JTR Captivator - Page 49

I agree with most of your post, with the major caveat "IF" the tests are unbiased and performed properly. The problem is, most (not all) of the test results I have seen get picked apart, questioned, "but what about"...

and maybe i'm just more skeptical/less trusting than you. Never know who has what agenda, or even subconscious bias. But the idea that more testing is better, sure...if three of three tests draw the same conculsion, or four of five...that gives clout and helps the buyer make an edjucated decision.

would the industry benefit from more truly independent, unbiased testing? Sure.

Now...on the "I don't think anyone should make a decision"...that is a rather strong statement and comes down to your opinion. This is all about fun, or it should be. For starters, not everyone buying a sub puts technical qualities first. Looks, size, WAF matter too...which can be judged pretty well without a microphone. Folks buy cars without reading so much as a one page review, or even without a test drive for that matter ("I'll take the red one") and there's nothing wrong with that.

Just scrolling up the page briefly, I quickly found the phrases "fairy-tail" and "made up" in your posts, in reference to Jeff's SPL numbers.

Using phrases like that in reference to a well respected manufacturer's numbers, without posting even your own test numbers (which would not be conclusive either but would at least be something concrete) is in my book "throwing rocks".

Of course it's my opinion, that's why I said "I think". I agree with you, that if someone chooses to buy a new sub simply because the color matches their curtains then more power to them! I'm certain that most people on this forum, however, are more concerned with VERIFIABLE performance.

Agreed, many of us tend to research things to death....as is the nature of technical or product specific forums. There are also times when I just like to read enough to be confident it's a "solid" performer (even if it's based on subjective reports...and do the verifying myself.

Just looking at this from the business side of things, somehow JTR has managed to let the products speak for themselves and has been successful enough with the product to warrant increasing the price, which is a good place to be.

anyone have a pic of the cap driver ?

The "made-up" numbers you're quoting were referring to mojomike's estimation of his passive Captivator's performance- and he never made them out to be anything but that, it's just his opinion and I have no issue with that. Context.

"Fairy-tale" refers to 130dB at 20Hz. In my opinion, magical, idealized, maybe exaggerated. Who knows. It's fairly-tale by the nature of the claim. I don't know of a similar sub claiming anything in that ballpark. This is a first.

Now maybe fairy-tales come true every now and then...

If you don't find the 130dB at 20Hz claim to be extraordinary, I'm genuinely curious to know how you justify that position? That's why I thought the discussion would be interesting after all.

I think he's got new ones now, but this was the original pic. It's quite intimidating!

I'm reminded of an old adage..."In the business world to be successful you need to do more than make yourself look good, you also need to make your competition look bad". Curious...................

that's beefy looking

Found the newer pics:

So the subwoofer bickering/trolling/pissing match flu has made its made way to jtr as well. Well, I guess it had to at some point.

Why should JTR or any other company be immune to the the same sort of treatment as anyone else? As long as the company continues to deliver solid, well-made products like it always has, it's got nothing to worry about.

When you boast 130dB at 20Hz CEA-2010, you are indeed starting a pissing match if not participating in one already begun (see HSU and the VTF-15).


Right on. That's why I think JTR should stick to quality performance and leave the drag racing to the desperate who need ambiguous claims to mask an inferior product. JTR has the goods, they don't need stuff like this.

I never expected that jtr would be immune from it, but it was nice to read a discussion about a product without it devolving into the worst of the what internet has to offer. I'll never really understand why people act like such asses towards others when they have any little bit of anonymity. If these were actual discussions with more rational talk than hate it would be fine and would be welcomed, but they almost never start out that way and never end that way.

Oh, and I'm certain jtr has nothing to worry about from this. This is more of a bother to readers such as ourselves than jtr.

I wonder who's gonna catch this flu next? Don't wanna give any ideas.

You're saying specs should never be questioned? What's more irrational than that?

I don't see anyone in here being rude to anyone else, it's been very civil. That doesn't mean we all have to agree about everything.

You're right. Nobody has been rude, uncivil, or has gotten personal. If all discussions and debates on this forum went this smoothly, you would never see the fireworks and implosions that have taken place in other memorable threads in the past.

Please reread the last sentence of the first paragraph. That please is sincere(not sarcasm).


Then perhaps your and my idea of "very civil" is different. Though, I will say that of all the sub threads that devolved in all out bickering this one has retained more civility than most, but it's early.

