F113s x2 and 802 Diamonds-crossover/setup questions

[thebeatles67]

Trying to do a little advance work and understanding--I have a question for all F113 users. I will soon be the proud owner of 2- JL F113's and anchor stands. These will be used in a 2 channel setup only. I understand about running ARO--- I own a Mc C2300 Preamp and will be running both as "Master" as Ivan has advised. Plan on running the 802s full range-- I do not have any external crossover---having read most of the threads here and it looks like I need to begin experimenting in the 35-40Hz range to cross to the F113 as I own B&W 802 Diamonds ( latest 3rd gen). Below is what is listed in the B&W spec sheet for the 802's freq range and response.

-6dB at 27Hz and 33kHz
34Hz - 28kHz ±3dB on reference axis

Any helpful comments or suggestions very much appreciated. Thanks.

Mike

[Masterlu]

Mike... I would start dialing in the F113's right where you mentioned 35~40hz. Your room will play a large factor also.

[thebeatles67]

Thanks Ivan----One last question for today--I see a few reviews where an additional electronic crossover is recommended in a 2 channel system with the pair of Fathoms---with just my C2300 preamp and the two F113s controls I can achieve a decent blend?

[Masterlu]

Originally Posted by thebeatles67

Thanks Ivan----One last question for today--I see a few reviews where an additional electronic crossover is recommended in a 2 channel system with the pair of Fathoms---with just my C2300 preamp and the two F113s controls I can achieve a decent blend?

Beyond decent; I have JL subs in 6 of my Systems. I don't use an external crossover in any of them.

[chessman]

You can use the low-pass filter setting on the Fathoms to integrate the subs with the mains, BUT I think you lose one of the big benefits of an active cross-over: when the low end of the signal is not sent to the speakers at all. The low end notes require the speaker cones to move a lot of air, which in turn pushes the amp hard. In short, you can gain some headroom with an active cross-over. Of course if you have a beefy amp, that may be a non-issue.

[chessman]

Just saw Ivan's post. He, of course, has the requisite "beefy" amps.

[thebeatles67]

Thanks again Ivan and Chessman---my amp is the Mac 601 mono--pretty beefy but not 1.2kw--below is a quick excerpt from Stereophile review addressing the issue:
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I decided to set up the subwoofers in stereo—which the f212's manual calls the "Master/Master configuration"—because it had been what worked best with the f113s.
I reviewed the notes I'd taken while setting up the Fathom f113s in Master/Master mode, and the same procedure worked just fine with the Fathom f212s. The full-range audio signal was run from my Bryston BP26 preamplifier to the Bryston 10B SUB crossover via a pair of balanced interconnects. After setting the 10B SUB's right and left high-pass-filter switches for the Quads to 100Hz and its low-pass filters to 70Hz (all filters set to 18dB/octave), I set it to provide the f212s a stereo low-pass subwoofer output. Balanced interconnects were run from the 10B SUB's high-pass outputs to the Mark Levinson No.334, which then drove the Quads. The crossover's low-pass outputs were connected via balanced interconnects to each f212's XLR input jacks, their rear-panel switches set to Master.

I would have preferred that JL Audio included internal high-pass filters for managing the bass, so that an external electronic crossover would not be needed when using the f212 in a two-channel audio system.

[chessman]

With MC 601's you got no issues.

[thebeatles67]

Excellent ---really really looking forward to my early Christmas presents to me----gonna have some bass now my friends.

[Masterlu]

I'm running a pair of F113's in Master/Master configuration, along with my Strads driven by 2301's.

The 113's are feathered in right at 30~32Hz, it sounds Heavenly.