Are RAAL Ribbons More Delicate?

[sonicboom]

Hi there,

Just a quick question: Are the RAAL ribbons more delicate than dome tweeters? Can you break them by too much spl?

Thanks,
Daniel

[Mag_Neato]

They are definitely different than domes, but that does not make them delicate in the way you mention. They can really get dynamic when called on. I have pushed my Sierra-2's pretty loudly at times and have actually witnessed the ribbon element move as if a gust of air had blown across its surface, but I did not hear anything out of character while that happened. It only happens on high dynamic peaks of, for example, brass instruments or powerful female voices. This is at higher spl than I usually listen.

I think what you really need to look out for, at least in the case of domes, is frying the voice coil by feeding it too much power for extended periods, or sending it a clipped signal full of distortion.

[sludgeogre]

If anything they are more durable. RAAL ribbon failures are almost unheard of. Hand built from quality components and no voice coil to overheat.

[Jaybeez]

I asked that same question recently when I demo'd a set Sierra 2's, with a frame of reference on recording microphones (ribbons are more delicate than condensers).

I'm sure Dave will weigh in here, but suffice to say his answer to me was more than sufficient to secure my purchase.

[davef]

Hi there,

Just a quick question: Are the RAAL ribbons more delicate than dome tweeters? Can you break them by too much spl?

Thanks,
Daniel

Hi Daniel,

Far too broad of a question. Which RAAL ribbon, which dome tweeter? In general, certainly they are more delicate than some dome tweeters, and at the same time, they are certainly more durable than some dome tweeters :)


If anything they are more durable. RAAL ribbon failures are almost unheard of. Hand built from quality components and no voice coil to overheat.

The ribbon diaphragm is technically the voice coil, as this is what the current passes through. It also happens to be the same element that produces the sound waves.

Generally speaking, the same issues that will destroy a voice coil will destroy a ribbon. Amplifier clipping is very bad, as is any amount of DC. In the case of heavy clipping or a strong DC offset, a ribbon tweeter will probably fail quicker than a high quality dome. On the flip side, with a RAAL ribbon, there are actually less components that can mechanically fail, far less adhesives that can break down overtime -- no surround, no former, no coil... Never have to worry about voice coil rubs or alignment issues, surround deterioration etc.

On our end, since we use ridiculously high quality dome tweeters and simply the best ribbon tweeters available, it is hard for me to say which has a higher failure rate. In the case of our ribbons, just about any failure we have seen was brought about by user error -- I actually don't think we have ever seen one simply fail mechanically. For domes, we have seen a few that have mechanically failed.

Just treat the speakers properly, avoid clipping and DC at all costs, and if you are listening to them and hear distress or distortion, turn the volume down...

[curtis]

In case you haven't seen it, or are interested, this is the ribbon diaphragm element that Dave is referring to. This is the from the the larger RAAL in the Sierra Towers.

https://changpics.smugmug.com/Other/Ascend-Acoustics-pictures/i-2GK5Gn9/0/L/CA_03011216495846-L.jpg

[sludgeogre]

The ribbon diaphragm is technically the voice coil, as this is what the current passes through. It also happens to be the same element that produces the sound waves.

Generally speaking, the same issues that will destroy a voice coil will destroy a ribbon. Amplifier clipping is very bad, as is any amount of DC. In the case of heavy clipping or a strong DC offset, a ribbon tweeter will probably fail quicker than a high quality dome. On the flip side, with a RAAL ribbon, there are actually less components that can mechanically fail, far less adhesives that can break down overtime -- no surround, no former, no coil... Never have to worry about voice coil rubs or alignment issues, surround deterioration etc.

On our end, since we use ridiculously high quality dome tweeters and simply the best ribbon tweeters available, it is hard for me to say which has a higher failure rate. In the case of our ribbons, just about any failure we have seen was brought about by user error -- I actually don't think we have ever seen one simply fail mechanically. For domes, we have seen a few that have mechanically failed.

Just treat the speakers properly, avoid clipping and DC at all costs, and if you are listening to them and hear distress or distortion, turn the volume down...

Right, the ribbon is the voice coil, and it is a true ribbon in that there is no voice coil etched on it, the actual ribbon is the voice coil. From what I've read, you can't overheat a ribbon in the same way as a dome tweeter because there is no mechanical connection between the magnet and the voice coil. Just as you said, there is a lot less that can mechanically fail.

My problem has been inexperience with them, I couldn't tell if they were distorting or if it was source material for a little while, but Dave set me straight and now I have zero concerns.

This tour of RAAL from 2008 on 6moons is really cool. They go through the build of a complete omnidirectional speaker that RAAL built as well as how they make their ribbon tweeters. The tweeter stuff is on page 4, here:

http://www.6moons.com/industryfeatures/roadtourserbia/raal_4.html

One excerpt from it: "Raal reports very low failures in the field"

[davef]

Right, the ribbon is the voice coil, and it is a true ribbon in that there is no voice coil etched on it, the actual ribbon is the voice coil. From what I've read, you can't overheat a ribbon in the same way as a dome tweeter because there is no mechanical connection between the magnet and the voice coil. Just as you said, there is a lot less that can mechanically fail.

My problem has been inexperience with them, I couldn't tell if they were distorting or if it was source material for a little while, but Dave set me straight and now I have zero concerns.

This tour of RAAL from 2008 on 6moons is really cool. They go through the build of a complete omnidirectional speaker that RAAL built as well as how they make their ribbon tweeters. The tweeter stuff is on page 4, here:

http://www.6moons.com/industryfeatures/roadtourserbia/raal_4.html

One excerpt from it: "Raal reports very low failures in the field"

RAAL and Ascend have very similar business practices and philosophies. I believe there is a picture floating around in the forum of Mladen working on some tweeters here in our facility.

[sonicboom]

In the Verified User Reviews section, I was the one who used 340s at church for a movie night. The CMTs performed very well, at satisfying SPLs, in a huge room approximately 80x40x30 feet in internal dimensions. More than a hundred people were there that night, and everone came out satisfied with the sound. Some even commented that it got too loud at some points in the movie.

If the CMTs were able to perform that well in such a large venue at SPLs that are way above normal home use, is it safe to assume that the Towers with RAAL tweeters will be able to at least equal the playback volume? I know that I am sounding vague because of the absence of measurable dB values, but can I assume that the Towers with RAAL will outperform the CMTs in EVERY performance parameter?

Thanks,
Daniel

[Jaybeez]

The CMTs are solid speakers, and if I was putting together a surround set up from scratch, would probably go that route.

The towers with RAAL tweeters are truly amazing speakers. I went with the Sierra 2's to get as close as I could to them without completely blowing the budget.

Now, you reference EVERY performance parameter. If in reference to technical, I would say most definitely bass, midrange and highs are far superior on the towers. If in reference to value that could be debatable, and may well depend on your use case. If for a large crowd (with presumed background noise) the nuance the towers would reveal could be lost.

If you are getting for your own use, and can afford the towers, you won't be sorry. I may well end up with a set within the next few years.

[davef]

If the CMTs were able to perform that well in such a large venue at SPLs that are way above normal home use, is it safe to assume that the Towers with RAAL tweeters will be able to at least equal the playback volume? I know that I am sounding vague because of the absence of measurable dB values, but can I assume that the Towers with RAAL will outperform the CMTs in EVERY performance parameter?

Thanks,
Daniel

I would say that our ribbon towers and 340's will have very similar max SPL capabilities. The towers will likely fill such a large space slightly better due to having wider horizontal dispersion, but ultimate max SPL will be similar.