Originally Posted by da5id1
I have a pair of LS50's in transit to my home. As usual, I have a few misgivings/buyers remorse after paying my money but before using the product.
I have read enough reviews to know that these bookshelf speakers are uniformly considered best in class. I am wondering why, given the specifications of these and other speakers in the KEF Q class range of speakers. The LS50 includes a single 5.25" "coincident" driver — the exact same size of the one contained in KEF's entry-level Q 100 bookshelf speaker. Even the Q 300, which I seriously considered, has the larger 6.5" coincident driver utilized in the top two larger and much more expensive (compared to the Q100 and Q300) Q series tower speakers.
Let me begin my question with the observation that I am most assuredly not a troll. But, is there any reason to believe that the driver used in the LS50 is not the exact same driver used in the entry-level Q100? If so, where did the other $1100 go?
Also, I do have a substantive question. There is much discussion about the flexible elliptical rear port and all of the state-of-the-art technology and R&D that went into that design feature. It seems that without any explanation whatsoever and, rather cavalierly, the LS50 comes with a plug or "bung" to completely eliminate the feature. What's up with that?
Thanks very much – Gene
PS: I would also note that by KEF's own specifications the LS50s are inferior in speaker sensitivity, amplifier requirement (a function of speaker sensitivity?), frequency response, and maximum output when compared to KEF's own specification sheets for the Q100 and Q300.
Congratulations! You'll be pleased. To answer some of your questions...
As far as the driver, it seemed like eons ago when I researched this stuff, so take what I say with a grain of salt. From my understanding, the driver is closer to what you'll find in the R100 series. Take a closer look, the Q100 series doesn't have the lines extending from the inside to outside periphery. As far as the mechanical differences, I have no idea except the the LS50 has magnesium alloy, while the Q100's are all aluminum. What you're paying for in difference is the unique enclosure design, such as the curved front baffle, and unique internal bracing as well as the unique driver. Is it worth $1100 more? Usually, economic scaling and the world of audiophilia rarely go hand in hand, however, having listened to most of the range at a dealer, it is a very different sound profile compared to the q range when you put all those things together.
It's been already answered, that the back ports are if you're placing near a back wall, which would be closer than two feet. I have mine at 20 in. and don't use them and they're fine. They're supposed to improve imaging at the expense of bass extension. I definitely recommend to space them from the back wall enough to get the bass extension.
The most important thing... these were WAY MORE finnicky than I thought as far as placement. I angled these speakers a hair too much inward and spaced too far apart by 6 inches each side, and I was getting a smaller, incoherent soundstage. Made the small adjustments, and the results were dramatic. Made them sound like the huge speakers I heard from the dealer. Positioning them back and forth definitely ruled out a possible psychoacoustic effect.