My SVS has developed a fault. :(

[Malice]

Last night I turned on War of the Worlds on satellite (DD soundtrack) and was looking forward to re-living the experience of the film having watched it on DVD when it was first released.

Well, after the first real bit of sub action (probably @ -6db) I thought that my large display cabinet with glass doors and a few ornaments was rattling more than usual to the tune of my SVS PB12-ISD. So I went closer to the cabinet to find that it was not the cabinet. Shock horror when I found that the rattling sound was emanating from my sub!

Even using the test tones on the Denon, the sub rattles as if it has a bag of spanners in it. I turned the unit upside down just in case something had dropped onto the back of the driver, but it still rattled merrily.

As there is a 3 year warranty there shouldn't be an issue, but I am now more concerned that I won't get it fixed in time from the guys in the UK for the Christmas holidays !

Would anyone like to hazard a guess as to the likely fault? Does it sound like one of the driver cage/basket "arms" has broken? (Not sure of the correct name for the cast iron thingy which supports the driver)

Woe, woe and thrice woe!

[Ron Stimpson]

Malice,

Sounds like you were getting some serious "power useage" out of this sub, but despite its tough construction a woofer can let go.

Kent Home Cinema should have some NSD woofers if you want to upgrade (highly recommended since they are even more durable and powerful than the ISD woofers) though it's possible an ISD woofer would have to come from the US.

I'd say 90% likely a simple woofer replacement (about 30 min. of time, tops) will fix you right up so give them a call ASAP.

If something else loosened up we'll be able to fix that easy enough. Your best move for now is to simply flip the sub upside down (fully removed from AC/Mains and the signal cable removed from the receiver first of course). Do it on a flat and soft surface like a rug or carpet.

Peel off the foam foot pads and remove the leg bolts and set them aside, then lift off the baseplate and leg dowels. Push evenly down on the woofer, it should move smoothly, if it scrapes or is stuck, then we've upped chances it's the woofer to about 95%. Once that's done, very carefully remove the ISD woofer (there are phillips head screws around the mounting gasket).

Look for any damage to the woofer (around the "spider" or around the cone and surround assembly). Of course, look for anything loose inside the sub. If anything is floating around inside (subs live hard lives clearly) all heck can break loose.

Fire us off a note back when you have peeked inside and we'll take it from there. With your input and that of Kent Home Cinema we should have a solution in place well before Christmas.

Ron
SVS
sales@svsubwoofers.com

[Malice]

Hi Ron,

Well, I followed your instructions to see what I could see.

On gently pressing the driver it moved quite freely and easily with no resistance that I could see. How far should one be able to safely move the unit along its axis? The unit disassembled and came out much easier than I thought! Which is a good start.

On close inspection I could not see any apparent fault with any of the spider assembly at all. Of course with proper diligence on safety I fed a signal and power to the unit to see if I could locate the rattle. To my ear it appeared to be emanating from the centre of the driver area. The "rattle" sounds as though a small bearing is about to go in a bearing assembly. It's about the same loudness as the test tone I fed and is neither regular in tempo nor loudness. It nearly is random, but not, if you get my drift! With just the slightest of pressure around the periphery of the unit (rubber mount?) the rattling stops. Equally with slightly more pressure on the flat circular area under the driver (atop the magnet assembly), the rattle stops. There is nothing to suggest there is anything in the unit (enclosure) itself which is rattling.


Thanks for the response Ron.

Bob

[Malice]

Ian @ AV-Sales has been in touch with me by telephone today. I'm getting sorted, thanks for your help Ron!

[Malice]

Just to let you know that I received a newer NSD driver yesterday via Ian Scorgie. Installation was a little trickier than the removal as the new driver did not have push-fit connections, only spade terminals. Desperate to fix my sub I decided to solder the cables to the driver terminals. Anyway, all is normal again. In fact better than normal, the NSD is a noticeable improvement on the ISD! Great news!

