Too crazy of a sub idea? - Page 4 - AVS Forum | Home Theater Discussions And Reviews
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post #91 of 159 Old 08-06-2015, 07:09 AM
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Quote:
Originally Posted by Scott Simonian View Post
But can it run Crysis?
I've been playing FarCry, Crysis, Crysis Warhead, and Crysis 2 for years with the same system that runs JRiver. In recent years I've even been able to use JRiver for bass management with all games.

Just played through Crysis Warhead SP again a few weeks ago. I've also probably played 50+ SP maps for Crysis. Its amazing how well the Crytek games play now with a GTX 970.
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post #92 of 159 Old 08-06-2015, 07:51 AM
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Quote:
Originally Posted by bluewizard View Post
This is just a secondary consideration that you might want to think about. Though for Subwoofers, I'm not sure what the solution is.

In the original drawing we see a bank of Subs in the front under the screen, and we see a bank of Subs behind the seating area. But those Subs are not working together. While they may be Electrically In-Phase, they are Mechanically Out of Phase.

To illustrate, when the front Sub drivers move South, the rear Sub drivers move North. They are mechanically in conflict, They are going to create colliding wave fronts.

However, if you wire the rear speaker Electrically Out of Phase, then the driver would work in a synchronized fashion. When the front drivers move South, the rear drivers also move South. Rather than colliding forces, you have combining forces.

As illustrated in this diagram -



The problem is, with Subs, it is much more difficult to invert the signal. With normal speakers you just reverse the wires. but I'm not sure that is going to work with a Sub that has coaxial inputs.

Still, it is a concept to keep in mind. It is a question of the Subs opposing each other or re-enforcing each other.

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Originally Posted by Stereodude View Post
Not exactly the same thing, but actually proves his point. If you couldn't cancel out sound waves with drivers firing in opposite directions, the DBA wouldn't work. The DBA requires a delay on the rear speakers so that they intentionally cancel out the sound waves from the front subs at the rear wall so there is no reflection of the sound waves / bass off the rear wall back toward the listener.
I guess I took his use of the term "combining forces" a bit more literally. Cancelling out sound waves is not "combining forces." I can't seem to find the post at the moment, but I believe @Mark Seaton has used the term "pitch and catch" for the type of setup that bluewizard mentions above. Even so, physical placement of the subs (1/4 points of your walls?) is important when attempting to employ such a technique. @FoLLgoTT and/or @LTD02 maybe able to shed a bit more light on the topic.

I'm not a physics expert, so it's not my place agree or disagree with bluewizards "theory," but the terminology used to explain said theory seems to go against what I've seen in the past. I mean, if this theory was correct, wouldn't that imply that any speakers behind the user should have their phase inverted? Do AVR's automatically invert the electrical phase of the rear speakers to ensure they are in "mechanical phase?"

Just isn't clicking with me.

Shucks...shame on me not providing any objective data.
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post #93 of 159 Old 08-06-2015, 07:52 AM
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Quote:
Originally Posted by asarose247 View Post
"Sub harmonizer with the addition of Voxengo's LF Max Punch Sub harmonizer VST plugin"


is this function something that would provide/ extract/synthesize "more" ULF signal for something really "crazy" like a ROTARY SUBWOOFER
LF Max Punch only adds content down to 10 Hz. Here is the 30 Hz tone from Edge of Tomorrow without (red) and with (purple) LF Max Punch activated. At the 25, 20, 10 and 10 Hz tones it didn't add anything noticeable. Screenshots aren't time aligned so they are slightly different.





That's a pretty extreme example with the settings turned up high. For music it adds in a nice low frequency addition to the existing content.
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post #94 of 159 Old 08-06-2015, 08:41 AM
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Nice of you to post that, Mike.

