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post #6541 of 6585 Old 06-27-2020, 06:02 PM
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Finally got my holes cut. I'm excited, if everything goes good tonight i might be up testing! Seeing everyone's enjoyment with their BOSS has only made me want to finally see what the hype is all about.

Just one road block right now tho. Mojo sent me his diagram how he wired his 4 jbls for 4 ohm on one channel of his nx3000. Im wiring 4 jbl's on one channel but on the nx6000. So I'll be copying his diagram. Ive never used an ext amp like this before (just a small $50 one to run 2 of my rear height speakers with).

I know nothing about XLR or the nx6000. Once i get my final positive and negative wires, where do they go on this XLR adapter?
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post #6542 of 6585 Old 06-27-2020, 06:24 PM
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Originally Posted by GeoJustGeo View Post
Finally got my holes cut. I'm excited, if everything goes good tonight i might be up testing! Seeing everyone's enjoyment with their BOSS has only made me want to finally see what the hype is all about.

Just one road block right now tho. Mojo sent me his diagram how he wired his 4 jbls for 4 ohm on one channel of his nx3000. Im wiring 4 jbl's on one channel but on the nx6000. So I'll be copying his diagram. Ive never used an ext amp like this before (just a small $50 one to run 2 of my rear height speakers with).

I know nothing about XLR or the nx6000. Once i get my final positive and negative wires, where do they go on this XLR adapter?
So you have a neutrik 4 pole connector? If yes, then the positive should go to +1 and the negative should go to -1.
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post #6543 of 6585 Old 06-27-2020, 08:23 PM
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Originally Posted by trhought View Post
Those looking for a great comedy/action film to show off your BOSS's....look no further than this underrated gem.
Perhaps "poorly-rated" gem?

The problem I have with so many of these movies is that they may be great demo material, but they're mediocre movies.
Michael
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post #6544 of 6585 Old 06-27-2020, 08:53 PM
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Thoughts on 2 tubes with 2 iso's for a 2 seater platform HB with one driver under seat and 1 driver cantilevered using a nx6000? Basically is this ok, or do i need more iso's, or should i put a 3rd tube sideways in that open space where our feet will go?
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post #6545 of 6585 Old 06-27-2020, 09:12 PM - Thread Starter
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Originally Posted by LastButNotLeast View Post
Perhaps "poorly-rated" gem?

The problem I have with so many of these movies is that they may be great demo material, but they're mediocre movies.
Michael
Count me in the 57% that didn't like it when it first came out which is why I had forgotten about it.

I totally changed my mind after a second viewing almost 10 years later......we were rolling laughing during a few scenes

Dare I say there was even a life lesson that came full circle at the end of the movie. Didn't see that coming nor did I remember it the first go around.
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post #6546 of 6585 Old 06-27-2020, 09:16 PM - Thread Starter
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Originally Posted by GeoJustGeo View Post
Thoughts on 2 tubes with 2 iso's for a 2 seater platform HB with one driver under seat and 1 driver cantilevered using a nx6000? Basically is this ok, or do i need more iso's, or should i put a 3rd tube sideways in that open space where our feet will go?
Lookin' good Geo! I'd add a tube up front for some isolation for sure. Maybe two of them...one at each corner if your furniture legs land in those corners.

Can't wait to hear your impressions.

Won't be long now before your experience the hype
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post #6547 of 6585 Old 06-27-2020, 09:44 PM
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Originally Posted by trhought View Post
Lookin' good Geo! I'd add a tube up front for some isolation for sure. Maybe two of them...one at each corner if your furniture legs land in those corners.

Can't wait to hear your impressions.

Won't be long now before your experience the hype
Cant add 2 more, my tubes are 27.5 inches, only have space for 1 tube sideways right there.

Im gonna be up all night messing with this thing lol. Im about to start the wiring process now.
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post #6548 of 6585 Old 06-28-2020, 09:04 AM
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Originally Posted by GeoJustGeo View Post
Thoughts on 2 tubes with 2 iso's for a 2 seater platform HB with one driver under seat and 1 driver cantilevered using a nx6000? Basically is this ok, or do i need more iso's, or should i put a 3rd tube sideways in that open space where our feet will go?

