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CoolGeek's Concrete Bunker Home Theater Build - Page 3

post #61 of 99
Quote:
Originally Posted by coolgeek View Post


Exactly... I definitely need the OS hooked up...

Wait, don't the ULS have gain control knobs? Can't you just turn them down or are you maxed out as far as how low you can turn them?
Edited by jlpowell84 - 7/31/13 at 12:51pm
post #62 of 99
Quote:
Originally Posted by coolgeek View Post

If you can afford it, then sure.. it'll be great to cover all the frequencies...

But I think to get anything meaningful below 10 hz, you need to spend a LOT of money.. I heard people needing 8x18inches (and each driver cost like $1000 above), and not even counting the amps, and boxes... The OS is equivalent to at least 4x18s.. and it's only 3K

I only have 3K to spend and i went with 1 OS...

Well that has a lot to do with room size and room gain. A single OS or Cap S2 could do the trick in say a sealed 12x12 room. Heck RMK is flat to 10 hz in his room with his dual OS's
post #63 of 99
Thread Starter 
Quote:
Originally Posted by jlpowell84 View Post

Wait, don't the ULS have gain control knobs? Can't you just turn them down or are you maxed out as far as how low you can turn them?

I have set the gain at 2 oclock now.. (quite high), and the receiver at +8.. the woofers are really moving... i don't want to set the gain any higher or it might blow my sub... it's as loud as it can get now and can't match the Noesis (which was set at -10) on my receiver.

Quote:
Originally Posted by jlpowell84 View Post

Well that has a lot to do with room size and room gain. A single OS or Cap S2 could do the trick in say a sealed 12x12 room. Heck RMK is flat to 10 hz in his room with his dual OS's

Ah,.. that would be a very tiny room...

What about a 14x22 room? or about 3000cfu?
post #64 of 99
Quote:
Originally Posted by coolgeek View Post

I have set the gain at 2 oclock now.. (quite high), and the receiver at +8.. the woofers are really moving... i don't want to set the gain any higher or it might blow my sub... it's as loud as it can get now and can't match the Noesis (which was set at -10) on my receiver.
Ah,.. that would be a very tiny room...

What about a 14x22 room? or about 3000cfu?

I got ya. I am not experienced enough to give you an accurate estimate on your room. But you will surely get some nice low end boost gain in your concrete bunker. From the couple of pics I have seen RMK's room is not a small room, perhaps average? anyway I will be going with the OS or Cap S2 if I don't go DIY. My future HT room I plan on building a bigger small room. What I mean by that is comfortable but I'm not concerned about having multiple rows of seats. I am going to stay on the smaller side for mainly bass, pressurization and a flat EQ into the single digits. It's all about the room. I once heard it said that the room is the speaker.
post #65 of 99
Thread Starter 
Quote:
Originally Posted by jlpowell84 View Post

I got ya. I am not experienced enough to give you an accurate estimate on your room. But you will surely get some nice low end boost gain in your concrete bunker. From the couple of pics I have seen RMK's room is not a small room, perhaps average? anyway I will be going with the OS or Cap S2 if I don't go DIY. My future HT room I plan on building a bigger small room. What I mean by that is comfortable but I'm not concerned about having multiple rows of seats. I am going to stay on the smaller side for mainly bass, pressurization and a flat EQ into the single digits. It's all about the room. I once heard it said that the room is the speaker.

I understand. But you know, after spending so much money in a dedicated home theater, wouldn't you want to have a bunch of friends over for movie night?

That's why I wanted at least 2 rows of seats.. right now, I think i can fit in 8 ppl... 4 each row...
post #66 of 99
Thread Starter 
Here's a video of me on one of my trips to Cambodia... this is a chamber in one of the ancient temples in Angkor Wat.

This spot I am standing on is known as a sound chamber. it's purposely designed this way by the ancients.. notice what happens when I thump my chest.

My basement is a bit like this.. but not even close to the sound 'amplifications' you see here.

BTW: You need to have a subwoofer to hear the 'gong' or 'bass'.. if you're just hearing it from your laptop or regular computer speaker, this video won't do much for you...