I was going to mention I had read up a lot on these "sub-harmonic synthesizers" long ago and the TL;DR version is that they aren't really that effective for movie watching but great for music and/or music/sound editing. Might bring some life to older movies but I wouldn't bother with a modern soundtrack.
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post #95 of 159 Old 08-06-2015, 10:22 AM
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Quote:
Originally Posted by bluewizard View Post
Think about my Shoe Box Example. Think of the air in the room as a single mass of air, we want all the air in the room moving in the same direction at the same time. That creates the greatest impact.
Air wooshing past is not db.
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post #96 of 159 Old 08-06-2015, 10:48 AM
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blue wizard,
speed of sound across the room is not infinity.
most sound waves are less than the length of the room.
as a result, your "mechanically in phase" subs at the front and rear of the room are not actually in phase.
when the driver at the front of the room "pushes" air as it begins to make some sound, the driver at the rear of the room will begin to "pull" some air. BUT that air is not coupled together like it would be in a shoe box. as a result, a high pressure peak starts moving from the front of the room, and a low pressure trough starts moving into the room from the rear. with no delay, they will meet in the middle of the room and cancel each other out.

Listen. It's All Good.
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post #97 of 159 Old 08-06-2015, 10:57 AM
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@ desertdome & Scott: TY


neat graphics (and wizardry) to say the least and the info wrt to any RS development pretty much at a dead-end
Maybe the guy with the RS could get access to that type of comparative analysis capacity and show us , anything ?


I'll be busy with pushing 2 300 lb. subs into my house. more my speed

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post #98 of 159 Old 08-06-2015, 01:20 PM
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Quote:
Originally Posted by popalock View Post
I...

I'm not a physics expert, so it's not my place agree or disagree with bluewizards "theory," but the terminology used to explain said theory seems to go against what I've seen in the past. I mean, if this theory was correct, wouldn't that imply that any speakers behind the user should have their phase inverted?...
This has gone farther than I intend, indeed this is a 'theory', and it is simply a concept I put out there, others are free to consider it and make any decision they want.

As to rear surround channels being inverted, not so. When I did this with two pair of speakers, one front and one in the rear, they were both playing the same content. But that is not how front and rear/side Surround speakers work. They each have, perhaps similar, but generally unique content.

The same would be true for Subs, the content in the Front Subs would be identical to the content in the Rear Subs.

When the Front Subs try to move air South, it is trying to force a wavefront or compressed air in one direction. It is better for the Rear Subs to re-enforce that direction or oppose it?

The options are -

Front and Rear Subs both move South. (re-enforcing)

Front moves South and Rear moves North. (opposing)

For common Subs, this is very easy to test. Simply reverse phase the Rear Subs. You will either like what you hear or you won't.

Again, the concept only works with speakers that have the same content, as you would fine in four main speakers or in multiple Subs.

However, for Surrounds, because they are unique sound channels with unique content, we have a very different set of circumstances.

Steve/bluewizard
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post #99 of 159 Old 08-06-2015, 01:45 PM
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Quote:
Originally Posted by LTD02 View Post
blue wizard,
speed of sound across the room is not infinity.
most sound waves are less than the length of the room.
as a result, your "mechanically in phase" subs at the front and rear of the room are not actually in phase.
when the driver at the front of the room "pushes" air as it begins to make some sound, the driver at the rear of the room will begin to "pull" some air. BUT that air is not coupled together like it would be in a shoe box. as a result, a high pressure peak starts moving from the front of the room, and a low pressure trough starts moving into the room from the rear. with no delay, they will meet in the middle of the room and cancel each other out.
Good explanation. But I don't think the speed of sound is the issue, it is the coupling or compliance of the air.

Take a plastic shoe box and fill it half way with water, the water representing the air in the room. Create coordinated waver-fronts (south-south) in the water, and create opposing wave-fronts (north-south). I suspect when opposing waves collide in the middle, you will get a larger wave, but only at that one point.

When the Front Sub pushes and the Rear Sub pulls, the rear Sub is not sending a rarefied wave into the room, rather it is pulling air toward the speaker, or I suppose within a limited context, pulling air into the speaker.

When the driver rebounds and pushes compressed air into the room, at the same time, the other driver is pulling on the air in the room creating a ratification on the other side of the room. (south-south)

Rather than think of the air in the room as individual compression fronts moving through the air, think of the air in the room as one mass of air that you are trying to move in a given direction.

Again, I've only tried this for a couple of days with two near identical speakers, both 3.5-way with 2x8" drivers each, placed about 13 feet apart. That is the only time in decades of using my turntable that I ever had a problem with it. At some point, the turntable platform was literally bouncing around making it impossible for the stylus to stay in the groove. Four speakers in front, or four speakers front and rear but electrically in phase didn't create this substantial resonance problem.

