DIY MTMs design question (1 Viewer)

[Travis G]

I'm building some MTMs with these Bravox 5 1/4 Shielded 4 Ohm Woofers. I have been breaking them in with track 35 off my Bass Mechanik cd (12 hours per driver). Two of the four that I have broken in make a slight fluttering sound. I know that I can't expect the world of $8 drivers but is this somewhat normal? Should I send the drivers back?
Travis

 

[Dan Hine]

A few questions:

There are a few BM CD's. Is this the one that has track 35 playing a 35hz tone? If so, how loud were you playing it? You may have killed your driver that way. If it's a different cd, or if you were playing it very softly then...


Have you double or triple checked that the drivers are completely sealed to the cabinet? It is possible that the fluttering sound is simply air escaping from around the driver as that could making a "fluttering" sound.

That's all I can think of off hand. Maybe someone else will jump in. You could also call up PE and ask them.


Dan Hine

 

[Travis G]

Yes it is about 35 Hz. I didn't kill the drivers. When you do this you just need to keep an eye on the drivers excursion. I was only running them with a couple volts.

I know that it is not the cabinet because they were unbaffled during the break in. The sound is really not noticable when playing program material. Only when they are being pushed to their excursion limits with low frequency sine waves.

I wouldn't even be concerned if all the drivers made the sound but after breaking in all 6 drivers only two of them do it.

Travis