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post #91 of 152 Old 11-09-2013, 04:49 PM
 
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No, but in her younger days, she was able to pose as Elizabeth Montgomery's twin sister.

My apologies. I associated your post in error with Cowboys post and without the proper association, the post won't make any sense at all. For proper associative purposes, I have edited my above rambling so hopefully it makes more sense.

D'oh!

I'm quite positive, as long as a smooth graph, I'll be tickled with the output of a pair of FV15HPs.

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post #92 of 152 Old 11-10-2013, 05:15 PM - Thread Starter
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Originally Posted by basshead81 View Post

ground plane...i provided links. The Rythmik graphs are not to determine max output, they are for showing frequency response. You can not lay them over the top of each other and determine what has more output. Yes sealed will extend lower but you can not use them to determine how much more output. Bottom line there is no way the F15HP will have the same output of the FV15HP around its tune, its the laws of physics. Not sure how many times I have to repeat that. Rythmiks site even proves it by showing the FV15HP +5db @ 20hz, put it into 1 port 12hz tune and the difference will be the same down @ 12hz because thats its tuning point... The data-bass measurements back this theory up since output increases 9db going from 2 port 18hz tune to 1 port tune 12hz.
Now if you have a Small 1000-1500^3 room, sure the F15HP might get enough room gain to match the FV15HP, but in rooms over 3000^3 its highly unlikely...this was my point from the get go when conversating with Beeman.

The graphs are relative. They don't have absolute values. You are right, you cannot look at say 10Hz on both graphs and determine which one has the higher output. However, if we have a known measurement on both graphs, we can use the graphs to compare. In our case, we can use the measurement at 20db where we know that the FV15HP does 108 and the F15HP does 103. Since the vertical axis are distributed uniformly, I overlayed the F15HP graph at 5db lower at 20HZ. The graph shows the FV15HP in one port mode vs the F15HP.


The readings from the graph agree with the values in ULF thread as well as the calculations of rcohen.

@ 20HZ
FV15HP=108db (point #1) , according to ULF thread (really doesn't matter. If higher or lower all values will go up or down accordingly.)
F15HP=103db (point #2) according to the fact that it is 5db lower than the FV15HP (per Rythmik).


@12HZ
FV15HP=98db (point #5 in graph)(10 down, matches ULF thread measurement as well as the curve).
F15HP=101db (point #3 in graph) (3 down than its measurement at 20hz)


@10 HZ
FV15HP=86db (point #6) (22db down than its value at 20HZ)
F15HP=97db (point #4) (6db down than its value at 20HZ)


quoting Audiophile2k and rcohen to get their take.

Quote:
Originally Posted by Audiophile2k View Post

I think you are confusing usable extension modes with tuning frequency. From my understanding, 12hz is not the tuning frequency, but the in useful room extension you can expect. The actual tuning frequency is higher on the FV15HP. rcohen breakdown is pretty spot on regarding what you can expect from the sealed vs. ported. Sealed gains low end extention, ported gives higher output over 18hz.
That sounds about right. Per the graph, the FV15HP can give output all the way down to 12HZ at 98db. At 10HZ, it significantly drops to 86db. The F15HP is still fairly stable with 101db at 12Hz and 97db at 10HZ.
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Originally Posted by rcohen View Post

Thanks...I didn't see the part that said they were ground plane.

I agree with your point that all else being equal, a vented sub should be much more power efficient than a sealed sub at the tuning frequency. So, either it's actually tuned higher, and the usable extension is what's quoted, or else the high-pass filter is limiting the output at normal listening levels.

Regardless of all this, I can tell you that in my room, level matched, listening to real movie material at normal listening levels (not sine waves at max spl), the bottom line was that although the FV15HP in 1 port mode was good, the F25 had significantly more quantity and more detailed subsonic than the FV15HP. I didn't do the synthetic 12hz max spl sine wave test.

I believe you're right, though, that the FV15HP has more headroom, even compared to the F25. Different people have different priorities and preferences.
It should have more headroom down to 18Hz or so then the F15HP should do better.
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post #93 of 152 Old 11-10-2013, 05:28 PM
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I disagree....The FV15HP netted 98db @ 12hz 2m rms open ground plane according to data-bass.com. It easily digs to 10hz and dominguez has provided graphs of his in room response.

