heres another contentious thread....gosh i do walk on narrow ledges..
I was answering a question on the other place some time ago that amounted to me recommending that IMO speakers should be mounted with bolts and not screws......IIRC I was poo pooed by established gurus..
It seems that there is some debate on DIYAudio at present about this very subject and some respected persons are saying 'Bolts not screws'...it seems a lot to do with control of tightening and progressive tightening to avoid warping the driver frame and such...
from MJK I believe
However, you do not want to twist the driver's frame so a sequence of tightening should be followed just like for an engine's head.
Apart from anything else, I still thinks its tacky to screw in an expensive driver to something that was built with TLC...
btw nobody turned up to stone me outside the guildhall on Saturday last
There's nowhere you can be that isn't where you're meant to be
I'm with you on this. I use bolts and 'T' nuts. I've never had the problem of them working loose or the T nuts dropping off into the cabinet. I was a bit surprised by Peter's response at the time, but as he uses screws in his kits, he might just have been defending his product.
As for tightening unevenly and distorting the driver chassis, well yes, like Philip I progressively tighten but that is basic good mechanics. Also, I use drivers with properly cast baskets. Plastic and pressed steel is not for me.
In my experience, if you use captive nuts through a chipboard or MDF baffle, the baffle will compress over a period of time, resulting in the bolts loosening off, and dips in the mounting face of the baffle around the bolt holes which will cause the chassis of the drive unit to become deformed when the bolts are subsquently tightened up. This process actually ended up in fracturing the basket of the bass unit in one of my old Heybrook HB3s. If you use wood screws, there is no reason why they shouldn't be done up sequentially in a controlled manner, just as with bolts. Wood screws of suitable size are quite strong enough for the purpose.
Yes it's an interesting observation that would screws are threading in evenly throughout the thickness of the material, so the pull is not all from the back, which would reinforce your above point Shane,
Are you saying that the baffle will compress over time with bolts but not with wood screws?....
I think what Martin King is referring to is the improvement in control that comes with bolts....its easier to judge the torque when your trying to tighten up evenly.
My original interest started on this because I find myself changing drivers when testing things and wood screws would lose their integrity if undone a few times......and...what about when the gasket gets tired or wants 'nipping up'
I don't think this question is quite as straightforward as it originally seems
There's nowhere you can be that isn't where you're meant to be
i've had problems with t-nuts falling off and coming loose over time, but it is easier to get the bolts in and out (asuming t-nut security isn't compromised), and not to over tighten and damage the driver
screws give a nice secure fixing, i've never had a problem with the wood deteriorating after repeated removal, but i did once slip and stick my scew driver through the paper driver. less likley to do this with t-nuts i feel. screws used to make my forearm ach but now i put a screw driver bit in my drill. much nicer
prehaps screws are better for fit and forget, but for us hapless fiddlers....
I've had the drivers in and out several times since I first built the KLS3's. I doubt the fixing would now be reliable if the drivers had been screwed in, even with the high quality socket fixed screws WD use (I've built a pair of WD25A's for onother person). I suppose my 25mm MDF may make the difference. I've never dropped a T nut and before fixing the drivers I pulled these tight into the wood using the bolt and a piece of steel with a hole in it as a puller. I suppose one could always use a smear of Araldite to be sure. I agree Ed, much easier to gauge torque with bolts.
