I have researched this more than anything else! For audio needs, best to go for an online sine-wave UPS (which you have already zeroed down), with at least 1.5 times your rated capacity (especially true if you have an external amp or a sub) and finally, Emerson is better than APC in terms of TCO and service.
This knowledge was true two years ago and should totally hold good even today for first two points and partially for the last point.
I purchased a 3 kVA online UPS from Emerson two years ago, tucked it out in my balcony (it was a little noisy inside) and has been working without batting an eyelid ever since (touch-wood). It works very well with my apartment genset. Every 6-12 months, a service person visits my place (totally without my intervention), checks the unit, certifies it and leaves. Sales and installation was as smooth too. The electrician ran the wire under the walls to ensure I get pure UPS power at given wall sockets. Very neat.
If you must read more, following link is a bible for AV power needs. Its 40 pages of pure information!
http://www.hifivision.com/audio-vid...er-games-servo-stabilizer-cvt-online-ups.html
Now, I know I have obviously not answered your question! I however could not stop myself considering I very strongly believe this has been my BEST investment in the last two years and others must benefit from my experience. If I have swayed your fancy towards it, will be happy to share contact#

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