Subwoofer for Ayre AX-7e?

Rythmik Audio's PEQ plate amps provide both line-level inputs on RCA jacks, and high-level inputs (from a power amp) on speaker cable binding posts. REL's and Vandersteen's also have provisions for high-level inputs.

Check out HSU!
http://www.hsuresearch.com/index.html

Or JL Audio! I own the D110 and it is outstanding!
http://www.jlaudio.com/home-audio-powered-subwoofers-dominion

jazztherapist

as above, you have several nice subwoofer options. Listen to as many subwoofer(s) as possible to make the best buying decision.
Another +vote for REL.
Happy Listening!

Its real simple
We did this experiment with Epos and 17 other cute boxes
Borrow a pair of Vandersteen 1Cis their Boxless and Phase and time correct design and matching w Ayre will take full advantage of the Ayre's Balanced bridged zero feedback design.
It should instantly be obvious making bass and all else is amazingly better.
Johnny Cash's voice, as well as many other things, will be predictably more genuine, as well while speakers soundstage will seem to disappear and have a completeness that you will never get with a Box and sub.
 With Ayre you are 50 percent there Vandy should make it 100%
  Best,
 JohnnyR
Audio Connection
Vandersteen dealer

In addition to the fact that the AX-7e doesn’t provide volume-controlled outputs from its preamp section, there are significant potential issues if its speaker-level outputs are connected to a sub. Note the following statement in its manual:

The Ayre AX-7e drives the loudspeakers with balanced outputs. Since none of the output terminals are grounded, connecting any of them to ground may result in damage to the amplifier. Do not connect the loudspeaker outputs to any speaker switch-box, accessory, or test equipment that has a common ground connection.

The negative speaker-level input terminal of many and probably most powered subs which provide speaker-level inputs is connected to AC safety ground through a low impedance, or in some cases perhaps even directly. In those cases connecting the negative speaker-level input terminal of the sub to the negative output terminal of the amp risks damage to both the amp and the sub, depending on how circuit ground and AC safety ground are interconnected within both the sub and the amp.

And what would probably be a much worse possibility is that if you were to use just one sub, and if that sub provides inputs for two channels, if you were to connect the sub’s two negative input terminals to the two negative output terminals of the amp the result would most likely be a direct short between the amp’s two negative output terminals.

An approach that would probably work ok, which REL recommends for use in such cases, would be to connect the sub’s negative input terminal(s) to a chassis screw on the amp. Although it is possible that hum could result with that approach, depending on the specific designs that are involved. An even better approach, IMO, would be to solder the wire from the sub’s negative input terminal(s) to the ground shell of an RCA plug, leaving the center pin unconnected, and inserting that plug into an unused RCA connector on the amp.

Regards,
-- Al