Sealed subs roll off 10-12db from 20hz down to 12hz. The F15HP is not going to do anything more magical then the other DIY sealed subs that were tested @ data-bass.com. The F15HP will be down more then 2db from 20hz to 12hz. Read the ULF thread.
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Quote:
Originally Posted by basshead81 View Post

I disagree....The FV15HP netted 98db @ 12hz 2m rms open ground plane according to data-bass.com. It easily digs to 10hz and dominguez has provided graphs of his in room response.

Sealed subs roll off 10-12db from 20hz down to 12hz. The F15HP is not going to do anything more magical then the other DIY sealed subs that were tested @ data-bass.com. The F15HP will be down more then 2db from 20hz to 12hz. Read the ULF thread.

The 12Hz reading at databass agree with the graph above. Databass does not list a reading at 10Hz. In the F15 graph below, I highlighted the output at 20Hz and at 12 Hz and they are 2-3 db apart.

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post #95 of 152 Old 11-10-2013, 06:00 PM
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I have done some more reading in Dominguez's ULF thread, and he has put together some pretty solid estimates. At this point I don't agree with Rythmik's claims.

The lms ultra 5400 18" which has much more surface area and throw of the rythmik driver put up 98 dB at 12.5 hz CEA on a 12,000 watt amp. The F15HP won't get close to that number period. Now the FV15HP did 98.5 dB in its one port (14hz) tune.

Read this thread. Good discussion on the differences found between sealed and ported. Also we did some ULF testing followed by some discussion that some might find interesting over the last few pages.

http://www.avsforum.com/t/1489801/bought-four-sealed-18-cabinets-on-a-wild-hare-direct-me-to-a-driver-setup-at-least-competitive-or-superior-to-jtr-captivators
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post #96 of 152 Old 11-10-2013, 06:23 PM
 
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Those are open plane graphs. What about in a room with expected room gain? The way I read the above, with two FV15HPs running in the same room, with the longest wall being 22', the subs would co-join at 12Hz so I would expect 9dB to be added to the 98dB or 107dB at 12Hz, max output, both subs running. The addition of a third FV15HP, I would expect an additional +3dB so unless I need the additional subwoofer for smoothing purposes, assuming no more than a down -6dB graph, the above is as good as I can expect?

...confused.gif

According to the ULF thread and what I have cobbled together, two FV15HPs running in the same room, at 16Hz, should be able to do reference and I would expect a max output, with room gain and co-joined reinforcement of 108dB at 12Hz. And if I were to want or expect more, I would have to step up our game to the subwoofers one would expect to find in the +4.5 star rated category.

I was hoping to get reference @ 12Hz with the output of a pair of sealed subwoofers but basshead81, via the ULF thread, has shown, that's not going happen or I'd consider a pair of F25s.

..........................................................................................

4.5 Stars - Reference Output (10hz & 12.5hz systems), Above Reference Output (16hz and higher)

miniht - 301@10hz 842cf - 2.8 SI - 1 JTR Cap S2

steveo1234 - 324@10hz 1300cf - 4.2 SI - 6 AE IB 15 (Infinite Baffle)

carp - 379@10hz - 3035cf - 8 SI - 8 x 18 SIs

notnyt - 395@10hz - 6000cf - 15.2 SI - 8 x 18 LMS-U powered by 2 clone amps

desertdome - 384@10hz - 2153cf - 5.6 SI - 8 AE IB 15

laugsbach - 395 @10Hz - 3000cf - 7.6 SI - 4 x 18 SI, Ricci's DIY Ported w/RE Audio MX-18 D2 driver - all powered (3) EP-4000 amps

dominguez1 - 432@10hz - 1900cf - 4.4 SI - Dual FTW-21 in sealed cabs powered by 2 ep4000s, Dual FV15HPs

