subwoofer connection

I have read about an alternate connection for subwoofers. The alternative is to bypass the A/V processor and connect the subwoofer to the output from amplifier.  In my case I have MX 122 Mcintosh A/V processor with two sub out connections, RCA or XLR.  Instead of using the sub out of the processor, connect the sub to one of the front channel mono block amps in this case a Mcintosh 611.  Would this improve bass response and would I have to go into the bass settings of the processor to increase the low frequency range of the amp and change any additional settings for subwoofer connections. Any thoughts would be appreciated.
No difference, because ultimately its the levels you set on the sub that determine its output. Connecting to the amp does not affect the amp at all. Only real difference is a practical one- which wires, how long, and where they go. In terms of sound the end result is all the same.
Thanks for your response.  Okay let me ask about a two sub configuration.  The one sub, I will call it front sub, is located within 2 feet of the processor and the other sub, I will call back sub, about 18 ft from the A/V processor currently connected by about 25 ft balanced XLR.  The back sub is located about 3 feet from the amp, Macintosh 452. that powers the two surround speakers.  Would it be better if the A/V processor only recognized, through the speaker set up menu, the front sub and  reconnect the back sub via short XLR to the MAC 452? Thanks

A couple years ago, we got REL subs especially for two channel listening in our showroom. I added just one at home. A T5i to enhance drastically for 2 channel music listening.

Astounding how it can take a pair of bookshelves (2-way speaker, Olympica Nova I’s), and deliver powerful and perfectly blended base for a full 3 way sound. Just the right balance of base. (yes, there is some tuning, but they have excellent videos on their website to help)

By connecting the High level connection of the sub (leave the lfe connections for theater alone), but the high level connection which is done with a speak-on cable that comes with them.

The other end of the cable has the red, yellow & black, all pre-stripped for you. So, if you are using stereo subs , then you connect them to the back of each speaker. Twisting the yellow & red together connected to the + (red) speaker connection, and the black goes to the (black) - side connection.
Then the subs get the same signal as the 2 way bookshelves, and it is perfectly balanced.
If you have just one REL sub , then you connect the red to the plus on the right speaker output on the back of amp and the yellow to the left plus terminal and leave the black wire just floating.

Page 13 of their manual here. Granted, this is with a REL sub, but the transformation to your two channel listening from a processor or a stereo system is absolutely amazing.

Oldwaverider (Art)
Ok thanks.  I think my set up may be a little different.  I have a dedicated mono amp (3) for each speaker except the surround speakers that are tied into a 2 channel amp.  I don't use the subs (2) except for 5.1 home theater and video games. The front speakers magico have plenty of bass for music I believe down to 20HZ.  Previously the back sub was hooked up to the A/V processor via long run XLR as is the 2 channel  amp that powers the two surround speakers.I just thought by connecting the the back sub to the two channel amp and eliminating the long run of wire to it may be more efficient.  But now I am wondering if I have to go into the A/V processor and make some type of adjustment to the two channel so the low frequency signal is set to the amp for the amp output that sends the signal to the sub.  Does that make any sense? Thanks