So, you have one driver under each seat and one behind, then you have a bunch of plywood out in front beyond that? Is that correct? You definitely want some isos, another tube or a combination of those in that other area, to keep the platform even and balanced if nothing else. Be prepared to experiment with iso placement, tube pressure, etc until you find the right combo for your setup.
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post #6549 of 6585 Old 06-28-2020, 02:37 PM
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Going to take the HB plunge. I ordered three 26” fat tire tubes for my 6 speaker boss.
Question: is it practical to place the flat tubes under the couch and speakers and inflate them while they are underneath? The reason I’m asking is because I have a heavy triple layer birchwood boss and the couch is anchored to all of the wiring. Want to avoid having to detach everything by lifting up the platform.
Also, Hoping that the weight of the platform might effectively seal the tubes against the boss and tile floor?
Regarding, the psi of the innertube... I’ll use the 4 quarter method which should leave the isolators in contact with the ground? I’m getting the stem extenders and psi gauge to monitor.
Feedback is appreciated.
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post #6550 of 6585 Old 06-28-2020, 05:13 PM
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Originally Posted by FLViking2011 View Post
Going to take the HB plunge. I ordered three 26” fat tire tubes for my 6 speaker boss.
Question: is it practical to place the flat tubes under the couch and speakers and inflate them while they are underneath? The reason I’m asking is because I have a heavy triple layer birchwood boss and the couch is anchored to all of the wiring. Want to avoid having to detach everything by lifting up the platform.
Also, Hoping that the weight of the platform might effectively seal the tubes against the boss and tile floor?
Regarding, the psi of the innertube... I’ll use the 4 quarter method which should leave the isolators in contact with the ground? I’m getting the stem extenders and psi gauge to monitor.
Feedback is appreciated.
Don’t count on the weight of the platform to seal your tubes. Even though it’s a pain, you should seal your tubes at the top with double sided tape, then seal on bottom with painters plastic or acrylic disk, etc (again with double sided tape).
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post #6551 of 6585 Old 06-28-2020, 05:34 PM
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Quote:
Originally Posted by m0j0 View Post
Quote:
Originally Posted by FLViking2011 View Post
Going to take the HB plunge. I ordered three 26” fat tire tubes for my 6 speaker boss.
Question: is it practical to place the flat tubes under the couch and speakers and inflate them while they are underneath? The reason I’️m asking is because I have a heavy triple layer birchwood boss and the couch is anchored to all of the wiring. Want to avoid having to detach everything by lifting up the platform.
Also, Hoping that the weight of the platform might effectively seal the tubes against the boss and tile floor?
Regarding, the psi of the innertube... I’️ll use the 4 quarter method which should leave the isolators in contact with the ground? I’️m getting the stem extenders and psi gauge to monitor.
Feedback is appreciated.
Don’️t count on the weight of the platform to seal your tubes. Even though it’️s a pain, you should seal your tubes at the top with double sided tape, then seal on bottom with painters plastic or acrylic disk, etc (again with double sided tape).
I thought that was only for carpet? I’m on flat tile. Have you tried both on tile or carpet?
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post #6552 of 6585 Old 06-28-2020, 09:20 PM
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Originally Posted by Zallou3 View Post
I finally had the time to install the hoverBOSS under my bed, the bed alone is around 300 kgs and the way everything is shaking is just insane!!
I'm yet to find a way to seal the tubes without having to take to bed off and flip the platform, tried painters plaster but they made a lot of noise and had to get rid of them, they are unwanted noise coming out of the tubes and drivers, the air pressure is lifting them from the ground! going to attach a youtube vid of them playing a 5 hz sine wave! i;m strong down to 2 hz!
@trhought

https://www.youtube.com/watch?v=4cRUqq8jYgA

Boss platforms ready to be marketed to hotels, movie rentals might go through roof.

-The single digits are where the magic lies.....they deliver a 'touch of god' sensation that sometimes makes the hairs on one's arms stand up. It's hard to describe but it feels like you are there in the recording studio with the artist and "feeling" them move as they are playing the instrument. You can't see them, but you can feel them as movements are happening on the floor below you. - trhought
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post #6553 of 6585 Old 06-29-2020, 05:30 AM
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I thought that was only for carpet? I’m on flat tile. Have you tried both on tile or carpet?
If I recall, @Nalleh has a heavy platform and is on tile and reported air escaping the tubes on big transients. I myself am on carpet so that is all I have first hand experience with.
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post #6554 of 6585 Old 06-29-2020, 09:09 AM
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If I recall, @Nalleh has a heavy platform and is on tile and reported air escaping the tubes on big transients. I myself am on carpet so that is all I have first hand experience with.
I am on hardwood floors, but had absolutely NO problem blowing air past the tubes before i taped them! Taping them both above to the plywood and below with discs or heavy duty plastic is highly recommended !
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post #6555 of 6585 Old 06-29-2020, 11:07 AM - Thread Starter
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Originally Posted by FLViking2011 View Post
Going to take the HB plunge. I ordered three 26” fat tire tubes for my 6 speaker boss.
Question: is it practical to place the flat tubes under the couch and speakers and inflate them while they are underneath? The reason I’m asking is because I have a heavy triple layer birchwood boss and the couch is anchored to all of the wiring. Want to avoid having to detach everything by lifting up the platform.
Also, Hoping that the weight of the platform might effectively seal the tubes against the boss and tile floor?
Regarding, the psi of the innertube... I’ll use the 4 quarter method which should leave the isolators in contact with the ground? I’m getting the stem extenders and psi gauge to monitor.
Feedback is appreciated.
FLViking.....Thanks for the update on your plans for the HB add-on. No problems inflating the tubes while they're underneath. As inflating, just bounce the platform up and down to get any folds out of the tubes as the platform starts to rise.

Regarding sealing....HB doesn't produce much pressure...fractions of a psi in most cases. So, the game becomes preserving as much of that pressure/vacuum as possible when in operation. Tile floors are better than carpet for leakage, but the grout lines can be a challenge as they present leak points when the tubes don't fill those voids completely.

Hope this helps.

