The SBLs have landed
Posted by: Matt Gear on 27 November 2003
All
After humming and hah-ing about upgrading my speakers (Castle Avons) for rather a long time, I have finally taken the plunge when a very reasonaly prices pair of 2nd hand SBLs became avaiable.
I've been running the Castles for over 6 years now initially with a (whisper it) Pioneer system, and then with the Naim kit which I'm currently using (CDi/02/82/Hi/180). All the upgrades they I made in the front end were suitably reflected through the speakers, but I was becoming tired of the slightly boomy bass, shrill treble at high volume, and generally "cuddly" presentation they had.
The first time I heard SBLs about 8 years ago, I really wasn't all that impressed, but I've become very familiar with them since then (my father has a pair), and have grown to love them. In the context of my all Naim electronics they seem like the obvious choice, and at 2nd hand prices, the bargain of the century.
I picked the speakers up on Tuesday evening, a very rainy evening and not much fun to drive. Thanks Steve for the help in packing them up, and sorry to have taken them away from you!

By the time I got back home though, it was too late and I was too tired to even think about setting them up.
So I was, sat at work all day yesterday, itching to get home to get my new babies set up.
It was a lot easier than I thought. I'd read much on the forum about gaskets, and silicon gel, and was expecting quite battle, but the gaskets had only recently been re-sealed, and had stayed intact during transit, so all i needed to do was bolt on the treble unit, and pop them into place.
First impressions were gob-smacking. As I said, I've heard SBLs before, but wasn't really prepared for the improvement that they brought to my system. Gone was the shrill treble, the smoothing off of the notes, and the thump-thump bass. It was as if I'd been listening behind a curtain before, which had now been drawn back, giving me a clear audio view of the performers.
Listening to choral music, it was possible to follow the individual parts much more easily, whilst still retaining a feel for the whole piece. You could hear the subtle inflections of the voices, and also get a much greater sense of space around the performers.
Switching to more modern music I could really start to understand what people mean by PRaT. Drums started and stopped far quicker, and acoustic guitars had a wonderful zingy punch to them which I'd not heard before on my system.
And as for the bass: well, absolutely no complaints there. SBLs have been criticised for being bass light, but I spun "Cochise" from the Audioslave album and it ROCKED! I kept wanted to turn it up louder, as there was no sense of strain at all.
The rest of the evening was spent ploughing through my CD collection, and discovering nuances and phrases that had previously only been hinted at.
Suffice it to say I'm a very happy chappy. In the context of my system I would confidently say that it's the biggest upgrade I've made, and probably the most cost effective too.
The good point too, as made by the chap I bought them off, is that they will continue to get better as I upgrade the front end, though for the moment I'm more than happy with what I have, and will be investing future funds in expanding the CD collection, which after all, is what it's all about!
Cheers
Matt
Posted on: 27 November 2003 by Rasher
Are you sure you don't need to remake the seals again with new sealant? I dunno, my dealer set mine up, but I thought once the seal was broken...
I cannot see any circumstance where I will ever need another pair of speakers - except when they wear out of course. Long term grin factor investment to be sure.
Welcome to the club.
Now the fun starts..

Check out the forum as to what to put them on, and you will not believe what will happen

