Your Home Theater ULF Score - Page 75 - AVS Forum

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Subwoofers, Bass, and Transducers

MKtheater's Avatar MKtheater
10:16 AM Liked: 530
post #2221 of 2755
08-22-2014 | Posts: 14,804
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I love them but like the RExxx Ricci tested, the enclosure is too small and to create the low end they can they need a bigger box.
BassThatHz's Avatar BassThatHz
03:17 PM Liked: 455
post #2222 of 2755
08-22-2014 | Posts: 3,346
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Quote:
Originally Posted by MKtheater View Post
That's with mic+SC corrections applied?

You have no output above 30hz, what's up with that?
MKtheater's Avatar MKtheater
05:12 PM Liked: 530
post #2223 of 2755
08-22-2014 | Posts: 14,804
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That is a too small of an enclosure mixed with an inductance hump. The good part is I can bring down the 10-30hz and be flat to reference anyways. If you don't do that it is boomy as hell. When I bring down that peak I am flat from 6-100hz.
derrickdj1's Avatar derrickdj1
07:55 PM Liked: 156
post #2224 of 2755
08-22-2014 | Posts: 1,584
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It looks like a lot to bring down MK. I may be different from a lot of people because I don't like using over two to three filter under 60 Hz. How many will you need to use and what type of Q in the PEQ? I usually tolerate a 5-7 db+/- FR. This type of FR curve may result in some loudness in the mix above 30 Hz that is not objectionable in my large room.
MKtheater's Avatar MKtheater
08:16 PM Liked: 530
post #2225 of 2755
08-22-2014 | Posts: 14,804
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I used 5 cuts. Pretty simple and still enough headroom. The reason is the small enclosure creates a hump on top of the inductance peak. The 8 drivers model in a 490 cubic foot box or IB, they are in 178 cubes. If you model these in my size box and then compare them in a proper IB you can see I lose lots of sensitivity down low which IB drivers are designed for. I still get away having the best bass ever but these drivers are not being utilized properly. They still sound awesome though. I will throw in the stereo integrity drivers in the Wall and see how they measure to compare. It should have a fat bottom end which I am looking for but I can fit 12 drivers if need be or 8 more robust drivers made for 24 cubes each. I need semi IB drivers.
basshead81's Avatar basshead81
10:22 PM Liked: 1722
post #2226 of 2755
08-22-2014 | Posts: 6,484
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Just curious, why did you choose the IB3 drivers if going into the build you knew you were severely limiting their low end performance by putting them in a enclosure 1/3 of the recomended space?
dominguez1's Avatar dominguez1
07:41 AM Liked: 220
post #2227 of 2755
08-23-2014 | Posts: 1,913
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Quote:
Originally Posted by Fatshaft View Post
You, my friend, are definitely a subaholic and a real one!
And here i thought I was a subaholic
Ummm, ^^^this. MK, you've got one strong strain of the upgradeitus infection.

Still not sure why you're upgrading though?

You've stated that you had the best bass/low end ever with this setup.

I know you're not using these to their potential, but will replacing them get you more? For example, couldn't it be possible that 8 IB drivers in an undersized box would be the same output or more as 4 FTW21 in an optimal size box? I just used that as an example, but you get the picture.

Have you sim'd 8 IBs in your size box, and compared it to other subs that fits your box better to see if that would be the case?
MKtheater's Avatar MKtheater
08:33 PM Liked: 530
post #2228 of 2755
08-23-2014 | Posts: 14,804
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I thought the wall was 3 feet away from the front wall. The IB was supposed to be 300 cubes which is close enough. I never paid attention before after reading about enclosures and stuff. The drivers are fine and the reason I blew a breaker is because the box is so small for the drivers that you can sink lots of power and I used all of my 20 amp breaker. This IB is supposed to use little power compared to small sealed subs. I have all the drivers about sold now anyways! This system added up to 12 SI's but there is no way I can port it because the box is too small. If I put 12 SI's in there I will have the same output and I can LLT it if I wanted to. I am putting the dual SI ported subs in the back for sure. That or 4 SI sealed each. The 24 cubes is a little small for dual ported SI's as well.
MKtheater's Avatar MKtheater
08:35 PM Liked: 530
post #2229 of 2755
08-23-2014 | Posts: 14,804
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Oh and yes, it has been the best bass to date. What happened is I tripped my breaker running my subs with a 10 dBs boost LT. I want to be able to run a 10 dBs boost LT with 6 dBs hot LFE which will result in devastation.
DotJun's Avatar DotJun
08:45 PM Liked: 59
post #2230 of 2755
08-23-2014 | Posts: 975
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Quick sort of off topic question for people doing IB in the attic: how much of the bass escapes from your roof vents/gables/soffits and what have you?
popalock's Avatar popalock
12:39 AM Liked: 935
post #2231 of 2755
08-24-2014 | Posts: 4,021
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Quote:
Originally Posted by MKtheater View Post
I thought the wall was 3 feet away from the front wall. The IB was supposed to be 300 cubes which is close enough. I never paid attention before after reading about enclosures and stuff. The drivers are fine and the reason I blew a breaker is because the box is so small for the drivers that you can sink lots of power and I used all of my 20 amp breaker. This IB is supposed to use little power compared to small sealed subs. I have all the drivers about sold now anyways! This system added up to 12 SI's but there is no way I can port it because the box is too small. If I put 12 SI's in there I will have the same output and I can LLT it if I wanted to. I am putting the dual SI ported subs in the back for sure. That or 4 SI sealed each. The 24 cubes is a little small for dual ported SI's as well.
Rewind like 18 months ago and you could have gotten in on our SI group buy...saved a couple benjamins...

