How close should tubes get to Speaker Magnets?

[CapRoss]

Hi all - My first time posting on this forum.

I have done some of the Aloha mods to my C30, and am contemplating others - namely Master Vol and Pseudo Presence. There is no room on the top of the stock combo amp chassis to stick more pots, but there is room for mini pots on the back (near the Clean Ch Vol), or on the chassis 'underside'.

Because of relative ease of access during playing, I would prefer to stick pots on the back rather than underneath, but am concerned about the potential threat to their longevity on the back of the chassis the way the stock setup is. So I am contemplating cutting a deeper cutaway at the rear of the top board on the cabinet (along with new screw holes) to facilitate sneaking the chassis forward 1/2" to 3/4". This will give rearward mounted knobs some protection from being accidentally knocked off, but it will bring the tubes closer to the speaker magnet. Question is, apart from the obvious rattles (which I doubt will be any worse than they are now), I wonder what this may produce in terms of normal/abnormal tube function, having the speaker magnet real close?

Tubes of concern are EL84s, and as shown in teh attached .jpg, the tubes are currently 2and1/4" away from the magnet at their closest point (the tips), and with my hairbrained scheme they would end up being about 1and1/2" away. The speaker is a Carvin BR series 100W Eminence re-brand with a 5and1/4" diam. ceramic magnet. All suppositions, theories or other conflab welcome please.

Cheers

I don't have any engineering knowledge in this matter but I am currently running an Eminence Red Fang with the magnet cover less than 1.5 inches from the 6l6GC output tubes in a Peavey Valve King 1x12 amp(very tight fit). I have not experienced any problems at this point.

[TD_Madden]

my Tweedy is running a Redfang and small-bottle 6L6s...probably 1/16 inch away. No problems.