Trust me.
Posted on: 27 November 2003 by garyi
Mate you need to do the seals, don't assume they are alright,
Posted on: 27 November 2003 by Rasher
Talking of sealant, what to use when the original suff has been used up? Is it worth doing as a periodic service - say yearly?
Posted on: 27 November 2003 by Matt Gear
Garyi
You may be right. I was under the impression though that there was a quick test to do to check, namely gently pushing in the bass driver, and if it comes back to position slowly, the seal is ok. Is this right, or should I keep my grubby paws off?!
Either way, they're sounding damn fine. May have to get the old silicon gel gun out at the weekend though...
Rasher...I've actually got them sat on a pair of M*** soundbases, which is what I had the Castles on. I'm using them because they were free to me, and because I'm on a sprung floor. Whether they make any difference I have no idea, as I didn't hear the SBLs without. With the speakers sounding as they are though, I have no inclination to remove them.
Cheers
Matt
Posted on: 27 November 2003 by blythe
Remember that silicon is flexible.
Once you significantly move the SBL's, the driver box WILL move around to some extent, so even if the seal is not actually "broken" the interface between the spikes and the bottom of the cabinet will have been disturbed. I would urge you to invest in a new gasket and sealant from Naim and whislt doing the rebuild (truly not a big job if you have even only a small DIY ability) check the condition of the spikes and the pads that the Spikes come into contact with - in fact, get replacements ready anyway! It is quite likely that some damage (not serious) will have occured through transporting the SBL "assembled".
After resealing them, leave them preferably overnight before using the speakers and don't drive them hard for a few days - just to allow the sealant to go off properly.
A cracking speaker which I used for about 14 years until NBL's took their place.....
Computers are supposed to work on 1's and 0's - in other words "Yes" or "No" - why does mine frequently say "Maybe"?......
Posted on: 27 November 2003 by greeny
quote:
You may be right. I was under the impression though that there was a quick test to do to check, namely gently pushing in the bass driver, and if it comes back to position slowly, the seal is ok. Is this right, or should I keep my grubby paws off?!
Yes this is true and can indicate that the seals need remaking. i.e a quick rebound indicated seals gone. However this is not foolproof and there is another concern, the seals may be OK but the spikes may not be providing the correct contact from the bottom box. The only real way of telling is by disassembling. Unfortunately you might find on disassembly you damage the foam seal, additionally you might need new aluminium pads for the corners so please buy a reseal kit (£25) before you take them appart or you may be without speakers for a while.
It's worth ensuring you have them correctly positioned before you take them appart as you can then reassemble in situ and not need to move them.
Sorry blythe I seem to have posted the same advice at the same time!!
Posted on: 27 November 2003 by Dev B
Matt,
Because you moved the SBL with the Seal intact the bass will become imprecise and flabby. The Mana soundbases are masking this by tightening and attentuaing the bass. Reseal and take the soundbases out, you will find the SBL's will give everything you are getting plus more body, depth, weight, tone, etc.
regards
Dev
ps. Garyi has first hand experience of removing the soundbases under my SBLs and what it did for the sound.
Posted on: 27 November 2003 by Allan Probin
Matt,
The purpose of the foam gasket and silicon seal is to provide an acoustic coupling between the mid and bass boxes with the minimum of mechanical coupling. If you've moved and transported the speakers assembled then it's almost certain that the mid box will have sunk down on the spikes compressing the seal and increased the coupling between the boxes.
Just to re-itterate something that greeny mentioned, find the ideal location for the speakers before you rebuild. In my experience, moving SBLs around, even very carefully, adversly affects the performance.
Allan
Posted on: 27 November 2003 by Matt Gear
Chaps
Thanks all for your replies. It would seem that the overwhelming advice is to do a proper re-seal. Not something I mind at all as of course I want to get the best out of my new babies, but was just being a lazy bugger!
Would I be correct in assuming that you can't re-use the gaskets once you take the top off?
Dev...can you expand on the effect of removing the soundbases? I thought they would help as I am on a sprung floor, but would like to hear your experiences...
Cheers all
Matt
Posted on: 27 November 2003 by Dev B
quote:
Originally posted by Matt Gear:
Chaps
Thanks all for your replies. It would seem that the overwhelming advice is to do a proper re-seal. Not something I mind at all as of course I want to get the best out of my new babies, but was just being a lazy bugger!
Would I be correct in assuming that you can't re-use the gaskets once you take the top off?
Dev...can you expand on the effect of removing the soundbases? I thought they would help as I am on a sprung floor, but would like to hear your experiences...
Cheers all
Matt
Matt,
Put simply in my room they tightened the bass, made the speakers brighter and has a general cleaning effect on the sound. Taking them out the sound gained PRAT, bass and was less bright. It also had body and depth which is important also. When you are resealing take them out, but let your speakers settle for a week afterwards.
If you are worried abo bass leakage on the floor and want to have the flexibily with placement, try some Naim chips.
regards
Dev
Posted on: 27 November 2003 by Thomas K
What phase were you on with the SBs?
BTW, we have the exact same sistem now (apart from the fact that I don't own a TT or a tuner).
Thomas
Posted on: 27 November 2003 by garyi
You can reuse the gasket provided its not damaged. This will depend on the last person to seal them, you need to use a little detergent on the gasket and box so that although sealed, they will come apart when required. Chances are if they stayed together on a car journey, the gaskets will be damaged, so its well worth the small investment for the gasket kit which laso has the silcon and alumnium pads
Posted on: 27 November 2003 by andy c
Ok so if you are replacing the gasket and silicone this is what my dealer suggested, which I have done and it works well.
Replacing the actual gasket itself is a pain, and you get instructions with the gasket kit on how to do that.
Once the gasket is in place before application of the silicone smear some fairy liquid (a very thin layer) on the top of the gasket and where the silicone will meet the bass unit.
Then carefully place the bass unit in position. The silicone will seal correctly, but be easier to remove should you need to in future.
If you do not intend to move your sbl's for some time then don't do the liquid bit.
I move mine about once a year (for various reasons including re-setting the M*** up, so have used the liquid, and they sound fine...
(thanks to Peter at Cymbiosis for this tip - when I purchased them 4 years ago).
Posted on: 27 November 2003 by Frank Abela
Matt,
If, when you push in the drive unit, it takes a couple of seconds to come out, then the seal is fine, no matter what these doomsayers say! You can even time it to make sure both speakers are the same. If they're different, then reseal both of them.
Regards,
Frank.
All opinions are my own and do not reflect the opinion of any organisations I work for, except where this is stated explicitly.
Posted on: 27 November 2003 by Matt Gear
OK
So if I do redo them (which is looking increasingly likely), the gasket has two sides, the white shiny side and the soft dark side. It's white side down right? And do you use the sealant on the white side AND the rough side, or just on the rough side? (Same goes for the detergent)
Cheers
Matt
Posted on: 27 November 2003 by andy c
Matt,
You have a private topic!
andy c
Posted on: 27 November 2003 by Peter Gear
Well there you go Matthew - I told you we should have changed the seals!
And you did'nt even give me credit for helping you install them last night!!
That will cost you another bottle of Chilean Pinot Noir!
pa
Posted on: 27 November 2003 by Matt Gear
Cheers Andy, you have mail!