GoCaboNow - 433@10hz - 2600cf - 6 SI - 4x Fi IB3 18's paired with an EP4000

cubalis2 - 561@10hz - 3200cf - 5 SI - 2 x LMS-U 18's FP14K clone, 2 x LMS-R 15"s dual opposed inuke 6000DSP

pbc - 625@10hz - 1750cf - 2.8 SI - 2 dual opposed AE IB 15 subs (4 drivers) powered by Funk Audio 2400x2 - also (515@12.5hz)

Toe - 577@12.5hz - 1500cf - 2.6 SI - 3 SVS PB13-Ultras, 1 SVS PB12/2 Ultra

stereo2.0 - 515@16hz - 3500cf - 6.8 SI - DTS-10, powered by a Proton D1200

mastermaybe - 603@16hz - 2172cf - 3.6 SI - 4 x 18 Dayton HO's powered by Crown xti 4002

archaea - 565@20hz - 3500cf - 6.2 SI - 2 Passive Caps (20hz model) with Crown XLS5000 amps.

..........................................................................................

(i ain't gonna try to obtain 4.5 star output, just trying to understand what's what with what)

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post #97 of 152 Old 11-10-2013, 06:29 PM
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Quote:
Originally Posted by Luke Kamp View Post

I have done some more reading in Dominguez's ULF thread, and he has put together some pretty solid estimates. At this point I don't agree with Rythmik's claims.

The lms ultra 5400 18" which has much more surface area and throw of the rythmik driver put up 98 dB at 12.5 hz CEA on a 12,000 watt amp. The F15HP won't get close to that number period. Now the FV15HP did 98.5 dB in its one port (14hz) tune.

Read this thread. Good discussion on the differences found between sealed and ported. Also we did some ULF testing followed by some discussion that some might find interesting over the last few pages.

http://www.avsforum.com/t/1489801/bought-four-sealed-18-cabinets-on-a-wild-hare-direct-me-to-a-driver-setup-at-least-competitive-or-superior-to-jtr-captivators

Thanks Luke!! This is what I have been try to say...there is no way the F15HP is putting down 101db @ 12hz with 600watts rms whenthe LMSU 18" did 98db with 12000watts.
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post #98 of 152 Old 11-10-2013, 06:35 PM
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Quote:
Originally Posted by BeeMan458 View Post

Those are open plane graphs. What about in a room with expected room gain? The way I read the above, with two FV15HPs running in the same room, with the longest wall being 22', the subs would co-join at 12Hz so I would expect 9dB to be added to the 98dB or 107dB at 12Hz, max output, both subs running. The addition of a third FV15HP, I would expect an additional +3dB so unless I need the additional subwoofer for smoothing purposes, assuming no more than a down -6dB graph, the above is as good as I can expect?

...confused.gif

According to the ULF thread, two FV15HPs running in the same room, at 16Hz, should be able to do reference and I would expect a max output, with room gain and co-joined reinforcement, of 108dB at 12Hz. And if I were to want or expect more, I would have to step our game up to the next subwoofer category one would expect to find in the +4.5 star rated category.

..........................................................................................

4.5 Stars - Reference Output (10hz & 12.5hz systems), Above Reference Output (16hz and higher)

miniht - 301@10hz 842cf - 2.8 SI - 1 JTR Cap S2

steveo1234 - 324@10hz 1300cf - 4.2 SI - 6 AE IB 15 (Infinite Baffle)

carp - 379@10hz - 3035cf - 8 SI - 8 x 18 SIs

notnyt - 395@10hz - 6000cf - 15.2 SI - 8 x 18 LMS-U powered by 2 clone amps

desertdome - 384@10hz - 2153cf - 5.6 SI - 8 AE IB 15

laugsbach - 395 @10Hz - 3000cf - 7.6 SI - 4 x 18 SI, Ricci's DIY Ported w/RE Audio MX-18 D2 driver - all powered (3) EP-4000 amps

dominguez1 - 432@10hz - 1900cf - 4.4 SI - Dual FTW-21 in sealed cabs powered by 2 ep4000s, Dual FV15HPs

