Axiom Home Page Forums General Discussion Technical Questions low freq. sweeps cause rattling from M60s

I was running Avia's calibration disc this morning (hey I'm snowed in, and it's tedious and fun in about equal parts). At one point, the test disk runs low frequency sweeps through each channel, one at a time. It starts at 200 Hz and works down to around 20 Hz. The VP-150 and the M60 I use for the right front did great within their spec ranges. The M60 I use on the left front also performed well except for one thing - I got a metal-on-metal rattling sound at many of the freqencies throughout the sweep, even at some of the relatively high freqencies (i.e 150 Hz). I hope that it just means there's a screw somewhere that needs tightening... but I've not really ever been a take-it-apart guy, so I don't even know where to begin or what to do.

Any thoughts?

Try tightening the drivers. I had a similar situation a few months ago.

PM me if that doesn't work. I can fill you in with what my issue was. This is for the respect I have for Axiom and the owners.

(also via PM)

Thanks. They're now as tightly screwed in as I can manage, and that reduced it some. But there's still some distinct rattle, particularly at specific frequencies and less so but noticeable at various frequency ranges. I think I've also isolated the problem, physically, at the upper of the two woofers, just from getting right up next to the tower while it was playing.

I'm still in my 30 day, so even if the problem is a real issue, I at least should be able to exchange it, no problem. But since I suspect it's just something loose, it should be fixable from home.

engine_joe,
forgive me if tleigh had already mentioned this in the pm, or if you've tried it yourself already, but have you tried tightening the binding posts? Just a thought but it could be that simple.

I would give Axiom's wonderful customer service a call. They will probably send you a couple of drivers to fix this. It will take five minutes to fix .
What crossover freq. are you using?

Checked the binding posts, and they're ok, but thanks for the suggestion! Guess I'll give Axiom a call; they'll certainly have some ideas.

Oh, and my crossover is set at 60 Hz. It generally seems to be smoothest for the music and films I've tested with.

Please keep us posted.
Good luck!

Tom

Keep in mind frequency sweeps are not (often) found in music, so the chances of regular program material exciting those same resonances are slim. Still, now that you know it's there, it'll probably bug you until you know it's gone.

You might try pulling the drivers out one by one and repositioning the wires a bit. One wire pair could be touching and buzz against each other at specific frequencies.

This is what I went through: Here

I really didn't want to dig it up but thought it might help.

Alan (I think) mentioned that sometimes the speakers get banged around in shipping enough that an internal wire ends up touching the inside of the cabinet and buzzing at certain frequencies. IIRC the solution was to remove the driver from the front and move the wire.

I always had a problem with this when building speakers -- if you keep the wires short enought to never touch the sides then they're too darned short when you try to take them apart.

I ended up trying elastic bands as tensioners for the wires -- works OK if you solder the connections but bad news if you use push-on terminals