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post #91 of 2215 Old 08-29-2013, 10:28 PM
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Only measurements I could find for the VTF-15H are from 2011 by Sound & Vision, but the lowest they measured were at 20Hz. So, I'll have to go with those numbers for the moment until Josh posts his findings, which hopefully will be soon. smile.gif I also have a slot-ported, dual-opposed DIY build, but I won't add that into the equation until I make proper measurements with mic and REW.

Hopefully, I'm doing this right.
VTF-15H is 114 @ 20Hz (1 port open, EQ1) inside a 2500ft^3 Space, which comes out to 809@20hz
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post #92 of 2215 Old 08-29-2013, 10:38 PM - Thread Starter
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Quote:
Originally Posted by eNoize View Post

Only measurements I could find for the VTF-15H are from 2011 by Sound & Vision, but the lowest they measured were at 20Hz. So, I'll have to go with those numbers for the moment until Josh posts his findings, which hopefully will be soon. smile.gif I also have a slot-ported, dual-opposed DIY build, but I won't add that into the equation until I make proper measurements with mic and REW.

Hopefully, I'm doing this right.
VTF-15H is 114 @ 20Hz (1 port open, EQ1) inside a 2500ft^3 Space, which comes out to 809@20hz

Is the 114 @ 2m? 

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post #93 of 2215 Old 08-29-2013, 10:39 PM
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Quote:
Originally Posted by dominguez1 View Post

Is the 114 @ 2m? 

no thats 1m peak...need to subtract 9db. should be within a db or so of the xv15.
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post #94 of 2215 Old 08-29-2013, 10:50 PM
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Quote:
Originally Posted by eNoize View Post

Only measurements I could find for the VTF-15H are from 2011 by Sound & Vision, but the lowest they measured were at 20Hz. So, I'll have to go with those numbers for the moment until Josh posts his findings, which hopefully will be soon. smile.gif I also have a slot-ported, dual-opposed DIY build, but I won't add that into the equation until I make proper measurements with mic and REW.

Hopefully, I'm doing this right.
VTF-15H is 114 @ 20Hz (1 port open, EQ1) inside a 2500ft^3 Space, which comes out to 809@20hz

No thats not correct. The 2m rms numbers would be 104-105db...so the si number @ 20hz would be 1.0

2500÷ 1 = a ulf score of 2500 @ 20hz.

You need 3 VTF-15's to get a ulf score of 833 @ 20hz.
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post #95 of 2215 Old 08-29-2013, 11:04 PM
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Quote:
Originally Posted by dominguez1 View Post

Is the 114 @ 2m? 

Probably @ 1m from Sound & Vision review, which is why I'm anxiously awaiting Josh's measurements, but I think basshead is right that the 15H is comparable to the XV15.
So, plugging in those numbers, this looks more accurate

2451 @ 16Hz
2874 @ 20Hz
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post #96 of 2215 Old 08-29-2013, 11:13 PM
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BTW, dom, really love the thread, though it only makes want to add more subs to my room. Looking at probably making a pair of Othorns with SI 18s.
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post #97 of 2215 Old 08-30-2013, 06:04 AM
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Hi Dom, great thread! smile.gif

Here is my score with some guess work:

3000 cubic foot theater room...(3) EP-4000 amps.

10Hz - Ricci's DIY XXX Ported with a RE Audio MX-18 D2 Driver = 836

(IIRC, Josh said to subtract 2dB down low from the XXX...)

12.5Hz - (4) CHT 18.1 = 1027

(I am using the numbers from the eD A7S-450...should be close)

Total score of both = 461

As you are gathering the ULF scores maybe add the room size next to the score to see the effect the room has...just a thought.
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post #98 of 2215 Old 08-30-2013, 06:11 AM - Thread Starter
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Quote:
Originally Posted by laugsbach View Post

Hi Dom, great thread! smile.gif

Here is my score with some guess work:

3000 cubic foot theater room...(3) EP-4000 amps.

10Hz - Ricci's DIY XXX Ported with a RE Audio MX-18 D2 Driver = 836

(IIRC, Josh said to subtract 2dB down low from the XXX...)

12.5Hz - (4) CHT 18.1 = 1027

(I am using the numbers from the eD A7S-450...should be close)

Total score of both = 461

As you are gathering the ULF scores maybe add the room size next to the score to see the effect the room has...just a thought.
Thanks L! Good idea with the room size. I'll put that in.

Have you seen what the big guy can do at 12.5hz??? Check the first post (updated last night). It's like 10 SI! Calculate your score at that hz and see what you get...
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post #99 of 2215 Old 08-30-2013, 06:32 AM
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Sorry for the temporary thread jack. Paolo, thanks for coming over last night. It was a pleasure meeting you and Larry. Sorry I had to cut it short but I had "dad" duties I needed to get to. We will have to carve out a bigger window of time next go around so you can measure out my dual JTR S2 subs. I am sure there is plenty of room for improvement with sound treatments,etc.. Take care.
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post #100 of 2215 Old 08-30-2013, 08:21 AM
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Quote:
Originally Posted by dominguez1 View Post


Have you seen what the big guy can do at 12.5hz??? Check the first post (updated last night). It's like 10 SI! Calculate your score at that hz and see what you get...

