Crapola.
I'd written a very long reponse, very detailed, model specific to the "T", then the power went out on the 'puter. I lost it all.
I'm too tired to re-do it all.
But I'll give my best effort, my best crash-course, abbreviated answer.
And, for what it's worth, I like West coast speakers too. I prefer the East coast sound and design, but still love my JBL L46 speakers for a good night of fun, and a good night of rocking and rolling.
I have, however, recently given away my Pioneer CS201 IIs and Cerwin Vega HED CV3000 speakers. The CV-3000s were a wild, lovely pair- but as fellow AKer Birddog has a pair already, I figured they'd make a nice stack, so he's getting them tomorrow.
Back to east coasters-
AR- AR did something very right with many of their models- their overall viewpoint was to make all their speakers sound neutral, natural, closely similar. And they often succeeded, in spades.
KLH- A grand-daddy to the sound. Best models? Arguably the most famous, the KLH 6s and KLH 17s. Henry Kloss was involved in this company.
Advent- It's hard to find fault with the original, the Large Advent, or it's close brethren, the New Advent, or the almost identically the same 5002/5012 or the 25th anniversary models. That said, the Small Advent is well regarded too. Designed by Henry Kloss, and others.
EPI/Epicure/Genesis speakers- the EPI 100 is Winslow Burhoe's darling- a perfectly matched 8" woofer and infamous inverted-dome tweeter. The sound is polite, yet strong and incredibly accurate. The 150 is a larger cabinet, same drivers, and produces more bass. Genesis speakers used a version of that excellent mellow but accurate as hell tweeter and that unimpressive looking but over-delivering and suprisingly impressive woofer, and usually a passive radiator, in the design.
Another, underrated speaker is the line from manufacturer Boston Acoustics. Their 2 way, the A70, is a legend- flat response, small in depth and overall stature, and very impressive. comes in two series- series 1, a 6 ohm model, and series 2, an 8 ohm model. A very pleasant dome tweeter, and an 8" woofer. Kicks the poop out of the smaller A60 (but the diminutive A40 is a darling). Then there's what BA calls its first "no-nonsense speaker", the A100. It's a 2-way, the last "real" 2-way in the series. Following this is the pretty rare and lesser-known 2-way with passive radiator A120 (so I can't give much of an impression on this one, other than indicating it's sucess is questionable), then the A150 and A200, both serious powerhouse big-boy 3-way songbirds. Lastly, the A400, a bi-ampable 3-way macho heavy-hitter from the company. The BA line often sells for cheap, though they shouldn't. They are true diamonds i the rough- a delight to own. Ask anyone (well, 99%) who's ever owned them. Delightful.
Other speakers that are kind of a "grey area" "East coast" speaker?
Early Polk Monitor series. 5s. 7s. 10s.
ADS speakers. German speakers, in my opinion, a mix of English speakers and East coast american speakers, although of purely German heritage (braun), though marketed by ADS of New England.
Dynaco speakers. I believe of Scandanavian design, nonetheless, they have the "sound" associated with "East coast".
There's others, too. But here's a start.
My list, so far, in order-
Boston Acoustics A200 (I own)
Boston Acoustics A150 (I own)
ADS L810/L830/L880, ect...
ADS L630 (I own)
ADS L570 II (I own)
Advent 5012 (soon to own)
dynaco A25 (waiting for delivery)
New Large Advent (I will soon own 2 pair)
Large Advent original (own one pair)
Genesis II (I own)
EPI 150
Boston Acoustics A70 (I own two of them)
Polk Monitor 7 (I own)
EPI 100 ( I own)
Polk Monitor 10
Polk Monitor 5
I'd surely re-list these if I owned either the KLH 6 or the KLH 17, and an AR model. I'm sure they'd be near the top of my list.
I'd say the KLH, AR, and Advent line are the purest, most definitive "east coast" line, though all the rest are stunning examples as well.