Subwoofer for Ayre AX-7e?

Hi @jazztherapist,

I have an AX-7e with a REL T-9 and it sounds great, but has some serious caveats that have been pointed out here.

1. The speaker inputs of the REL are isolated and do indeed work with the Ayre's balanced outputs, as well as other tricky ones like Class D amps. However you need to connect the ground wire of the REL to the chassis on the Ayre, NOT a negative speaker terminal. I wound up drilling a hole in my Ayre chassis to install a binding post. This was a serious PITA because the Ayre bottom chassis is stainless steel which unlike aluminum is very hard. It's doable with the right drill bit (cobalt) and some drilling fluid, but not a lot of fun. Plus you are mangling the chassis, but whatever, it's just a small hole that is easily patched with a screw. (I can show you a picture.)

1b. After I drilled the hole, I realized a much easier solution was to use one of the screws that secure the XLR jacks. These are grounded, and actually this cheap Radio Shack binding post I had lying around was the exact same screw size/thread, and I could have just screwed it in there. Oh well... it kind of blocks one of the XLR inputs that way anyway.

2. This wiring setup works, HOWEVER, if you turn off the Ayre, you will get a fairly loud hum from the REL. This is because the Ayre outputs are floating and not referenced to ground at all. I haven't figured out a way to get around this short of modifying the Ayre with a dedicated output for the sub with a muting relay. Referencing the speaker outputs to ground with a high-value resistor would probably muck up the sound to some degree. Anyway, my solution is to leave the Ayre powered up at all times, which sounds better anyway...

Other than these major inconveniences, I highly recommend REL with the AX-7e - the T-9 blends seamlessly with even difficult speakers (I heard you can even use it with Maggies!), and it should go well with your Epos. I've used them with Merlin TSM's as well as multiple Role Audio and Silverline speakers with satisfying results. Placement is easy (just follow REL's recommendation of tucking it in the corner) and as long as you follow their conservative "augmentation" approach of keeping the x-over point and level low, it will not only not interfere with the mids and highs, but actually make them sound better by balancing out the spectrum.

I am not sure I agree with the recommendations to upgrade to a specific speaker based solely on the match with your Ayre. It sounds like Ayre + Vandersteen is a nice combo but there are a lot of considerations and personal tastes involved. If you really want to turn this into a speaker hunt, this is a totally different discussion that I'd be happy to chime in on too! But on your original topic, hopefully the above info helps. :)

Cheers,
@taww
http://taww.co

p.s. if you're keeping the Ayre for the long haul and are reasonably handy, there are a few tweaks (damping and cap upgrades) that I can recommend.

p.p.s. I’m enjoying the $1k REL with a $7500 monitor speaker right now. I’m not saying it’s perfect but subwoofer vs better speaker is certainly not an either-or proposition. In fact the point of a good subwoofer is to augment the bottom 2 octaves where it’s very difficult to get proper room loading from 2 speakers positioned for best imaging and tonal balance. If you do get a good sub it should survive an upgrade to the Epos, and even help a speaker that has good bass. And in a room as small as yours, I think a full range speaker could be a bad idea - monitor + sub will likely be a lot easier to tune well.

((And in a room as small as yours, I think a full range speaker could be a bad idea - monitor + sub will likely be a lot easier to tune well.))
Well, easy isn't always best.
The reason I disagree a single sub by the time he hears the bass for what op has paid for can easily overload that room spoiling or confusing what he already has right in the midrange balance, to begin with, it's still a can of worms.
2 properly adjusted small subs work better than one but forward firing drivers tend to draw more attention away chuffing and mooing with artifacts. The Vandy ICIs/Ayre pairing 90 DB effeicient lets bass into the room at 4 points 2 front and 2 back low to the floor transmission line allowing a smoother even in-room response
with its boxless midrange performance.
Best JohnnyR
Audio Connection
Vandersteen/ Ayre dealer

Taww 4-2-2018
... This wiring setup works, HOWEVER, if you turn off the Ayre, you will get a fairly loud hum from the REL. This is because the Ayre outputs are floating and not referenced to ground at all. I haven’t figured out a way to get around this short of modifying the Ayre with a dedicated output for the sub with a muting relay.

A solution might be the suggestion I made earlier:

... 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.

That would result in a direct (essentially zero ohm) connection between the circuit grounds of the sub and the amp. While I would expect in the case of an Ayre or other well designed amp connecting to chassis would interpose a significant impedance between the two circuit grounds, resulting in the possibility of hum as I had mentioned. Although whether or not my suggestion would be helpful when the amp is turned off is probably not predictable, since as you alluded to the outputs of the amp are not in a controlled state in that situation.

In any event, thanks for your informative and well written posts.

Regards,
-- Al