GoCaboNow - 433@10hz - 2600cf - 6 SI - 4x Fi IB3 18's paired with an EP4000

cubalis2 - 561@10hz - 3200cf - 5 SI - 2 x LMS-U 18's FP14K clone, 2 x LMS-R 15"s dual opposed inuke 6000DSP

pbc - 625@10hz - 1750cf - 2.8 SI - 2 dual opposed AE IB 15 subs (4 drivers) powered by Funk Audio 2400x2 - also (515@12.5hz)

Toe - 577@12.5hz - 1500cf - 2.6 SI - 3 SVS PB13-Ultras, 1 SVS PB12/2 Ultra

stereo2.0 - 515@16hz - 3500cf - 6.8 SI - DTS-10, powered by a Proton D1200

mastermaybe - 603@16hz - 2172cf - 3.6 SI - 4 x 18 Dayton HO's powered by Crown xti 4002

archaea - 565@20hz - 3500cf - 6.2 SI - 2 Passive Caps (20hz model) with Crown XLS5000 amps.

..........................................................................................

(i ain't gonna go there, just trying to understand what's what with what)


2 FV15HP's co-coupled will yield 104db @ 12hz 2m rms, then add another 6db for in room = 110db. You could see more or less depending on room gain. Your ULF score with dual FV15HP's indicates reference level output down to 16hz and below reference output @ 12hz.
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Quote:
Originally Posted by basshead81 View Post

Thanks Luke!! This is what I have been try to say...there is no way the F15HP is putting down 101db @ 12hz with 600watts rms whenthe LMSU 18" did 98db with 12000watts.

You had it right! If you read the thread we linked from page 5 on, we found four 18" SI to not have useable output below 15 hz in Archaea's room. Carp and Desertdome are both 4.5 stars on the ULF thread and don't find below 15hz useful to them in their rooms.
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Well, being off two dB won't get me a passing score in a acoustics class but would get me points in horseshoes.

At 12Hz, I can live with 110dB as pretty much, the rest of the output is at or better than reference. I guess if I want better, I'm going have to spend more dough and I have assured my wife that I wasn't going do that. I have already informed her that the subwoofers were going happen sooner than later so mentally, she's been properly prepped. I still need to run final placement measurements with what we're currently using.

We're going from a set of three twelve inch subs. Two of the subs are nineteen year old, Klipsch SW II subwoofers using existing 150w Amps and a pair of decent driver/passive radiator replacement combinations purchased at Parts-Express. The third subwoofer is a new Klipsch RW12D so the FV15HP will be a huge upgrade over what we've been listening to.
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post #101 of 152 Old 11-10-2013, 06:47 PM
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Here some more context around the F15HP from the ULF thread. I've extrapolated its output based on data-bass testing results of how sealed alignments typically perform at max output CEA testing, as well as comparing ported and sealed alignments using the same driver and amp.

 

It just isn't possible for the F15HP to produce 101db@12.5hz. I estimate that the F15HP would test at around 90db@12.5hz.

 

 
Quote:
Originally Posted by dominguez1 View Post
 

This was a good exercise trying to estimate from a ported sub to its sealed counterpart. If I use the same methodology, I can get pretty close with a variety of subs. Here's the methodology I'm using for estimating (this was all derived by looking at data-bass measured results). Also, I'm estimating more optimistically in general (benefit of the doubt).

 

Again, this isn't perfect, but should get us pretty close.

 

Going from ported to sealed:

  • Sealed is aprox. 10db down at the ported subs tune. If the measured result is not exactly at tune, I'll subtract 1-2 db to compensate for the difference: 18hz tune, I'll use 8db down instead of 10db, since there measurement on data-bass is 20hz.
  • Example: The FV15HP outputs 108.1 at 20hz. The F15HP is it's sealed counterpart (using the same driver and amp), so I adjust it's 20hz output by 8db (FV15HP's tune is 18hz) to 100.1 at 20hz.