Why don't you scoop up the HST 18's that SI is offering. Bit more expensive but, from what I understand it pretty much uses the same motor as the 24" and will be a viable alternative to the LMS-U and the UXL-18. Not sure the pricing yet though.
MKtheater's Avatar MKtheater
07:38 PM Liked: 530
post #2232 of 2755
08-24-2014 | Posts: 14,804
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I know but I thought I was building a bigger enclosure at the time. I ran a sim of a ported 8 SI system and winisd picked a 170 cubic foot box which I have a 178 cubic foot box! Perfect and it will be 10 dBs over my current system and 6 dBs more at 5hz and that is with my system in a true IB! I figured out that my ported system came out to be a 19.69 hz ported sub which is very bad! You really can't port these unless you have 500 plus cubes! Oh well, they are awesome drivers though and wish I had more room.
Pain Infliction's Avatar Pain Infliction
07:01 AM Liked: 212
post #2233 of 2755
08-25-2014 | Posts: 2,870
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I think that the new SI drivers are around 550 dollars shipped and they can be used in a smaller enclosure.
Brian Fineberg's Avatar Brian Fineberg
07:08 AM Liked: 748
post #2234 of 2755
08-25-2014 | Posts: 3,768
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please update mine..with the new HT room

Your Home Theater ULF Score Thread
***Input in yellow boxes as well as cost per sub detail below
Input Room Size in Cubic Feet >>> Room Size 1155
Total number of subs for your HT (Do not input) >>> Number of Subs 2 Member:
Total sub cost for your HT (Do not input)>>> Total Cost $2,498
10hz 12.5hz 16hz 20hz
Based on your sub's output, this is how many equivalent SIs > SI Equivalent 1.8 1.8 1.8 1.4
ULF Score 642 642 642 825
Groundplane SPL in room (1/8 space) w/sub 4M away (no room gain)> Groundplane SPL 100.3 103.8 108.9 113.1
Stars 4.5 4.5 4.5 4.5
Guideline for achieving reference output or above >>> Reference Estimate Reference Reference Above Reference Above Reference
Cost / SI (indication of bang for the buck for your subs) > Cost per SI $1,388 $1,388 $1,388 $1,784
Cost / Star (indication for bang for the buck for your room) >>> Cost per Star $555 $555 $555 $555
jbrown15's Avatar jbrown15
12:14 PM Liked: 1220
post #2235 of 2755
08-25-2014 | Posts: 6,667
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Quote:
Originally Posted by Pain Infliction View Post
I think that the new SI drivers are around 550 dollars shipped and they can be used in a smaller enclosure.

I always thought SI's price were before shipping?
popalock's Avatar popalock
03:43 AM Liked: 935
post #2236 of 2755
08-26-2014 | Posts: 4,021
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Quote:
Originally Posted by Pain Infliction View Post
I think that the new SI drivers are around 550 dollars shipped and they can be used in a smaller enclosure.
$589 shipped.

Quote:
Originally Posted by jbrown15 View Post
I always thought SI's price were before shipping?
Would be nice if there was consistency across the board...

At this point in time, the HST-18 price includes shipping to the lower 48.
jbrown15's Avatar jbrown15
10:12 AM Liked: 1220
post #2237 of 2755
08-26-2014 | Posts: 6,667
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Quote:
Originally Posted by popalock View Post
$589 shipped.


Would be nice if there was consistency across the board...

