What could be the differences between the Spendor A4 and A7 in terms of sound quality?

Room size may dictate your choice as well in terms of how much bass, and thus speaker, is appropriate.

the A7's, in my 13 x 23 room, produce superb bass at times and are pretty easy to position. I have the front baffle about 26" out, positioned along the long wall. I actually seek out music with lots of upright bass now. Not as chest thumping as some other speakers but they dig deep and very articulately. Almost like a larger sealed box.

I don't think the A4 can go there with the simpler bass port, D7's have even better bass of course but may need to be further out as per @kren0006 above, again depending upon room.

I think the various opinions on how detailed or forward or sparkly or bright or whatever term you want to use for Spendor are interesting.

Here’s my take on it.

For decades, Spendor has had the reputation of producing very laid back speakers. I have read all of the professional reviews on all Spendor speakers going back 10-15 years, and what you see over and over, at least in the background portion of the review, is a description of the brand as belonging to the "pipe and slippers" camp, or the "comfortable pair of shoes" camp, or similar descriptions. That seems to be the prevailing opinion of many of these folks who review speakers for a living.

Nothing wrong with that - it’s probably what helped the brand survive and thrive for 50 years now, and build the following they have.

But as that old reputation pertains to the current lineup, I think maybe it fits (as you’d expect by the name) moreso with the "Classic" line (which I haven’t heard as much of), than with the current A Series (I’ve heard all extensively), and even less so with the current D series (I own).

Some may say the D series really departs from the long-held reputation, and maybe that’s right.

Think of it as a spectrum from dull to overly hot, 0 to 100, if you will, with precisely neutral at 50, just for argument’s sake.

Maybe the historic reputation of Spendor put it in the 25-35 slot on that spectrum (just a guess, not claiming to be a super authority on this). Maybe the A series now is at 35-45 on that spectrum, and maybe the D series is now at 45-55.

My point is that (IMO) it is wrong to consider D series to be a "forward" or "bright" sounding speaker in the universe of all speakers. Brands like B&W, Paradigm, Focal, Klipsch and others based on my listening auditions (note, my opinion only -- I’m sure some may disagree, but that’s what I heard) rank above 70 on my hypothetical "hotness" scale (again, just my opinion), and Spendor D nowhere near that.

So are Spendor D more engaging and lively than historical Spendor? Sure, but keep it in perspective, Spendor D probably now right in the sweet spot of neutrality around that median 50 on the dial.

just my opinion. Nothing scientific about any of the views described above, just pontificating.

For those not familiar with the lines, the D uses a Spendor proprietary LPZ tweeter that differs from the tweeters offered on A and Classic lines. Spendor designed and manufactures the LPZ themselves, making them one of a fairly small number of speaker manufactures that design and manufacture without 3rd party help all drivers of the D line.

Kren0006. Excellent comparative much appreciated. Will help a lot in my A7 v D7 decision. I have to listen again and then decide. Like many here I’m really cautious about bright, tilted up, over analytic etc., so it leads to a little paranoia whenever it’s mentioned. Again v helpful thanks. 

Don’t take it as gospel : ) Just one person’s opinion.

That’s what I heard, but let your ears guide you. One person’s bright is another person’s neutral. And it depends what electronics you’re using of course as well. Before purchasing my D7’s I heard them with 3-4 different amps and ended up buying the one I liked with them the best.

I've not heard the D7.2's but it uses the same drivers as D7.

I’ve owned many Spendors over the years. I just sold the A5r because I have too many speakers. The A5r is a 2 1/2 way sealed design. It is not in the Spendor line up anymore but it was the best sounding Spendor that I have owned. You can still get a new pair from this place. I doubt that you will go wrong with it!!
https://store.acousticsounds.com/d/103549/Spendor-Spendor_A5R_Stereo_Speakers-Speakers