Just a little bit of nostalgia:

When Tom Nousaine tested the Epik Conquest in his 7,500 cubic foot room, his maximum distortion limited 20 Hz output at 2 meters was 109.3 db. At 16 Hz output was 104.7 db, and at 12.5 hz output was 103.9 db. The Conquest came with a 1,000 watt BASH amp. The box dimensions are 36 X 22 X 30. It has two 6 inch ports.

In a smaller room users could expect up to 3 db more output, and 2 to 3 Hz deeper extension. It's a shame that Tom can't test a Cap, it would make for good reading.

Comparing the Conquest's output, (109.3), at 20 Hz to the oft repeated 127 db at 20 Hz for the Cap, it just makes me wonder......

That 4,000 watt amp surely makes a difference. The measurements on the Conquest were amp-limited IIRC.

I have both, and although nothing on them is exactly the same, they have the same xmax. I pushed them all the way, from all in to out, and they measured the same distance. The surround on the TC PR is slightly thicker, and it's slightly stiffer, which is probably why Vas an Fs is a bit less accommodating for low tuning, but more accommodating for SPL use.



I didn't realize this was the point you were making.

Take a look at:
http://jtrspeakers.websitetoolbox.co...66&postcount=4

They measured 121dB@15Hz and 4096W when tuned to 15 Hz. Assuming they are getting a 3db gain with ground plane, that's 118db@15Hz 4096W. In WinISD, the LMS-5400 can do 118.1db@15Hz at 4096W in a ported 8 ft^3 enclosure tuned to 15 Hz. They seem to be right on par, except that the Captivator is not nearly that large and a large enough port couldn't fit in the volume of the Captivator cabinet.

The Captivator is 30″x20″x22.5″ outer dimensions, likely 28.5"x18.5"x21" inner dimensions, and 6.4 ft^3 internal volume. Then subtract driver displacement and volume to fit the port, which we don't know the volume of, we'd have to assume a net volume surely under 5 cubic feet. The LMS-5400 can do 114.8db@15Hz at 4096W in a ported 5 ft^3 enclosure tuned to 15 Hz.

So I'm sure the Captivator driver is capable of this, but how in the world in that small of an enclosure.

Now when tuned to 20 Hz, LMS-5400 can do 122.5db@20Hz at 4096W in a 8 ft^3 ported enclosure, or 119.3 dB in a 5 ft^3 ported enclosure. Take 3db off the Captivator's 127db ground plane measurement, and you have 124 dB to compare. They are borderline comparable with 8 ft^3, but again the Captivator is a much smaller volume.

I've modeled tons of drivers and in a net 5 ft^3 volume, under 120 dB seems to be a practical limit. The Captivator far exceeds this, and can also somehow solve the issue of such a large port volume that normally necessitates the use of passive radiators for such low tuning in a relatively small cabinet.

For me, all this comes down to is that either the Captivator is truly a remarkable feat, beyond what I ever thought possible, or their numbers are way off. I'm here because I'd like to know which it is before I either continue my DIY build, or scrap it and go for the Captivator. I did send off an email to JTR and hadn't received a response, and that's why I asked here.

Let say Conquest amp was 1,000 watts, when you double the power 2,000 watts you gain +3 dB than at 4,000 watts you gain +6 dB to compare to 1,000 watts if the Conquest would be useing 4,000 watts you get (109.3 dB + 6 dB) = 115.3 dB still missing +12 dB to catch Cap and Cap is not Horn Loaded Subwoofer to gain so much to Conquest so one subwoofer numbers are incorrect

Sorry if I was making it more complicated than it should have been- referring to multiples of things made it confusing. I think we're on the same page now, from the numbers you are crunching.

Just an FYI (and all of the following is either clearly included with Ilk's data or simply general knowledge):

1) The LMS passy sub you referred to in Ilk's test results is a poorly executed DIY version. It's said to be tuned to 16 Hz, but it clearly isn't so. They also used a very odd combination of HPF and 20 Hz EQ boost to arrive at that naked response.

2) The Cap is dead flat to 20 Hz, the DIY passy is down -5dB at 20 Hz. 2 different tunes, so 20 Hz is not the optimum frequency for comparison.

3) Ilk's CEA numbers are at 2M and are clearly noted to be RMS numbers. JP is talking 1M, BURST numbers. So, add +9dB to Ilk's numbers to be talking apples to apples.

