Originally Posted by Chu Gai
Nfraso, in the graph that Bossobass provided, even though the CHT sealed sub does not fare as well as the others, Chse has often touted the price as an important factor. Along those lines, I have a couple of .questions.
1) in your estimation, how many of the CHT sealed units would be required to be comparable to the PSA unit?
2) given the number above, would one also expect compression to be comparable?
3) there have been some CHT sealed owners, MKT aside, who have stated that their in room response does extend to 10 Hz with fairly flat response. Regretfully, I don't recall their names, the number of subs, what the levels were, or whether some form of room correction was applied. If you do, do you have any comments on this?
4) Sandbagger/Seaton developed a modification to the Dayton amp that provides increased capabilities at some incremental price increase. If you're aware of this, does this change the performance of the sealed unit to the point where it really doesn't deserve the MBM moniker?
1) I'd have to say you'll need 3 x Chase 18's to match displacement with a single Triax. I would also not be surprised to find out one of those 15's actually out-perform a Chase 18 on a 1:1 basis. Is that enough to call it a day? See below.
2) We have some graphs from PSA starting to show:
Personally I think the Chase would be doing well just to cleanly playback the same compressed
Triax response at serious levels. (Again, more covered on that below.)
Bosso would probably be able to give us a better idea of what type of compression story each option would tell given the systems he's compared that way.
3) Sure, it gets posted on CHT forum all the time. You'll see an Omnimic graph (stretched out horizontally with a massive vertical range) showing ruler flat to 10Hz. Whether you use the Dayton's PEQ cut, outboard EQ or a combination with Audyssey boosting the rest it's fairly trivial to measure a flat response to 10Hz.
Take for example the Husker/Desertdome shootout. You had an SS-18.2, with a typical +6dB L/T applied by DD. It was up against a range of various subs, and was beat handily by the Submersive. Two 15's vs two 18's. Again, this goes back to question #1. Equivalent displacement more or less, was that enough? Clearly not. Even then, it wasn't flat to 10Hz- you'd need more boost to achieve that.
So throw more low end boost at the already hamstringed 18's to get that nifty flat-to-10Hz graph everyone loves to share. Crash and burn.
Take now the KC shootout, and find the EQd Chase 18 pair:
This is an example of what you'll see owners posting on the CHT forums, and you know who will eventually come around with something like this:
"Look folks, he's flat to 10Hz +/-5dB with nothing more than an iNuke 3000 and it's built in EQ. We sell this as a package for yadda, yadda, yaddda..."
We all know how that response worked out in practice. Dead last. Think the SA1000 with roughly the same juice as that NU3000 but added ULF shutdown issues is going to perform better in Craig's latest super-EQd response?
4) This is more or less a great "bandaid" (not in terms of execution which I'm sure is flawless, but purpose or reason for being) by the guys at MCA to solve some glaring issues with the configuration a lot of people bought into and may be stuck with. The most obvious fix being, "The amp also no longer shuts down that required a physical reset of the power button."
For someone else to say, ship me this guy's product and I'll fix it so that you can actually use it normally, you have to bring quite a lazy offering to the table!
Of course the response was tailored internally leaving the PEQ available to the user- it's now right at what the product was originally intended to deliver. It's quite embarrassing that someone else had to do this.
Even still, the boost required to get this originally promised response is not going to bring back the ridiculous performance "intended" (nothing as originally was claimed- under the assumption that the great top end sensitivity would be fed 475w from the Dayton and blow away the LMS-Ultras of the world while matching the low end with just a pair). Yes, with the response fixed it's now capable of acting like a subwoofer- does this mean it does the job well?
For example, the great AE TD18H+. It actually has more rated xmax (14mm) than the Chase Eminence 18 and the same 20mm physical limits. Can you EQ this thing flat to 20Hz and use it as a sealed subwoofer system? Sure, fill your room with them, add SA1000s, iNukes or whatever, cross them at 80Hz to your HT monitors and go to town. Does it make a heck of a lot of sense? It's a waste of the TD18's strengths, and a lousy way to achieve ULF. And even then, you can pick up 8 of those TD18s at $399 a pop and put together a system not all that different in cost from the Chase stuff and have some ultra-low inductance among other benefits.
Dave, I just realized MCA I believe has the their measured response posted:
Given the ~40Hz -6dB similar to my close-mic, I think that's what we're looking at. (Red line, labeled "Stock". Green line of course is their modded SA1000 response. I'd be curious to see those hidden "Max Boost" graphs as well.)