Suitabilty of TC-3000

[mtbvince]

Hello IB disciples,

Would Thomas or other technically proficient members please weigh in on the suitabilty of the TC Sounds 15" TC3000 currently on sale for $299. tcsounds.com/tc3000.htm These beasts certainly look the part and I know TC Sounds was the OEM manufacturer of a number of the decent to good value-for-money subs listed on the driver comparisons.

I'm considering a stereo ceiling mounted manifold install with 2 (to 4 if neccessary) drivers per manifold in a 3200 cubic foot dedicated music/theater room. This along with a Crown K2 (or similar) would replace a pair of Paradigm Servo 15s located in the back corners now. The manifolds would be mounted in the same corners immediately above where the Servo 15s currently reside. I'm looking for very low distortion, single digit response up to 50 hz or so. The AVS gallery of our room is here: gallery.avsforum.com/showgallery.php?cat=500&ppuser=7486810 Thanks.

Happy Trails!
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[ThomasW]

Hi and welcome...

The Le on the TC-3000 is extremely high. So for IB use I'd choose the Fi .Q18" instead.

Single digit response is a bit much to ask unless you plan on buying a boat load of drivers. In my experience output at 10Hz can't be distinguished from 5Hz, when using cone drivers, it's a different world from using something like the TRW.

If you want usable output ~10Hz buy a Rane PE17. It's a analog parametric EQ that has 10Hz hinge points. Set 2 filters for boost at 10Hz, they'll overlap and you'll get boost to ~8Hz. There's no telling the impact that will have on the room and the stuff stored in the racks at the rear of the room

[mtbvince]

Thanks for the quick reply Thomas. I've been lurking for a long while. A few questions more questions if you'd be so kind...

So what is the audible significance of the high Le of the TC Sounds driver?

If I could achieve solid 10 hz reproduction in my room I'd be a happy guy. Despite the room having really solid walls, no windows, and weather strip sealed solid core doors, the sprung hardwood floor and ceiling construction of our century building has proven to be somewhat lossy at low frequencies. There doesn't seem to be much in the way of room gain present in this 20.2x14x11 foot room. I'm managing 20hz pretty solidly now but it required corner loading and 6 or 7 BFD filters per channel to pull down peaks between 30 and 60 hz along with a few db of lift at 20 hz. The Servo 15s don't sound stressed during loud low frequency passages but they don't sound as tight or effortless as I'd like either. Notes which should sound have distinct pitch just sound muddier than I'd like. How many driver's(how much displacement) do you suppose I'd need to accomplish low frequency nirvana?

Also, I noted that along with it's somewhat higher Xmax, the TC-3000's Qts was significantly lower than that of the Fi Q18. In my 25+ year hi-fi enthusiast experience, I know that I prefer an overdamped bass alignments. The smoothest in-room frequency response, lowest distortion, tightest low bass was produced by the .5 to .6 Qts bass alignments of the big sealed Dunlavy designs or the QB3 reflex Merlin VSM design to higher Q. I understand that the driver's Qts ends up being the Q for an un-equalized IB install. What typically happens to the system Q after EQ with my trusty and much appreciated BFD?

Happy Trails!
[e-mail]

[ThomasW]

Higher Le means a quicker top-end roll off and usually somewhat higher levels of harmonic distortion.

Yes the TC-3000 has a higher Xmax than the .Q18", however the 18" of course has higher Vd, so the .Q18 moves 6.8L which is virtually a tie with the 3000.

I've never heard a Servo-15" so I can't comment about them.

Highly overdamped alignments roll-off the bottom end more quickly. I think that Fi can create somewhat lower Qts units if you ask.

It's strange that the room is so lossy. As you reach for added output at really low frequencies the lossy room will be more problematic.

EQ adversely effects Qtc when the filters used have a narrow passband. The wider the passband the less the effect on "Q"

I think you'd do fine with a 4 pack of the .Q18"s

[crackyflipside]

4 q18's would be a better choice anyway you look at it for an IB.

[htnut]

See the link on multi buy on the loudspeaker threads.

And you might want to wait to see what pricing comes in on the new 18 from Mach also on those threads. It has the same Vmax as the fi Q.

And Fi offers discounts to Cult members on 4 or more speakers.

My room is also 20 by 14 so I get those resonances. The height is only 8 feet. Sub 20 hz my two 15 inch drivers shake the wall they are mounted into substantially. Haven't cranked them yet and don't at present have a way to boost the infrasonic. Suffice it to say that my humble IB already is on the thresh hold of being WUF, which is Wife Unacceptable Factor.