Edited by coolgeek - 8/5/13 at 3:56am
post #67 of 99
How far away from Cambodia are you? I have some friends that moved there. Very warm they say lol!
post #68 of 99
Thread Starter 
Quote:
Originally Posted by jlpowell84 View Post

How far away from Cambodia are you? I have some friends that moved there. Very warm they say lol!

I live in Malaysia... not sure how far that is.. but prob about 4 hours flight...
post #69 of 99
It usually takes me 2 hours to fly from Phnom Penh, Cambodia to Singapore. I assume KL is a shorter flight time.
post #70 of 99
Thread Starter 
Quote:
Originally Posted by NWCgrad View Post

It usually takes me 2 hours to fly from Phnom Penh, Cambodia to Singapore. I assume KL is a shorter flight time.

I think you're right... it's been a while since i went there... the 4 hours is prob to the philippines
post #71 of 99
Wow Ezer,

Travel much? I just watched several of your videos.

Great stuff.

Any updates on the theater construction?
post #72 of 99
Thread Starter 
Heya Papalock,

Actually no changes yet. I have just done water proofing. The house is still about several months off from completion. I'll wait till I move in, before messing with the basement.. .

Right now, I have hired Bryan from GikAcoustics to help me design the treatments i'll need.

I am thinking at least 6 months down the road...

As for travels.. haha.. yes, i have been travelling extensively... I think i might have visited more than 40 countries... it's awesome to meet different people from all over the world...

I hope one day i can come audition your super duper home theater.. hehehe... smile.gif I am so jealous of you guys who knows how to build your own speakers and subs...
post #73 of 99
Quote:
Originally Posted by coolgeek View Post

Here's a video of me on one of my trips to Cambodia... this is a chamber in one of the ancient temples in Angkor Wat.

This spot I am standing on is known as a sound chamber. it's purposely designed this way by the ancients.. notice what happens when I thump my chest.

My basement is a bit like this.. but not even close to the sound 'amplifications' you see here.

BTW: You need to have a subwoofer to hear the 'gong' or 'bass'.. if you're just hearing it from your laptop or regular computer speaker, this video won't do much for you...


This is very cool, thanks for sharing, .. I missed this first time around.

I'd enjoy experiencing this effect. I'm getting a lot of ~64hz across my cheapo mini system. So the fundamental may be 64hz, or maybe even 32hz. At 32hz, the dimensions may be 35.3 feet, 10.75m, or for 64hz, the architectural dimensions may be closer to 17.6 feet, or 5.4m. Interesting for sure. Obviously, this is all wild guesses, there may be much more at play here. I'd love to read more about this room specifically.

One could excite the effect even more by placing yourself up against a boundary. Or better yet, in a corner of two boundaries.

Thanks for sharing
post #74 of 99
Quote:
Originally Posted by coolgeek View Post

Heya Papalock,

Actually no changes yet. I have just done water proofing. The house is still about several months off from completion. I'll wait till I move in, before messing with the basement.. .

Right now, I have hired Bryan from GikAcoustics to help me design the treatments i'll need.

I am thinking at least 6 months down the road...

As for travels.. haha.. yes, i have been travelling extensively... I think i might have visited more than 40 countries... it's awesome to meet different people from all over the world...

I hope one day i can come audition your super duper home theater.. hehehe... smile.gifI am so jealous of you guys who knows how to build your own speakers and subs...

With your current speaker selection... The only thing you could be missing out on is saving a few bucks. But for the most part, it doesn't really get much better for the money than what you went with. Great choices for sure!

If you ever make it to the DC area give me a shout. We can demo my system then maybe find a place locally to save a few more birds.

No ancient temples out here though, so don't get your hopes up.

wink.gif
post #75 of 99
Thread Starter 
Quote:
Originally Posted by FOH View Post

This is very cool, thanks for sharing, .. I missed this first time around.