I attribute this to the mechanically in-phase speakers shaking the air more effectively.

Again, easy enough to try.

Steve/bluewizard
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post #100 of 159 Old 08-06-2015, 04:24 PM
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So basically the north and south drivers playing against each other caused enough db to shake the needle off the track and the other option which didn't manage to do this, is the one that "shake the air" more effectively out of the two options? The first is the one with lots of db, the other one has much less db. That's the reason to their difference.
Place the record player on a concrete slab and we welcome you to the bass experience. With just one good closed 15" at full blast everything nearby (that isn't on especially solid furniture) wander across surfaces like paperclips on a snare drum. The trouser-legs feels like they shake the hairs on your legs and if the floor isn't especially solid you may feel that the floor moves enough to tickle you in the soles of your feet. That's the effect of a handful of pounds per square meter of air pressure swing does (100db is 2 newtons per square meter).
EDIT: If less bass is preferred, just use an EQ.
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post #101 of 159 Old 08-06-2015, 05:33 PM
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Quote:
Originally Posted by bluewizard View Post
This has gone farther than I intend, indeed this is a 'theory', and it is simply a concept I put out there, others are free to consider it and make any decision they want.

As to rear surround channels being inverted, not so. When I did this with two pair of speakers, one front and one in the rear, they were both playing the same content. But that is not how front and rear/side Surround speakers work. They each have, perhaps similar, but generally unique content. Fs is fundamental resonance. Fs is the natural resonance the cone will vibrate at when externally taped by a finger. Similar to tapping a drum skin. The natural Fs of a speaker cone is measured in free air outside of the box. Hold the speaker in your hands (not connected to the amplifier) and tap the cone. It will sound like a drum skin. The system Fs is measured with the speaker inside of the box. A smaller box will cause the Fs to raise to a higher frequency. This is dependant on the box being sealed. Fs becomes more complicated with a ported box.

At Fs the cone vibrates naturally, almost of its own accord and because the voice coil is in a magnetic field it will partially generate electricity. It appears from the outside, that the voice coil Impedance Z has risen. At 'Fs' the speaker is also at maximum efficiency, requiring only the smallest amount of input signal for the cone to vibrate.

The same would be true for Subs, the content in the Front Subs would be identical to the content in the Rear Subs.

When the Front Subs try to move air South, it is trying to force a wavefront or compressed air in one direction. It is better for the Rear Subs to re-enforce that direction or oppose it?

The options are -

Front and Rear Subs both move South. (re-enforcing)

Front moves South and Rear moves North. (opposing)

For common Subs, this is very easy to test. Simply reverse phase the Rear Subs. You will either like what you hear or you won't.

Again, the concept only works with speakers that have the same content, as you would fine in four main speakers or in multiple Subs.

However, for Surrounds, because they are unique sound channels with unique content, we have a very different set of circumstances.

Steve/bluewizard
I get what your saying and the theory of it but it doesn't work that way. It's like a dipole sub. You can't just stick a sub on an open baffle board and throw it in a room. It doesn't quite work that way. It's a lot more complicated. Same here. Theory and real world testing and experience can and do have different results. I can tell you for a fact what inverting a rear array will do in a front/rear array. You won't flatten the room modes nearly as effectively, if at all, as you would with time alignment and you will destroy Room Gain which is reinforcement desperately needed by all subs, whether sealed, vented or horn-based.

Having said that, I've been experimenting with inverting polarity mainly for testing purposes and I see value there. The whole particle velocity equation is so complex, with the velocity/acceleration relationship being different at the walls and opposite in the center of the room and then still changing by the inch, literally, throughout the room, there's just no way to theorize or quantify what inverting subs will do.

This is not a knock on you or what your saying though. I dig this type of discussion. I get where your coming from.
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post #102 of 159 Old 08-06-2015, 06:43 PM
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Quote:
Originally Posted by bluewizard View Post
Good explanation. But I don't think the speed of sound is the issue, it is the coupling or compliance of the air.

for the drivers to be "coupled", they have to be within the same portion of the sine wave that they are producing. this normally means less than about 1/4 wave length separation. the faster the speed of sound, the further apart they can be and still be coupled.



