So it’s a question of where does it all fit? Perhaps raising the window level cheaper than a 500?
I’m much lower down the system chain but I also recall being told the next level up is generally desirable to going active.
However, some speakers appear to benefit an active system, perhaps where passive crossovers not quite the ticket or crossover capacitors have degraded ? - \inspired guess.
Nice problem to have really!
Actually, I think it was 2x250 vs 1x300, but did go with the 500 which is in a world if its own…
It is a nice problem to have - and I wouldn’t even call it a problem, really. I did wonder about getting a third rack of Fraim and reversing it so that the back was at the front - need to measure up if that would work (though the half qs rack would then have to move forward) as adding a third 300 would not be ruinous, though I would need a 3-way snaxo and of course the 808s are a pretty hefty cost. To put it mildly 
With a supercap, 2x300dr and a snaxo, I am not far off the cost of a used 500dr - or one of the 300s and Sc and snaxo could contribute to the cost of 808s, and then later on go from a single 300 to 500. I would hate to do this and then find that 3x250dr is superior though
I have liked every set of titans I have heard (all courtesy of acoustica - liked them more than anything else at their shows in 2018 and 2019) - passive 505s, active 606s, 707s and 808s (all powered by one or more 300dr). Not heard one powered by a single 500 - and have only heard 500 powering a friend’s B&W 802d3 (and I prefer my SL2s to that setup, despite his second 555 on his nd555)
Even speakers with excellent crossovers may benefit from active drive, while degrading capacitors are infinitely cheaper to replace than going active! I suspect it is more the case that the more difficult a load the speaker presents (which is down to the drivers used and driver loading by the cabinet design, as well as crossover design), the more it may be likely to benefit from active driving - but I don’t know that for a certainty.
Having recently heard ATC50 driven by Klimax LP12 /Urika/252/500 I much prefer my Active Isobariks with 252/3x250DR and Superline. Different systems with very similar front end and of course different rooms. The difference was not subtle however as I was hugely pleased when I got home to my own system with the ATC/500 fresh in my mind for comparison. The Isobarik of course is almost a different speaker in active mode vs passive. Would like to hear the Active ATC at some point.
Hi Tim! The game changing I mentioned is the difference in the sound I get from the Kudos T808 in comparison to the Naim NBL I owned 16 years. Both speakers were in active mode driven with the same equipment. For me an active system delivers more space, silence, clearness, separation of instruments and frequencies independently from the volume level you are playing. I would compare it with the lifting of curtains in front of the speaker.
Unfortunately there aren‘t so many events where it is possible to demo the difference between active and passive. One last sentence. I have been told that the Kudos Titan range was designed for active use and afterwards the passive crossover was designed to offer passive use. Not sure if this statement is correct.
Those differences of course might not be anything to do with active drive: in my experience there can be, and frequently are, huge differences between different speakers, even at similar price points, however exalted. I, too, had thought your ‘game changer’ comment was the same speaker model, 3x250 active vs passive with some amp undefined.
I have heard ATCs a couple of times- didn’t do anything for me. Whereas I have really liked titans (my ho hum feeling on 606s is in comparison to 707s and in the context of already having active SL2s
FWIW, about two years ago I compared 2x250DR vs. a single 500DR driving my SL2s, with 552DR, listening to both setups for several weeks each. It wasn’t even close, the single 500 was far superior. I haven’t heard 2x300DR, however.
Hi Tim, how big is your room and how are the penguins playing into it, also any acoustic issues worth mentioning and also how far are you sat listening from them? ATB Peter
Hi Peter
The room is L-shaped, or perhaps it is easier to say that it is about 25 feet x 19 feet with the staircase nicking a corner (12 feet x 6 feet). The speakers are on the long wall firing in the 19 feet direction from the heel of the L.