 

Estimating sealed max output from 20hz

  • Looking at data-bass, most sealed subs are down 10-12db at 12.5hz compared to 20hz. Being optimistic, I use 10db down to get to the 12.5hz
  • Example: Since I estimated the F15HP at 100.1 at 20hz, based on the above, it's 12.5hz output is 90.1db.
  • In order to determine whether or not a sealed sub can dig cleanly to 10hz, I referenced data-bass again. Looking at 20hz, the lowest output where a sealed sub has clean CEA output at 10hz is when it had 99db or higher at 20hz (LMSR12-Sealed). Generally speaking, any sealed sub that produced 99db or higher, was able to get clean output at 10hz.
  • To estimate 10hz output, looking at data-bass, most sealed subs are down 4-6db from 12.5hz. Being optimistic, I use 4db down from 12.5hz to get to 10hz.
  • Example: Since the F15HP is estimated 100.1 at 20hz (>=99db), I will estimate it's 10hz output. Subtracting 4db from it's 12.5hz estimate puts it at 86.1db at 10hz
  • For 16hz, I just took the midpoint between the 20hz output and the 12.5hz output.
  • Example: The F15HP at 20hz is 100.1, and at 12.5hz is 90.1. The 16hz output is estimated at 95.1db. 

 

Based on the above, I've filled in the blanks from 10-20hz for all sealed subs we've estimated so far. I've also completed some ported sub estimates based on mfg data being up or down certain db compared to their big brother ported subs on data-bass.

 

Note, I've re-estimated all Rythmik subs. The 20hz output looks more realistic to me compared to other estimates and data-bass data.

 

 

Look at the results, am I close here?

 

Quote:
Originally Posted by dominguez1 View Post
 

 

To be consistent as possible with the other estimates, I extrapolated the F15HP based on the measurements of the FV15HP on data-bass, as well as how typically ported designs and sealed designs (using same amp and driver) differ at tune. Look at this post to see the details. Also look at the SVS PB12 and SB12 results on data-bass. Same driver and amp, but different designs.

 

Also, if I were to use the information from the Rythmik site, that would put the F15HP at 103db @ 20hz. This output doesn't seem accurate when you look at other sealed designs that have similar output. For example, if it were 103db, it would be greater than or equal to the output of the following subs:

  • Funk Audio, FW18.0 (18in)
  • eD A7S-450 (18in)
  • Epik Empire (dual 15's)
  • Velodyne DD18 (18in)

 

I'm a Rythmik owner and big fan, but I wouldn't expect the Rythmik 15in driver can have the same or more output then the above. The displacement is just not there compared to the above.

 

As for the F25, it's basically two F15HP's but with less power. So instead of being 6dbs up with 2x power and displacement, I just estimated 4.5db instead.

 
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post #102 of 152 Old 11-10-2013, 07:02 PM - Thread Starter
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Something seems way off! We are talking 10db difference. Here is what is listed on the Rythmik website:

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.
F12: 0db (baseline)
F15: +2db D15: +2db
FV12: +3db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9db
F25: +8db

We know for a fact that their graph for the FV15HP in one port is accurate as verified by databass. So either the graph for F15HP is off (IMO unlikely since the FV15HP was verified) or the offsets above are not accurate or I missed something in my calculations however you mentioned that the 103db output at 20hz is also hard to believe. Unless someone measures the F15HP, it will be hard to tell.
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Originally Posted by dominguez1 View Post

Here some more context around the F15HP from the ULF thread. I've extrapolated its output based on data-bass testing results of how sealed alignments typically perform at max output CEA testing, as well as comparing ported and sealed alignments using the same driver and amp.

It just isn't possible for the F15HP to produce 101db@12.5hz. I estimate that the F15HP would test at around 90db@12.5hz.

 


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post #103 of 152 Old 11-10-2013, 07:03 PM
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You had it right! If you read the thread we linked from page 5 on, we found four 18" SI to not have useable output below 15 hz in Archaea's room. Carp and Desertdome are both 4.5 stars on the ULF thread and don't find below 15hz useful to them in their rooms.

I've found that perception of ULF is VERY room dependent.

 

In my room, I feel it is very evident...some of my favorite scenes are the ones where there is strong content between 10 and 15hz. I describe it as the 'wobble' effect...the cheeks on my face wobble (move your face very quickly from side to side so that your cheeks wobble). That is the sensation, except it also shows up in the couch and on your body.

 

At 12.5hz, I have 5 star bass.