WOW...my score is 247 @ 12.5HZ...cool.gif
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post #101 of 2215 Old 08-30-2013, 08:25 AM
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Originally Posted by Frohlich View Post

Paolo, thanks for coming over last night. It was a pleasure meeting you and Larry....

Same here Martin! smile.gif

I look forward to coming back...
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post #102 of 2215 Old 08-30-2013, 08:31 AM
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Quote:
Originally Posted by basshead81 View Post

I do not think thats figured correctly. you are suppose to use the si conversion number from dominguez chart, not the output at the given frequency from my understanding.

Using the PB13, the si number is 1.0 @ 16hz and .7 @ 12.5hz

Dual PB13's would have a si of 2.0 in 20hz mode @ 16hz and a si of 1.4 in max ext. mode @ 12.5hz
2500÷1.4=1786 @ 12.5hz
2500÷2 = 1250 @ 16hz

The PB12 plus would have a si of .7 @ 16hz, so duals would give you a si of 1.4.

2500÷1.4 = 1786 @ 16hz
I knew it was too good to be true. tongue.gif
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post #103 of 2215 Old 08-30-2013, 08:48 AM
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Quote:
Originally Posted by laugsbach View Post

Same here Martin! smile.gif

I look forward to coming back...

I always thought I had overkill for subs in my set-up..now, after meeting some felllow local HT nuts, I realize I have "underkill" :-)
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post #104 of 2215 Old 08-30-2013, 08:50 AM
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Originally Posted by landshark1 View Post

I knew it was too good to be true. tongue.gif

actually I hosed your score...since dominguez changed the chart this is what I come up with


The 12+ has a si of 2.0 in 16hz mode @ 16hz. 2500÷4 = 625


The 12+ has a si of 1.8 in 20hz mode @ 20hz. 2500÷3.6=694
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post #105 of 2215 Old 08-30-2013, 01:48 PM
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Quote:
Originally Posted by basshead81 View Post

actually I hosed your score...since dominguez changed the chart this is what I come up with


The 12+ has a si of 2.0 in 16hz mode @ 16hz. 2500÷4 = 625


The 12+ has a si of 1.8 in 20hz mode @ 20hz. 2500÷3.6=694
Now I feel better. LOL.... tongue.gif
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post #106 of 2215 Old 08-30-2013, 03:16 PM
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Originally Posted by popalock View Post

Carp. If it's too much trouble to move a few subs behind your LP this weekend, can you try something else for me if you get the chance.

Take one of your subs currently under your screen. Move it a few feet out from the wall. Play those same two tracks again...but this time, sit on one of the subs. Let us know how the 6-7hz tactical feeling is when you sit on the sub.

Impractical?...Maybe...but should provide a slightly better ideal of what ULF adds to the experience in a near field situation.

Do it for the Science of it!
tongue.gif

I'll try it out when I get a chance, I'll try moving one of the subs out from the screen and sitting on it.

It looks like I should try some more scenes too, I probably shouldn't completely make my mind up from just bass I love you and Irene.
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post #107 of 2215 Old 08-30-2013, 03:45 PM
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Quote:
Originally Posted by carp View Post

I'll try it out when I get a chance, I'll try moving one of the subs out from the screen and sitting on it.

It looks like I should try some more scenes too, I probably shouldn't completely make my mind up from just bass I love you and Irene.

Olympus Has Fallen. About 29min in. Washington Monument Scene... Epic.

 

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post #108 of 2215 Old 08-30-2013, 04:12 PM
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Originally Posted by popalock View Post

Olympous Has Allen. About 29min in. Washington Monument Scene... Epic.

Haven't seen that one. Got to love funny typos.

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post #109 of 2215 Old 08-30-2013, 05:52 PM
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Haven't seen that one. Got to love funny typos.
lol... I hate my mother ****ing phone with a passion.

 

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post #110 of 2215 Old 08-30-2013, 06:23 PM - Thread Starter
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Originally Posted by Frohlich View Post

Sorry for the temporary thread jack. Paolo, thanks for coming over last night. It was a pleasure meeting you and Larry. Sorry I had to cut it short but I had "dad" duties I needed to get to. We will have to carve out a bigger window of time next go around so you can measure out my dual JTR S2 subs. I am sure there is plenty of room for improvement with sound treatments,etc.. Take care.

Hey Fro!

 

Thanks for having us! You've got some stellar equipment, that's for sure. Your S2's were very impressive. I'd be glad to come over and really help optimize your system! Shoot me a pm and we'll get it on the calendar.