Looking forward to learning more about your HB retrofit and impressions afterwards.
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post #6556 of 6585 Old 06-29-2020, 04:21 PM
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Quote:
Originally Posted by trhought View Post
Quote:
Originally Posted by FLViking2011 View Post
Going to take the HB plunge. I ordered three 26&#226;€ fat tire tubes for my 6 speaker boss.
Question: is it practical to place the flat tubes under the couch and speakers and inflate them while they are underneath? The reason I&#226;€&#x2122;&#xfe0f;m asking is because I have a heavy triple layer birchwood boss and the couch is anchored to all of the wiring. Want to avoid having to detach everything by lifting up the platform.
Also, Hoping that the weight of the platform might effectively seal the tubes against the boss and tile floor?
Regarding, the psi of the innertube... I&#226;€&#x2122;&#xfe0f;ll use the 4 quarter method which should leave the isolators in contact with the ground? I&#226;€&#x2122;&#xfe0f;m getting the stem extenders and psi gauge to monitor.
Feedback is appreciated.
FLViking.....Thanks for the update on your plans for the HB add-on. No problems inflating the tubes while they're underneath. As inflating, just bounce the platform up and down to get any folds out of the tubes as the platform starts to rise.

Regarding sealing....HB doesn't produce much pressure...fractions of a psi in most cases. So, the game becomes preserving as much of that pressure/vacuum as possible when in operation. Tile floors are better than carpet for leakage, but the grout lines can be a challenge as they present leak points when the tubes don't fill those voids completely.

Hope this helps.

Looking forward to learning more about your HB retrofit and impressions afterwards. [IMG class=inlineimg]/forum/images/smilies/smile.gif[/IMG]
Thank you. Approximately what kind of difference in TR vs OG-BOSS can be expected? 20% more TR?
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post #6557 of 6585 Old 06-29-2020, 05:03 PM - Thread Starter
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Thank you. Approximately what kind of difference in TR vs OG-BOSS can be expected? 20% more TR?
Good question. It depends on frequency. Below 10Hz, there will be about 7-10x more shaker potential with the JBL's with HB add-on....especially below 6Hz. Above 15Hz, there won't be much of a difference because the pressures generated inside the HB tubes aren't very much at these higher frequencies. The OG-BOSS shaker potential (Xmax times Mms) is still the biggest contributing factor at these higher frequencies with the prescribed isolators in the system.

Hope this helps.
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post #6558 of 6585 Old 06-30-2020, 07:18 AM
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While catching up with this thread, I noticed growing interest in stuffing the HoverColumn for increased pumping efficiency. While many of the methods being considered have excellent mechanical compliance(-eg. pillows), it's density that's going to bring the efficiency #'s up. My intention has been to experiment with glycerine, water/alchohol & gelatin mixtures along with an antimicrobial agent - possibly adding sugar as well.

This material is used by artists for creating permanent flexible printing plates. It's cheap & fast to make, while allowing for a direct mechanical connection between the speaker and your platform base. Aron7awol has reported good results with his experiments with direct mechanical coupling to speakers, & this would do essentially the same thing but leave your speakers unmolested and without need to modify them in any way. I was also considering wrapping the material in saran wrap - ie drape the plastic wrap over the cone, then pour the material into it using the cone as a mold. Once set, wrap the excess plastic wrap around the top of the material to seal it up.

I should also mention, that my plan was to add a shirt carboard or similar ring - maybe 1" tall around the cone just at the inside of the surround to the mold, to form a stub flange to bear against the floor directly, without impeding the surround accordian pleat at all. This carboard ring will be removed once the cast is set.

On youtube, there's also a vid of someone making silicone based mold material that's very tough. That would likely be my 1st choice, but it seems to be a bit more work & expense to get there. If you wrap & well seal your speakers in plastic wrap entirely, you could protect them from possible damage from the outgassing of that material - should that be a concern for you. Here's a link to the homebrewed silicone material: www.youtube.com/watch?v=D9Coa01vRz4

Here's the basic recipe & a couple links for the glycerine flexible printing plate material:
1.5 cups water, 8 packs of gelatin, 3/4 cup glycerin, 3/4 cup alcohol(optional). Whisk, nuke, whisk, nuke until clear, pour into speaker cone & let sit overnight. www.youtube.com/watch?v=eSWARB2QXFk
www.youtube.com/watch?v=JmOS3MBamK4

On a different matter, it was recently posted(again) that there is periodically a vacuum present within the HoverColumn. For this to happen, the tube to platform/floor interface would have to be leaking like a sieve AND the system would need to experience considerable overshoot for protracted periods at low frequencies, far beyond what I've ever experienced. I suppose it's possible, but rather unlikely.

Think of your chair/couch being tossed up in the air at the top of the cycle like a little kid on a teeter totter with an adult on the other end, and you'll have the idea. Maybe this can happen with the big guy - Alpha-TR heavy hitter systems, but definitely not on my 14KW(~18HP) system. I suspect their systems are tuned better than that in any case.

