Replacement Woofer for Q's !!!

[SicMan]

:beerchug:

:sigh: yeah baby :banana: 12,000 WATTS, 320lbs, 23inches high. Have to hog out the old Q3's and install this puppy! :music:

[Negotiableterms]

OK, I'm lost...

[SicMan]

forgot the picture

[Charivari]

Ah, the return of the MTX Jackhammer (http://www.mtxaudio.com/caraudio/products/subwoofers/jackHammer.cfm). Joking about these was all the rage a few months ago.

Sicman, you do realize that the driver is twice as deep as the Q3 cabinets? It also only has a Fs of 32Hz, which means it's difficult to get the deep Watkins-like bass out of.

Here's what one looks like installed in a boom boom car, most likely with requisite fart muffler:
http://www.lightav.com/ces/mtx3.jpg

- JP

[SicMan]

I know , but I thought it might perk up the Infinity forum a little. They had one of those in the MTV car unless the one you show is it. Man that'll cause alot of "drain bamage" :music:

[Negotiableterms]

JP- Have you any idea why Watkins woofers are no longer used by anyone? One would think that with modern materials and design, the principal would work even better, no?

[SicMan]

Here's a dual coil Infinity, but needs a smaller box. Mostly car audio stuff though. Wonder if they'ed work in a set of small infinties like my Q5's.

http://www.crutchfield.com/S-zJqbf3CQ2K2/cgi-bin/ProdView.asp?search=infinity+subwoofer&i=108PER121D

[Charivari]

JP- Have you any idea why Watkins woofers are no longer used by anyone? One would think that with modern materials and design, the principal would work even better, no?
I haven't the faintest idea of why and I have wondered about it myself. Perhaps the design was just too hard on amps that most buyers balked at the Watkins principle? :dunno: I have yet to find current drivers that have differing impedance voice coils to at least allow for a DIY implementation of this design.

Sicman, while the Watkins was the earliest dual-VC woofer that I am aware of having come about, it works on a principle of operation that a normal dual-VC subwoofer just cannot do. The Watkins has one ~4.5ohm VC (not too sure) and one ~2.3 ohm VC. The higher impedance voice coil is the main driving force with the woofer for most of the frequency range, but when the frequency drops down to around the system resonance (not the woofer resonance of 18Hz except in the QLS-1) something unusual happens. Most single VC woofers experience an impedance spike at the system resonance that raises the amplifier's distortion significantly while dropping the power creating what is essentially a wall to lower frequency output, at least of good quality. With the Watkins, the second, lower impedance VC kicks in to work with the other while it's spiking, (determined by the crossover on the woofer, hence the huge inductors and caps in the Quantums) forcing the overall impedance to remain relatively flat maintaining higher audio fidelity while granting tighter, deeper bass. When both VCs first take over, the impedance can actually dive down to ~1.8 ohms, which is a major reason why these drivers are hard on amps.

Nearly all dual-VC drivers have both coils at the same impedance, be it 8ohms, 4 ohms, or 2ohms with some car subwoofer drivers. The driving force behind this is that depending upon how you serial or parallel the two VCs, you can tailor the impedance to match what you're amp can handle -- the more it can handle at lower impedances, then the lower impedance you arrange the VCs for higher output). I believe the dual-VC design can allow for greater control over the driver as well, but the old nemesis of the impedance spike is still there.

I suppose it might be possible to put one of these dual-VC designs in a quasi-Watkins arrangement where the second VC kicks in at resonance to parallel the other, keeping the impedance from spiking. However, the Watkins VC values were chosen to keep the resultant impedance relatively flat, which might not be possible to fully implement with a newer driver of equal VC imp.

Sorry man, but the Q5s still need the Watkins to function properly, sfaik.

- JP

[SicMan]

Thanks for the info and your opinion JP. Just hunting around for some replacements that may work for the time being until I can pick up a pair or 2 of Watkins. I may have to wait awhile though hence the replacements. :music:

[OldSchoolCool]

The Watkins woofer is a fantastic design. Designed for that application.
Those NEW Infinity car woofers...I would be shocked if the woofers sounded any good in that box. Designed for free air applications AND a 96 Db/ watt/ meter sensitivity make this a bad choice for an Infinity box... especially a Q. :nono: The crossover and effiency difference will create unbalanced dynamics. Guarantee. :yes:
Like putting a Vega motor in your Chevelle... prob works... but....

My $.02

Steve

[SicMan]

Thanks Steve, :yes: almost the same words came from a buddy of mine that's into these too. Car stuff and home stuff very rarely match. :no:
I just received one Watkins I snagged on Ebay that was redone looks kinda funky close up. I may have to have it done over again. I will test this one tonite in one my Q3's. :music:

http://uspug.com/B/blood_stream.jpg