OK... let's take those facts and do the math. Ilk's result at 20 Hz = 114.5dB. Add +9dB and you get 123.5dB CEA 2010 BURST at 20 Hz. Add +5dB to that if the passy were designed to be flat to 20 Hz and you get... drum roll... 128.5dB.

This is quite likely a more realistic actual number for the Cap, but JP said 130dB should be within the realm of possibility after doing a quick calculation. He has never said it was a measured result.

I agree that irrational exuberance doesn't belong in subwoofer specs, but, welcome to the real world and deal with it.

This is just a note to suggest you tone down the rhetoric just a bit, since you were far more wrong in your accusations than JP was in his irrationally exuberant 20 Hz number.

Bosso

My only accusation is that JP had an irrationally exuberant number, so that statement cannot be true.

Let's read his quote again:

130dB is the most conservative number you can take from this claim, if we want to believe he was only saying this was within the realm of possibility, you have to consider that he is indicating it could be higher ("in the 130db's"). How much higher was he considering within the realm of possibility? What is the actual measured result of a 20Hz 7200w burst? Why would he speculate something that is thrown around as a benchmark for comparing subs between manufacturers (CEA-2010)?

To speculate on his speculations (as this is all he's left us the ability to do), we can assume whatever number he came to on a napkin (low 130's somewhere) after this claim was settled as ~130dB burst in his final "measurements". This leads us to his spec of 127dB on his product page. His spec states up to 4000 watts RMS, 127dB at 20Hz. I would hope that this RMS number is a measured number and not a quick calculation.

Use the PB13 with no plugs, that should be a valid comparison being the same tune?

Ilkka's burst measurement of 111.5dB at 20Hz +6dB to adjust to 1m: 117.5dB

Jeff's claim of "in the 130dB's" burst puts it a minimum of 12.5dB better.

The claim is that a single Cap outperforms four PB13-Ultra's. The SVS 13.5" woofer is nothing to sneeze at, and four of them (over double the surface area of the Cap's 18") in well over triple the volume (going by outer dimensions the PB13 is only shy 3" in length to the Cap, identical in the other two)... you can't fight physics.

You add +9dB going from 2M RMS to 1M Burst.

The Cap has +8dB more amp than the PB.

JP said "should".

He's probably closer to right than you are suggesting he's wrong.

That sums it up. The more you accuse using bad math and extrapolation, the more you go backwards.

Bosso

Thank you.

I will say that I would personally expect the Captivator to hit serious port compression by that point but the limitations at port tuning would not be determined by the driver's xmax, at least. It's all about thermal power handling, driver SD, the port, and the amp.

That's incorrect, I already used the burst number (+3dB) from Ilkka's measurement for the PB13. My comparison was valid.

If his 130dB claim is only "should" but not reality, then his 127dB RMS spec is also "should" and thus also not reality. You can't have one and not the other.

To be extra clear:

Ilkka's burst measurement of 111.5dB at 20Hz +6dB to adjust to 1m: 117.5dB

or, using your method:

Ilkaa's RMS measurement of 108.5dB at 20Hz +9dB to adjust to 1m burst: 117.5dB

Both are identical, please refer to Ilkka's output graph to verify.

There's nothing incorrect in my post.

How could anyone's "should" be reality? Until it's actually measured, it's "should". What part of that confuses you?

You started out mistranslating Ilkka's numbers into CEA 2010 burst numbers, you used a DIY PR'd sub that's down -5dB @ 20 Hz to compare to the flat-to-20 Hz tuned ported Cap @ 20 Hz, errantly looked at driver X-max to compare ported and PR'd subs at tune where their respective drivers are at minimum X-max and then switched to a commercial sub with a driver that has 35% less displacement driven by -8dB less power with yet another errant comparison that lacks sufficient data to do anything but say "should" in the first place.

Try to focus here: I do not disagree that Danley, Hsu, Chase and now JTR have and still are engaging in whacky numbers games.

This should have been painfully obvious in the case of Danley claiming 120dB at 12 Hz, which turned out to be off by a factor of 20 times or more. Yet, fans of his horn remained unfazed and supportive.

Hsu popped out of the gate claiming 125dB CEA numbers, the measurements revealed 3-4dB less. Yet, fans of Hsu say 'close enough for government work' and remain avid fans.

