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My Mahogany / Invisible Speaker build - Page 8

post #211 of 385
Thread Starter 
Definitely time for some progress on this thread!

First and most importantly, I'm happy to report that my draft beer situation is now under control. Thanks to Tim for getting me back on track! After cooling the keg down to 36 and getting rid of the excess carbonation (by letting it warm up to room temp), I now have perfect mugs coming out:


So with that, I can get back to woodworking... Next cabinet to build is the bar's peninsula, which juts out into the room at a 45 degree angle. Some pieces, which are exposed in the final plan, are Mahogany plywood; the rest are the pre-finished Maple:



This shows some wasted space under the single drawer dishwasher. I planned to use it to house the junction box for the electrical service for the dishwasher, but after putting it together I realized that I wasn't going to have enough room to reach in there to wire things up. Doh!


So I marked out a cutting template:



And used that to open up an access hole underneath that junction box:



With that problem solved, I could continue on with the carcass assembly. This piece of plywood will support the eventual work surface on the serving side of the bar:



And here's the carcass assembled, ready for a face frame:
post #212 of 385
Thread Starter 
To start the face frame, I like to use chalk to lay out all the pieces...


From there I cut each to length (leaving about 2" extra per piece), then plane them flat and to 3/4" thickness, then joint one edge, rip them to width, and then finally cut them to length. I've learned that the length of the face frame components is truly critical in order to get the face frame to fit, so it's fiddly work that takes some time...

Another tip I picked up was to take pieces of common width (like these 3" wide stiles) and mill their final width all together by running them through the planer. Works great!



Here's the face frame mostly assembled:



Note the 45 degree turn on the frame on the left side. To get that joint nice and tight, I decided to pre-glue those two together. Took just a couple / three clamps in a rather complicated setup:



All that trouble seemed worth it, though, as the joint nearly disappears on the final assembly:



During the process of attaching the face frame to the carcass, I found that I wanted some more pocket holes, but only after the frame was mostly installed. I got lucky and figured out that you can remove the inner drill guide portion from the normal locator and just clamp it to the plywood (with a 3/8" spacer above it) in order to drill more holes:



The final result, with the frame permanently attached and the dishwasher just set in there for now to confirm that it fits:



Now I just need to find someone to help me move this thing from my shop and down to its final home... smile.gif
post #213 of 385
Great job Bryan, as always!

Remember, you will probably have to conduct at least 100 sample draft pulls to verify proper operation . . . it's the only way you can generate statistically significant data! If your wife asks you what you are doing, you are justified in claiming a scientific experiment! biggrin.gif
post #214 of 385
Thread Starter 
Got some more construction time this week and wanted to share some of the results.

First thing was to secure the bar peninsula to the floor. I debated a bit on how much I wanted to "destroy" the floor (e.g. drilling holes into it), but in the end I figured that if/when I (or someone else) rips this bar out, I (they) will probably want to re-do the floor then, anyway, so with that freedom, I stripped the wax from the floor in a couple places, abraded the surface with some sandpaper, and epoxied a couple of blocks to the floor:


Then it was a simple matter of driving some screws through the cabinet and into those blocks...


Next, I took advantage of that access hole that I had made previously to get the power feed to the dishwasher installed and ready to hook up:



Then it was time to construct three frame/panel assemblies that will face the front of the bar. Here's one dry assembled:


Notice that the left-most opening is square (left open for a door for storage), while the right openings get molding and filled with a raised panel. This was easy to do on my 3D model, but a bit trickier when I got out to the shop and started scratching my head on how exactly I was going to pull that off... In the end, I made those joints so they were half butt-joints and half cope/stile joints:


I don't know if that's how it's supposed to be done but it seemed to work out okay...


Then it was time to make all the panels. For the four panels in the main section, I was lucky enough to find a Mahogany board that was nearly 16" wide!!


I actually had to rip it down a bit just so it would fit through my planer:



Cutting them to length:



And I used biscuits to help align the panels, along with some screws to help pull them tightly together:



Sidebar: If one measures progress by the amount of sawdust you create, it must have been a productive week for me... it was a two-barrel-into-the-garbage-can week! smile.gif



Finally, here's a shot of the bar as it stands today. The panels are attached and I've started building out the top front of the bar with a 6" overhang:



Next I need to finalize some wiring and outlets and then I'll start working on installing the top, which will eventually support the granite...
post #215 of 385
eek.gif

biggrin.gif

Well done and looking good as usual. I love seeing your updates. Sometimes you impress me so much I don't know what to say. This is one of those times. Well done.
post #216 of 385
Thread Starter 
Quote:
Originally Posted by Mfusick View Post

eek.gif

biggrin.gif

Well done and looking good as usual. I love seeing your updates. Sometimes you impress me so much I don't know what to say. This is one of those times. Well done.