Dad...3 glasses not enough for you eh? Maybe the Wolf Blass Shiraz on Friday evening?

Matt
Posted on: 27 November 2003 by Martin Payne
Just to add my weight to the advice above - re-do the seals.
The seals themselves may not be compromised, but the spikes will surely have penetrated the bass/mid boxes, and these will need to be repaired to get the full performance of the speakers.
Also, be careful taking the speakers apart. If washing up liquid was not used to reduce the stickiness of the sealant then they might be hard to get apart. Use a long kitchen knife to cut through the foam rubber. This will allow you to separate the boxes without digging the spikes even further into the basses. (Be careful not to damage the PAR on the bottom of the bass/mid box - very expensive to replace).
cheers, Martin
E-mail:- MartinPayne (at) Dial.Pipex.com. Put "Naim" in the title.
Posted on: 27 November 2003 by greeny
quote:
So if I do redo them (which is looking increasingly likely), the gasket has two sides, the white shiny side and the soft dark side. It's white side down right? And do you use the sealant on the white side AND the rough side, or just on the rough side? (Same goes for the detergent)
The white shiney side is a peel off bit, remove the white paper and the poition the foam on bottom speaker cabinet (self sticks), ensure you hav eremoved all reminents of previous gasket first.
Then apply washing up liquid around top of foam gasket and on underside of speaker box. Then add sealant on top of detergent on foam seal.
To dissasembe your boxes put a couple of chocks in the gap between bottom and middle boxes at the back to prevent the box seal being compressed, then prise apart from the front, using a suitale thinkness spanner or bit of wood.
Posted on: 27 November 2003 by andy c
Quote from greeny:
quote:
The white shiney side is a peel off bit, remove the white paper and the poition the foam on bottom speaker cabinet (self sticks), ensure you hav eremoved all reminents of previous gasket first.
Then apply washing up liquid around top of foam gasket and on underside of speaker box. Then add sealant on top of detergent on foam seal.
Could not have put this better...only add on tho is not to use too much fairy liquid - you should use sufficiant that if you rubbed your finger end over it you'd get most of it off - if you know what I mean...in other words use the liquid sparsly...(I think thats how u spell it!)
Posted on: 27 November 2003 by Matt Gear
Aah...
All becomes clear!

Thanks Greeny
Matt
Posted on: 27 November 2003 by Rasher
Dev - Sorry mate but have to disagree with you on the Soundbases. I know they work for me.
Posted on: 27 November 2003 by andy c
The comments re mana depend on what floor/room you are using the sbl's on/in. Dev has been very fair in referring to the effects in his room.
In my room which has a concrete floor the 'bases are in and staying there due to the positive benefits they bring....
Clearer, cleaner, tighter without losing PRaT...
[This message was edited by andy c on THURSDAY 27 November 2003 at 16:21.]
Posted on: 27 November 2003 by garyi
Regarding getting rid of all remenants of the old gasket. Use a little bit of white spirit to clear off the old glue and leave it nice and clean for the new gasket.