 

However, I went over to my buddy's place, laugsbach, and played some of my favorite wobble scenes. He also has 5 star bass at 12.5hz. The wobble effect was much less apparent. I had to sit right next to the XXX ported monster that Ricci built in order to get a similar effect, but even then it wasn't as strong.

 

I'd love to understand why it's so apparent in my room, but not so much in his, when we have similar displacement per cubic foot...I would guess, Carp and Desertdome have the same ULF perception as laugsbach.

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post #104 of 152 Old 11-10-2013, 07:09 PM
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Quote:
Originally Posted by ahmedreda View Post

Something seems way off! We are talking 10db difference. Here is what is listed on the Rythmik website:

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.
F12: 0db (baseline)
F15: +2db D15: +2db
FV12: +3db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9db
F25: +8db

We know for a fact that their graph for the FV15HP in one port is accurate as verified by databass. So either the graph for F15HP is off (IMO unlikely since the FV15HP was verified) or the offsets above are not accurate or I missed something in my calculations however you mentioned that the 103db output at 20hz is also hard to believe. Unless someone measures the F15HP, it will be hard to tell.

Normally, I would agree that it would need to be tested to be sure. But in this case, there is pretty overwhelming data that the F15HP is not even close to 101db at 12.5hz. My 21in driver with 34mm xmax can only produce 100db@12.5hz.

 

The F15HP is a 15in driver with ~20mm xmax?

 

Also, like I mentioned above, the F15HP is more likely down 8db from the FV15HP, not 5db.

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post #105 of 152 Old 11-10-2013, 07:13 PM - Thread Starter
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That would still make it on par with the FV15HP at 12hz unless you believe the graph is flawed as well.
Quote:
Originally Posted by dominguez1 View Post

Normally, I would agree that it would need to be tested to be sure. But in this case, there is pretty overwhelming data that the F15HP is not even close to 101db at 12.5hz. My 21in driver with 34mm xmax can only produce 100db@12.5hz.

The F15HP is a 15in driver with ~20mm xmax?

Also, like I mentioned above, the F15HP is more likely down 8db from the FV15HP, not 5db.
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post #106 of 152 Old 11-10-2013, 07:35 PM
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Originally Posted by ahmedreda View Post

That would still make it on par with the FV15HP at 12hz unless you believe the graph is flawed as well.

Not sure what you mean? What is on par?

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post #107 of 152 Old 11-10-2013, 07:36 PM
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Quote:
Originally Posted by ahmedreda View Post

That would still make it on par with the FV15HP at 12hz unless you believe the graph is flawed as well.

He is saying the graph is flawed, as is Luke and myself. The F15HP is not going to put out 101db 2m rms @ 12hz...no way no how. That would be within 1db of the Captivator S2 that has dual 18" 30mm xmax drivers with 4k watts of power.
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post #108 of 152 Old 11-10-2013, 07:49 PM - Thread Starter
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This is from their website. They claim the 14HZ is 3db down from their max. Also, the graph they listed is actually for the F15 with the F15HP being close which could be part of the confusion.
"A quick glance at our frequency response plot will reveal that our subwoofers do exactly what we claim. In the chart below, with bass extension controls set to 14 Hz, the response is 3 db down at 14 Hz. The response is flat and extended. F15HP has a response very close to F15 which is shown below."

What he is essentially saying is that the offsets @20hz are wrong as well as the stated frequency response.confused.gif
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Originally Posted by basshead81 View Post

He is saying the graph is flawed, as is Luke and myself. The F15HP is not going to put out 101db 2m rms @ 12hz...no way no how. That would be within 1db of the Captivator S2 that has dual 18" 30mm xmax drivers with 4k watts of power.
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post #109 of 152 Old 11-10-2013, 08:01 PM
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Quote:
Originally Posted by ahmedreda View Post

This is from their website. They claim the 14HZ is 3db down from their max. Also, the graph they listed is actually for the F15 with the F15HP being close which could be part of the confusion.
"A quick glance at our frequency response plot will reveal that our subwoofers do exactly what we claim. In the chart below, with bass extension controls set to 14 Hz, the response is 3 db down at 14 Hz. The response is flat and extended. F15HP has a response very close to F15 which is shown below."