Thank you, sir, that's very kind of you to say. As long as you're enjoying the update, I'll keep 'em coming... smile.gif

This weekend was maple work surface top time. I wanted a hard-working surface that I could cut stuff like lemons and limes on and not worry about it, so I decided to build a maple top. Here's what I started with:

Three 8/4 boards about 8' long or so. ($180 worth of Maple here locally in case anyone is interested...)


I ripped each board multiple times into pieces roughly 1-5/8" wide, jointed / planed the ripped edges, and then used those machined edges to glue up 3 sets of 4 strips each:



That produced 3 sections about 7" or so wide each, and those were small enough to fit through my jointer and planer so I could mill each one perfectly flat, straight, and square:



More biscuits and lots of glue between each of the three sections:



And more clamps, plus my favorite gluing cauls to keep everything nice and flat:



Happily, that process resulted in a slab that seemed flat in any way I could measure it, so it was just a matter of smoothing out the surface:


I don't use that little scraper plane very often, but for a job like this, it is pure joy to use!!


The track saw worked well for squaring up one end and knocking two 45 degree angles off the other:



After some final sanding of 100, 120, and 150 grits, it was ready to set into place on the bar's peninsula:



Now I need to figure out how to treat that surface. I was thinking either mineral oil or perhaps something called salad bowl finish. Any other ideas on what to do with this? I want something food safe that won't mind being chopped on a bit...

Thanks!
Bryan
post #217 of 385
There is another transducer thread here, and wanting to learn from your experience I re-post my Q to him now also to you:
Quote:
Originally Posted by mtbdudex View Post

I come to this thread looking for acoustic measurements, like to learn about all the wall mounted transducer performance.
I'm looking for waterfall for below 250hz and gated ETC for above 250hz, did not see them posted.
Also, you are not using Audyssey EQ at all?
( I can't recall reading if you did or not).

Specifically what acoustic calibration was done?

From what I've gathered there are 2 suppliers, I've not seen any Freq response / gated ETC charts / waterfall plots, or spec sheets, nor any objective measurements by those that have used them in their website.
http://www.invisiblestereo.com/html/faq.html and http://www.hiddenaudiosystems.com/index.html

So, looking for your take.
post #218 of 385
Those "two" suppliers are actually one and the same, however it must be noted that I am the factory representative for Hidden Audio Systems. I don't advertise that fact because I'm not on here to do so.

Specs are such:

20 hz-20,000khz +/-3db (... depending upon the surface on which the transducer is mounted...)
Drywall is 35hz-18,000khz

Power Handling: 200 watts Peak / 100 watts Continious.

Each Transducer comes supplied with a Ray Chem Poly Switch, which is a liquid, self resetting device which prevents over powering the unit when is seriesd inline between the transducer and the amplifier. It is rated for 90 watts, but I find myself seldom using it because of the robust nature of the transducer and the simple fact that quite often I am paralleling at least 2 or more when using them for high performance, home theater applications. That effectively doubles are rated continuous power input capability.... and there are not many audio applications which will be delivering a continuous 180 watts to any specific channel.

As a point of reference, most of the channels in RedTopDown's system have four transducers in parallel, which are in turn serise'd with another for transducers, making for a total of 8 transducers per channel. That configuration allows for a rated the power input of 360-watts continuous per channel.

The real object of using transducers to produce audio through a structual solid is too and put enough energy to make the solid resonate accurately to any and all given frequencies. Certainly, the density, mass, and structural makeup of a structural solid will play an important role as far as the efficiency of the transducer and. the accuracy of the reproduced sound.
post #219 of 385
Quote:
Originally Posted by MississippiMan View Post

Those "two" suppliers are actually one and the same, however it must be noted that I am the factory representative for Hidden Audio Systems. I don't advertise that fact because I'm not on here to do so.

Specs are such:

20 hz-20,000khz +/-3db (... depending upon the surface on which the transducer is mounted...)
Drywall is 35hz-18,000khz

Power Handling: 200 watts Peak / 100 watts Continious.

Each Transducer comes supplied with a Ray Chem Poly Switch, which is a liquid, self resetting device which prevents over powering the unit when is seriesd inline between the transducer and the amplifier. It is rated for 90 watts, but I find myself seldom using it because of the robust nature of the transducer and the simple fact that quite often I am paralleling at least 2 or more when using them for high performance, home theater applications. That effectively doubles are rated continuous power input capability.... and there are not many audio applications which will be delivering a continuous 180 watts to any specific channel.

