important as that of diffusion techniques. This design is an example of high performance coefficients over a very large portion of the frequency spectrum where it counts the most.

I have experimented with large diaphragmatic designs in the past, which were coupled directly into the room corners from floor to ceiling. This provided a spectacular result in itís own with a dramatic transformation within the roomís frequency balance. I have no doubt that these modules will provide that level of improvement when placed properly within the room.

If you do not remember anything else, just keep this critical rule in mind for all of this to be justified.

Know the Minima / Maxima rule! Maintain the Odd-Order Quarter-Wave principal in all of your designs, and placement within the room.

Do that and results should be optimum for you.

I am well aware of the RPG designs past and present. I maintain full respect for what they offer in a technological perspective. After all, I have put many of their designs into practice with great results.

If you had observed the large Binary Grid Diffuser units placed behind the speakers at the top of this thread, you would notice that they are patterned very closely to that of RPG's design.

These are practically clone's with a computer generated grid of binary code that is of the same principal and tactic. This type of unit built with a degree of curved proportion as shown represents a new generation of diffusion design, with vastly improved coefficients over a much greater area of the audio spectrum.

These offer significant improvement over that of the QRD designs in more than one aspect. Not only do they maintain far wider range with superior coefficients, but also they are more effective at closer range within a small room. The detrimental aspect of periodic lobing which is inherent within QRD repetitive placement, is no longer a problem with these modern designs.

Through sophisticated computing techniques, new innovative design standards are quickly placing the old QRD & primitive root based designs into obsoletion. The movers and shakers behind this technology just happen to be a major influence behind the information focused upon within the well-respected Master-Handbook-Of -Acoustics series of publications. These movers and shakers just happen to be those responsible for RPG's success.

The major drawback to actually acquiring products from RPG is that of cost. If you can afford these products then that is fine. I think that the average audio enthusiast will have a hard time justifying the total cost for these products on a large scale.


If you understand the principles and how to put those principles to work for you at the greatest benefit possible, plus have the ability to build your own versions with respectable accuracy, then it is of your best interest to build your own when budget restraints are the deciding factor.

That is what we are doing here. The best techniques are considered as the basis for design, while cost no longer presents prohibitive barriers for which a designer must place limitations. The bang for the buck ratio here is of tremendous value within a very affordable outcome.


Back to top
 
 
  IP Logged
Azul Shiva
Senior Member
***


Visit
www.ambiophonics.org
for a better sound!

Posts: 76
Re: Current listening_evaluation room acoustics
Reply #34 - 02/02/09 at 06:46:27
 
Dear Paul,

Unfortunately I cannot afford to build the RPG diffractal and should be looking towards something simpler. "Hotsauce" posted a link to a calculator for diffusion walls.
http://www.digitalaudiorock.com/cgi-bin/qrd.cgi
What range should a good diffusor work at? Is it enough, starting at 300Hz, and do I need it to go up to 20KHz? Close to the ceiling and floor I understood I'll need vertical diffusors. What range should these go for?
And how many wells should I be aiming for?


Kindest Regards,
Wolfgang
Back to top
 
« Last Edit: 02/02/09 at 06:49:00 by Azul Shiva »  

Visit www.ambiophonics.org for a better sound!
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #35 - 02/03/09 at 17:56:12
 
This will all be addressed at the following link:

http://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1233352097

Thanks.
Back to top
 
 
  IP Logged
Lonely Raven
Seasoned Member
****


Jack of all Trades,
Master of None

Posts: 1447
Re: Current listening_evaluation room acoustics
Reply #36 - 02/12/09 at 20:15:27
 

Great thread! I'm glad I've wandered into here after many, many years of being away.

I'm a big fan of Decware design concepts, and have been chatting on and off with Steve for over 10 years now.

I've unfortunately had to give up two channel listening for a while, but am branching out into 7.1 Home Theater, and I'm looking to kill some flutter echo in my theater room without making the room sound dead. So I'm looking into building some wall hangable QRDs.

I'll keep an eye on your new thread, Paul. Thanks for sharing!
Back to top
 
 
WWW Lonely Raven   IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #37 - 02/13/09 at 21:36:24
 
Hello Lonely Raven,

Welcome back and thanks for the interest. It would be great for you to become directly involved with some of these projects, gaining from them first-hand, rather than just reading anotherís review of the results. Why not let it be you that post the review regarding the huge transformation that is obtainable within your listening sessions? Too many people have been sitting on the fence regarding the very thing that will make the most difference in their perception to music reproduction.

I hope that this inspires you and many others to get involved. After all, you guy's are the ones that receive direct compensation for your efforts. The resulting benefits can be quite substantial. For many, the results will extend beyond expectation.

I understand about the multi-channel choice. Both worlds can be integrated with great success, so nothing really has to be given up in either regard.

Not only will I be discussing QRD concepts and design builds, there will be focus concerning advanced, next-generation number theory designs as well.

The modern advancement in design allows for many benefits to the end user.

This ranges from much better performance, to that of a lighter, slimmer profile with clean surface lines. Better performance with improved aesthetics in a package that is much more user friendly, at a build cost factor that should fit the average budget very well.

The d.i.y. approach is extremely practical when it comes to projects such as this. You are practically building these units for a mere fraction of their actual worth.

This is where the affordability issue becomes a NON-issue! There is no reason why someone cannot reach the goal of obtaining adequate acoustical control once cost is no longer the major reason for holding off.

The next general excuse for those that hesitate seems to be that of room decor and aesthetic acceptance in general. This all depends on how skilled the installer is along with the degree of creativity for which governs the outcome of this.