Thanks for your help and to those at AV-Sales/Kent Home Cinema.

Out of interest, what model number can I assign to my updated sub?!!! PB12+NSD?

Bob

[lienly]

right, it's not so easy to secure wires on such spade terminals of NSD when I upgrade from ISD which has much better design :holycow: in this! don't know why SVS downgrade to this poor design?

anyway, NSD is improved over ISD. good job, SVS!

Malice wrote:

I received a newer NSD driver. Installation was a little trickier than the removal as the new driver did not have push-fit connections, only spade terminals

In fact better than normal, the NSD is a noticeable improvement on the ISD! Great news!

Bob

[Ron Stimpson]

Lienly,

Yes, we know. The spades were a necessary concession to allowing us the budget to improve entry-level 12" subwoofer performance, without increasing prices or compromising quality where it really counts (surrounds, spiders, voice coils, "motor" design, etc). The spades are of course the same sort of terminals used in automotive design, the vast majority of even top speakers, computers, you name it. While hardly glamorous, they work well (if you don't forget to pack them in the woofer's box as happend with Malice in the UK), they are inexpensive, and are the only sort of connection that's really practical on the stamped steel basket we used on the NSD (for its weight, durability and compact dimensions. Even UPS has a hard time damaging a steel woofer basket).

Performance is indeed improved in all respects, and cosmetics too (when mounted in a cabinet) so save for the power lead connection it was a win/win for our customers. We sold many MANY of those NSD woofers to the perpetual upgraders out there, and while a couple also noted the less sexy binding posts (the ISD woofer had some nice ones for sure) not a single person took issue with that improved performance. We haven't ruled out some nicer binding posts in the future but given 99% of all customers buying subs with NSD woofers installed today won't ever see much less touch the spade connections, it's a tough sell when you have to figure out where to spend time and money for re-design.

Hope that helps a bit, as always if not for comments from customers like folks here, we would be guessing as to what to work on next. Keep those cards and letters coming in other words, we read it all ;^)

Best regards,
Ron
SVS

[lienly]

Ron.

I don't know the prices of quick clip vs simple spade. just think if can have such handy clip for easier job, it's better. I understand most users won't even bother to discover each component structure. and upgrade is a one time only job, so spade is ok. to the end of my NSD upgrading, I use 'shrink tubes' to secure wires.

bare wires on spades
http://photo.pchome.com.tw/lienly/116399110894
put shrink tubes to secure
http://photo.pchome.com.tw/lienly/116399111549

tks and happy new year to everyone!

Ron Stimpson wrote:

Lienly,

Yes, we know. The spades were a necessary concession to allowing us the budget to improve entry-level 12" subwoofer performance, without increasing prices or compromising quality where it really counts (surrounds, spiders, voice coils, "motor" design, etc). The spades are of course the same sort of terminals used in automotive design, the vast majority of even top speakers, computers, you name it. While hardly glamorous, they work well (if you don't forget to pack them in the woofer's box as happend with Malice in the UK), they are inexpensive, and are the only sort of connection that's really practical on the stamped steel basket we used on the NSD (for its weight, durability and compact dimensions. Even UPS has a hard time damaging a steel woofer basket).

Performance is indeed improved in all respects, and cosmetics too (when mounted in a cabinet) so save for the power lead connection it was a win/win for our customers. We sold many MANY of those NSD woofers to the perpetual upgraders out there, and while a couple also noted the less sexy binding posts (the ISD woofer had some nice ones for sure) not a single person took issue with that improved performance. We haven't ruled out some nicer binding posts in the future but given 99% of all customers buying subs with NSD woofers installed today won't ever see much less touch the spade connections, it's a tough sell when you have to figure out where to spend time and money for re-design.

Hope that helps a bit, as always if not for comments from customers like folks here, we would be guessing as to what to work on next. Keep those cards and letters coming in other words, we read it all ;^)

Best regards,
Ron
SVS