As a point of reference, most of the channels in RedTopDown's system have four transducers in parallel, which are in turn serise'd with another for transducers, making for a total of 8 transducers per channel. That configuration allows for a rated the power input of 360-watts continuous per channel.

The real object of using transducers to produce audio through a structual solid is too and put enough energy to make the solid resonate accurately to any and all given frequencies. Certainly, the density, mass, and structural makeup of a structural solid will play an important role as far as the efficiency of the transducer and. the accuracy of the reproduced sound.

Can you share 3rd party testing done in a anechoic chamber with a "typical" wall install method that you use?
I'd like to confirm the results.

btw, we have a few anechoic chamber's at my work, here's my daughter at "bring your child to work day" in one of them
post #220 of 385
Thread Starter 
Quote:
Originally Posted by mtbdudex View Post

There is another transducer thread here, and wanting to learn from your experience I re-post my Q to him now also to you:
From what I've gathered there are 2 suppliers, I've not seen any Freq response / gated ETC charts / waterfall plots, or spec sheets, nor any objective measurements by those that have used them in their website.
http://www.invisiblestereo.com/html/faq.html and http://www.hiddenaudiosystems.com/index.html

So, looking for your take.

Mike, unfortunately I don't have any of those technical answers for you, sorry. I am using the Audyssey feature of my Onkyo receiver, FWIW.

Perhaps Maurice could point you to someone there locally with an installation, or if you're ever here in Northern Cal, you're welcome to swing by, if that would help.

Bryan
post #221 of 385
Quote:
Originally Posted by mtbdudex View Post

Can you share 3rd party testing done in a anechoic chamber with a "typical" wall install method that you use?
I'd like to confirm the results.


  1. Due to the omnidirectional dispersion characteristics of the Transducer, measurements are slanted toward somewhat false readings. For instance, db levels are high while SPLs are markedly lower.
  2. Simply placing a partition wall assembly upright does not allow for the structural mass coefficient that is required to allow the sound to propagate effectively, and develop the full range of frequencies.
  3. Measurements taken via the use of a Audio Spectrum Analyzer have often shown a remarkably Flat response, even in some very extreme acoustically deficient environs.(Churches / Large Halls / Bare Rooms.

In the end, Transducers have primarily depended upon an effective installation, done correctly, and using optimal materials. Years ago before I ever considered installing them instead of "speakers" for home and commercial use, I focused on installing the on the front and rear windshields of Cars, and building them into the walls and cabinets of Vans. Glass is the absolute ideal medium for accurate resonance, with select Non-Void Plywood w/hardwood veneers. (Marine Grade Douglas Fir / Oak / Mahogany Paneling) Drywall comes in after those,but constitutes the vast majority of applications.

However they are used on the Steel Bulkheads of "every" ship in our Navy, (...and more than a few other countries as well...) as well as most every Shore Based Office application for Sound masking / Security apps as well as "explosion proof" audio within volatile environments. (...ditto with Hyperbaric Chambers and Floatation Tanks...) where they interface with FiberGlas, Steel, and Wood. They have been used for years in Spas / Hot Tubs / Saunas....everywhere sound is wanted but usually cannot be accommodated. They work very well affixed to Drop Ceiling Tiles (...solid Fiberboard variety...)

I have helped design Acoustical Art projects for years among the Scholastic and Artistic groups. David Tudors "Rain Forest" exhibits are world renowned for the use of Transducers on a wide variety of surfaces..In Spain a couple years back, I went over to help design and install a 40' long Steel Tunnel with 80 Transducers where groups of 8 each received various feeds of frequencies supplied by Dripping water into various sized thin Copper Bowls that themselves had Transducers applied to their bottoms and used in reverse as Microphones.

It was a surreal experience..... eek.gif

On and on it could go...but that is not my intent here. Suffice it to say that for over 25 years prior to my interest in DIY Screen making, and the resulting Patents obtained therein, I was pretty much instrumental in the development of every Transducer application previously listed, but ya gotta know, turning a Wall into a Center Channel and then painting a Screen onto that spot hold the nearest and dearest spot in my heart.

In truth, since Julian Hirsch http://en.wikipedia.org/wiki/Julian_Hirsch last reviewed the Audio Transducer back in 1972,(..and gave it high marks BTW...) my Peers have either overlooked or discounted the use of Transducers....leaving me as the sole individual promoting their use across the globe. Such was my fate.....a Teamster converted in 1977 into a Audio Pioneer.

Somebody stick a fork in me....I'm done here. biggrin.gif
post #222 of 385
Quote:
Originally Posted by MississippiMan View Post

Quote:
Originally Posted by mtbdudex View Post

Can you share 3rd party testing done in a anechoic chamber with a "typical" wall install method that you use?
I'd like to confirm the results.