So, to avoid any misconceptions about the operating principles involved with the tubes OF hover, I thought I'd again mention that there is only an increase or reduction in pressure, not a vacuum present during the operational cycle. IMHO, to foster further innovation, it should be made clear how this stuff actually works to the best of our ability to define it.
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post #6559 of 6585 Old 06-30-2020, 07:52 AM
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So @Longeze , I believe I joked about Jell-o being used some time ago. It sounds like you're going to make a jell-o mold for your JBL's then? Cool!
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post #6560 of 6585 Old 06-30-2020, 10:15 AM - Thread Starter
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Quote:
Originally Posted by Longeze View Post
While catching up with this thread, I noticed growing interest in stuffing the HoverColumn for increased pumping efficiency. While many of the methods being considered have excellent mechanical compliance(-eg. pillows), it's density that's going to bring the efficiency #'s up. My intention has been to experiment with glycerine, water/alchohol & gelatin mixtures along with an antimicrobial agent - possibly adding sugar as well.

This material is used by artists for creating permanent flexible printing plates. It's cheap & fast to make, while allowing for a direct mechanical connection between the speaker and your platform base. Aron7awol has reported good results with his experiments with direct mechanical coupling to speakers, & this would do essentially the same thing but leave your speakers unmolested and without need to modify them in any way. I was also considering wrapping the material in saran wrap - ie drape the plastic wrap over the cone, then pour the material into it using the cone as a mold. Once set, wrap the excess plastic wrap around the top of the material to seal it up.

I should also mention, that my plan was to add a shirt carboard or similar ring - maybe 1" tall around the cone just at the inside of the surround to the mold, to form a stub flange to bear against the floor directly, without impeding the surround accordian pleat at all. This carboard ring will be removed once the cast is set.

On youtube, there's also a vid of someone making silicone based mold material that's very tough. That would likely be my 1st choice, but it seems to be a bit more work & expense to get there. If you wrap & well seal your speakers in plastic wrap entirely, you could protect them from possible damage from the outgassing of that material - should that be a concern for you. Here's a link to the homebrewed silicone material: www.youtube.com/watch?v=D9Coa01vRz4

Here's the basic recipe & a couple links for the glycerine flexible printing plate material:
1.5 cups water, 8 packs of gelatin, 3/4 cup glycerin, 3/4 cup alcohol(optional). Whisk, nuke, whisk, nuke until clear, pour into speaker cone & let sit overnight. www.youtube.com/watch?v=eSWARB2QXFk
www.youtube.com/watch?v=JmOS3MBamK4

On a different matter, it was recently posted(again) that there is periodically a vacuum present within the HoverColumn. For this to happen, the tube to platform/floor interface would have to be leaking like a sieve AND the system would need to experience considerable overshoot for protracted periods at low frequencies, far beyond what I've ever experienced. I suppose it's possible, but rather unlikely.

Think of your chair/couch being tossed up in the air at the top of the cycle like a little kid on a teeter totter with an adult on the other end, and you'll have the idea. Maybe this can happen with the big guy - Alpha-TR heavy hitter systems, but definitely not on my 14KW(~18HP) system. I suspect their systems are tuned better than that in any case.

So, to avoid any misconceptions about the operating principles involved with the tubes OF hover, I thought I'd again mention that there is only an increase or reduction in pressure, not a vacuum present during the operational cycle. IMHO, to foster further innovation, it should be made clear how this stuff actually works to the best of our ability to define it.
Rather than trying gelatin, try the pillows....much easier to implement. Just toss some pillows into the hover cavity and check it out. I think you'll like the improvement if seeking to increase displacement. It was a bit much for my liking, but for those seeking a theme park ride experience, it's an easy add-on taking only minutes.

With the high velocities we're talking about here, the viscosity differences between the 2 materials are negligible. At the lower frequencies, sub 6Hz, there could be enough of a difference I suppose with the gelatin not doing as well as the cushions because of it's non-newtonian behavior at those lower speeds causing it to give more than the pillow. Would be interesting to see a comparison.

Regarding vacuum.....just rig up a homemade manometer like I did and you'll see there is both pressure and vacuum that exists in the hover cavity during operation at lower frequencies where it counts The vacuum occurs when the platform goes upward beyond it's normal resting condition which happens at the lower frequencies with tubes as hover. It's a very easy experiment and costs less than $10 for some tubing from the local hardware store.
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post #6561 of 6585 Old 06-30-2020, 11:19 AM - Thread Starter
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^^^ I should also add. @Longeze The above is for the baseline JBL's and the 16" diameter tubes with 180 lbs on each JBL. The platform starts to go above it's resting position at frequencies below 6Hz.

If your tubes are larger than 16"/driver, or the weight on top of the platform is more than 180 lbs/driver, or you're not using the JBL's anymore, the pressure inside may not be getting high enough to move your platform beyond it's resting position in the upward direction. In this case, I agree, it is indeed different levels of pressure and no vacuum is being achieved.

At the lower frequencies, at top dead center (platform all the way up above resting position), there is decompression of the trapped HB volume, then the cone starts to move upward as top dead center is being achieved which further decompresses the HB volume.

At higher frequencies, not enough pressure is generated in the HB volume because cone excursion is very small and the platform movement is more a function of vibration and less about pressure in the HB volume.

Just wanted to provide a bit more context for the subject we're talking about here.
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post #6562 of 6585 Old 06-30-2020, 01:17 PM
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Rather than trying gelatin, try the pillows....much easier to implement. Just toss some pillows into the hover cavity and check it out. I think you'll like the improvement if seeking to increase displacement.
You're posting this as if you're teaching me something new, yet when I brought up the idea over six months ago, it should be said that you didn't acknowledge the idea as having any merit. Moreover, why do you encourage people to dismiss a perfectly reasonable, inexpensive and easy alternative for mechanical coupling of a speaker cone to the platform, or for that matter, as a method to fill the cavity to improve pumping efficiency? I thought we were after the same things here.

