Originally Posted by wth718
I'm using 2 Stereo Integrity 18s. The raw, un-eq'd, ground plane, long-term response looks like the finished 12012. Throw in an amp with flat response down to 5 Hz feeding duals, no limiters (as yours DOES employ), with an applied LT, and room gain, and this is what you get:.
To correct you on one point; all amplifiers employ limiters. Hard, soft, progressive, clip, voltage peak, etc., needs to be qualified, but all of them have blocking caps and limiters.
Originally Posted by Luke Kamp
Bosso's post has a link explaining how different subwoofer designs boundary influences react in a corner placement. However even the dual opposed tested that stayed the same with rotation, is still ~+/-15 dB. Many of us have measured our systems, and the gear to do so is a small fraction of the price of one of these subwoofers. I recommend anyone on this forum not measuring, run, don't walk, to get this ability. Bosso has also shown in the past how stacking subwoofers can smooth a response.
My point was aimed at Fitz's claim that all subwoofers benefit equally from corner loading. Josh clearly proves that is not true with a single, simple exercise. The FF sub shows 12dB swings placed in the same corner. I would call that significant. My own tests (all in-room and far more comprehensive than the one I cited from Josh) show similar results. Again, the point being that all subwoofers do NOT benefit equally from corner placement.
Originally Posted by Luke Kamp
Like Bosso states KK is no dummy. I havent seen any in this thread say its a bad design or doesn't sound good. Its the output for the $. For reference level full spectrum playback multiples will be needed. Bosso uses 4 of his up/down firing dual 15" bringing the total to eight 15" drivers to get him in his room to it.
So heck get a quad drive, maybe it will take an octo. But if you could get flat, broadband, uncompressed reference level playback with a single, why does Ken sell multiple packages?
I think the confusion here is the whole "My sub handled WOTW at reference level with no problems" thing. In AF's defense, this is not a new problem. Folks have been claiming that since the movie was released on DVD a decade ago.
Heck, Josh made similar positive subjective comments in the discussion of his review of the P'digm Sub 2 regarding its heavy use of limiters and no one broke his balls like they are here with AF.
I know of no subwoofer system on this planet that "handles" WOTW with no problems in the defined sense of full BW playback with no distortions (save a +/-3dB FR non-linearity). Some will claim the TRW can, but that will have to be shown to me with the appropriate data.
The key word here is "handle". Sub owners really mean that their subs didn't explode or make bad noises or catch fire. They generally have no earthly idea what playback of WOTW at reference level means, and that includes the double-octo 18" build with multi-5 figure watts systems.
One reason I know this to be true is that in all of the thousands of references to scenes in WOTW, the most difficult scene in the movie to reproduce "with no problems" is never mentioned at all. That simply tells me that all of the subs that had "no problem" with WOTW at 0dBRL simply did not even approach playback of that scene in flat full BW with no distortions.
As you can see, although my system "handled" this scene, it did so 'only' down to around 4 Hz, but still left 2 octaves on the table.
It wouldn't matter if I had 60 15s and any # of watts, the signal simply is not getting to the drivers for them to react to.
I have to admit that I'm partial to anyone who has the sense to know that stacking, specific driver config, no HPF, sealed systems are a necessary part of the formulae for successful design. But, that's where it ends for me in this case. I'm a decade ahead of KK in this arena and I really need to see more specifics regarding the "Transflux Photon Injector Warp Drive Eco-Flush Driver Loading", or whatever the he!! it's called before I'd offer any actual specific opinions.
Just quickly looking at the review FR graph and assuming it's accurate (which I do not), the sub would not yield a flat response to 10 Hz in my room without some post-PEQ doctoring:
(KK in black, Raptor in green)
KK claims low 500s CM^2 Sd (a pair would have more surface area than a UXL-18), but doesn't mention throw (to calc displacement), so how many might be needed is a missing variable, but $/dB is a tough one to nail down. It can be free and matter not if it can't reach the bottom octaves for any # of reasons (sig chain roll off, not enough power, etc.).