  1. Due to the omnidirectional dispersion characteristics of the Transducer, measurements are slanted toward somewhat false readings. For instance, db levels are high while SPLs are markedly lower.
  2. Simply placing a partition wall assembly upright does not allow for the structural mass coefficient that is required to allow the sound to propagate effectively, and develop the full range of frequencies.
  3. Measurements taken via the use of a Audio Spectrum Analyzer have often shown a remarkably Flat response, even in some very extreme acoustically deficient environs.(Churches / Large Halls / Bare Rooms.

In the end, Transducers have primarily depended upon an effective installation, done correctly, and using optimal materials. Years ago before I ever considered installing them instead of "speakers" for home and commercial use, I focused on installing the on the front and rear windshields of Cars, and building them into the walls and cabinets of Vans. Glass is the absolute ideal medium for accurate resonance, with select Non-Void Plywood w/hardwood veneers. (Marine Grade Douglas Fir / Oak / Mahogany Paneling) Drywall comes in after those,but constitutes the vast majority of applications.

However they are used on the Steel Bulkheads of "every" ship in our Navy, (...and more than a few other countries as well...) as well as most every Shore Based Office application for Sound masking / Security apps as well as "explosion proof" audio within volatile environments. (...ditto with Hyperbaric Chambers and Floatation Tanks...) where they interface with FiberGlas, Steel, and Wood. They have been used for years in Spas / Hot Tubs / Saunas....everywhere sound is wanted but usually cannot be accommodated. They work very well affixed to Drop Ceiling Tiles (...solid Fiberboard variety...)

I have helped design Acoustical Art projects for years among the Scholastic and Artistic groups. David Tudors "Rain Forest" exhibits are world renowned for the use of Transducers on a wide variety of surfaces..In Spain a couple years back, I went over to help design and install a 40' long Steel Tunnel with 80 Transducers where groups of 8 each received various feeds of frequencies supplied by Dripping water into various sized thin Copper Bowls that themselves had Transducers applied to their bottoms and used in reverse as Microphones.

It was a surreal experience..... eek.gif

On and on it could go...but that is not my intent here. Suffice it to say that for over 25 years prior to my interest in DIY Screen making, and the resulting Patents obtained therein, I was pretty much instrumental in the development of every Transducer application previously listed, but ya gotta know, turning a Wall into a Center Channel and then painting a Screen onto that spot hold the nearest and dearest spot in my heart.

In truth, since Julian Hirsch http://en.wikipedia.org/wiki/Julian_Hirsch last reviewed the Audio Transducer back in 1972,(..and gave it high marks BTW...) my Peers have either overlooked or discounted the use of Transducers....leaving me as the sole individual promoting their use across the globe. Such was my fate.....a Teamster converted in 1977 into a Audio Pioneer.

Somebody stick a fork in me....I'm done here. biggrin.gif

So are you saying that there are no 3rd party testing to share?
Or, there is but the readings do not match what you claim the ears hear?
Please share what objective testing has been done.

Also - explain how "db levels are high", yet SPL are lower? Please post the charts that back up these statements, I'd like to "grok" them.
post #223 of 385
Quote:
Originally Posted by mtbdudex View Post

So are you saying that there are no 3rd party testing to share?

Yes...and I know that is strange for some to accept, but the emphasis on distribution has be within Commercial Industry and Military applications, and the attributes of the Transducer has been / is well known and accepted in the Educational & Artistic communities for many years. when the most recent version was released, one that was / is 4x more proficient than the former, it didn't take much convincing within those fields to accept it "as is".

As for using within the A/V realm, such is / has always been limited to specific trained Dealer/Installers, with no direct sales allowed, for just the sort of reasoning you might expect....the Mfg and myself do not want improper installation...or the issues that result from "Sellers" making the product seem to be something that youy just stick on the wall or a window and have at it.

As such, showing it in action in actual, properly installed applications is the primary way to exhibit / test the Transducer. Trade Shows, Home Shows, or direct demonstrations get that accomplished...with the expected "OMG" results that do all the convincing.
Quote:
Or, there is but the readings do not match what you claim the ears hear?
Also - explain how "db levels are high", yet SPL are lower? Please post the charts that back up these statements, I'd like to "grok" them.

You realize what happened to the "Stranger in a Strange Land" right? He got a little too "Grok'ed" eek.gif People were just not ready to accept what he had to offer them...or at least failed to understand.
I have often felt that way myself when explaining the Transducer to those who could not accept the possibilities inherent in the unit. Instead, I simply let the "Jaw drop" syndrome do all the convincing...."IF" I could arrange for a decent demonstration. wink.gif

But consider this "layman's" explanation.