 

Also, you're more then welcome to swing by either of our places to hear our setups! It's always fun to hear other's HT rooms.

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post #111 of 2215 Old 08-30-2013, 06:26 PM - Thread Starter
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Originally Posted by laugsbach View Post


WOW...my score is 247 @ 12.5HZ...cool.gif

Impressive. Looks like we both have 12.5hz sweet spots...

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post #112 of 2215 Old 08-30-2013, 06:40 PM - Thread Starter
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Originally Posted by basshead81 View Post


actually I hosed your score...since dominguez changed the chart this is what I come up with


The 12+ has a si of 2.0 in 16hz mode @ 16hz. 2500÷4 = 625


The 12+ has a si of 1.8 in 20hz mode @ 20hz. 2500÷3.6=694

Had to use the calculator on this one. As you said Landshark, I used the PB13 Ultra and subtracted 3db: 2500cf room

 

Hz SI Sub/Driver Your Sub's lowest freq's max output (ground plane) dB Difference Equivalent SI(s) Quantity Total SI(s) HT ULF Score
 (cf per SI)
16 97.8 PB12 + (16hz) 102.1 4.3 1.6 2 3.2 781
20 104.2

PB12 +

(20hz)

107.6 3.4 1.5 2 3.0 833
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post #113 of 2215 Old 08-30-2013, 06:46 PM - Thread Starter
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post #114 of 2215 Old 08-30-2013, 06:49 PM - Thread Starter
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Quote:
Originally Posted by carp View Post


I'll try it out when I get a chance, I'll try moving one of the subs out from the screen and sitting on it.

It looks like I should try some more scenes too, I probably shouldn't completely make my mind up from just bass I love you and Irene.

Have you seen OHF or Oblivion? Those scenes have strong <15hz content.

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post #115 of 2215 Old 08-30-2013, 07:11 PM - Thread Starter
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post #116 of 2215 Old 08-30-2013, 07:15 PM - Thread Starter
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Quote:
Originally Posted by eNoize View Post

BTW, dom, really love the thread, though it only makes want to add more subs to my room. Looking at probably making a pair of Othorns with SI 18s.

Thanks eNoize.

 

Othorns would be killer...but why not the Gjallarhorn? Extends down to 10hz, and at 16hz it equals 10.6 SI! Two of those and it's 21.2 SI at 16hz??? Wow.

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post #117 of 2215 Old 08-30-2013, 07:59 PM - Thread Starter
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Quote:
Originally Posted by lukeamdman go_quote.gif




lukeamdman's horn setup


2 gjallarhorns and 2 othorns in a 2500cf room!


1 gjalla = 10.6 SI, 1 othorn = .6 SI, all at 16hz


luke has an equivalent of 22.4 SI @ 16hz!


2500 / 22.4 = 112@16hz.  Pure insanity...and lowest score for 16hz!
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post #118 of 2215 Old 08-30-2013, 08:02 PM
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Originally Posted by dominguez1 View Post

Thanks eNoize.

Othorns would be killer...but why not the Gjallarhorn? Extends down to 10hz, and at 16hz it equals 10.6 SI! Two of those and it's 21.2 SI at 16hz??? Wow.

I'm tempted to go Gjallahorn, but not too sure I have enough space. My goal is definitely for 10Hz with as small a footprint possible, so we'll see by the time I ready to start building.
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post #119 of 2215 Old 08-31-2013, 07:45 AM - Thread Starter
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Originally Posted by eNoize View Post


I'm tempted to go Gjallahorn, but not too sure I have enough space. My goal is definitely for 10Hz with as small a footprint possible, so we'll see by the time I ready to start building.

Sounds like single SIs or Dual Oppossed SIs might be the best fit. For the smallest size and most capability, you may want to step up drivers. More costly, but will save on space. 

 

What interested in the othorn? I didn't think that extended low.

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post #120 of 2215 Old 08-31-2013, 08:59 AM
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Hi Dom,

Great stuff, thanks for the efforts.

My problem is in the assumption that each SI-18 (or equivalent) is equally powered.

The SI reference being used for these calcs was powered by a K10 on a 220V/50A line. eek.gif

It's not realistic to assume that (for example) a system of 8 of them would each have its own K10/220V/50A power plant.

It's also not realistic to assume that a system of 1-SI-18+K10/220V/50A would last more than one sitting of WOTW in my 3500 cubes HT at any sort of spirited playback level.

I think that your formula will only work accurately with commercial subs, using a commercial subs results as the reference.

I apologize for this post in that I usually I have some alternative choices or an equalizer to the existing formula, but in this case I don't because I haven't had enough time recently to do much extra-carricular thinking. I've just been watching the greatest MWB ever made and enjoying the heck out of it. cool.gif

Anyway, keep up the great work and hopefully this will evolve into a world class standard for actual use in actual rooms... something that has always been sorely lacking for the general sub-buyeing public.
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