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It was a bit much for my liking, but for those seeking a theme park ride experience, it's an easy add-on taking only minutes.
The purpose of this isn't just to create a "theme park ride experience", although that sounds fun. For me(and others) it's about recreating the input signal accurately at ALL Hz's. If that's not what you want, that's fine but did you read @aron7awol 's posts comparing his results to his Crowsons and the linear response he's achieving? I'm just saying that for people wanting to obtain possibly competitive results, or to experiment with mechanical coupling, I'm presenting a method to accomplish that without sacrificing their drivers or having a need to possess any particular fabrication skills. Where's the downside in that?

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With the high velocities we're talking about here, the viscosity differences between the 2 materials are negligible. At the lower frequencies, sub 6Hz, there could be enough of a difference I suppose with the gelatin not doing as well as the cushions because of it's non-newtonian behavior at those lower speeds causing it to give more than the pillow. Would be interesting to see a comparison.
Yes, gelatin is a non-newtonian fluid, and foam compresses. Horses for courses. If the purpose is using the material for stuffing, then the gelatin may exhibit some extrusion like behavior but will remain within the hoverColumn to displace the air, while the cushion material will displace less of the air in the chamber & compress increasingly as it's loaded at lower Hz's. The cusions are permeable regardless, which is why they won't outperform the gel even at low Hz's, as long as both materials are contained within the chamber. I should just say that a lot of the area within a cushion is just air, so you've taken up a lot of space but havent displaced as much working fluid as you otherwise could be with something of greater density. I'll readily acknowledge that it's "possible" that the gel or silicone based compound "could" have some slight damping effect at certain Hz's, but the same is true of the cusion material, albeit likely not at the very lowest Hz's.

By trying to couch this discussion in such overtly technical terms, you realize that you're likely losing most everyone in this discussion, making it inaccessable for people to participate, let alone form an opinion either way. I'd rather keep people included and engaged. But hey, it's your thread, so non-Newtonian fluids, stress, strain, sheer & fluid viscosity it is - apparently. Personally, not being an expert in fluid dynamics, I'll bow out on that at this point and leave it to you and the other experts in that discipline to determine the merits in those respects.

To your comment about high velocities rendering the differences between materials negligible, assuming you were able to contain both materials to position them securely over the top of an air compressor's piston, with a 1/4" thickness(representative sample), which material would yield a higher chamber psi? My bet is it won't be the cushion material, as long as the pressures are kept within the gel sheet's sheer or elastic limits as it will be in this application(stuffing), so that it won't rupture. You "may" have a point that for direct mechanical coupling, the gel might prove unsuitable, which is why I said I favored using the silicone based mixture in that application, which I expect will be just fine.

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Regarding vacuum.....just rig up a homemade manometer like I did and you'll see there is both pressure and vacuum that exists in the hover cavity during operation at lower frequencies where it counts The vacuum occurs when the platform goes upward beyond it's normal resting condition which happens at the lower frequencies with tubes as hover. It's a very easy experiment and costs less than $10 for some tubing from the local hardware store.
I won't need to rig a water manometer. Although I do possess several viscous damped calibrated gauges, they're not the right tool for this job, so I wouldn't use either of them. What's required is a gauge that measures absolute pressure not gauge pressure. Which are you measuring? I think your answer lies there. I stand by my statement that there isn't a vacuum present in the hoverColumn, barring the circumstance of EXTREME overshoot as I originally stated(which you were then kind enough to reiterate, so as to explain to me what I had just said) LoL In such circumstance, the inertia carries the platform out of phase to an extent that you've exceeded your systems ability to keep it under control, in which case your system is severely underdamped and you should look there to resolve that issue, but under normal(controlled) operating conditions, there shouldn't be a vacuum present. EDIT: I was writing this while you posted again about this, and since it seems that you're acknowledging my point here - sort of. I don't mean to beat a dead horse, but I can't re-write this now, so this will have to suffice - I hope. FWIW, I'm using the original JBL's loaded as per my design roughly inline with your 180lbs & using mostly standard 16" tubes, but I don't experience the overshoot you describe. Maybe you're bouncing off your iso's, or maybe we're running very different pressures &/or EQ and gain profiles IDK.

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post #6563 of 6585 Old 06-30-2020, 06:04 PM - Thread Starter
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^^^^ I would be interested in seeing the comparison of gelatin vs. pillow like I said. Not discouraging you or anyone esle from experimenting with gelatin. Just offering a different (maybe simpler) approach with the pillows. Maybe the gelatin approach will be more simple. It just sounded more complex given the ingredients and methods described. Cushions are usually more readily available and most homes probably already have a few of them laying around.

Regarding the vacuum...I measured vacuum and additional platform bending due to the vacuum forces acting down on the platform in the single digits. You say there isn't any with your setup. That's believable because each setup is unique and there's a lot of variables that go into the ability to create the vacuum. Also, the vacuum only happens below 10Hz so maybe that's what you were trying to get at with your original post about vacuum not existing....not sure.