"Take a plastic shoe box and fill it half way with water, the water representing the air in the room. Create coordinated waver-fronts (south-south) in the water, and create opposing wave-fronts (north-south). I suspect when opposing waves collide in the middle, you will get a larger wave, but only at that one point."


that experiment will work fine, but if you are "sloshing" the water at very low frequencies, you will get a completely different result than if you vibrate the water creating lots of ripples. sound in a room is more like a pebble thrown into a pond. only in the VERY low frequencies do you get the sloshing effect that you describe.

"When the Front Sub pushes and the Rear Sub pulls, the rear Sub is not sending a rarefied wave into the room"


yes it is. that is exactly what it does.


"Rather than think of the air in the room as individual compression fronts moving through the air, think of the air in the room as one mass of air that you are trying to move in a given direction."

that is how it works in the VERY low frequencies--frequencies where the wave is so large that both drivers are effectively at the same point on the sine wave. for most rooms, this tends to be down around 10hz and lower.


"Again, I've only tried this for a couple of days with two near identical speakers, both 3.5-way with 2x8" drivers each, placed about 13 feet apart. That is the only time in decades of using my turntable that I ever had a problem with it."


reversing phase can create constructive interference that can excite room modes causing a lots of vibration.


"At some point, the turntable platform was literally bouncing around making it impossible for the stylus to stay in the groove. Four speakers in front, or four speakers front and rear but electrically in phase didn't create this substantial resonance problem. "

when you switched the phase of the rears, the peaks and nulls in the room changed. this can be seen by taking a measurement with the phase of the rear speakers normal and then inverted.


"I attribute this to the mechanically in-phase speakers shaking the air more effectively."

no. again, for the speakers to couple that way, you have to be roughly at the same part of the sine wave. if your room is 12 feet deep and we are talking about 1/8 wavelength separation to more or less be on the same part of the sine wave, we are talking about something like 96 foot long wavelengths. 1130 fps/96 ft = roughly 12hz.
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post #103 of 159 Old 08-06-2015, 06:54 PM
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forgot to mention that REW has a room simulator that is pretty easy to use. it allows for placement of up to 4 subs in all three axes (width, depth, and height) and allows for individual inversion of each source. then it allows you to move the listening position around the room in 3d space as well.

http://www.hometheatershack.com/foru...oads-page.html


just pick the room dimensions, check the boxes to turn the subs on/off, moves the subs and the listening position around the room with your mouse.


there are two perspectives of the room. the one on top is the view looking down on the room. the one on the bottom is the perspective from the rear of the room. the way the subs are arranged in the picture, they are all on the front wall roughly 1/3 of the way in from the side walls. the listening position is about 25% from the rear wall and 50% from each side wall. as it turns out, that arrangement is a good one. with only one band of eq to pull down the 90hz mode, response is smooth and rising and with the arrangement of subs on the front wall, the sound is pretty much identical across the whole row of seating at that distance, so everybody would get good bass.


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post #104 of 159 Old 08-07-2015, 12:34 AM
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LTD02 and COOLRDA -

Very insightful. Thanks for the perspective.

Nice to have a civil discussion.

I think ...when I win the lottery... I'll use REW and do an analysis with both configurations, and see what comes of it. Though again, that hinges on me winning the lottery.

As it stand now, I'll stick with Stereo.

Thanks.

Steve/bluewizard
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post #105 of 159 Old 08-07-2015, 12:38 AM
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Originally Posted by bluewizard
Quote:
Good explanation. But I don't think the speed of sound is the issue, it is the coupling or compliance of the air.

Quote:
Originally Posted by LTD02 View Post
for the drivers to be "coupled", they have to be within the same portion of the sine wave that they are producing. this normally means less than about 1/4 wave length separation. the faster the speed of sound, the further apart they can be and still be coupled.
Keep in mind, I've only done this with Stereo Speakers, not Subs. Also, as you can see, the graphic was made for a Stereo system.

I know what I experienced, but I only speculate on why I experienced that event.

Steve/bluewizard

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post #106 of 159 Old 08-09-2015, 01:58 PM
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In to see what you end up going with. Nearfield is fun for sure, but I wouldn't only do nearfield. Spread some other subs around the room so that the bass sounds complete and not locatable. I would also recommend low passing the nearfield subs and boosting the low end if you are going sealed. You will not have the room to help your subs since they are right behind you. This is what I have found to work the best for me. I also, have two 1260W's per seat on a suspended floor and that is plenty for me! I don't know how N8 does it with his powerhouse!

