Do you think you need a subwoofer?

As usual Raul you are not without an good opinion. Dragging us kicking and screaming to better sound.

My point was just because you have a big expensive full range speaker does not mean you don't need subs.
As for what the crossover point should be and whether Jl or Velodyne is the proper sub I'll leave that fight between you and the Doc. I'm in enough controversy.
Gregadd

The sub's alternative IMHO is a tremendous " tool " to improve almost any home audio system quality performance that use tube amplifiers.

Due to tube technology characteristics and the fact that in a sub's system the amplifier does not " see " bass frequency range this improve the tube amplifier overall " power " in the remaining frequency range ( main speakers ) and permit that this un-stressed tube amplifier performs and match better to the main speakers.
The quality improvement is really significant and IMHO this " road " is a must to go specially when we are using tube amplifiers, I can't imagine a better system up-grade everything the same.

Regards and enjoy the music.
Raul.

Dear Gregadd: No fight, I respect that great system owner: it is only that maybe there is a tiny " room " to improve. Always is a temptation try to help, no critic at all.

Regards and enjoy the music.
Raul.

Raul:

I agree with your basic thesis about using stereo pairs of subwoofer for improved performance in virtually all sonic categories. I note that you are proposing using a high pass filter to prevent the bass drivers from handling the lower frequencies. In fact, you are suggesting this approach even for such stellar bass producers like the Wilson Alexandria. I prefer a slightly different approach: I would characterize it as “low bass augmentation”. In my system, I am running the Magnepan 3.5 full range. In my room the Maggies are down about 3dB at about 30Hz. I am running a stereo pair Sunfire Signature subwoofers with x-over point about 30 Hz. The slope and phase are adjusted to ear. I have been able to obtain seamless blending among the Maggies and the subwoofers.

I did not want to use the high-pass filter in the subwoofer because I felt that any gain in freeing up the Maggies from handling the bass frequencies would be offset by the added distortion or corruption of the signal due to the additional filtering. In fact, I experimented with both scenarios and preferred running the main speakers full range. The sound was less mechanical sounding.

Dear Gmorris: As you point out a different sub's integration with different trade-offs ( advantages/dis-advantages ).

I prefer to lower the IMD on the main speakers in favor of an improve in the quality performance on the main speakers and to handle the low bass with a dedicated speaker ( sub s) that was designed in specific to that frequency range along its self-powered amplifier.
IMHO no full range passive speaker ( like the great Alxandria's. ) can show/even the quality performance in the bass range like a dedicated self powered sub, the right sub and at the same time I don't know any amplifier ( SS/tube/hybrid. ) that can even the matching between the driver ( woofer ) and the amplifier in the sub's that was designed to the specific needs of that woofer for that specific frequency bass range, synergy is the name of the game.

The key is the quality of the crossover that in Velodyne, Revel, and the like are very " decent ".
The ideal " key " is to make directly the crossover high-pass filter at the main ( internally ) speaker amplifier(s) and if you can't do it then through the sub's own crossover.

The choice of the sub's model is a critical subject, not all the sub's are the same and not all the sub's have the same quality performance and the same quality " self " electronics specially its crossover.

I prefer too the use of the same amplifier in the main speakers, the right amplifier.

When we use two different amplifiers ( like in your system ) IMHO we have two different performances due to the diferences between these two amplifiers: different output impedance, different frequency response, different THD, different gain, different slew rate, different colorations,...different noise level,....different.....diferent..., etc, etc, the only and almost the one similarity between both units is its name: amplifier.
I know that you like it and this is the important factor because is you who are living each day with that system.

I respect your approach, however the targets and its quality level that you achieve are totally different from the targets and quality levels that we achieve trough the alternative that I support.

Regards and enjoy the music.
Raul.