Double Bass Got a loose screw?

[macmrkt]

From my high-end audio days...we always used to tighten all the driver screws on any speaker before using it. You'd be surprised how loose the woofers and tweeters were on new speakers. It made a big difference to the clarity of sound. In fact, we recommended this as part of regular maintenance. It would often revitalize a high-performance system that lost its edge (there's more we'd recommend too, but I'll stay with my loose screws for now.)

I just got some new Epi UL speakers. Of course, I opened them up first and tightened all the screws (don't overdo them - especially with these poplar plywood cabinets!) The looseness of the screws on the 112UL was silly - I got several full turns on some screws. Be sure to pull the grills off by grabbing onto the loosened screw heads - don't pry out a grill.

My question is this - I never really listen to my cabinets with loose screws, so I can't compare - I always tighten when the cabinets arrive. If any of you players out there decide to do a tightening and notice a difference, please post it. It'll be interesting to know.

Remember...nothing loosens screws like deep bass; and a loose driver looses energy to unwanted vibrations.

 

[fdeck]

I find that #10 screws sound so much better than #15 screws.

 

[jmain]

Makes sense. Guess I know what I'm doing tomorrow afternoon. Too curious (or neurotic?) not to check mine. My cabs are a few years old, but relatively new to me.

 

[Passinwind]

FWIW, Ted Weber specifies "finger tight" only for his drivers. He uses fairly lightweight stamped frames though.

 

[mje]

I find that #10 screws sound so much better than #15 screws.

The black oxide coated ones, of course. Galvanized screws lends a certain chalkiness to the midrange, don't you think...?

 

[tornadobass]

Not really for DB, but I was given recently an old Ampeg 2x15 cab (V-6B) and when I tried it, there wasn't much bass and it rattled a lot.

Looking into it, the speakers were Eminence with gaskets on front and back. I think they were designed to be mounted from the inside, but this cab mounted them from the outside. Lots of air was leaking around their edges.

(Nowadays, Eminence speakers have a front gasket only but will usually be mounted with the stamped metal frame screwed directly to the front of the baffle board.)

Anyhow, the gasket had a curved cutout for each screw and there were once either wax or rubber inserts to fill the gaps. These inserts had dried up and were falling apart. The screws had Allen heads and were difficult to tighten, too.

My fix was to pull the speakers and remove all the little fragments of inserts around the screws. Then I put a dab of silicone sealer on each screw hole and installed the speakers with new Phillips head sheet metal screws with round heads.

Voila, no more rattles and the end bottom came back. Now it's a loud, efficient cab, although still a pain at 120 lbs.

 

[Bob Gollihur]

Great stuff, Loctite: [Invalid or Expired Link Removed]

though I've never had any similar problems with cabs that I can recall. Permatex makes some real nasty threadlocker, too: Invalid Link Removed