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post #107 of 159 Old 08-11-2015, 07:19 PM
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@bluewizard

If i where you, i would definitivily read up on DBA setups. You might get a clearer picture on the connection of the front and rear subs. And also why time alignement is needed etc.
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post #108 of 159 Old 08-17-2015, 12:03 AM - Thread Starter
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Ok well Bi-polar Home Theater enthusiast Jlpowell is back at it! @lukeamdman 's Mega beats mains were going to be expensive and A LOT OF FREAKING WORK x3!!! After deliberation I decided to settle on LCR JBL 4722n screen array speakers running full blown active crossovers with Crown DSI 1000 amps. The card has already been swiped, so hopefully I like them lol! Appraisal on the home was the last step before we sign the book size stack of papers and that went through 4 business days ago. The HT build will be a marathon for sure and no where near a sprint considering I will DIY EVERYTHING besides attaching the dedicated lines to the panel. And maybe attaching the mini split calling system but I'm not sure on that yet. Anyway I have had my 2x Seaton Submersives in the classifieds for only a couple of weeks and no bites. I want to prepare myself for if they don't sell and I'm stuck with them. Tough problem to have right? Truly though it would be ideal because it means they will be my weaker pair and therefore will need to be the near field subs. I plan on SI HST18's all around if they sell, if not I will add the HST's up front and integrate the 2x Submersives into the bar I plan on. So this brings me to the bar/Submersives/near field subs. My room will be about 22x17 with a single row of four theater style seats, about 12ft viewing distance with about a 12ft wide 2:35 screen with just under a 12ft wide bar behind the single row of seating. Being stuck with the Submersives means my bar will need to be fattened from about a 14-16 inch fat bar to about a 22 inch fat bar. 11-14 inches of overhang would be on either for adequate leg room when sitting at the bar.

So I have created a Google Sketchup to give you all a visual. I left the side that will go behind the seats open and would design on some sort of detachable acoustically transparent big piece to put there. My questions are more on the science side here. Am I going to create issues having the Submersives inside a mostly closed bar/enclosure? For example the walls will create boundary gain yes? I have also read some concerns about the dual opposed design causing phase and or cancellation issues with drivers facing each other. I had never heard of that particular but did read recently. For you science minded subwoofer nuts out there, what issue will I cause by doing this? If it's bad then perhaps I could essentially "knock out all the walls" and have acoustically transparent material on all four sides and just put some trim on all the vertical and horizontal lengths to give it a bar appearance still. Let them fly!!!

Edit: This is what happens when I stay up late. I forgot to mention I designed it to have the 3 inch gap on the AT material/seat back side and use this right angle 90 degree Neitrik. specs say 2.8 inches. Funny that because where the Speaker Power amp is it causes additional fatness to the bar. I suppose I could shorten it down and cut a small hole in the AT fabric to plug in the subs power cable and signal cable. Not sure I want them sticking out though...
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JLPowell84's Room
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Last edited by jlpowell84; 08-17-2015 at 01:05 AM.
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post #109 of 159 Old 08-17-2015, 02:18 AM
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As long as you do not run the subwoofers out of phase they won't be cancelling each other out. Are these closed enclosures? If the whole thing was enclosure volume you could probably get a lot more for your money. Because enclosure volume adds efficiency, a lot of it. Much more than boundary gain.
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post #110 of 159 Old 08-17-2015, 05:11 AM
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I'd be more inclined to have it open (or AT fabric) on at least 3 sides, rather than the one you're showing now. Why bother with AT fabric on the side that faces the seats? Won't it mostly be hidden by the seats?
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post #111 of 159 Old 08-17-2015, 05:39 AM
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Originally Posted by Stereodude View Post
I'd be more inclined to have it open (or AT fabric) on at least 3 sides, rather than the one you're showing now.
Why?
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post #112 of 159 Old 08-17-2015, 07:21 AM - Thread Starter
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Quote:
Originally Posted by ronny31 View Post
As long as you do not run the subwoofers out of phase they won't be cancelling each other out. Are these closed enclosures? If the whole thing was enclosure volume you could probably get a lot more for your money. Because enclosure volume adds efficiency, a lot of it. Much more than boundary gain.
Got it. You mean don't have one side open with AT material?

