SL2 owners: re. foam

I spent hours listening to my SL2s this afternoon after replacing the foam in the top cabinets and it has made a big difference to SQ (for £16).

If you have SL2s and have not tried this read on…

This morning I replaced the 4 small internal foam pads in the top cabinets of my SL2s because the original foam was crumbing into dust.

The details are all recorded on this thread:

This has had a really good consolidating effect on SQ.

Especially on the high frequencies, but also overall.

The Paul Motian drum solo on ‘Turnaround/When Will the Blues Leave’ sounds definitively better than ever.

‘Crisp’ is the word that springs to mind.


A bit more detail:

At the same time as replacing those 4 foam pads on the side walls of the top cabinets, I also tightened the spikes on my left SL2 and corrected the leveling on that speaker - so that will also have improved clarity of sound.

One other factor is that I had removed the crumbling foam from that left speaker a couple of weeks ago and so it sounded thinner and slightly more out of focus since then.

So the change today got rid of that bald left speaker SQ and it got rid of the right speaker with crumbled foam in it.

And replaced both with a matched pair of well damped top cabinets - i.e. the crucial part where the magic mainly happens.

Anyway, in a nutshell, my advice to SL2 owners is - check those foam pads and replace if they are not perfect.

They are not glued in, so come out very easily.

Just get some acoustic foam and cut to size.

The sizes and details are in the other thread linked to above.

I got foam from efoam {.co. uk}

Others used PureSoundSales on t’Bay, or other foam suppliers - see other thread for details.

In case anyone thinks I’m exaggerating, the other thread contains quotes from other people who replaced the foam in their SL2 top cabinets and said things like:

“Highly recommended, they really rejuvenated my SL2s.”

And: “I’ve now fitted the dampening foam to my SL2s. I wasn’t expecting to hear much difference but I’m pleasantly surprised. The top end sounds much smoother.”


One further satisfaction if you do this is that you are adding new longevity to the stock of Naim speakers and increasing the chances of people enjoying them for years to come…

Thanks.I may investigate although it does strike me that tightening and leveling your speakers may well have had an effect that is hard to seperate. Still for £20 nothing to lose for trying it!

cheers Bruce

yes tightening the spikes had a positive effect on the left speaker

but the improvement in SQ is across both speakers.

I didn’t adjust the spikes on or move the right speaker because it didn’t seem to need adjustment.

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I had very low expectations of an improvement in SQ from changing the foam.

I had wanted to change the foam since I bought the speakers as some of the foam had crumbled on the journey home.

So my main reason for doing it was to remove a source of dust (i.e. the 4 old foam pads) that was inside the top cabinets.

Mine are early SL2s, so may have been more decayed than younger pairs.

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Strange that no one responds, as there are so many SL2, SBL, NBL…users here.
I hope you have some good holidays Jim .

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Hi, very interesting. How old are your SL2 speakers?
I brought some matched tweeters from Naim last year (yet to be installed) and have just ordered some solder…OMG as I write it arrived!! @Richard.Dane i think this is the solder you said to use at the time. Even though post 06’ Naim stopped using it Naim customer services confirmed with my set (08’) it will be fine. I’ll be getting a competent friend to do the work. My foam is still fine but I get some in anyway.
If you don’t know and I’m sure you do Torquing mid driver bolts and face plates to 3.6Nm is a good thing too.

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Naim used Multicore Crystal 505. Is that Stannol Kristall 505 similar?

I have recently checked the inner foams on my SL2s and so far they are OK, although inevitably they will need replacement at some point. Jimdog, I’m glad to hear that the replacement foam has restored performance for you.


It’s pretty much impossible to get into the tweeter and bass boxes of SBLs without doing more harm than good FR. It’s a case of ignorance is bliss!

The stand section that loads the bass is wool and does not deteriorate.


Oh dear, think I’ll look into that :grimacing:

Wow I’ve had to do a bit of research in the last couple of hours. It would seem they have very similar properties, as far as I can tell the “Crystal/Kristall” is a clean finish and the “505” %0.5 Halide content. Bit confusing to me, I guess best practice would be to hunt down the Muliticore Crystal 505.

I really thought it was going to be Crystal 505 coming :upside_down_face:

Yes, thanks, FR - we a great time in New Quay, Wales with family and friends.

Various coastal walks and great weather.

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Thanks for this @JimDog . Now I just need to find some of the correct specification foam. When purchasing from efoam, was it just the “acoustic flat sheet” (at 1" thickness) that you bought?

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Yes, acoustic flat sheet.
(I think I mention the details on the other DBL thread).
Free delivery and it took about a week to come.
They sent it in a thin grey plastic bag as a once-folded sheet.
The sheet is 10x bigger than you will need.

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Mine were made in 2003.

So my foam would have probably been on the crumbliest end of the spectrum.

There are photos of it on the other thread, I think.

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I did swop messages with Guy of Pure Sound about his foam.

From what I can gather, Guy sells a type of ‘reticulated’ foam that was used in DBLs.

But he sells it in expensive DBL-sized packs, and doesn’t have any smaller pieces or offcuts for sale.

The foam I bought is sold as acoustic foam, and the company - efoam - was recommended to me by another acoustic foam manufacturer who will only sell in quantity.

I have no idea what type of foam was used in SL2s originally - but if anyone finds out please let me know.

For reference, I scanned the following possible suppliers:

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Just checked mine ( 2006 ) and the foam looks excellent. The grilles are starting to show their age though!