Great results require great effort! The rewards here greatly out-weigh the effort-cost ratios that go into a major project such as this.

I will be covering ways to approach the control of flutter echoes somewhere along these project lines. It is a very important issue to deal with which is really not that difficult to correct. Remove the cause and you remove the effect. Just like extinguishing a fire. Remove any or all of the elements which feed the fire and the fire goes out. Pretty simple right? It can be if approached correctly.

I hope that something offered from this thread will result into the ideal solution for your needs. There is no mystery here. Just the application of proven methods put to work in a manner that best suits our needs.

Paul.

Back to top
 
 
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #38 - 02/13/09 at 21:46:29
 
Quote:
This thread is dead (I think). Check the link posted by paul (RFZ_Quest) above


As far as I'm concerned, this thread is not dead yet nor do I intend for it to die out any time soon.

This is a general thread here to post general responses or whatever comes to mind. I just do not want to cover any technical details here when it will be placed in the dedicated project thread.

General discussion here frees up the clutter which distracts from the outline of the project thread. This helps a great deal in keeping some sort of structure and order in place.

Hope that makes sense.
Back to top
 
 
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #39 - 02/19/09 at 21:38:44
 
Thought I might show some of the other experimental configurations that I evaluated in this room prior to moving out of that residence.

Each set of speakers revealed a totally unique signature as would be expected. This room set-up allowed these speakers to perform on a level, not usually experienced in the typical home environment.

Room acoustical behavior proves time after time to be the determining factor in how well the sound quality of a system is perceived.

There was no exception to that fact here, as quality level consistently expanded to new heights, beyond my previous endeavors. It will really surprise you as to what is possible from these variable-testing platforms.

This whole set-up was just that. This allowed me to perform listening evaluations free from the usual restrictions typically imposed in most household situations. The outcome was most favorable to say the least. †

I no longer have this set-up, as this was only a temporary situation.

This allowed me to try many variables that were previously unobtainable. The purpose was to show degree of effect for which any or all of these measures proved to provide. It definitely reveals the influence for which any or all of these combined tactics contribute to the overall room response.



These speaker mock-ups were quickly assembled from leftover prototype cabinet sections as a testing platform for a new concept that I wanted to try.

These are a dual chamber concept for which separate enclosures work independently for discreet frequency enhancement. As seen, these have the new variable rate ports for the passive loaded drivers.

These are ported at both sections, which one is at the top and the other is at the bottom. It is in the way that the two sections are isolated that makes them work so well.

A strategically well-placed baffle section is placed behind the DFR-8 drivers. Above the drivers, I built special barrier plates, which contained inverted radial cones with sealed centers; similar to that of the passive radiators used in the upgraded HDT models.

The upper chambers simply had a matching hole with a sealed circumference for which mated directly to the passive radial cone perimeter on the lower chamber. The loading that occurred from this set-up proved to be exceptional, and very worthy for future consideration in design tactics.

I could have really screwed with peopleís minds by listening to this set-up. If it were a blindfold test, one would be in utter shock once the visual aspect comes into play. †It was a huge surprise to me! In this room, the experience was satisfying well beyond expectation.

These speakers turned out to be some of the most impressive sounding design concepts that I've experienced to date! I set them up for which was supposed to be a short and simple test for a new design that I am working on based upon the DFR-8 driver. †The idea was to test the gain provided by the top loaded chamber, in order to see if this concept was worth pursuing. The results proved clear as to the significance of its enhancement.

These remained in place for just over TWO WEEKS! I found these to be extremely entertaining in all aspects. So much, that I did not want to take them down. As crude as these were in form, the overall synergy proved to be one that works extremely well. I can only imagine how much greater these could be if advanced R&D were introduced to this concept.



Back to top
 
 
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #40 - 02/19/09 at 22:39:35
 
Here is a wide, expanded view of the room layout tested with an early version of the retail Radial Towers. The pair shown here is the only set in existence enhanced with the greatly improved modifications that these have.

This set was recently sold for a fraction of its worth. I'm sure that the new owner understands this in a way, only possible through experiencing their unique sound character first hand. If I had not been in a situation forcing me to sell these, I would never have done so.



You can see the additional treatment that I placed along the upper portion of the room's perimeter. I just happened to have a large supply of these webbed air pillows that were used for shipping protection. I strung these up along the entire section above the speakers in order to test the reduction of flutter-echoes as a result.

I filled the entire corners with sealed cylinders in order to remove bad artifacts, typically compounded by room boundaries. In addition, I built a hanging absorption pod in the center of the room which acts to break up ceiling/wall disturbance.

These last seemingly simple modifications proved to enhance the rooms imaging qualities by a very large margin. The improvement was immediately noticeable with strong significance.

This really cleaned up upper-frequency artifacts, with a sense of clarity unrealized in prior tests. I can tell you that spatial information took on a refined sense of relaxed state, seemingly natural in overall presentation.



Back to top
 
 
  IP Logged
RFZ_Quest
Seasoned Member
****


The key to a perfect
resonating chamber.

Posts: 296
Re: Current listening_evaluation room acoustics
Reply #41 - 02/20/09 at 01:45:49
 
Here is another stage of testing involving a set of retail 'Kadence' models.


These are of premium design and build quality, based upon a twin configuration of full-range drivers within a transmission-line concept.

Remarkably efficient, unprecedented in form, these bear strong presence among the finest of speaker designs.

Offering a degree of speed that others merely hint at!






Back to top
 
 
  IP Logged
Pages: 1 2 3 
Send Topic Print