I've heard thousands of times to steer clear of the ns-10's unless you're using them as a second or third source. I've heard they're way too colorful to get an accurate mix unless you really know what you're doing.

if you are looking for a pair of first monitors then i would have to recomend the yamaha msp5s they are really good monitors and they are active so that eliminates the need for a high quality power amp, like the only you would need for thouse ns10s.

but sorry i dont know the difrance between the two.

The Yamaha MSP5As are pretty good but you'll need a sub-woofer to 'hear' the lower bass content in your mixes.

I had a pair of NS10's for years. I did not like them either. :(

To answer your actual question:

The NS-10M was first introduced in 1977. This is instantly recognizeable because the logo is right above the woofer and is parallel to the woofer. The original NS10M was designed to be placed with the woofer on the bottom and the tweeter on top. Yamaha introduced the NS-10MS in 1987 and the logo was changed because Yamaha found that users were placing the speakers on their sides. When the NS-10M speakers were placed on their sides the Yamaha logo was sideways. This is a very quick and easy way to tell the difference. Both speakers use the same woofer and crossover, just the tweeter changed. The original was fairly bright and so the tweeter was changed.

Yamaha only carries replacement tweeters for the new version, and perhaps most of the tweeters on Ebay are the new version as well. One thing to consider is the cost to maintain these speakers. I know that woofers and tweeters are easily and sometimes frequently blown. The question is how long will replacements be readily available. If you do decide to go with the NS-10's, you would be smart to stock up on tweeters and woofers as a precaution.

Here's the answer to a queastion you didn't ask... :lol:
When I had my NS10's. I blew my tweeters out twice. The 1st time I replaced them. $70 a piece=$140
The 2nd time I threw them in the garage for a make shift radio. And the next step was the dump. And went and bought some new "different" near fields.
I have never had any other speaker "fry" the damn tweeters so easily.
Yamaha makes great stuff, but the NS10's were just not for me.

ns10's were vertical-the earlier version which were not aimed at horizontal position on a console...these were often "fixed" with tissue paper over the tweeter.

The ns10m's were later model, designed to lay flat on console with redesigned tweeter.

I have a pair I'm looking to get rid of if you're interested (with spare tweeter and extra woofers)...email me at info at bhennies dot com.