Chase, although he's measured every ID sub available over the past 8 years and even took to rating them by his own unvetted system, can't seem to muster the technology to measure his own sub. He also has thrown out all sorts of output claims, none of which have been verified. Yet, his fans claim there is a plethora of technical data available (maybe one has to purchase a special map to find them?) and they remain undaunted in their praise.

Now, sadly, JTR has jumped on the wild and crazy numbers wagon. Looking at the claims pragmatically, if the Hsu was CEA burst 1M clocked at 121.7dB max, I don't have a problem believing that 50% more cone and +9dB more amp won't reach 130dB under the same test regimen.

I do however have a problem with the compression sweeps graph JP posted of the "2011 Captivator in 15 Hz tune with 4096W", and it may offer some insight into the claim JP made regarding the CEA guesstimate.

The CEA numbers are based on the THD limited output resulting from a shaped tone burst signal. That test pays no regard to compression. Since the sub should be at a THD minimum at tune, one could drive the sub well into port compression with no effect by the THD limitations of the test.

The posted Cap compression graph was so baffling to me, I decided to transpose the data onto a TrueRTA graph that's scaled to what we're all used to seeing in a compression sweeps graph.

First, I'll note the problems I have with this 'data':

1) It's amazing to me that the folks who created the Tef system would have decided on a graph background of royal blue and traces you can only read if you're wearing the Hale telescope around your neck with a vertical scale of 10dB per division. WTF?

2) As if that weren't bad enough, JP stretched the graph horizontally so as to all but completely render this graph unreadable, as well as to give the impression to the casual reader that the sub has a near ruler flat response.

3) After tediously and meticulously scaling this graph to a readable form, several things struck me:

a) The 16W sweep, above tune, shows minimal compression, but every sweep after that shows expansion.

b) The 1024W sweep shows 3-4dB of port compression, yet, when the level is bumped +3dB for the 2048W sweep, the port compression drops to 2-3dB. This is a new phenomenon to me and I certainly wouldn't mind hearing the explanation for how it might be possible for this to happen.

c) The 2048W sweep shows 2dB of expansion, almost uniformly across the BW above 20 Hz, yet the 4096W sweep shows less than 1dB across the same BW. IMO, this probably means that none of the Watt values in this graph are accurate, and it makes me wonder why a dB increment scale wasn't used to describe the sweeps. In any case, there is no explanation with this graph, so it would again be nice if one was made available.

d) Sweeps 1-5, starting at the bottom, show a normal progression to compression from the port, but the next 2 sweeps take a rather drastic departure from that trend to a new trend that certainly would seem to lend itself to a higher output reading at 15 Hz (where the graph is flagged) than otherwise, Had the first trend continued.

The data:



I agree with you that once any company official posts technical data regarding the performance of any of his products, he is then open to scrutiny of that data.

Having said that, I stick to my first admonition that you have your ducks in a row before you post and learn to acknowledge your mistakes before moving on. If JP decides to respond, but adopts your 'yeah, but, yeah, but' method, you wouldn't accept that, nor would we ever get to the bottom of anything.

Bosso

^^^ Good work

There was nothing incorrect about my PB13 math using +6dB because it's a 2M burst to 1M burst conversion. You seemed to have glossed over this and moved on, but you were indeed wrong in implying I had bad math in response to that post:

"You add +9dB going from 2M RMS to 1M Burst."

"The more you accuse using bad math and extrapolation, the more you go backwards."


I find this quite ironic.

I have no problem admitting the PR'd LMS comparison wasn't ideal and probably doesn't tell us as much as a reality check as I thought- you made a fair point, and I acknowledge that. Which is why I look at the PB13 as another commercial, optimized offering with an identical tune. It also helps that it until now has been revered as the ported "king" more or less (not solely output per say, but as a complete package), and is probably near the top of the competition for the Cap. It's a practical comparison because many people know what a PB13 is capable of, and what quad PB13's can do. JTR claiming it's single 18" sub barely larger than one of these units can outperform all four is the practical reality check.


Again, if 130dB burst is "should" and not reality, then the 127dB RMS that is his official specification on the product page has to also be a "should" and not reality. What part of that confuses you?


Again the irony, if this is the case let's focus on that instead of nitpicking a decibel or two when orders of magnitude of discrepancies are on the table.