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I'd be more inclined to have it open (or AT fabric) on at least 3 sides, rather than the one you're showing now. Why bother with AT fabric on the side that faces the seats? Won't it mostly be hidden by the seats?
Yes it would be hidden by seats? I guess I assumed that I don't want any barriers between the subs and me right? Why would I put a piece of plywood between my subs and MLP?


Thanks for the responses

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post #113 of 159 Old 08-17-2015, 09:37 AM
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Do you have the equipment to do measurements?
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post #114 of 159 Old 08-17-2015, 09:44 AM
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Ok well Bi-polar Home Theater enthusiast Jlpowell is back at it! @lukeamdman 's Mega beats mains were going to be expensive and A LOT OF FREAKING WORK x3!!! After deliberation I decided to settle on LCR JBL 4722n screen array speakers running full blown active crossovers with Crown DSI 1000 amps. The card has already been swiped, so hopefully I like them lol! Appraisal on the home was the last step before we sign the book size stack of papers and that went through 4 business days ago. The HT build will be a marathon for sure and no where near a sprint considering I will DIY EVERYTHING besides attaching the dedicated lines to the panel. And maybe attaching the mini split calling system but I'm not sure on that yet. Anyway I have had my 2x Seaton Submersives in the classifieds for only a couple of weeks and no bites. I want to prepare myself for if they don't sell and I'm stuck with them. Tough problem to have right? Truly though it would be ideal because it means they will be my weaker pair and therefore will need to be the near field subs. I plan on SI HST18's all around if they sell, if not I will add the HST's up front and integrate the 2x Submersives into the bar I plan on. So this brings me to the bar/Submersives/near field subs. My room will be about 22x17 with a single row of four theater style seats, about 12ft viewing distance with about a 12ft wide 2:35 screen with just under a 12ft wide bar behind the single row of seating. Being stuck with the Submersives means my bar will need to be fattened from about a 14-16 inch fat bar to about a 22 inch fat bar. 11-14 inches of overhang would be on either for adequate leg room when sitting at the bar.

So I have created a Google Sketchup to give you all a visual. I left the side that will go behind the seats open and would design on some sort of detachable acoustically transparent big piece to put there. My questions are more on the science side here. Am I going to create issues having the Submersives inside a mostly closed bar/enclosure? For example the walls will create boundary gain yes? I have also read some concerns about the dual opposed design causing phase and or cancellation issues with drivers facing each other. I had never heard of that particular but did read recently. For you science minded subwoofer nuts out there, what issue will I cause by doing this? If it's bad then perhaps I could essentially "knock out all the walls" and have acoustically transparent material on all four sides and just put some trim on all the vertical and horizontal lengths to give it a bar appearance still. Let them fly!!!

Edit: This is what happens when I stay up late. I forgot to mention I designed it to have the 3 inch gap on the AT material/seat back side and use this right angle 90 degree Neitrik. specs say 2.8 inches. Funny that because where the Speaker Power amp is it causes additional fatness to the bar. I suppose I could shorten it down and cut a small hole in the AT fabric to plug in the subs power cable and signal cable. Not sure I want them sticking out though...
http://www.amazon.com/Neutrik-NL4FRX...dp/B004BR2YDO?
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I had a feeling...

Didn't want to dissuade you at all but .... two or three active full range 3-way mains is a BIG project. Throw in AE speakers and you're looking at going bald or grey in no time.

The JBL's will be very, very awesome though. No worries.

I like the idea of keeping your Submersive's and built a bar/counter around them. This will be a project that you can spend time finishing and not building and designing. Get to the meat and enjoy the fruits of your labor instead.

Also like the idea of using AT material on the back. This isn't necessary at all but if the counter you're going to build is very close to the next row of seats then with no solid wall there you should get more intense tactile response from the Submersives to the seats in front of them. Having a solid wall there should be fine and will still get a sense of them but no wall would be even better (tactile-wise). Also less weight to and solid materials to worry about.
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post #115 of 159 Old 08-17-2015, 10:22 AM - Thread Starter
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Quote:
Originally Posted by Jag768 View Post
Do you have the equipment to do measurements?
ABSOLUELTY!

