The first step to listen to any speaker is to remove the front baffles!!
Whoever don't do this is obviously not a pro or don't want to show you the real potential of the speaker.
Check with the speakers designer on this. Sometimes they want it loose, sometimes tight, ( you need a torque spec. on that). Jeffsefu...in your post above, when you say "remove front baffles" if you mean grills, I surely disagree. Some companies voice the speakers with the grills in place. All in all....check with the manufacturer.
I am not a pro and agree with Stringreen. I have had quite an experience with many loudspeakers and removing the grills is not always the obvious and best way to go; it depends on design,voicing and...set up. Regarding the screws I was expecting an answer on the torque issue but Cello is no longer available and I do not have the tool anyway...
Which manufacturers recommend leaving the screws loose?
I've always thought you should regularly tighten the screws for best performance. I didn't know this differed by manufacturer. Examples?
Agree with Narrod. Why on earth would you leave the screws loose? I remember this was an all-too-frequent ritual with my old ProAc Response 3s, with the ever-present concern that some day I'd strip the threads. Dave
BTW, stripped screw holes, especially in MDF is always a potential issue when tightening the screws. Don't overtighten them or the holes will strip out. If you do have a hole strip out, a quick "fix" is to remove the screw and stick a few pieces of toothpick into the hole. The screw will tighten against the new wood (toothpicks) which will expand out against the sides of the hole and provide some grip.
This "trick" is not a substitute for proper torquing of the screws in the first place, but it can help if you are already in the situation where you have a stripped hole.
Check this for advice:
..regarding Narrod's question. B&W require specific torquing for some of their speakers. The drivers have a foam gasket which if tightened too tight can squash the gasket and nullify the good research that went into the speaker itself. There are many manufacturers that have tightening issues. Check with your builder to see if they recommend tightening...and also, if you tighten the drivers too much, you can warp or strip the attachments. Be careful.
Stringeen, that makes sense. I just can't imagine any benefit to leaving them "loose".
My advice is to tighten the screws just to the point of firm resistance. I have owned several Meadowlark Audio speakers that also had a dampening material between the drivers and the baffle. I simply stop turning the screwdriver when the screw tells me to.
Don't leave the screws loose but don't over tighten either.
I believe the logic of leaving the screws loose is to convert vibrational energy to heat by having friction between the driver flange and baffle. It's a bit of a stretch...
I believe the foam under the driver is to achieve an air seal. Silicone caulk works even better, and holds the driver in place without need for any screws at all. If it becomes necessary to remove the drive this is not too difficult to do using a razor blade.
Here's an interesting video about tightening loudspeaker screws and changing to brass screws. Starring Rick Schultz of Virtual Dynamics.
His reasoning for using brass screws is pure bs. Then again, what do you expect from guys selling the acoustic system resonators?
"I simply stop turning the screwdriver when the screw tells me to."
I didn't know screws could talk.
I haven't tried the brass screws, but the Wheeler Engineering F.A.T. Wrench that Rick recommends is a very useful tool.
I am in the same line of thinking as Jeff. In addition to removing the baffles, I would also like to see the crossovers pulled from the cabinets or boxes to inspect them. My grandfather always said, "If you want to know how a good speaker is made get plenty of rest and a good breakfast." I don't know what that means but I still wanna see them x-overs.
I have received a professional the most answer from Matthew James Systems (they are servicing Cello and manufacturing new products with the same philosophy) and this kind of service is the one still building the brand even if it is not any longer in the market(!). They suggest to tighten up the screws every five years and do it by hand just to the point the screws will "tell" you to stop...and they certainly do it(!). Mt to you all and hope this to be useful for everybody.br.dgd
Rotarius said..."His reasoning for using brass screws is pure bs".
Of course the bs is pure. Second class bs would not be high end.
If it was pork s***, it wouldn't be kosher.
Maybe, just maybe, the screws of my Merlin VSMs would need to be checked and retightend every few years to 17.5 in/lbs on the tweeter and 11 in/lbs for the woofer and crossever panel. Yes they come with torque ratings, not be cuase they are prone to getting loose, but the speaker is "tuned" to that torque setting. Basically worrying is mostly bogus and nothing you could not "maintain" with some help from the manufacturer - it would not be a reason to buy a speaker one way or another IMHO.