At this point in time, the HST-18 price includes shipping to the lower 48.
Nice! Well that will certainly make it even more enticing to people now.
dominguez1's Avatar dominguez1
07:06 PM Liked: 220
post #2238 of 2755
08-28-2014 | Posts: 1,913
Joined: Dec 2008
Version 16.1 of the ULF Calculator now available (post 1):

Click to download ULF Calculator

Example ULF Card


Latest ULF Calculator Updates:

August 28, 2014
  • Now all member scores for all frequencies are stored in spreadsheet and can be sorted by frequency or metric (ULF Score, Stars, SI, or GP SPL)
  • New ULF Card format
  • Tactile Feedback FX added

Member ULF Stars


Member ULF Scores


Member ULF SI Equivalents

dominguez1's Avatar dominguez1
07:28 PM Liked: 220
post #2239 of 2755
08-28-2014 | Posts: 1,913
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The ULF score is a reflection of the overall output you have in the ULF range in your specific room, but unfortunately that doesn't tell the whole story to describing what your ULF experience is.

Why? Because everyone has different rooms with different construction (suspended floors, concrete walls, dry wall, etc.) with different furniture with different subs and with different placement of the subs. As a result, the sound waves produced by your subs will interact with those items very differently. Two people with the same ULF score could have a drastically different ULF experience because of their room's DNA so to speak.

I had originally wanted to come up with a Tactile Feedback score to augment the ULF score. The two combined would give folks a better understanding of how it "felt" to experience ULF in your room; the ULF score would give you an idea from a pressure/weight/kick in the chest standpoint, and the TF score would give you an idea from a "shaking" standpoint.

The problem with trying to come up with a Tactile Feedback score is that even that has so much variation dependent on the makeup of your room; two people with the same ULF score and suspended floors may have completely different experiences. One floor may have a resonant frequency of 6hz versus the other one having a resonant frequency of 30hz. Furniture is the same way; once HT seating may have a ULF resonant frequency vs the other one not having a ULF resonant frequency at all.

So instead of trying to assign a score to your room's Tactile Feedback, I believe the next best thing is to just identify Tactile Feedback enhancers (FX for short). This will at least give more details about your overall ULF experience.

Below is a list of Tactile Feedback FX that typically enhance the ULF experience:
  • Suspended Floor
  • Riser
  • Transducers (ULF capable)
  • Nearfield Sealed
  • Nearfield Ported
  • Nearfield Horn
  • HT seating with a ULF resonant frequency

Are there any I'm missing?

Note that it's possible to just have 1 of these and it could potentially perform better than having all of these...it's truly dependent on the room and personal preference. However, generally speaking the more you have, the more tactile it will be.

I've adjusted the ULF calculator so that you can now record what you have in your room. These will be added to the member scores. I took a shot based on what I know below:



Feel free to add any Tactile Feedback FX I missed for your HT room by posting here. I will update the list accordingly. Note that you should only include Tactile Feedback FX that occur to your Main Listening Position. For example, if you have a second row riser, but that's not where your "Money Seat" is, don't include it in as part of your ULF card.
Attached: Member ULF Scores Nearfield 8-28-14.jpg (351.1 KB) 
laugsbach's Avatar laugsbach
08:01 PM Liked: 135
post #2240 of 2755
08-28-2014 | Posts: 2,681
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I have a riser on my first row allowing me to "float" the theater chairs for even more tactile feedback...
ellisr63's Avatar ellisr63
09:10 PM Liked: 253
post #2241 of 2755
08-28-2014 | Posts: 2,166
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dominguez1... I have a suspended floor, and my MLP is on top of one of the DTS-10 subs... MLP is about 2' in front of the opening for the DTS-10. I don't know if that effects the score or not.
basshead81's Avatar basshead81
10:02 PM Liked: 1722
post #2242 of 2755
08-28-2014 | Posts: 6,484
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This is my favorite thread!! Just thought I would share lol.
Luke Kamp's Avatar Luke Kamp
11:35 PM Liked: 116
post #2243 of 2755
08-28-2014 | Posts: 1,201
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Always liked this thread and dominguez1's exploration of the depths. Time to join the fun.
10' wide
8' 6" ft height (measured top boundary as floor above, bass doesn't care about my drop ceiling)
17' 6" length

1487.5 cubic feet
4 SI HT 18" d2 sealed enclosures on Peavey IPR2 7500
ULF score of 372 at 10 hz and up. This graph is nearfield driver vs. in seats with no eq, naked response.