What he is essentially saying is that the offsets @20hz are wrong as well as the stated frequency response.confused.gif

If I understand you correctly: the Rythmik graphs is all a relative comparison. Does it explicitly show that it can product 101db @12.5hz? Please post the graph if so.

 

IMO, I do believe the offsets to be incorrect from the Rythmik site. Likely because the FV15HP had very favorable results; throwing off the sealed counterparts.

 

What you seem to be glossing over is the overwhelming data that even much larger, more capable subs compared to the F15HP can't produce those levels of output. Put the Rythmik claims aside...do you think based on db.com data that a 15in driver could produce that?

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post #110 of 152 Old 11-10-2013, 08:26 PM - Thread Starter
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The rythmik graph as I understand it will tell you something like the response at 12.5hz is 3 db lower than the response at 20hz. It does not tell you what either one is. If you figure the response at 20HZ is 103 (using rythmik's claim) and it is 3 db lower at 12Hz, you can conclude that it will be around 100.

Note that we used two pieces of information, first the -5 offset @20hz from the FV and the graph to come up with the 3db lower at 12hz



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Originally Posted by dominguez1 View Post

If I understand you correctly: the Rythmik graphs is all a relative comparison. Does it explicitly show that it can product 101db @12.5hz? Please post the graph if so.

IMO, I do believe the offsets to be incorrect from the Rythmik site. Likely because the FV15HP had very favorable results; throwing off the sealed counterparts.

What you seem to be glossing over is the overwhelming data that even much larger, more capable subs compared to the F15HP can't produce those levels of output. Put the Rythmik claims aside...do you think based on db.com data that a 15in driver could produce that?
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post #111 of 152 Old 11-10-2013, 08:39 PM
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Quote:
Originally Posted by dominguez1 View Post
 

If I understand you correctly: the Rythmik graphs is all a relative comparison. Does it explicitly show that it can product 101db @12.5hz? Please post the graph if so.

 

IMO, I do believe the offsets to be incorrect from the Rythmik site. Likely because the FV15HP had very favorable results; throwing off the sealed counterparts.

 

What you seem to be glossing over is the overwhelming data that even much larger, more capable subs compared to the F15HP can't produce those levels of output. Put the Rythmik claims aside...do you think based on db.com data that a 15in driver could produce that?

Again, you avoided this question.

 

Care to respond?

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post #112 of 152 Old 11-10-2013, 08:51 PM
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No you can not because compression is not factored in that graph. The response of a 90db sweep will be much different then a max spl sweep. If the F15HP was that good, popalock would have 16 of those instead of his 16 LMS U 18's. No sealed sub will only be down 3db from 20 to 12hz unless it has massive amounts of low end eq boost, which would cripple its head room and be on the limiter before it hit 90db.

Again,.go to data-bass.com and compare the PB13U 15hz tune vs Sealed. Sealed extends lower but has alot less output compared to the 15hz tune. Look at the VTF-15 16hz tune vs Sealed, same thing. Look at the PB-12NSD vs the SB-12NSD, GUESS WHAT SAME THING Lol.
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post #113 of 152 Old 11-10-2013, 09:17 PM - Thread Starter
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Originally Posted by dominguez1 View Post

Again, you avoided this question.

Care to respond?

If we put all the data available aside, what you are saying makes sense. However i am convinced that the real response is somewhere in between. Unless we measure it out, it will be hard to tell exactly. I am new to all this and i am in the process of setting up rew to measure my room response so may be that will give me a better idea.
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post #114 of 152 Old 11-10-2013, 09:30 PM - Thread Starter
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Quote:
Originally Posted by basshead81 View Post

No you can not because compression is not factored in that graph.The response of a 90db sweep will be much different then a max spl sweep. If the F15HP was that good, popalock would have 16 of those instead of his 16 LMS U 18's. No sealed sub will only be down 3db from 20 to 12hz unless it has massive amounts of low end eq boost, which would cripple its head room and be on the limiter before it hit 90db.

