Is there a modern equivalent of Allison Ones?

Gradient makes some very high quality products that might meet your needs.

I own the active version of the Gradient Revolution and I highly recommend them, because they (a) sound great; and (b) work as designed in that they have very little interaction with the room. They significantly outperform the much more expensive speakers I have owned in my troublesome basement listening room. They are very natural sounding, very coherent and have tight/tuneful bass that does not draw attention to itself.

If you have a difficult room or have restrictions on placement that are less than optimum, you would be remiss in not demoing the Revolutions. As an added bonus, with the active version, you can run a moderately powered SET (I use a 15 watter)on top and a SS amp on the bottom. Very versatile and largely underrated speakers.

The Gradient Revolution has been suggested, and I'd like to toss out a few comments.

The Revolution can be placed up against one wall, but Gradient recommends keeping them 6 feet from corners. Springbok's original post mentiones corners, unfortunately. But if placement away from corners is feasible, then in my (admittedly dealer-biased) opinion the Revolution will perform as Ejaynycrrom describes.

The Evidence can probably be placed closer to corners than the Revolution can. The difference is the bass system - the Evidence uses a reflex enclosure, and my understanding is that the tuning can be varied somewhat (I've never had a demo pair - only the Revolutions).

As demonstrated by the Evidence, one possibility is to lower the tuning on a conventional reflex enclosure. The tuning can be lowered by either increasing the port length or decreasing port diameter. This will change the shape of the bass response and result in more extened (rather than boomy) bass from corner placement. It would be nice to know the woofer's parameters and the net internal volume, as then the speaker could be evaluated on paper to see if this will work well. User-variable bass tuning is a feature I incorporate into my designs, which are listed on Audiogon.

One other consideration with corner placement is this: The intersecting walls will act like a big 90 degree horn and reflect the off-axis energy of the speaker back towards the listener much earlier than normal room placement would. So in my opinion this application in particular calls for speakers with smooth off-axis response (the Allisons were designed for smooth power response, which is a similar concept). The Gradients do much better than average in this respect, as do other coaxials (KEF, Tannoy, Pioneer). Also, horn or waveguide loaded speakers (Amphion, SP Tech, GedLee, Klipsch Heritage, PiSpeakers, and yours truly) tend to have relatively smooth off-axis response and smooth power response.

Springbok, I have the impression that speaker size is definitely an issue so I doubt that my largish boxes will work for you. I'm sure you have a Gradient dealer closer to you than me, so my suggestion would be to look into either the Revolution or Evidence, the latter being probably better suited for placement close to a corner. And if necessary, with a little creativity you can lower the tuning of the enclosure. For instance, you could get a piece of PVC pipe from Home Depot and wrap it with electricians tape until it friction-fits into the existing port. It would be trial-and-error to a certain extent, but having some familiarity with the priorities of the designer I'm pretty sure he's using a woofer and enclosure size that would work well in a corner if the tuning had to be lowered.

Duke

Springbok10: Forget any technical limitations - just tell me of any high quality floor-stander that is designed to be close to the rear wall, please!

Look for front-ported speakers. Besides looking for a model that was designed with a front-port, if you deal with a small quality company (Tyler is one but there are others too) they can actually tweak a model to your needs. Another one who can accommodate such needs (and is known for beautiful cabinet work in addition) is Salk. Give them a call or email, explain your needs, and see what they can offer.

Aktchi, if a rear-ported speaker is designed and tuned for corner placement, that can work well. The AudioNote AN/E is an example of a rear-ported speaker that's intended to be placed in a corner. What they do is tune the speaker quite a bit lower than normal in anticipation of the generous boundary reinforcement from the port's being almost right in the corner. The result is very good bass extension without boom.

Lower tuning calls for a longer port, and longer ports are more likely to have internal midrange resonances (think of talking through a cardboard tube). By placing the port on the rear of the cabinet, any midrange resonances are less likely to be audible out in the room.

I think the Audio Note technique is good enough that I paid 'em the ultimate compliment: I copied it.

Come to think of it, the AudioNote AN/E should be among the recommendations for Springbok's system, as it's designed for smooth power response when placed as intended - definitely an Allison-esque approach. In fact the speaker's lineage traces back to Allison: The AN/E is a modern incarnation of the Snell Type E, which was designed by Peter Snell, who was a disciple of Roy Allison.

Duke