I have a riser and near-field sealed.
BassThatHz's Avatar BassThatHz
11:44 PM Liked: 455
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08-28-2014 | Posts: 3,346
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Looks good, except you have me listed as non-DIY though.

What is the maximum distance allowed to the golden-seat to be considered near-field... 3ft from ear XYZ 3D-axis or just 2d distance?
I would imagine that that would exclude a lot of people that have multi-rows and/or if their golden seat isn't in the back-row with a sub eating their face (unless they have a VOG IB sub hanging from their ceiling that "somehow" doesn't interfere with their projector beam... LOL!)

I only have one row (at the moment) but my extreme left and right seats each have a sealed 21" sub that is within 4ft on the width-axis, but that's 7ft from the golden seat so I guess it would be excluded. Two of my UM-15's are within 7ft of the golden seat too.
In theory those guest seats would have slightly more bass than the golden seat does... how strange!

If we are taking distance into consideration, I have 20 subs all within 15ft of ANY seat, with the average distance being 10ft to 10 subs from ANY seat, so the "density" is fairly HIGH when you look at it from a distance perspective.
BassThatHz's Avatar BassThatHz
12:07 AM Liked: 455
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08-29-2014 | Posts: 3,346
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popalock probably has some of the highest "density" of all members, with something like: 4 18's within 4ft of ANY seat, 8 18's within 7ft average, and all 16 within 15ft of ANY seat. (I think?)

If my memory is correct, MK and N8 have fairly high densities too...



I think you should collect the average distance ("density") from all member's systems, and come up with a way to try to use that in calculating a "real-world" in-room SPL score, based on room volume and average distance to LP. Might be interesting to compare the theoretical-groundplane score to something more approximating a real-world type score.

There might even be an approximate correlation pattern between groundplane and such a real-world score I'd wager.
-6db for every doubling of distance, plus some sort of pressure vessel curve added etc; whatever algorithm is best.
popalock's Avatar popalock
04:15 AM Liked: 935
post #2246 of 2755
08-29-2014 | Posts: 4,021
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Quote:
Originally Posted by BassThatHz View Post
popalock probably has had some of the highest "density" of all members, with something like: 4 18's within 4ft of ANY seat, 8 18's within 7ft average, and all 16 within 15ft of ANY seat. (I think?)

If my memory is correct, MK and N8 have fairly high densities too...



I think you should collect the average distance ("density") from all member's systems, and come up with a way to try to use that in calculating a "real-world" in-room SPL score, based on room volume and average distance to LP. Might be interesting to compare the theoretical-groundplane score to something more approximating a real-world type score.

There might even be an approximate correlation pattern between groundplane and such a real-world score I'd wager.
-6db for every doubling of distance, plus some sort of pressure vessel curve added etc; whatever algorithm is best.
Thought I would correct your post.

Dom, can you update my score. I just calculated the volume of my new space. Two (2) SI24's in roughly 16,621ft^3 of open concept living should theoretically put at 2,968 @ 20Hz.

I guess I'll be out of the penis measurement game for a few years.

I'll just have to sit back and enjoy the show.


basshead81's Avatar basshead81
08:04 AM Liked: 1722
post #2247 of 2755
08-29-2014 | Posts: 6,484
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Lol
MiniHT's Avatar MiniHT
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post #2248 of 2755
08-29-2014 | Posts: 93
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Dom, I'm on a suspended floor. Thanks for the update!
MKtheater's Avatar MKtheater
08:33 AM Liked: 530
post #2249 of 2755
08-29-2014 | Posts: 14,804
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Yeah, but these type of threads are fun. There used to be a spl at LP during certain scenes thread a while ago.


My new seating arrangement has 5 seats going across the front row on a riser. The back row is for kids on another riser. The two subs in the back take up everything else back there so they take up 4 seats across which means they are directly behind 4 of the 5 seats and less than a foot from the top of the seats. Of course they are not finished yet so they are big ugly surround stands for now. I will port them at 10hz because as anyone can see when you run sealed subs nearfield they don't get the low end boost unless you EQ the crap out of them. I won't need to do that with the port but they won't add much to the 5hz rating either. they will add 2 Si at 5hz each rather than the 8 Si at 10hz each. I probably won't need more than 100 watts for them to blast me.
ahmedreda's Avatar ahmedreda
11:03 AM Liked: 44
post #2250 of 2755
08-29-2014 | Posts: 498
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How does the buttkicker LFE compare to the Crowsons. I noticed you have both.
Quote:
Originally Posted by laugsbach View Post
I have a riser on my first row allowing me to "float" the theater chairs for even more tactile feedback...

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