JL Audio Fathom

I haven't been without subwoofers since the sixties.

After giving away my early Technics SL 1200 for a belt driven Well Tempered Classic I experienced that Basis Audio's A.J. Conti was defiantly onto turntable drive belt irregularities and aging. 

I missed my SL's drive power and torque from day one. I should mention I've been conformationally swayed by Oswalds Mills Audio's Jonathan Weiss direct drive philosophy. After over a decade without an audio purchase I'm currently squirreling away for an affordable Technics SL-1200G-S.   

Dear @upstateaudiophile :  The main issue and target with added subwoofers is to achieve first than all a benefit to lower the IMD in the main speakers as can be in your WA Sabrina X and a side benefit is to have a lower and better bass range handled by a dedicated amplifiers and woofers in those true active subwoofers ( I'm not talking of your ML but any self powered true subwoofer. ).

To maximization those 2 targets you need that the subwoofers must be sealed design and needs to comes with not only low pass crossover filter but it's desired high pass crossover filter too to take advantage and really lower that high IMD that your Sabrina has in this moment due that its woofers crossover the mid range at around 300hz and from here down to 30hz and this is what develops that IMD levels that with the sub high pass crossover filter ( or external High pass. ) will permits a lot better quality levels in the Sabrina mid range, high frequency and mid-bass ranges.

To all those happens and you really can enjoy your system as never before you need to croosover both crossover filters at around 80HZ. Other great benefit that you will have is that at 90hz the Sabrina woofer impedance is at 1.1 that it's really low to handled with aplomb by almost any amplifier and this fact develops higher distortions that makes a degradation in all your room/system quality level performance.

Your ML subs can't do the job neither the JL ( has to high THD. ) and you can go with a noy to expensive alternative like these Velodyne that measured at 20hz and over 100 SPL the lower than 0.5% THD that no JL can even dreams:

Digital Drive Plus - Velodyne Acoustics

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

@upstateaudiophile --

What's the rationale behind your interest in the Fathom subs? The 112's house woofers of the same diameter compared to the ML's, but the former is no doubt more powerful, both driver- and amp-wise. The question is what it amounts to in your context apart from more headroom/sense of power perhaps, but the DSP section of the Fathom's (that has been pointed to already, and which is more sophisticated), may be the most determining factor for potentially better room integration. In addition I'd argue that subs-main speaker integration, as well as overall main speaker potential, would be further enhanced high-passing those Sabrina's, but that involves adding a digital processing layer via a DSP (unless done passively), which may invite controversy either for simply being handled in the digital domain, and/or that it's a second processing layer on top of the passive crossover prefitted in the Sabrina's.

I share the sentiment expressed about the miniDSP route for less money and same-ish results, but if money isn't an issue (and it seems it isn't, certainly up to about $10k) I'd up the ante and challenge even further for a separate amp + DIY subs solution of a considerably larger and more efficient kind. There are many options of such a large, high eff. and separated sub+amp+DSP (+ high-passing the mains) route, and I'll refrain from elaborating any further here being it's likely an option most will choose not to embark on, but the sonic perspectives offered with such a solution is one that really separates the sheep from the goats; those small all-in-one subwoofer cubes, expensive they can be, and added to full-range running main speakers are really only the tip of the iceberg performance-wise, but who am I to argue against a convenience-catering industry and its followers. 

In any case I'd try and make some sense of the madness. From all I can assess the inclusion of the Fathom's will likely be more of a sideways step to your ML's than a ballistic upgrade, so why not spend your money on a turntable and more music? 

Lots of great discussion and valuable opinions. Honestly, I thought the ML’s just didn’t cost enough to be as good as the rest of my system. Acoustically, they sound great. I took measurements with a UMIK-1 and REW and I’m happy with the results.

I liked the “ballistic upgrade” statement from @phusis. When I got the Sabrina X setup in my ideal dimension and treated room, McIntosh MA8950 and Transparent Super cables, it was nothing short of a religious experience. I’m not sure if anything else matters much at this point but I had set aside some $$$ to gift to the audio lover in me and thought the subs were the step vs turntable.

I did listen to the JL’s with a set of Sasha V’s and they were good but I wouldn’t say I thought it was better than my system. Probably due to the room/acoustics.

@upstateaudiophile  : Your WA Sabrina are  not well served by your integrated amplifier that has not the abiñlity to handle with aplomb that 1.1 ohm impeance at that critical and way important frequency range that affects at least 2 octaves and its developed MUSIC harmonics and additional to that the MUSIC signal is obligated in that integrated amplifier to pass through an autoformer ( transformer ) instead directly to the output transisttors.

You own to very high quality speakers for that meiocre integrated amplifier. Sorry but thgis is the facts that normally owners don't want to hear/read it.

R.