Conventional Speakers produce sound by first resonating a diaphragm of some type, and with the resulting "push/pull action of the voice coil, pump those frequencies into the environment, resulting in both db and SPL production.

A surface that has a Transducer mounted behind it resonates a 360 degree, 1/2 hemisphere of dispersion...up to 8' in diameter, with every frequency radiating outward from center to it's specific point where the wave length can saturate that given point, making it accurately resonate. Highs only travel a short distant before doing such...each to a specific point, Mid-range travel further, and Bass the furthest. This is exactly what / how any full range speaker works, and it's pretty much accepted that a 10" full range speaker does a better job than a 5"er because of it's larger diaphragm area, and the obviously larger enclosure most such drivers would have if not a "Free Air" installation.

But there the differences between such "Air Motion Drivers" and Audio Transducers come into play.

The existent air pressure of a room lying against the surface a Transducer is mounted absorbs and propagates the resonant energy on the surface of the structural solid, outward into the room, air molecule to air molecule, in a cascade effect....furthering the omnidirectional dispersion. The wall does not move / travel back & forth. Instead, the Transducer itself moves very slightly within the wall / opposite side, and does so in conjunction with the amount of travel of the voice coil within the Magnet Structure / Gap.

this is why effective volume can be obtained without nearly the amount of SPL production a normal speaker produces. It is that property in and of itself that makes a Transducer system far less susceptible to acoustic concerns resulting from SPLs / and standing wave interference.

Oh....absolutely some degree of SPLs are produced, but they are markedly lower than the db levels would seem to indicate they should be. That is why at first, to many who are used to how convention speakers sound, the sound seems somehow "different" to them. Much the same as is experienced with Electrostatic Panels.

All of the above is why the Transducer is the most accepted device for sound masking applications Industry-wide. You cannot absorb frequencies into a solid if the energy of the incoming frequency does not match or exceed the level of resonant energy inherent within the material, or exceed the naturally suppressive properties of said material. And if the frequency of the surface is tuned to an appropriate level (...w/ White or Pink noise...) the surface can...and will effectively cancel out reflections, deadening the surface's absorption / reflective properties.

That is about the extent I care to delve into the subject on Cowger's thread, as I do not want the subject to become a primary focus. But I'm sure both Cowger and RedTopDown will confirm what I've related, so therein is you "Independent testing" examples....real world as it were.

But let me add this. The dearth of 3rd party Testing is really more a result of years of disinterest by those who fixate on conventional speakers, combined by the inability to test the Transducers in the many different varieties of applications it can potentially cover. The Transducer ain't a "One Trick Pony"....but just the same, it's not the "End All' in audio reproduction either, nor is it ever going to be acceptable to those who pursue and value sheer Volume / SPL production above all else.

But that's OK....let 'em regress into needing hearing aids. I myself suffer from hearing loss that comes from the excessive volume I allowed myself to suffer, from just 4-5 years involvement in the Pro Sound Reinforcement industry building and testing Live Concert PA and Discotheque systems that could...and did make my ears ring for days. Excessive use of Headphones during Mixing only worsened my loss. frown.gif
post #224 of 385
There are so many misstatements of fact in the above post I barely know where to start. The reason transducer technology is found in artistic, education and trade set-ups - because sound quality doesn't matter (primarily loudness) or it is designed to NOT be seen and/or easily stolen or damaged. There's a big difference between having exposed speakers make sound in an artistic display vs. integrated transducers into the piece in a stealth way because they want people to focus on the art. The military uses transducers as the most effective way to transmit underwater audio and signals as well as crowd-dispersing technology like the LRAD. Both are applications conventional speakers can't handle or do not perform as effectively as a transducer.

However, to equate a direct correlation from these market niche's into a high-fidelity home theater lacks the necessary translation. There is a reason why speaker manufacturers are aware of this technology and yet don't produce for high-fidelity home use....because the technology has limitations well beyond installation considerations. If a person is wanting a completely stealth look with no apparent speakers, no acoustically transparent fabric (including the screen), then transducers are the only option to get you there, but there are significant trade-offs and compromises.

MTbdudex is rightly justified in challenging your notions of fidelity as empirical measurement data is the only thing that truly evaluate actual in-room performance. What's the polar response of a transducer in typical building materials of 1/2" drywall, 5/8" drywall, 1/2" veneered plywood? All easily tested in a lab under controlled conditions and yet it's not done by the manufacturers, leaving for ad-hoc impressions as the best evidence. Every other speaker manufacturer publishes these specs for this reason. The whole realm of acoustics is focused on the science of sound reproduction for this reason....and yet you discount those of us who are of the opinion that we like to understand the performance data of our speakers, either conventional or tranducer.