I love single digit response and always have since coming up with BOSS. It brings that magical, god-like feel to any material....music and movies. Creating vacuum with my front row HB is a big part of the experience up there. Sometimes it's a bit much below 10Hz for my liking (motion sickness). But, that's why we have the back row OB BOSS which has less energy below 10Hz and is easier on the body.

The pillow boss has even more energy below 10Hz than HB You'll hopefully find a similar experience with the gelatin boss providing more energy and more accurate TR than the HB because of the direct coupling.

Keep in mind, I'm running the same signal to both my BOSS platforms since I BEQ remux without any DSP or gain control in my signal chain after the AVR (unless I count the DSP controls I have on my 3 subwoofers). But for TR like we're talking about, I depend on the AVR to do the heavy lifting with the BEQ material I feed it and shaping the sub-out signal that is fed to both BOSS platforms via its BM settings.

I love having this setup because not only are the BEQ filters added to my BOSS platforms, but my higher BEQ filters (sometimes up to 80Hz) also go into my bed channels which makes my LFE more full in sound and feel all around me. BEQ remux aslo allows boost to be added below 10Hz. My average BEQ has 20dB boost levels below 6Hz to bring the wobble I love so much to our back row BOSS. That's probably why the TR in our front row can be too much for my liking sometimes below 10Hz. But, our kids and their friends love it up there so I keep everything as-is for now.
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post #6564 of 6585 Old 06-30-2020, 09:25 PM
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...Just offering a different (maybe simpler) approach with the pillows. Maybe the gelatin approach will be more simple. It just sounded more complex given the ingredients and methods described. Cushions are usually more readily available and most homes probably already have a few of them laying around.

Regarding the vacuum...I measured vacuum and additional platform bending due to the vacuum forces acting down on the platform in the single digits. You say there isn't any with your setup. That's believable because each setup is unique and there's a lot of variables that go into the ability to create the vacuum. Also, the vacuum only happens below 10Hz so maybe that's what you were trying to get at with your original post about vacuum not existing....not sure.. The pillow boss has even more energy below 10Hz than HB.. You'll hopefully find a similar experience with the gelatin boss providing more energy and more accurate TR than the HB because of the direct coupling...
I was just using the gels as an example, since it isn't really any more difficult than making Jello shots. You could use latex or even silicone caulk - the hardware stores are full of the stuff but yeah, you spend a few bucks to get it, but it's an easy way to mechanically couple.

Using a large couch weighing ~200lbs as my platform, with 4 JBL 1214's I've never come close to having my HoverCouch lift off the tubes, even at max gain with +15db boost @ 10Hz while either of us are seated. If that's what you have going on, I can see why you think it's an amusement park ride. FWIW, I've run my HoverCouch down to 2Hz at max gain countless times without decoupling. What I'm getting at, is that my system won't pull a vacuum - at any Hz - period. I'm saying that unless you're platform is getting pitched off your tubes, that won't happen, and that if it is, that you might want to address your system damping if you're at all interested in recreating the signal being input with any degree of reasonable accuracy < 20Hz. Your pillow stuffed configuration has the same energy below 10hz as HB, it's just transferring it more efficiently is what I think you're saying.

FWIW, experiments with stuffing are a ways down the road for me for the same reason I haven't bothered with sealing, changing out all my tubes for fatter ones or any of a number of other worthwhile improvements - yet. I'm operating under the premise that my current drivers are going to be Xmax limited for my purposes no matter how efficiently I employ them, so I don't see the point in spending time & effort to improve their performance. You want a faster car, you start with something that's already fast and go from there.

I agree with the Dbox design premise, which says that huge Xmax is required to accurately recreate ULF signals in a proportionate manner at levels sufficient to pressurize the room overall. To that end, I'm working on collecting the drivers necessary to accomplish that objective(which I hopefully have done). Then I'll work on using them in a more efficient manner and in a configuration to yield a more linear platform response. I'd also like to change the fundamental configuration to ditch some weight so that the drivers aren't working against themselves. So many plans, so little time... Happy hovering Tim

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post #6565 of 6585 Old 07-01-2020, 05:38 AM
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So @Longeze , I believe I joked about Jell-o being used some time ago. It sounds like you're going to make a jell-o mold for your JBL's then? Cool!
PMSL!!! You know, I seem to recall that you did? You may have full blame .. errr.. "credit" for the idea then good sir. It was certainly not my intent to steal your fire.. errr.. jello

...Whipped cream???
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PMSL!!! You know, I seem to recall that you did? You may have full blame .. errr.. "credit" for the idea then good sir. It was certainly not my intent to steal your fire.. errr.. jello

...Whipped cream???
^^^ Actually, that sort of thing(appropriation of others ideas as your own) is kinda interesting to me actually. In this instance, I stumbled on the printing gels(jello) just by dumb luck while searching for conformal materials & silicone & latex alternatives on utube. My starting point being a DIY method for making breast implant type material that could be altered in viscosity to fit this application - either stuffing(sry no pun intended) or as a method for mechanical coupling.