Again,.go to data-bass.com and compare the PB13U 15hz tune vs Sealed. Sealed extends lower but has alot less output compared to the 15hz tune. Look at the VTF-15 16hz tune vs Sealed, same thing. Look at the PB-12NSD vs the SB-12NSD, GUESS WHAT SAME THING Lol.

edit: so those graphs are max output plots and not FR plots. In that case they cant be used to compare output SPLs. Kind of curious what the +5db advantage @20Hz of the FV15HP referred to.
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post #115 of 152 Old 11-11-2013, 07:39 AM
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What makes you think those are max output plots, and not FR plots? My impression was that they were FR plots, and that at max SPL, the limiter would kick in and the low frequencies would start to roll off. And, it makes perfect sense that he ported sub would have a substantial advantage at the tuning frequency. It's just unclear what the tuning frequency is.

For those who want the most power efficiency, no question that ported is the answer.
For those who want the FR and clean/detailed sound of sealed, corner loading and/or more subs is the answer. I'm going with "and". smile.gif
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post #116 of 152 Old 11-11-2013, 07:52 AM
 
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I want it all and I want it now but then there's this thing called money. confused.gif

Based on all I've learned, the FV15HP does it all in spades. To me, my opinion, based on my vast pool of ignorance, folks are arguing minutia as opposed to substance. What am I missing in this understanding?
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post #117 of 152 Old 11-11-2013, 08:31 AM - Thread Starter
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http://www.avsforum.com/t/1214550/official-rythmik-audio-subwoofer-thread/1320

see post #1325 on that page. It says those are max output even though the graph says frequency response.
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What makes you think those are max output plots, and not FR plots? My impression was that they were FR plots, and that at max SPL, the limiter would kick in and the low frequencies would start to roll off. And, it makes perfect sense that he ported sub would have a substantial advantage at the tuning frequency. It's just unclear what the tuning frequency is.

For those who want the most power efficiency, no question that ported is the answer.
For those who want the FR and clean/detailed sound of sealed, corner loading and/or more subs is the answer. I'm going with "and". smile.gif
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post #118 of 152 Old 11-11-2013, 08:39 AM
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Well, being off two dB won't get me a passing score in a acoustics class but would get me points in horseshoes.

At 12Hz, I can live with 110dB as pretty much, the rest of the output is at or better than reference. I guess if I want better, I'm going have to spend more dough and I have assured my wife that I wasn't going do that. I have already informed her that the subwoofers were going happen sooner than later so mentally, she's been properly prepped. I still need to run final placement measurements with what we're currently using.

We're going from a set of three twelve inch subs. Two of the subs are nineteen year old, Klipsch SW II subwoofers using existing 150w Amps and a pair of decent driver/passive radiator replacement combinations purchased at Parts-Express. The third subwoofer is a new Klipsch RW12D so the FV15HP will be a huge upgrade over what we've been listening to.

No matter which of the options you're currently considering that you go with, you are going to be seriously blown away. wink.gif

I have none of the fancy in-room numbers or measurements that some of these guys have, but my 4 XS15s don't have any significant drop-off until 10hz - just sayin' if you really want sealed, there are options. wink.gif

How about dual XS30s?
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post #119 of 152 Old 11-11-2013, 08:42 AM - Thread Starter
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You mentioned that you have 3300^3 area with 7300^3 total space. I would think the FV15HP would be a no brainer in the Rythmik lineup. The F15HP does not stand a chance there. My space is a lot smaller so the F15 could be an option.
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I want it all and I want it now but then there's this thing called money. confused.gif

Based on all I've learned, the FV15HP does it all in spades. To me, my opinion, based on my vast pool of ignorance, folks are arguing minutia as opposed to substance. What am I missing in this understanding?
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post #120 of 152 Old 11-11-2013, 09:10 AM
 
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How about dual XS30s?

From what I've recently read, they won't have the output in the lower octaves like the FV15HP. I will start with two FV15HPs and if needed, once I've dealt with the WAF, get a third FV15HP as I have a chair it can hide behind and do double duty as a lamp stand.

Seriously, if my wife is to take me seriously, at sometime and point, I have to draw a line and quit.

(looking forward to being blown away)
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