As far as I remember the ALT technology had another advantage and was introduced at the time that stereo tv's were placed in a surround setup and so both centerspeakers played the same mono audiotrack. Walking from one side to another side of the room resulted in a changing center (dialog) sound. ALT was then the solution that it didn't matter where you would stand in the room to have the same sound from the centerspeaker. A normal single mono speaker (Tweeter) had it's restrictions by its limited way of dispersion.

I've had the opportunity to listen to the BL28's for about 1 hour in 2 different sequences. Different music.
They can set a big stage and I like them more in the flesh than on pictures can be seen. Smart way how they placed the woofer inside the bottom floorpart. Not just a bricky thing like with the BL8000 or BL18's.

I was able to listen and compare to both a set of BL18's/19 and the BL28. The BL18/19's wins when you're addicted to heavy bass and more high treble.
I personally liked the more balanced sound (mid/high) combination of the BL28. They sound very impressive.
The only thing is, the BL28 delivers a decent low "punch", but can't maintain that when you're in heavy housemusic or so. And that's fine, only just one driver is responsible for the bass. But I couldn't repress the conclusion of my experience I have with my BS1. That also is capable is producing a nice amount of bass, but sometimes it sounds like it drowns and pushes too hard to produce and distorts.

The BL28 is a very nice speaker with a touch of B&O magic when it starts playing. How tempting the BL28's are, it wouldn't be my personal choice when I could afford a set of BL50's..

Mikipidia wrote:

Bl17, 90’s don’t have them either when 18’s 20’s 50’s do.

So today we have other means to deliver a very good treble that dismisses acoustic lenses. Even so, it was a distinctive visual feature to the brand. 

As long as I know 90s can deliver absolute superb sound in virtually any room conditions, without lenses.

Flere wrote:

I think the BL50 adjustable tweeter lens is a passive and cheaper alternative for the BL90 active tweeter lensing.

To keep the cost of the BL50 within bounds.

Best regards, Flere

- Flere

smile and enjoy the moment

Maybe the first brief review I came across, with some technical details

https://robbreport.com/gear/audio/review-beolab-28-loudspeakers-1234609895/

Andreas wrote:

Maybe the first brief review I came across, with some technical details

https://robbreport.com/gear/audio/review-beolab-28-loudspeakers-1234609895/

Very positive review, derived from real listening at a dedicated room at a dealer. Thanks for sharing!

I booked a demo at the local dealer. I don't know when it's going to happen but I will share with you all my experience 🙂

I have a question if anyone knows the answer that would be great.

If I hook these 28s up to a Marantz receiver using the pre-outs how does the motorized grills work exactly? Do they close on power down? Do they automatically go to the wide or narrow setting from the last power state? Can I only control this from the B&O app?

I assume they just stay the way the are all the time unless I tell the app to change them which is a disappointment.