But IIRC, I think it was on 60Minutes that there was a segment on human tendency towards IP appropriation. It's unsurprising that it's rather common, albeit unintentional in many cases. That's the bit that I think is most interesting. I always assumed people were intentionally screwing me LoL(long history of failure to keep my mouth shut) . FWIW, I've found that NDA's really don't help all that much, as people are going to do what they're gonna do. Also, as you might expect, some people have more of a tendency towards that behavior than others. I just thought that was a curious quirk of human nature, so thought I'd toss it out there while sort of on the subject. Carry on...

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post #6567 of 6585 Old 07-01-2020, 06:19 AM
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PMSL!!! You know, I seem to recall that you did? You may have full blame .. errr.. "credit" for the idea then good sir. It was certainly not my intent to steal your fire.. errr.. jello

...Whipped cream???
Too funny sir!
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post #6568 of 6585 Old 07-01-2020, 07:11 AM
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So we're back to this:

Full circle.
Michael

edit: for those late to the game, that was here, re isos:
https://www.avsforum.com/forum/19-de...l#post57723882
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post #6569 of 6585 Old 07-01-2020, 10:45 AM - Thread Starter
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What I'm getting at, is that my system won't pull a vacuum - at any Hz - period. I'm saying that unless you're platform is getting pitched off your tubes, that won't happen, and that if it is, that you might want to address your system damping if you're at all interested in recreating the signal being input with any degree of reasonable accuracy < 20Hz.
I'm not tracking with the vacuum topic. I use the term vacuum in the traditional definition as shown in the diagram below (negative gage pressure).

Using a simple open ended manometer like pictured, I've measured pressure as high as .75 psig during hard transients and vacuum levels as high as -.5 psig with the same hard transients using the JBL's and 16" tubes.

Using sine waves, the pressure is around .3 psig and vacuum is around -.2 psig as frequency goes below 6Hz.

My setup is sealed as much as possible and there's no burping that happens. Burping would only bring the HB volume presssure to atmosphere and not create any shaker potential. That's why sealing the HB cavity is so important...to minimize any leakage and preserve the pressure/vacuum created inside the HB cavity.

Despite my best efforts to seal with tape and plastic, my setup still leaks slowly. It takes about 30 seconds for the pressure to equalize to atmosphere when I sit down before testing. But once the driver starts to do work, it's clearly creating positive psig (pressure) and negative psig (vacuum). Both of which provide substantial forces up (pressure) and down (vacuum). This force has been measured as high as 30 lbs up and 20 lbs down per JBL.

Said another way, imagine the jar below having a rubber diaphram on top of it. When lifting that diaphram out of the jar there is negative psig created when reading the manometer (vacuum). When pushing the diaphram into the jar positivie psig is created when reading the manometer (pressure). This is essentially how HB behaves at lower frequencies with higher cone excursion....creating both vacuum and pressure, especially below 6Hz.

I also have models that predict with good accuracy (<10% error) how much pressure/vacuum any driver can generate in the frequency domain per normalized driver area. This is based on energy equations in Mathcad using inputs from WinISD for the driver. The model has been dialed in using 3 different drivers to date with decent accuracy. This has been handy in exploring different shaker potentials including the pillow boss alignment.

Making one of these manometers is crazy simple. Mine is just an 8mm OD soft rubber tube with 1mm walls. The size of the tube is only relevant because I insert it into a .25" hole drilled in the BOSS platform next to my drivers and inside the bicycle tubes. This press fit of rubber into the hole seals it nicely. Water works fine for the manometer fluid since the pressures/vacuums being measured are so small. Then it's just a matter of visibly watching what heights were achieved on the cardboard manometer stand with the tube duct taped to it. Very simple. I marked the cardboard in .1 psi increments in both directions (vacuum and pressure)...every 2.8 inches of displaced water equals .1 psi/vacuum

Hope this helps with your HB experiments.

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post #6570 of 6585 Old 07-01-2020, 06:52 PM
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I can't tell quite where you're coming from with this. For a DIALOGUE to happen, it helps a lot if both parties listen and acknowledge what the other is saying, for mutual understanding to take place.

What I'm seeing recursively, is you trying to "teach" me, while for the most part ignoring whatever you don't care to address that might conflict with your own confirmation bias. It's really rather pointless on both sides at that point. You're not listening to or acknowledging what I'm saying, and you keep saying the same things - redundantly ...as if I don't understand your posts(which I assure you - I do... all of them in their entirity). Maybe you're used to lecturing people - IDK, but this isn't that context. Since you've gone to considerable effort in your response, complete with diagrams presumably for my benefit, I'll take one more pass at this in the hopes that the penny will drop, and you'll realize what I've been saying from my 1st post on these topics.

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I'm not tracking with the vacuum topic. I use the term vacuum in the traditional definition as shown in the diagram below (negative gage pressure).
I can see this LoL... We're not working from the same playbook. If I were you, I might say "Putting it simply", 1 atm is 14.6956 psi = 760 torr which as it happens, is the standard unit measure for vacuum. Vacuum isn't "traditionally" measured as "negative gage pressure", it's conventionally measured (as I said) with an absolute pressure gauge which references a vacuum, not the atmosphere. In the alternative, you could use gauge pressure and subtract 14.7psi to get an approximation of value. The down side of using gauge pressure is that that atmospheric conditions can and do change wildly from one day/hr/minute to the next, resulting in significant variations in your values, especially when the values are small as ours presumably are. To be at all accurate, you'd have to adjust for deviation from STP(standard temperature & pressure).

