Is there a significant difference - tone wise, performance wise, whatever - between plastic speaker cabinets like the SRM450's and wood bodied speaker cabinets, like say the comparable Bag End passive 12" speakers?
Is this even a fair question?
My application is live sound for acoustic music, mostly with bluegrass bands with acoustic guitar, mandolin, fiddle, stand-up bass and dobro
I think that you would have to have two similar speaker systems side by side to compare. I doubt that anyone buys an IM speaker for sonics. They are cheaper and faster to build, lighter weight on average, can withstand the elements better than a budget wood box over time. They are not as user servicable.
That said, there are many ok sounding IM speaker systems that have no competition in the wood cabinet market.
For what it is worth, I don't like many of the IM boxes. Maybe the RCFs would be my first choice. It is my perception that IM boxes do not have the lower mid/bass detail that traditional boxes can have. Maybe I haven't heard them all, but I have come close.
i'm an avid live-sound enthusiast and, in fact, spent the last 7 months working at a pro sound music shop.
i was lucky enough to be able to A/B almost all the different speakers that the store carried (mackie, jbl, yamaha, b52, etc). i finally settled on the SRM450 for smaller acts .. less than 300 people.
a lot of what mackie says goes a long way. no parallel sides, multi-cell throat for the horn, and the linkwikz crossover... they all make it sound very defined and clean.
as for the casing itself... VERY rigid and sturdy. you could bang the hell out of the case with a hammer and your hammer would probably break before the speaker cab!
Sheet, from what i've noticed i get VERY definied low end. to be honest thats why i went with the powered speakers instead of an-amp-and-passive-speaks set up. i found that, without having to adjust anything, the active speakers put out very clean bass. granted, it only goes down to 80 or 100hz, but thats why i got a sub too :-P
my best advice is TRY a few different speakers. there are so many variables -- where you'll be using them, the type of music played, volume, etc -- that theres not a REAL answer for you.
the rigid-plastic casings (srm, eon, msr) look kind of cheesey.
if you can feel alot of flexing in the cabinett then your losing bass energy that ideally you want projecting out front... i helped a friend once put trim on his system thatwould allow him to C-clamp the cabinetts for rigidity... and was astounded how much better his lows were after we had done it...
I do a lot of live sound and PA work, and I've moved away from plastic cabinets. They are much lighter than wood, and are very robust, and can be dropped, chucked around and will sit at several angles for floor monitor use, but I'm sorry I don't like the sound. Put a plastic and a wooden cabinet side by side, and you can hear it. It's not to do with frequency response - some of the larger plastic units can produce amazing bass for their size - it's to do with colouration. As dementedchord said, the plastic cabinets flex and that flexing absorbs energy unequally over the frequency range, leading to troughs in the response.
I'll happily use plastic cabs for speech reinforcement up to moderate sound levels, but for music or for the larger venues, I've gone back to wooden cabinets, even though it takes two people to lift them.