Flat response monitors, piercing high mids...Help!!

[Chalan]

Can somebody help me out on this?
I have the Yamaha MSP5's and they claim to be flat down to 40Hz. I like the way they sound but I always hear some distortion and some kind of piercing mid-highs that wear your ears fast.
I finally analyzed them using Smart Live and they are indeed flat down to 65Hz and then start dropping below that, which is normal.

Can somebody explain me what factors I am not paying attention to?
If this is a flat monitor, why it doesn't sound good to my ears?
What else do you need in a pair of monitors? They are definitively flat.

I listen to the Dynaudio BM 5A's and they sounded good to my ears, but I would like to analyze them and see how they respond.

Can 2 different monitors have flat frequency response and sound totally different?
How can this happen?

Thanks in advance for your help.

[DAS]

Real Time Analyzers only give you overall energy (amplitude) at each frequency, and even that is an average over some (usually small) range of frequencies and time. What they don't tell you anything directly about are distortion and phase response...or in general what the "character" of the sound energy is.

When something distorts extra higher frequency energy is produced. Your ear can clearly hear the character that distortion gives to the sound, but it wouldn't be enough energy to show up to any significant degree on the typical RTA, and you wouldn't recognize it as distortion even if it did. Non linear phase response typically produces more subtle effects -- usually disturbing imaging, tightness, clarity, or the relative levels of elements of a mix -- things that aren't usually as immediately annoying as distortion, but do have a significant effect on the overall experience and can sort of "grate" on you after a while.

Flat response is important, but ultimately only gives you a sort of overview of what is going on. Other attributes have to be measured to give you the full story, and this is one reason why so many people say you have to listen to things before you really know what you are getting. For a lot of engineers the ear -- as inaccurate and subjective as it can be -- is the shortcut through a lot of this stuff.

Your monitors just may not be the right monitors for you. Or...they could be defective in some way, or (and this is a big one) your room may very well be coupling with them in a manner that accentuates a problem. Trying them in a different space would be worth a try. Many times it's the acoustics of the space that are much more at fault than the speakers.

Hope this helps.

[Chalan]

Thanks DAS, you helped me understand that there are few things that can't be measured so easily; I guess I'll trust my ears. I tried these speakers in different rooms and their response is very similar. I was able to get good drum sounds that translated well to other systems but I don't like the response in upper frequencies, to me sounds distorted and seems like some frequencies are out of phase or something, a blurry image, (is this what you called non-linear response?). Definitively, not every speaker is made the same, but for now I think I'll give my Yamaha MSP5's a break and try another model.

Thanks again, and if somebody else has any other info or comments, they will be appreciated.