This doesn't even begin to discuss integration strategies with a soundproof shell. How could a transducer perform effectively through a double 5/8" drywall / Green Glue wall? It can't, so now another wall has to be built in addition to the shell just to integrate the transducer technology....and how much will all this additional time and expense cost for what amounts to a lower fidelity system? And if you have a driver go bad in a room as nice as Cowger's, what has to happen to replace it? Tearing into all of the finish carpentry, at a minimum. Seems like a risky proposition, especially for someone without Cowger's skills (and tools) and talent to rectify the problem with surgical precision.

I think Cowger has a very nice looking theater and made the choice for what fit best with his design aesthetic while compromising on different design considerations every step of the way, including speakers. And I am sure Cowger is very happy. But it is not a responsible statement to say that transducer technology has equivalent fidelity to a conventional speaker system. Given the low cost, I am sure every other commercial theater would otherwise have transducer technology instead of an array of speakers if it didn't lack in performance in such a venue.
post #225 of 385
I plainly stated that the technology is not the "End All" nor for everyone to consider.

....and you really have no idea how widely dispersed the use of the specific transducer related is.....not at all. So don't be so wholly dismissive.
The construction methods you stated relate to what is required for conventional high db / SPL systems. Of course it is not meant to nor is applicable to use through 1 -1/2" of Fire Rated Drywall. Nope....but it does just fine through a single layer of 1/2" or 5/8". But I prefer Wood Paneling myself.

Your response parallels those I've heard over many years coming from those with little or no actual experience with the product discussed, let alone in a proper installation.

Why the adamant and negative post? Because the entire subject runs contrary to "know and accepted' beliefs. The "knee jerk" reaction is expected. But it's a little obtuse and somewhat myopic. And where did I "discount" anyone ....beyond stating that there was no vested interest or desire for many to pursue such technology?

That's really all just OK...but my intent was not to get any promotional discourse started, nor advocate the use of such in favor of or to the exception of the treasured conventional audio so many value.

So don't take it to be anything of the sort. I'll simply let Cowger and any other's make their own determinations....and so should you.

So let Cowgers project be the primary focus.
post #226 of 385
Subscribed!
post #227 of 385
Quote:
Originally Posted by popalock View Post

Subscribed!

Good move biggrin.gif. Lots of good in this thread.
post #228 of 385
Quote:
Originally Posted by cowger View Post

Now I need to figure out how to treat that surface. I was thinking either mineral oil or perhaps something called salad bowl finish. Any other ideas on what to do with this? I want something food safe that won't mind being chopped on a bit...

I use Danish Oil on mine, but I don't cut on them. Cutting boards are easier to throw in the dishwasher and keep clean.
post #229 of 385
Quote:
Originally Posted by MississippiMan View Post

I plainly stated that the technology is not the "End All" nor for everyone to consider.

....and you really have no idea how widely dispersed the use of the specific transducer related is.....not at all. So don't be so wholly dismissive.
The construction methods you stated relate to what is required for conventional high db / SPL systems. Of course it is not meant to nor is applicable to use through 1 -1/2" of Fire Rated Drywall. Nope....but it does just fine through a single layer of 1/2" or 5/8". But I prefer Wood Paneling myself.

Your response parallels those I've heard over many years coming from those with little or no actual experience with the product discussed, let alone in a proper installation.

Why the adamant and negative post? Because the entire subject runs contrary to "know and accepted' beliefs. The "knee jerk" reaction is expected. But it's a little obtuse and somewhat myopic. And where did I "discount" anyone ....beyond stating that there was no vested interest or desire for many to pursue such technology?

That's really all just OK...but my intent was not to get any promotional discourse started, nor advocate the use of such in favor of or to the exception of the treasured conventional audio so many value.

So don't take it to be anything of the sort. I'll simply let Cowger and any other's make their own determinations....and so should you.

So let Cowgers project be the primary focus.

The technology behind Cowgers invisible speaker project IS the focus here. There's no harm in discussing the invisible audio technology behind this theater in this thread, right? After all, it is in the title and you were the one that helped install the system. I can't think of a more appropriate place to discuss the details and design considerations, including trade offs. The entire AVS community benefits from these discussions.

