I purchased a pair of LSi15's to use as surrounds in my home theater system. Just to satisfy my curiosity, I did a brief comparison of the LSi15 and it's closest SDA kin, the SDA 1C. Oh, I'm sure there are some that would argue that the SDA 3.1TL is comparable also, but the 3.1TL is larger than either the LSi15 or the SDA 1C and is more comparable in size and frequency response to the LSi25.
The LSi15's sounded really sweet right out of the box. However, I let them "soak" for four days while continally playing the radio through them at medium volume. That loosened them up a bit. Not a night and day difference though. Notice how patiently the SDA 1C's on the right are awaiting their turn at the ends of the speaker cables. Also, notice how well the cherry side panels of the LSiC coordinates with my hardwood floor.
In "Big Brother's" shadow. The LSi15's were placed 6 feet apart and 4 feet from the rear wall. They were 2 feet in front of the SDA SRS 1.2TL's. I was sitting 10 feet away from the speakers. The manual says to angle them in if the distance between the speakers is greater than the seating distance from the speakers. This implies that if the distance between the speakers is less than the distance from the speakers, they can be placed facing forward. I listened to the LSi15's both facing straight ahead and toed in slightly. A slight toe-in of about an inch added a little more solidity to the center image.
Associated gear was an Adcom GFA-5802 power amp, Adcom GFP-750 preamp, Denon DCD-1650AR CD player, Yamaha PF-800 turntable with Yamaha MC-705 moving coil cartridge. Interconnects were Monster Z100i (turntable and CD player) and Monster Z200i XLR Reference (preamp to amp). Speaker cables were Monster Z2 Reference.
I picked a few well-recorded jazz instrumental and vocal CD's and LP's for source material (e.g., "Time Out" by Dave Brubeck, "Kind of Blue" by Miles Davis, "Saxophone Colossus" by Sonny Rollins).
The first thing I did after unpacking the LSi15's was the replacement of the stock binding post straps with homemade 4 inch lengths of 10 gauge speaker wire (DSR Silverline) that were finished with gold plated banana plugs. The stock straps seem (to me) to cause a slight loss of high frequency information.
The SDA 1C owner's manual states that better bass performance will be realized when the 1C's are close to the rear wall. The SDA SRS 1.2TL's weigh 180 pounds each. I wasn't going to move them. The 1C's were placed 3 inches in front of the 1.2TL's. These 1C's have modified crossovers with premium capacitors and resistors.
1. I liked both speakers, but for different reasons. For instrumental jazz I prefer the 1C. For vocal music, the LSi15 is excellent. The LSi15's projected voices a couple of feet forward of the front plane of the speakers. The LSi15's lend a lot of "immediacy" to well-recorded vocal tracks. Piano music sounds natural with all the little overtones and overhangs faithfully reproduced.
2. The LSi15 has an exceptionally clear midrange and upper treble. The bass was tight, punchy, and well defined, though not as articulate as the 1C.
3. The LSiC is a conventional speaker and images like a conventional speaker. The stereo image was confined to the area between the speakers. Depth, and the solid placement of instruments and voices within the soundstage were excellent. If you are an "imaging freak", then you might prefer the 1C. Depending on source material, the 1C produced solid images above the speakers, outside the outer edges of the speakers, in front, behind....everywhere but below the speakers.cool:
1. Each speaker performs its intended task very well.
2. The LSi15 is generally available from a variety of sources. The 1C was discontinued in 1991 and is available on a "catch me if you can" basis.
3. The LSi15 has sleek, contemporary styling and lends itself well to a variety of modern decors. The 1C is somewhat monolithic. The LSi15 wins hands down in the looks department.
With both the LSi15 and the SDA 1C, I could close my eyes and be fooled into believing that real musicians were singing/playing in front of me.
Some, and I would dare say, a lot of well-regarded high end speakers "loose the magic" once your ears are outside of the "sweet spot". One of my favorite tests for a speaker is to go into an adjoing room and listen to see if it sounds like a stereo is playing or if if it sounds like a real band is playing in the next room. On really good speaker systems, there is a sense real people playing in the next room and of being drawn back into the room where the music is playing. Both the LSi15 and the SDA 1C speakers passed this "realism" test with high marks.
As always, these are just my impressions based on my equipment, room, and music preferences. Your mileage may vary.;)