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Using a simple open ended manometer like pictured, I've measured pressure as high as .75 psig during hard transients and vacuum levels as high as -.5 psig with the same hard transients using the JBL's and 16" tubes.
You've measured pressures of +15.45psia ~ +14.20psia

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Using sine waves, the pressure is around .3 psig and vacuum is around -.2 psig as frequency goes below 6Hz.
Again, your pressure is +15.00psia to +14.50psia

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Originally Posted by trhought View Post
My setup is sealed as much as possible and there's no burping that happens. Burping would only bring the HB volume presssure to atmosphere and not create any shaker potential. That's why sealing the HB cavity is so important...to minimize any leakage and preserve the pressure/vacuum created inside the HB cavity.
Take a minute and think about what you've said here, starting with not creating any shaker potential. My tubes aren't taped or sealed, and the JBL's alone will shake my HoverCouch like hell at all frequencies.

Sealing the hoverColumn is useful to improve coupling efficiency and improve linearity.

Burping definitely happens with your hoverColumn as you state further on. It just doesn't happen to any significant extent(presumably) under dynamic conditions.

The thing I'm trying to point out to you is that if your column was truly sealed, then you would never go below 0psig, because you'd be starting with sufficient positive pressure in your column such that it wouldn't be offset below zero - barring teeter totter tossing. You'd only see variations in positive pressure during period oscillation, as your column becomes loaded and unloaded to varying degrees, even when referenced to the atmosphere as you're doing.

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Despite my best efforts to seal with tape and plastic, my setup still leaks slowly. It takes about 30 seconds for the pressure to equalize to atmosphere when I sit down before testing. But once the driver starts to do work, it's clearly creating positive psig (pressure) and negative psig (vacuum). Both of which provide substantial forces up (pressure) and down (vacuum). This force has been measured as high as 30 lbs up and 20 lbs down per JBL.
Geeez... The jury is out with me about the whole bleeding off pressure from the hoverColumn thing. What happens when someone gets up or sits down while a flick is playing, or adjusts their position(or their shorts)? If any of that happens during relatively quiet periods, or durations lacking <20hz content, where are you then? I "get" the idea of trying to work from the center of the Xmax/Xmech range and the possible benefits of staying within the most effective & safe working range of the magnetic gap and all that, but I'm unconvinced that bleeding offers any real benefit, especially if you have sufficient Xmax to begin with. I recall Nalleh & others seem to be advocates of bleeding so there is that. They were probably barbers in their last lives though...

Looking at it another way, say you don't bleed off pressure. Then you have more travel available in the positive direction with correspondingly less on the way down. If your bump stop dampers are properly positioned, then there's an arguement that could be made that this is a potentially good thing instead of a liability.

Going just a bit further, on the way down I maintain that the release of the energy of position is the primary motive force, not the drivers, so the fact that with 4 drivers you have 80lbs of "pull", pales somewhat against the presumed 6~800lbs bearing down on them, so I'm not sure that's an aspect of performance that I'd want to chase.

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Said another way, imagine the jar below having a rubber diaphram on top of it. When lifting that diaphram out of the jar there is negative psig created when reading the manometer (vacuum). When pushing the diaphram into the jar positivie psig is created when reading the manometer (pressure). This is essentially how HB behaves at lower frequencies with higher cone excursion....creating both vacuum and pressure, especially below 6Hz.
To follow this example, your system would have to be mechanically decoupled and working out of phase, which isn't desirable. I say work the problem & fix that rather than accept it as proper operational regime. If your system were critically damped, this wouldn't be happening. Even so, in your example, there still isn't a proper vacuum being pulled, but I take your intended meaning.

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Originally Posted by trhought View Post
I also have models that predict with good accuracy (<10% error) how much pressure/vacuum any driver can generate in the frequency domain per normalized driver area. This is based on energy equations in Mathcad using inputs from WinISD for the driver. The model has been dialed in using 3 different drivers to date with decent accuracy. This has been handy in exploring different shaker potentials including the pillow boss alignment.
Yes, I'm aware of it. You've posted "about' this numerous times, but you never show the model algo's or the data printout/ graphs. Post em up Man and lets all have a gander Do your models include a 180lb load sitting on the drivers - curious?

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Making one of these manometers is crazy simple. Mine is just an 8mm OD soft rubber tube with... .. .
Thanks, but having built one in the 7th grade, I'm familiar with the exercise As it happens, I already possess several adjustable multi-chamber manometers. If I were more dedicated, I could monitor the working pressure in all my hoverColumns simultaneously.

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Hope this helps with your HB experiments.
It's interesting, but unfortunately having recently retired from a 30yr career as an I&C engineer, {See: https//en.wikipedia.org/wiki/Instrumentation_and_control_engineering} it will not. Reading your response was akin to a doctor listening to his patient tell him how to use a stethoscope - for the 3rd time. Personally, I wouldn't respond to a peer in a related discipline with a treatise containing such rudimentary topics like that(unprovoked). I know you deal with a widely diverse group of people and are generous with your time in doing so, so no offense. Peace
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