I don't find it appropriate to make assumptions on my own personal experience or feelings with transducers. Although not as in-depth as you appear to be, it may surprise you to find that over the last 21 years I have used some transducer-based speakers, including in my current home with a variation made by Sound Advance, the SA2 speakers. I have a pair of these in my dining room for an ultra-stealth look and people are amazed with sound emanating directly from the wall. It's always a point of discussion for those that visit our home and hear the system. But I can tell you that even with a fully engineered transducer solution with complementary back box, the transducer technology has no where near the fidelity of a conventional speaker. Further, Sound Advance actually makes a compensation circuit device (essentially an EQ) that is used to help make the transducer speaker sound as good as possible. Although optional, the difference is so dramatic I think the device should be standard equipment with the speakers. An example can be found HERE.

You had mentioned that the speakers have a 35Hz - 18,000kHz frequency response through drywall, which indicates that this had been tested but then immediately turn around and state testing was not available when mtbdudex asked for additional information. I (and I am sure many others following this thread) was also interested in seeing and learning. It's obvious the radiating pattern for a transducer is different for different substrates and we were asking you to shed a bit more light on how these performed in real life from an acoustical measurement / scientific standpoint vs. the "it sounds good" more emotional standpoint as reiterated in the quoted post above. Certainly somebody who is actively involved in developments and patents would be able to offer more information to this point. But if you don't have it, then I guess you don't have it.
post #230 of 385
Quote:
Originally Posted by cowger View Post

Now I need to figure out how to treat that surface. I was thinking either mineral oil or perhaps something called salad bowl finish. Any other ideas on what to do with this? I want something food safe that won't mind being chopped on a bit...

Looks like salad bowl finish contains some sort of polyurethane, and while it might be safe for food contact it appears it is anti-recommended for a cutting surface. Then again the anti-recommenders might be crazies, so do what works for you.

Personally, for wooden cutting boards (which I prefer these days by a huge margin) I saturate them with mineral oil to keep them "wet" inside and eliminate splitting or water take-up from the occasional washing (in the sink, not the dishwasher for god's sake). Then, to for a longer lasting surface finish and to hold the oil in better I use a combination of beeswax and mineral oil that I make myself. It's something like this. I'm very happy with the results of this system.

The one drawback of this system in your situation is that that the mineral oil can actually go through the wood fibers if you apply enough to really soak the wood--which is a problem due to having a cabinet under this top. It may or may not be much of a problem for you since you'd be applying to side-grain rather than end-grain, but better safe than sorry. So I'd polyurethane the underside of the 'top to eliminate the soak-through issue, then keep the top as wet as possible with mineral oil for 2-3 days, remove the excess, then apply the beeswax mixture.

The Wood Whisperer does apply a thinned polyurethane to his end-grain boards to fill the grain and make it less porous. He doesn't seem to have been sued out of existence, so it's probably reasonably legit to use salad bowl finish, thinned polyurethane, or whatever works for you.

I'll throw in my 2 cents on the transducer issue: I wouldn't buy speakers (anymore) based on simply listening to them playing music or other material, and I wouldn't buy speakers based on a frequency response rating. At minimum I'd better see an on-axis frequency response (out of the near field), and probably still wouldn't without polars or off-axis FR curves.

I imagine one of the great things about this transducer plan is that if a person decided they didn't like their transducer install sound, you just stop feeding them and start using regular speakers--nothing lost.
post #231 of 385
One of the reasons I stay active with AVS vs the 4-5 other audio forums I am a member is the "S" in AVS is for Science.
Subjective statements need to be backed up with objective, fact based data. This is fundamental to the scientific method.

For sure I don't want to muck up Bryan's HT thread, like TMcG also stated this community can learn from a articulate and fact based exchange of ideas.

From what I see, Roland Maurice Boughton (MississippiMan) has a patent in Projection screen coating, not transducer technology.
For transparency, he is also the Registrant for Invisible Stereo, not sure who is behind Hidden Audio Systems transducers, though since Roland is their factory rep he may be the Registrant for that website as well.

Thru my "daily job" I've applied for a patent a few years back, but it was not awarded, I do understand the scientific method.

I simply originally asked Bryan these Q's:
Quote:
I come to this thread looking for acoustic measurements, like to learn about all the wall mounted transducer performance.
I'm looking for waterfall for below 250hz and gated ETC for above 250hz, did not see them posted.
Also, you are not using Audyssey EQ at all?
( I can't recall reading if you did or not).

Specifically what acoustic calibration was done?

Bryan stated he has not done any acoustic measurements.

I still request Roland to take acoustic measurements to back up his claims, to not further clog up Bryan's HT thread possible the Audio Theory forum may be a better place for such discussion.
Later I will start a thread there, and copy/paste from here to there to continue the discussion, exchange, and learning.
(too busy to create that thread just now, later today I will and edit this post and link above to point towards it)
Edited by mtbdudex - 10/16/13 at 3:32am
post #232 of 385
Quote:
Originally Posted by cowger View Post

Now I need to figure out how to treat that surface. I was thinking either mineral oil or perhaps something called salad bowl finish. Any other ideas on what to do with this? I want something food safe that won't mind being chopped on a bit...