I'd enjoy experiencing this effect. I'm getting a lot of ~64hz across my cheapo mini system. So the fundamental may be 64hz, or maybe even 32hz. At 32hz, the dimensions may be 35.3 feet, 10.75m, or for 64hz, the architectural dimensions may be closer to 17.6 feet, or 5.4m. Interesting for sure. Obviously, this is all wild guesses, there may be much more at play here. I'd love to read more about this room specifically.

One could excite the effect even more by placing yourself up against a boundary. Or better yet, in a corner of two boundaries.

Thanks for sharing

No prob.. at least you understand the 'science of it'... to me, it was almost magic... and to think ancient people have discovered how to manipulate sound like this...

Quote:
Originally Posted by popalock View Post

With your current speaker selection... The only thing you could be missing out on is saving a few bucks. But for the most part, it doesn't really get much better for the money than what you went with. Great choices for sure!

If you ever make it to the DC area give me a shout. We can demo my system then maybe find a place locally to save a few more birds.

No ancient temples out here though, so don't get your hopes up.

wink.gif

I am sure you're right... The problem is I haven't yet been able to set up my system until I get my new house ready.. currenly only setup with LCR Noesis + dual Hsu's 15s sealed... they sound fantastic for concerts and music... and i am also only hooked up to my receiver via analog... and prologic for surround sound... so, movies still sound a bit off (due to the pro logic and not dedicated sound channels)...

LOL... if I am ever in the DC area, you'll be the first I'll call upon... maybe next up might be N8DOGG...

And if any of you guys are in Asia.. give me a holler...
post #76 of 99
Whoa!!! I just played that video, that is amazing!!

That's just with hitting your chest, imagine what pounding on a big drum would sound/feel like in there.
post #77 of 99
Thread Starter 
Quote:
Originally Posted by carp View Post

Whoa!!! I just played that video, that is amazing!!

That's just with hitting your chest, imagine what pounding on a big drum would sound/feel like in there.

I know... it's insane...

Gives you a perspective on what 'horn loaded subs' mean...
post #78 of 99
Thread Starter 
Okay, LT have set me down a path of no return... lol!!!

I now want a WALL of sound, specifically BASS washing over me... The idea is to have ALL the bass I ever want on the front wall.

So, here's a question for LT or anyone who knows these stuff.

Currently I have this much space behind the screen:

10.5 Feet across, and 4 feet deep.

How best to do this 'wall of sound thing''?

I currently have LCR noesis (each will take about 14 inches of width, so that's 42 inches of horizontal space taken). I also have the Orbit Shifter, so that takes another 22 inches of horizontal space if i placed the mouth opening facing the back wall or facing the front. That leaves me with about another 60 inches (or 5 feet of horizontal space). If i build a couple of dual 18s boxes for my midbass, that'll basically be about 40 inches used so left with only 20 inches of space...

Now, I am also toying with building more 'deep' bass modules.. maybe 4 24inchers (found one in China which I might check out to see if it's any good). I figured since space is a constraint, instead of haing 12 or 16 18inchers, why not 4-5 24inchers???

Here's how I imagine placing the speakers:

Bottom: 5 x 24 Inch Bass Modules across the floor.
Sitting on top of those: Noesis L + Mid Bass Module + Orbit Shifter + Noesis C + Mid Bass Module + Noesis R

Would that work?

(then I might have to put a couple inch absorbers at the back wall)

I am putting this question on my Build Thread so that later people can find this info useful as well....
post #79 of 99
this paper provides some pictures of room resonances: http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White%20Papers/multsubs.pdf

and shows that one solution is to place the subs at 1/4 distances from the front and back walls. we are going to do just that, but on the wall, not the floor.
post #80 of 99
the placement on the wall behind the scree, would roughly be like this:

post #81 of 99
post #82 of 99
follgott discusses the concept and provides measurements of his test here:

http://www.avsforum.com/t/837744/double-bass-array-dba-the-modern-bass-concept/120#post_23666158

note, he is only uses two drivers for his sba test. that eliminates the side to side modes, but not the ceiling / floor modes. that is fine if everybody will be sitting at the same height.
post #83 of 99
"then I might have to put a couple inch absorbers at the back wall"

this is the key. BIG ASS ABSORPTION of one form or another is required to catch and destroy the bass wave before it reflects back. several feet of fiberglass if going that route.
post #84 of 99
"This is the idea, right?'

