Difference between ADS "L" and "M" series

I've had both. ADS owned include: L1290s series 1 (1983-84 vintage), M15s (different than M1590, but pretty similar), CM-7 compact monitors, contemporary of the M-series.
M are the later series, after Mike Kelly was out of the picture. Ultimately, I preferred my L-series over the much more expensive (at least for me at the time, both pairs were used) M15s. The M15s, despite having 2 10" woofers to the 2 8" L1290s, had less bass! significantly less. The top end was pretty good on both, but again, I think the nod goes to the Lseries. L-series come up on ebay from time to time, along with a few spare parts on occasion. the L1290s and 1590s could be biamped with active PA-2 amplifiers that fit into the rear of the speaker. Supposedly great sounding, though I never had a set. THey are rare but do trade hands on occasion. The M-series use poly tweets, woofs, and mids (dome or cone) where the L series used paper woofers, and the 'sticky' dome tweets and mids. If the price is right, the M1590s are still a nice speaker, but I'd take L1290s or 1590s over them. I'd say $1000 or less would be a fair price for M1590s, I sold my M15s a year or more ago for that amount.

Have fun,
-Ed

I have a set of L1590's in my home office with the rare PA1 biamp modules. These are great! Very smooth, very forgiving and easy to listen to. The cloth dome tweeter is relaxed, not like most modern speakers with too much sizzle up top. I don't know anything about the later M series, however I can tell you I have no plans on selling my L1590's.

1290/1590 series are keepers in my book, resale is very high on ebay right now, I bought my 1590's with the biamps for $900 a few years back, now the biamp packs alone will bring $500 on Ebay and someone just sold their 1290's at $822!

You may be better served pricewise if you can find a pair through a local source such as a "trader" or "wantad" type publication. I personally am thrilled that I could make money on the sale of my 1590's/biamps but I'd rather let the music play through them than count the money.

Paul