Thanks!
Bryan

Bryan - it seems multiple applications of mineral oil with at least some monthly maintenance is recommended according to this website: http://www.oldtownhome.com/2012/11/14/Best-Method-for-Treating-a-Butcher-Block-Counter-Top/
post #233 of 385
Quote:
Originally Posted by TMcG View Post

Bryan - it seems multiple applications of mineral oil with at least some monthly maintenance is recommended according to this website

This is why I went with the beeswax mixture -- I found that I don't need to replenish it monthly. More like quarterly, unless I have to wash the board an unusual number of times. Usually it's not required because a few scrapes with the baker's blade cleans it sufficiently.
post #234 of 385
Whoa, I just noticed your table saw jig. That thing is awesome.
post #235 of 385
post #236 of 385

Very nice job all around cowger.  And I must say that I'm actually rather jealous of your shop.  You have some tools that would make my life so much more simple, lmao, that track saw probably being the top one.  Do you also find those pocket holes to hold up on the face frames?  We still use a corrugate gun and glue for our faces, but these are apparently out now as we couldn't find a new replacement gun!

post #237 of 385
Thread Starter 
The discussion about the in-wall transducers is a good one and I, too, support the merits of the questions and answers. I wish I was in a better position to provide real data, but unfortunately I'm not.

FWIW, I'm sure there are speaker choices out there (some of which I've heard) which sound cleaner and crisper to me, and from these speakers I generally notice clarity in the upper frequencies that I don't necessarily pick up as readily in my HT. For pure music listening or those seeking reference-level sound reproduction in a theater, then I'm certain there are good solutions out there.

However, for my simple needs, which are to be able to watch a movie, show, or sporting event in my theater, I'm delighted with the performance of the transducers. With 9 channels all around the room, and with sound coming from 40 different transducers, it provides an immersive feel that my wife and I truly enjoy. In fact, I was just down there watching Oblivion, and the scene where Tom Cruise is first landing his ship around the first drone repair always brings tears (of joy) to my eyes. The sound system, combined with the tactile transducers in the floor, make it sound (and feel) like the ship is landing on top of the house. I love it!!

I appreciate everyone's questions and input, and thanks to mtbdudex for starting a new thread. Looking forward to a constructive continuation of the discussion over there.

Bryan
post #238 of 385
Thread Starter 
Quote:
Originally Posted by aackthpt View Post

Whoa, I just noticed your table saw jig. That thing is awesome.

Thanks! I'm assuming you're referring to the sled that's used just for 90 degree cuts. It's something I certainly enjoy having and there are numerous plans out there for sleds, which are very simple to build. (This one happens to be from a Fine Woodworking magazine article.)

I'd say that the only disadvantage of it is the space that it takes up when you're not using it. I ended up building a special shelf for it in my outfeed table. For me, it needs to be right there and convenient or I sometimes skip getting it out for just a cut or two (which I would generally end up regretting later... : )
post #239 of 385
Thread Starter 
Quote:
Originally Posted by wdeydwondrer View Post

Very nice job all around cowger.  And I must say that I'm actually rather jealous of your shop.  You have some tools that would make my life so much more simple, lmao, that track saw probably being the top one.  Do you also find those pocket holes to hold up on the face frames?  We still use a corrugate gun and glue for our faces, but these are apparently out now as we couldn't find a new replacement gun!

Thanks! I'm delighted with the results from the pocket screw jig and joints.

As far as strength, they seem far beyond how strong I would expect a joint based on two little screws to be. If you stress the joint to failure, you'll have major wood damage to go along with it, meaning (to me) that the joint is just about as strong as the wood itself.

This bar will likely contain 200-300 pocket screws by the time I'm done. Fast, easy, strong, and they deliver a face frame joint that with a minor amount of sanding is imperceptible to the touch. Good stuff...
post #240 of 385
Thread Starter 
Finally, thank you to the numerous responses to my questions about treating the maple counter tops. aackthpt brings up a great point about not wanting something that will polymerize and therefore be susceptible to coming off when cut upon. Before I read this, I had ordered a quart of that Salad Bowl Finish, which I'll try out on one of the scraps of offcut, along with the straight mineral oil on another, and report on how things go.

And the idea of mixing in some beeswax is a great one! Certainly something to keep in mind depending upon how well straight mineral oil ends up holding up.

Tim, thanks for the pointer to the article just about taking care of these types of counters. As usual, you are the master at finding stuff on the web! : )
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