there are two ideas there. the first is the double bass array. one set of drivers on front wall. one set on rear wall. set on rear wall is delayed to produce sound 180 degrees out of phase with front bass array in order to "absorb" it.

sba is single bass array. drivers just on front wall. absorption such as fiberglass on rear wall. less expensive solution. easier to set up. not quite as effective. takes more floor space.
post #85 of 99
additional topics include reading up on how line array speakers work and then understanding what we are doing with this concept is extending the line array concept into a full "plane".
post #86 of 99
Thread Starter 
Thanks LT... but I really don't have 4 feet of space to spare at the back wall. I have total 24 feet from front to back. And I can't place the speakers 1/4 distance either cause that'll be 6 feet out from the front, which I only have a recess of 4 feet which i can use.

So, does this mean this whole concept is out the window?

Basically, from the drawing of my basement, you can see I have a 4 feet deep recess where i can place all the speakers. I'll have a 10 feet wide screen then, followed by first row at either 10 or 11 feet away, and then second row at 15-16 feet away, leaving exactly 4 feet of space behind. I can probably do a few inches of absorbsion at best. Someone once told me to put up a thick wood on the corners to trap the bass... for instance a solid wood about 1-2 inches thick. Basically, between the wood and the concrete wall, there's some space... and the bass might bounce around in there and loses strength...

Also, there's a complexity to my basement, ie, it's not a straight forward rectangular shape. There's a 'recess' of 4 feet, then it recesses in and out of the side walls a couple times as in the drawing. The back-wall is bigger than the front recess.

And plus, I already have an OS, and throw in 2-3 mid bass modules i want to build, and subs.. it's not looking like an easy solution. There won't be a clear 'space' behind the wall for the 1/4 spacing etc. I guess it's all down to experimentations
Edited by coolgeek - 10/12/13 at 10:08pm
post #87 of 99
"And I can't place the speakers 1/4 distance either cause that'll be 6 feet out from the front, which I only have a recess of 4 feet which i can use."

the 1/4 distance spacing for the drivers is from the ceiling/floor and left/right walls. drivers mounted behind the screen.

absorption on the rear wall is ideal method.

eq is ok in this case because all seats in the house will receive same eq.

more or less.
post #88 of 99
post #89 of 99
Thread Starter 
First, let me say this, WOW, LT, you have gone above and beyond the good samaritan duty with drawings and all.. .smile.gif)) And your knowledge base is so incredible you seem to know just about everything anyone discusses...
Quote:
Originally Posted by LTD02 View Post

"And I can't place the speakers 1/4 distance either cause that'll be 6 feet out from the front, which I only have a recess of 4 feet which i can use."

the 1/4 distance spacing for the drivers is from the ceiling/floor and left/right walls. drivers mounted behind the screen.

absorption on the rear wall is ideal method.

eq is ok in this case because all seats in the house will receive same eq.

more or less.

Ah Ok, Understood on the 1/4 placements. But what if I had all these? There's virtually no way to do the 1/4 space thing with all these drivers.

3 Noesis
1 Orbit Shifter
2-3 Mid Bass Modules (each dual drivers cabinets)
And a bunch of subs?

The last 2 will be built as time goes by. Eventually I want to try to build a Noesis like speaker but with dual 18s and the same noesis compression driver...

Quote:
Originally Posted by LTD02 View Post


What is the purple area? And what are the arrows? Are we moving the front row to way front? and the back row to the front row?

If my screen is 10 feet, minimum seating distance is 10 feet from it, and if the second row is 5-6 feet away, then it's 15-16 feet away. So, that left me with a mere 4 feet to the back wall. I can't possibly use it all for 'absorbers'.... there'll be rear speakers, air cond to place there, etc. Therein lies the problem. The room is just too small.. and I need to have at least 2 rows because i'll have friends over all the time... for movie nights.
post #90 of 99
Thread Starter 
Quick question:

How do I build the screen so that it can sway open (to manage my speakers behind? Do I use magnets?
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