Sierra-2 Development Thread

[hornfan785]

[curtis]

Hey! I think that's different from the prototype I saw!

[pierreterrier]

What a cute baby ribbon

[avsnoob10]

In terms of length of ribbon area, looks about the same as ribbon tweet on my Sierra towers but the width looks to be almost half or less in comparison. Is that an unfinished cabinet? It looks more like an unfinished cabinet than natural?

[Dark Ranger]

In terms of length of ribbon area, looks about the same as ribbon tweet on my Sierra towers but the width looks to be almost half or less in comparison.

I agree with you here. The height/length of the ribbon appears nearly identical to the custom 70-20XR. Width is a bit harder to estimate because of the picture's skewed angle--1/3 to 1/2 the width of the 70-20XR looks to be about right.

The faceplate itself is remarkably similar to the current RAAL tweeter: the faceplate texture, the "zigzag" toothed edges (INOX), and the type of inset screws. Even the "cheesecloth" type barrier looks identical. However, it's obviously a smaller and lighter tweeter, too, because the 70-20XR has four inset hex screws while this ribbon has just two.

Point being, I'll be very surprised if this isn't a custom ribbon from RAAL.*

Is that an unfinished cabinet? It looks more like an unfinished cabinet than natural?

Yeah, I'm pretty darn sure that's an unfinished cabinet, hence au naturel. The vertically-laminated bamboo is much more apparent and carries more of a whitish color. These are prototype speakers, so it makes sense not to used a finished cabinet.


*I reserve the right to be incorrect about the tweeter manufacturer.


@ Curtis:

Looks like it's time to drop by the Ascend Skunk-Works bunker for another listen.

[davef]

Indeed, it is a custom built RAAL ribbon tweeter designed specifically for our requirements. It is 10mm in width (same width as the retail 70-10) and 1/2 the width of the OEM only 70-20 we use in our Towers. This tweeter marks the conclusion of an exhaustive project we started with Aleksandar (owner and chief designer at RAAL) nearly 2 years ago.

In this application, I must say I actually prefer this tweeter to the 70-10 as the response is more linear (with a low end roll off and frequency response shape specific to our needs) and it does not require any foam pads to tame the top end. It can not be crossed as low as the 70-10 (certainly not as low as the 70-20 our towers use) and it does not offer the same overall power handling, but -- in the way we are implementing it, we easily hit 108dB in our extremely well damped listening room measured at 12 feet back so power handling and dynamics are not an issue. This new tweeter has very broad horizontal dispersion but the polar response is not quite as good as the 70-20xr we use (I don't think ANY tweeter can match the remarkable polar response of the 70-20)

At some point there will be a retail version of this tweeter. This is something Aleks and I have discussed in detail as he needs to recoup his development costs, but while the retail version will look similar, it is not the same unit and the two have considerably different performance characteristics.

There is more to the Sierra-2 than just the custom RAAL ribbon tweeter though... More to come as we get closer

[Dark Ranger]

I think I understand what you're not saying.

In any case, thanks for the confirmation on the manufacturer. Some folks will be mighty pleased to hear that.

[RicardoJoa]

If the upgrade cost are within my affordable range, i think i may built another cabinet for the old drivers, or the upgrade drivers, depending how well the new cabinet are and the difference between MDF and bamboo.

[Mag_Neato]

Dave, that's awesome that the tweeter is, indeed, a RAAL! It looks great. Can't wait for more info on this little gem. Also can't wait for pics and info on the new mid-woofer!

[davef]

Dave, that's awesome that the tweeter is, indeed, a RAAL! It looks great. Can't wait for more info on this little gem. Also can't wait for pics and info on the new mid-woofer!

Wait, who said anything about a new mid-woofer? Isn't a custom RAAL true ribbon tweeter enough