Are the JL Fathom subs really that good....

Way to go guys! Very useful responses so far ... u don't know how to set up... I tweak... I measure .... patience ...

Jb8312, I have seen on your system page that you have the Verity Audio Parisfal Ovation speakers. If I am not mistaken their bass module can be placed so that the woofer fires either towards the listener of away from him (i.e. towards the back wall). Because some of the low frequencies will be reproduces by the Parisfal bass modules and also by the subwoofer, the orientation of the subwoofer with respect to the bass modules and also the placing of the three bass sources in the room is very important. Thus, your situation is not exactly the typical case.

Try to following set-up procedure:

Part One: determine decent parameters for the crossover and volume settings of the subwoofer

1) Play a double bass jazz piece. I usually make a loop using the loop function of my cd player. Most often I use the beginning of the track 3 from Norah Jones' Come Away With Me album, i.e. the first measure of the starting bass piece (3-4 seconds).

2) Than using some common sense settings for the crossover and volume settings of the subwoofer move the subwoofer around the room. You are looking for the ideal place to placed the subwoofer, i.e. the position that will give you no significant resonance or nulls at the listening position. This step is best accomplished with the help of a friend/wife.

3) Once you have found a good place for the subwoofer start playing with the volume and crossover settings for the subwoofer. Your goal is to make the double bass notes to sound all even (i.e. having the same volume) and tight (when you close you eyes you should be able to imagine that these notes are produced by the double bass cords).

Part two: determine the best place for placing the subwoofer

1) Now with the volume and crossover settings determined in Part One, move the subwoofer in your listening position.

2) Play again the same loop with the jazz walking bass and walk around the room looking/listening for the places where you get the best bass sound. Here you should look for the places with good sound when your ears are about at the same height as in your listening position. Most likely you will find more than one palce. Mark the one that is convenient for placing the subwoofer.

3) Change the phase of the subwoofer and repeat step 2.

Final step: move the subwoofer to the place (determined in the previous step) that gave you the best bass integration, and of course keep the phase setting that worked best. At this point it might still be necessary to slightly adjust the crossover and volume settings of the subwoofer but only slightly.

After caring out this procedure, you might want to repeat it with the bass cabinets of your speakers reversed. You never know, you might get even better results.

I have a REL Stentor 3 subwoofer and I have used this procedure successfully a few times already. This "procedure" is a bit of a hybrid between what REL recommends and what I have read here and on other forums. I "come up" with it while looking for bass in my new room. I ended up with the REL somewhere between the two speakers and I get much better bass integration and volume than when placing the subwoofer in the corner as recommended by REL.

Good luck and keep us posted!
Paul

Yes...and I started to give a one word answer.
I recently designed a Home Theater Room for an old friend.
Everything done as well as I know how to do it.
So, dry wall with OSB glued and screwed non consecutive seams...Golden Ratio 'shaped' room.
Incorporated were a pair, (two, not one) JL Fathom Subs.
The blend is marvelous.
They are fast, faster, fastest...and very smooth.
Typically I have never been a fan of trying to blend subs...but let's get real here.
What floor standing speaker has sub/bass response? Not many.
The JL's are just about perfect to my ear...and when you play a 20Hz, sweep to about 200Hz, there's this incredibly smooth blend that just makes you smile.
I chose two, not just because he could afford it, but because regardless of what some say, bass is not 'non directional', just 'less directional' and the two gave me great in room 'balance'.

Good luck.

Larry

Larry, I completely agree with you on bass being somewhat directional. If I had to go back to using a sub I would buy two and set them next to the speakers aimed at the listening position. In my car the sub is behind the seat and crossed over at 60hz. I can clearly tell were the bass is coming from.

If you place one sub in the same plane as the main speakers you can't tell where the sub is, assuming a 60Hz 12db/octave crossover. If you place the sub closer or farther from the listening position than the mains you may have to adjust the arrival time (which is tricky stuff).

Bass sounds are omni-directional, but in a car the shock waves through the structure of a car aren't, and that's why you can tell where the sub is. Even in a house I can tell that the bass is coming from somewhere in front of me, but I can't discern the sub's position between the speakers. Or even that it exists.

Still, I have to agree, two subs are better than one, and optimum positioning seems to be one near each main, assuming that's a good position considering room modes. (It often isn't.)

Bass may be omnidirectional but that doesn't mean you can't localize the source. I think that would be called "omnipresent". Like when my wife spots an audio purchase on our credit card online statement within minutes or hours of a new transaction.