Ovator S-400s maintenance / tightening

I’ve had my Ovator S-400s for about 14 years and never even removed the grilles but looking at other threads on here (eg “Ovator S400 - optimize performance?” ) I decided to check and if necessary torque the various spikes and bolts.

The floor spikes: these had come loose for sure so a while ago I carefully levelled, ensuring no rocking, and tightened the spikes.

Plinth fasteners - Naim tech support advised on torque setting for the plinth fasteners - both front and back. This meant lying the ‘speaker on its side and removing the crossover but was pretty straightforward - there was easily enough spare cable to get the crossovers out of the way. Some of the bolts were definitely a loose and they all were below spec. So far so good….

Bass units: again Naim advised on the torque settings: two drive units, 6 bolts each. Interesting some of these were definitely loose and I mean not even finger tight so I felt this was very worthwhile.

I had a listen and straight away noticed better bass performance - more weight and rhythm to bass lines so was well pleased with this. I spun a fair bit of vinyl last night with great results.

Now on to the BMR units: here I am a bit stuck. The guidelines Naim sent me were for the S-600 but the S-400 BMR mounting is quite different. I removed all the 6 visible bolts and lifted the unit out: the BMR drive unit remained attached to the ‘elastomeric’ mounting plate though I could see a further 6 nuts behind once I’d lifted the assembly away from the cabinet (photo). Out of ‘an abundance of caution’ and with no further guidance I did no more except replace the assembly and torqued the six outer bolts without touching those nuts. Maybe this is all there is to do? Anyone know if there’s more to it than this? Is the elastomeric ring (the bit I’m holding) supposed to detach from the BMR driver itself? Or do those nuts get torqued from the back? I SO don’t want to mess this up!!

Thanks, Ian

Well I don’t know the settings but be real careful with that bmr there are no spares available

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Yes thanks for reminding me!! I’ve been very careful so far and all good. I don’t want to take any unnecessary risks! If I am not sure I will leave well alone having already done the floor spikes, plinth and bass drivers. They are sounding wonderful at the moment.

Ian, I would second the warning here, and advise you get in touch with Naim support if you need further assistance.

OK thanks Richard. I am in touch with them and I will check back again to see if they have anything specific on the S-400s BMR. But yes I will leave alone unless 100% sure there is a proper procedure I can follow. It may be I have done all I need to do. They certainly sound better than ever at the moment.

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The elastomeric part is sandwiched between the silver ring & the front plate - it is an integral part of the BMR unit. The studs are pressed into the front plate & the nuts fitted/torqued from the rear. These are serrated flanged nuts, so shouldn’t have become loose (in theory).

Regards

Neil.

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Great thanks Neil. Sounds like I can now consider this ‘done’. Much appreciated.