Sierra 2 tweeter damage...

[davef]

Different tweeters between early and later S2's? Ruh-Roh Shaggy! Please clarify what differences there are?

No, well not really. I believe it was about 1.5 - 2 years ago, we compromised a bit with RAAL to make manufacturing of our custom S2 tweeter and the RAAL OEM 64-10 easier by having them share more parts. No differences in performance, just a very slight change in overall size of the components on the back side of the tweeter - such that newer S2/S2EX tweeters will require a little bit of cabinet filing to slightly open the internal cutout of the tweeter to fit it in older cabinets (a few mm's at most). For anyone doing a Sierra-1 to Sierra-2EX upgrade, or ordering replacement S2 tweeters, we provide the proper S2 tweeter so that filing isn't required. That is at least until we run out of our supply of the S2 tweets.

For the most part, this revision is invisible to our customers. I had previously discussed this in the forum somewhere. This helped RAAL lower manufacturing costs and in turn, helped us keep pricing the same, otherwise we were looking at an increase in price.

This has nothing to do with why we ask for serial numbers, we request this for all upgrades so that we can properly track the speakers. We have had issues in the past with people selling used speakers claiming they were upgraded, but were actually never upgraded...

[davef]

Additionally, at this point we have a bit over 1000 Sierra-2EX out there being used by our customers. We have yet to have a single reported "blown" ribbon tweeter in S2EX.

As I have mentioned several times, I would not call RAAL ribbon tweeters more fragile - in fact, the 70-20xram (the ribbon in our tower) is absurdly robust, we have only had one customer ever destroy one due to electronics (in many thousands sold) - and that customer melted every internal component of his towers. In fact, with regard to destroying tweeters, we see far more dome tweeters destroyed compared to ribbons.

The difference is that with a ribbon tweeter, you see the physical damage. In a dome tweeter, the burnt-to-a-crisp voice coil is not visible unless you physically tear the tweeter apart. Because the damage to a RAAL ribbon is so clearly visible, they often and wrongfully get a bad rap as being fragile. True, the ribbon diaphragm itself is materially fragile if an object hits or touches the aluminum - but this is why it is protected with the screen mesh.

In a RAAL ribbon, the aluminum "ribbon" element (more properly called the diaphragm) is technically both the voice coil and the dome itself. Any damage to the tweeter is visible - while in a dome tweeter, the voice coil can be damaged but you won't see it until the tweeter just stops working altogether.

Provided that the customer is aware of amplifier clipping, power and the inverse square law for SPL (distance vs spl requirements) - there will really be no issues or concerns. I have run S2's to insane volume levels - even louder with S2EX.

All that said, speakers are like any other mechanical device - they require care and need to be used within their limitations - no different than a car or bicycle - push a mechanical device past its limitations and something is going to give....

[davef]

Couldn't they have just replaced the ribbons?

Hey Jim,

Ribbon diaphragms are not replaceable in these tweeters, only in the 70-20xram. That said, the cost to replace the complete S2 tweeter is about the same as replacing just the diaphragm in the 70-20xram. If we had made the diaphragm replaceable, the result would have been a significantly more expensive tweeter with a potential compromise to overall performance due to keeping its compact form factor.

Plus, for the average consumer - replacing the diaphragm is complex and difficult, requiring solder skills as well as very steady hands and a heat gun.

[jimb]

Hey Jim,

..., the cost to replace the complete S2 tweeter is about the same as replacing just the diaphragm in the 70-20xram. ...

Sounds good to me!

[mikesiskav]

Is the protective screen in the slot nice and tight still or is it loose or warped in any way? That would indicate the magnet might have grabbed onto something metal and pulled it into the ribbon element. Those magnets are extremely powerful. I know. I tried to measure my towers from the front with a tape measure and it sucked the tape right into the screen. I 'bout shit myself...

Same thing happened to me! No damage.

[Pogre]

Same thing happened to me! No damage.

You too, huh? That's 3 of us now!

[audiohead]

You too, huh? That's 3 of us now!

I sense another Pogre sticker coming? Magnets are Powerful, keep metal tape measures and other metal objects far away.

[curtis]

I sense another Pogre sticker coming? Magnets are Powerful, keep metal tape measures and other metal objects far away.

LOL!

FWIW, i try not to put any metal close to the drivers. I’ve measured distance to the speakers before, but with the grilles on, and not exactly at the tweeter.

[Pogre]

LOL!

FWIW, i try not to put any metal close to the drivers. I’ve measured distance to the speakers before, but with the grilles on, and not exactly at the tweeter.

I was measuring the height of my speaker when it happened. The tape wasn't even touching the towers and the magnet sucked it right into the screen. In retrospect measuring from the front without the grilles on was not the best decision, obviously. I've owned many speakers. I currently have 9 pairs of speakers in my house now, have done lots of measuring and have never once run into this.

A testament to just how powerful the motor is in those tweeters, but I'm gonna go out on a limb here and say it's not common for something like this to happen with most other speakers. We can joke about a new Pogre sticker, but based on some of the replies it might not be a bad idea to at least include a warning in the paperwork or something. Clearly, I'm not the only one who's had this happen.

There's no change in sq or performance, but the screen protecting that tweeter is warped now and it drives me crazy. I was wondering if I use a hair dryer on it if it might tighten back up, but at this point I already feel like I'm doing everything wrong and knowing my luck I'd end up melting the ribbon...

[natetg57]

Yeah, the hair dryer sounds like a bad idea