It seems pretty good acoustically despite the stone floor tiles - the irregular shape helps and there is a fair bit of furniture and heavyish curtains. At the moment the my ears when sitting on the listening sofa are about 10 feet from the front of the speakers. There is a bit of scope to move the sofa back a foot or two but then there is a desk
You really need to restock up on your wine 
It’s there until the outside room is decorated and then will be going in there. With the wine that is currently in a couple of boxes
I went from passive 2 x 135 to 500
My rose-tinted memory glasses of the mid 90s reminds me how wonderful a 135 four-pack sounded with SBLs, but i’ve not done an A/B comparison with a 500.
There is something intrinsically musical, and satisfying about the 552/500, which i suppose is why one solitary 500 can trump an active system using mutable smaller NAPs
<>
Tim, can you simply borrow a 500 from a dealer for a week?
It’s an itch that needs scratching…
Hi Tim, whoah that’s a big space, and lovely flooring - almost like being at a pub OopNorth Beyond the need of stocking up 
In my former house I had my Sl2s firing across around a fireplace ( like you) in a room, which was 16 feet wide and 26 deep. I was running them with 2x300s in the days before DR. Looking at your room I suspect it is a lot less lively/reflective than mine was, which of course is a good thing. At the time of running wonky 300/500 into them I decided to move them down on the short wall ie playing them into a depth of space not dissimilar to yours. This was using my 500 passive. I don’t know what made the sound change, could be room acoustics kicking off using the beefier amp or simply that they were starting to implode a bit. At this point their passive Xovers had never been used, so it wasn’t a case of anything needing a fettle at HQ. Admittedly I like my music quite loud ( mainly rock and blues), but I remember starting to crave more bass, as they were sounding quite lean and out of their comfort zone.
Looking at your room I can’t help wondering how a pair of maybe PMC 25/26s or maybe even 606s would fair behind a 500. The 606s can go quite close to the front wall playing into the space you have, I would imagine as you certainly have the space for excessive bass to loose itself.
We are all helpfully guessing here, but that would be my humble suggestion, well you could even try the 808s I suppose 
.
You are in fact lucky to have a room that size, as it opens up a lot of potential speakers to choose from ( I’m not jealous… much!)
Enjoy the potential journey, but personally I would choose something different from SL2s if it was me, and let’s not forget just how good the 552/500 combo always is. ATB Peter
I probably can!
When you look at the power output of most power amps, it only tells a small part of the story. When you look at a lot of Naim amps their output appears low ( and perhaps is for the money).
My experience is to look much more closely at the power supply and even as crudely as at the VA rating of the Tx. The high tend Naim amps 500 and 300 appear to have a VA rating of about 4 times their apparent power output. The smaller amps VA rating drops more to 2 times. As we know the 250dr and 300dr are basically the same electronics with the 300dr having a bigger off board Tx and power supply.
So, what am I saying? Forget ( to a point) the power output, but look at the Tx VA rating. Statement uses a 4000VA Tx to deliver only 750 W per ch.
So a lot what we are hearing is related to how oversized the Tx appears to be.
My personal experience of my MF power amp is that once it had a decent pair of Txs fitted, the sound, and in particular the low bass was transformed. No significant increase in power output, but a much better sound.
Thanks for the comments - I am indeed extremely fortunate to have such a great space. I wasn’t really impressed with the 606s at acoustica’s active kudos event (they didn’t seem to bring much more compared to my SL2s) - whereas the 707s really brought a lovely quantity of bass. But I need to try 808s or I will always be wondering about them. The SL2s of course have more bass than the SBLs they replaced - but I am a bit greedy for more 
It’s not that I simply want more bass - I mentioned above that a local friend has B&W 802d3s (fronted by full 500 system) and that has lots more bass than the SL2s but there is something about them I just don’t get on with. The nearest I can get to an explanation is that the tweeter on the SL2s is really sweet
And ultimately I might be left wondering what 3x300s (or 3x250s) into 808s would be like compared to a single 500. 3x500s could never happen (a) cost (b) the ridiculous shelving that would be required. There’d be no view out of the window at all
