Axiom Home Page Forums General Discussion Stereo sound diff between MDF and "real wood"?

thanks Varkha, think i'll order that $330 regular M3 soon as possible. hopefully i can get it this week coz i'll off this weekend.

Mark

Alan, when I was looking at building my new sound system, I took a look at another speaker maker that used HDF instead of MDF. Is there an actual sonic benefit to using that over MDF, or is it just a bullet point, something to say they have over other companies?

i love classical music, but sometime i would also love to turn it up to shake my room with some ambient, morden jazz and/or techno. here is my last question, M2 or M3 may suit my style/room please?

Mark
ps: again, my room is 10X10X8 with 75wX7 receiver.

CV,

HDF (high-density fiberboard) has a denser core than MDF, but it isn't necessarily superior to MDF. The reason is that if you use too dense a material and/or over-brace a cabinet, you move the potential resonance to a higher frequency and the "Q" of the resonance gets larger--so it may become audible. (The Q of a resonance is its amplitude or relative loudness.) Note, too, that it's impossible to totally eliminate box resonances. Everything has a resonant frequency and it becomes a matter of controlling them.

The ideal is to create a box or enclosure whose resonant frequency is at a very low frequency and the "Q" is small. Research we've conducted at Axiom has shown that MDF and a moderate amount of bracing is ideal at keeping any box resonances below audibility. If you add too much bracing or use a more acoustically inert material, the resonance frequency moves up into the audible range and increases in amplitude.

So the other manufacturer who uses HDF may have bought into the folk wisdom that a denser material and more bracing makes for fewer resonances, or it may be a marketing ploy.

Regards,

Alan,

You're best post ever.

By the way, I heard quite a while ago, some speaker company was experimenting with "hardie board" (the siding with cement mixed in).

Now, THAT would be dense.

Larry

Yes, Alan, excellent post. Thank you.

So, I'm guessing the Q of concrete is pretty high? Wouldn't it take awfully high SPL's to excite that resonance, though?

Thanks, LT61, and "hardie board" is new to me.

Re Tom Tuttle, yes I would agree that it would take very high SPLs to excite a resonance in a concrete enclosure but this is conjecture on my part since I've never heard speaker enclosures made of concrete. However, if you follow the theory, once the resonance was excited, it would likely be at a very high frequency that might be audible.

Regards,

Hi Mark,

The M3 v2 is still your best choice because it has a larger woofer with more bass output, deeper bass, and better power handling at louder levels than the M2 v2 without a subwoofer.

I was just auditioning the M3v2 "blind" yesterday in the Axiom listening room at the plant driven by two aged Class A/B Denon monoblocs rated at 250 watts each into 8 ohms, and I was amazed at how clean and loud the M3 v2's would play on their own, without subwoofer assistance.

Regards,

Alan, thanks for the response. Very interesting.

Alan,

Oop's......I mean: Your best post ever.

It's nice to know the sonic advantages of MDF.........rather than someone saying "it's cheaper than real wood".
The "Hardie board" is a mixture of concrete powder and wood, a more durable material for exterior panels, than T-111 siding...which is moisture prone, etc.