Alright let me wrap up my now concluded experience with the XLS, life does tend to get in the way sometimes...
XLS vs Rest...
System chain: Yamaha 1800 SACD/CD source> CAT SL1 >XLS/XTi >VMPS 626R
Continung full range on the 626R...With XLS/stereo-bypass mode. Piano not sounding 'right', lacks weight on the notes. Female voices a bit too light. Stringed instruments lacking body. Soundstage decent, good depth and width.
Switching to Xti/DSP Bypass Mode: Fuller, richer midrange, upper bass, mid bass ranges , Xti has better weight in these areas. Larger, deeper soundstage...not a subtle improvement, easy to hear.
Winner Xti vs XLS running full range/Bypass mode on RM626R.
Onto biamping mode on VMPS RM1 whiuch I normally run with a Marchand X/O (@250Hz)after the CAT pre to power the mid/hi panels via my tube amp, with the Xti driving the twin 8" bass drivers. No Marchand X/O used with the XLS/Xti combo, not needed.
Crossover set to lowpass @320Hz on the XLS powering the twin 8" bass drivers, and Hipass set at 320Hz on the Xti powering the mid-hi drivers. Sound OK kinda flat, empty. Percussion is good.
Reversed positions, Xti on the bass drivers and XLS on the mid-hi panels, adjusting the amps' x/o's hipass to low pass and vice versa. better, but not quite filled out. Midrange still sounds a bit light.
Best combo was with the XLS hipassed at 250Hz and the Xti low passed 320Hz /6dB slope. Why the overlap? The mid panel drops off about 5-6dB from 400Hz to 315Hz. The 6dB slope and the overlap more closely follows VMPS original first order crossover.
Holly Cole's voice on "I can see clearly now" had a fuller tone with the piano notes sounding richer and more 'real'. Tuck's guitar string had more resonance and decay. The soundstage had nice depth and width, but height was lower than I usually get. Soundstage dimensions is important to me because my space is small, 11x14.
The XLS did not do it for me in my set up, I found it lacking weight, texture, richness, liquidity... call it something(s) all through the mid/hi-bass up through the midrange spectrum. It made the piano sound somewhat 'hollow' and glossy, voices 'lighter'. It clearly needs reinforcement in the upper bass/low midrange area.
The Xti is the better amp imo, comes with a full DSP engine which makes it more suitable as a sub/woofer amp. Even full range its sound trumps the XLS1500, very surprising to me I expected the XLS to be closer in comparison. Hearing the XLS driving the mid/hi panels above 320Hz. was quite an ear opener, however I think its the mid/upper bass area that contributes most of the body/weight tone which I felt is where the XLS came up short. Maybe the XLS2000/2500 with its beefier p/s might offer more body and weight to the mids and bass?
After boxing up the XLS and going back to my usual set up, tubes up top, Xti on the bass...the cons of the XLS sticks out like a sore thumb. But its a great value, it bettered the ClassD Audio CDA 254, made it sound 'dull' in comparison.
Bear in mind my ears may be older than others' on here and my system may not be on par with many...so your mileage will most certainly vary, as already shown herein.
Connections used: XLR in. SpeakOn out.
Primary test disc : Clarity Cable LV2009 demo disc.
Tracks: 2. 'Fever' Peggy Lee,
7. 'I can see clearly now' Holy Cole Trio. ,
10. 'Summertime' Ella & Louis.
11. 'Papa was a rollin' stone' GRP All Stars.
13. 'They can't take that away from me' Tuck & Patti.
16. 'Jesus gonna be here' Five Blind Boys of Alabama.
17. 'Flight of the Cosmic Hippo' Bela Fleck.
18. 'Will the Circle be unbroken' Nitty Gritty Dirt Band