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Originally Posted by Scott Simonian View Post
I had a feeling...

Didn't want to dissuade you at all but .... two or three active full range 3-way mains is a BIG project. Throw in AE speakers and you're looking at going bald or grey in no time.

The JBL's will be very, very awesome though. No worries.

I like the idea of keeping your Submersive's and built a bar/counter around them. This will be a project that you can spend time finishing and not building and designing. Get to the meat and enjoy the fruits of your labor instead.

Also like the idea of using AT material on the back. This isn't necessary at all but if the counter you're going to build is very close to the next row of seats then with no solid wall there you should get more intense tactile response from the Submersives to the seats in front of them. Having a solid wall there should be fine and will still get a sense of them but no wall would be even better (tactile-wise). Also less weight to and solid materials to worry about.
I feel the same. I was thinking the walls on the three sides would provide like a little amphitheater for the SubM's. I don't understand why a entirely solid enclosure would be recommended. My main coencern was I wanted to be sure I wouldnt cause any negative modes or anything over my head by doing it this way. Pretty cool to have dual Submersives as my weaker nearfield subs lol!

BTW it is only a single row of four seats. The bar immediatley behind it as close as possible without interfering with seat operation abnd thats it. So room will be about 22ft long. Lets say about 2-3 ft for AT acreen/false wall then 12 ft to seats, bar behind with four bar seats then the back wall behind that. I don't want to cramp it and want a decent distance to allow the JBL's to sing and also fit all three behind the AT screen.

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post #116 of 159 Old 08-17-2015, 10:38 AM
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ABSOLUELTY!



I feel the same. I was thinking the walls on the three sides would provide like a little amphitheater for the SubM's. I don't understand why a entirely solid enclosure would be recommended. My main coencern was I wanted to be sure I wouldnt cause any negative modes or anything over my head by doing it this way. Pretty cool to have dual Submersives as my weaker nearfield subs lol!

BTW it is only a single row of four seats. The bar immediatley behind it as close as possible without interfering with seat operation abnd thats it. So room will be about 22ft long. Lets say about 2-3 ft for AT acreen/false wall then 12 ft to seats, bar behind with four bar seats then the back wall behind that. I don't want to cramp it and want a decent distance to allow the JBL's to sing and also fit all three behind the AT screen.
Cool! I would love to make a seating plan just like yours someday.

Haha! I know, right? Dual Submersives as the "lesser" ones in your system. Quad sealed 15's with many kilowatt burst output is going to be killer, even if not nearfield but these will be. Hell yeah man.
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post #117 of 159 Old 08-17-2015, 10:52 AM - Thread Starter
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I think I will start out with two SI HST18's with a Peavy-IPR2-7500 running them for up front behind false wall. I would like to start with four but I need to put funds into other areas. Besides that should provide decent SPL for sure!

I would ideally like to go ported on the two HST 18's but I don't understand the science side of phase issues. Will it be a headache to go ported with the near field sealed Submersives? @LTD02 I know you have tried to explain this to me but I'm a slow learner

http://www.amazon.com/Peavey-IPR2-75.../dp/B003OURTDY

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post #118 of 159 Old 08-17-2015, 10:57 AM
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Phase isn't really going to be the issue but you may have some lumpy response around the Fb/tune. Maybe the nearfield subs will render that mostly moot. Hard to say for sure.

If you plan to go with quads anyway I'd just stick with sealed. More motivation to get the other two.

HST-18's will need a very large port area to properly "vent" them anyway.
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post #119 of 159 Old 08-17-2015, 11:06 AM
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Phase isn't really going to be the issue but you may have some lumpy response around the Fb/tune. Maybe the nearfield subs will render that mostly moot. Hard to say for sure.
I disagree, I worry that having one end of the dual opposed facing into a wood panel and two subs firing into each can actually result in phase/cancellation/interaction issues.

Do you have any other location to place a Submersive? One in the back would be great...could you put the other in front of your couch with a piece of wood to turn it into a coffee table sub?

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post #120 of 159 Old 08-17-2015, 11:07 AM
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Well, that's also why I suggested to keep it sealed up front.
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