Ribbons

[jostenmeat]

Silly question, but can someone tell me the correct way to pronounce Geddes? Thanks. (For that matter, anyone else run into a person or two who pronounce Denon with the accent on the second syllable: den-ON?)

randyb, I find your subjective blurbs to be very interesting, and so thanks for sharing. It is JMO, but I have the impression that midbass is the hardest thing for the typical speaker in an HT environment. While looks are only looks, I would still perhaps mistakenly look at a Salk as an "audiophile" speaker, and the Geddes as a commercial/HT looking speaker (without knowing anything more, for instance).

But going by your description, I'd opt for the Salks in an HT setting, and I might choose the Geddes for a 2ch classical music rig!

 

[KEW]

Are you asserting that ribbons have poor off-axis performance?

Perhaps I am inferring too much from using the SongTower RT as my sole reference for ribbon tweeters, but yes, that is my experience. I just did a comparison (with S-2's), and somewhere between 65 to 70 degrees the difference becomes apparent when A-B'ing the two speakers.

I'd welcome any comments on how typical this is.

 

[cschang]

Aren't there off-axis measurements of the two Songtower variations(dome and ribbon)? I could swear I have seen them before. Perhaps they do not measure far enough off-axis.

 

[randyb]

Silly question, but can someone tell me the correct way to pronounce Geddes? Thanks. (For that matter, anyone else run into a person or two who pronounce Denon with the accent on the second syllable: den-ON?)

randyb, I find your subjective blurbs to be very interesting, and so thanks for sharing. It is JMO, but I have the impression that midbass is the hardest thing for the typical speaker in an HT environment. While looks are only looks, I would still perhaps mistakenly look at a Salk as an "audiophile" speaker, and the Geddes as a commercial/HT looking speaker (without knowing anything more, for instance).

But going by your description, I'd opt for the Salks in an HT setting, and I might choose the Geddes for a 2ch classical music rig!

I think it is important to note that the Harpers were really developed as a surround speaker so you would typically route the bass to the subs. Earl is a big believer in using subs (multiple) with any setup both two channel and surround.

 

[TLS Guy]

I don't think you can compare different speakers with domes and ribbons, as other factors will be dominant.

It really all depends on how a device is used.

Ribbons come in two types. The aluminum foil strip type in which the signal is fed through the pleated aluminum ribbon in a strong magnetic field.

Then there are planar magnetics where there is a thin plastic film with a conductor bonded and magnets behind.

I have used both.

The aluminum strip type are very fragile and even at the best deteriorate over time due to stretch. You really have to limit power below crossover and crossover needs to be high, I usually go for 4 kHz in these types.

They have a rising high end response. Denis Murphy deals with this with a low value inductor in series with the ribbon.

Good ribbons have good horizontal dispersion and limited vertical dispersion. This is by no means a bad attribute. However it does provide a challenge in getting a seamless hand off to a cone or dome mid range.

Distortion is higher than for domes but only significant below crossover.

Since the ribbon is lighter than a dome transient response should be better.

The planar ribbons have greater efficiency and are generally more robust and reliable. They are not as prone to rising high end response as the metal ribbons. Otherwise problems are similar.

Infinity in their hey day preferred the planar mylar ribbons.

I think the only ribbon driver that really solved these problems is the Heil driver. A German form is producing these again. However manufacture is complex.

Domes are more robust now that ferro fluid is universally used. This has greatly reduced failure and increased power handling.

Fs can be got into the 500 Hz range. This allows for good power handling and low distortion below crossover. It also allows for lower order electrical crossovers. This helps to minimize time and phase aberrations. It also allows for lower crossover points to keep woofer/mids out of cone break up range.

The polar response tends to better match the polar responses of the rest of the drivers.

Problems occur with cone break up modes especially with aluminum domes. Personally I have a tendency to prefer soft domes. The fact there tends to be slight HF roll off, I think is all to the good and I find that preferable to a rising response.

So in the end it all comes down to how you want your poison.

 

[jamie2112]

I have a pair of BG Radia's and they are the 1st ribbon tweeter speaker I have owned. I am very happy with the hi end as its very concise and smooth.I like it better than my B&W 602's for sure and they may sound better than my B&W Matrix 804's as well. I do notice the "sweet spot" tweeter wise is a bit narrower on the BG's though.

 

[Swerd]

Perhaps I am inferring too much from using the SongTower RT as my sole reference for ribbon tweeters, but yes, that is my experience. I just did a comparison (with S-2's), and somewhere between 65 to 70 degrees the difference becomes apparent when A-B'ing the two speakers.

I'd welcome any comments on how typical this is.

Most people seem to think only of tweeters when they talk about off-axis performance. They overlook the fact that woofers also beam at high enough frequencies. Depending on the woofer size, this is in the upper midrange. In a 2-way speaker, the crossover frequency and slope will determine how much of that is heard. A low enough crossover point can greatly contribute to good off-axis performance in the upper midrange which is much more audible than the upper ranges of tweeters. This also requires a tweeter that can perform low enough to work in such a combination.

In the examples of SongTowers ribbon vs. dome tweeter, I know the dome tweeter version is crossed over at about 2.5-2.7 kHz with a relatively steep-sloped 4th order crossover. With 5¼" woofers, this works well. I don’t know the ribbon tweeter version’s crossover point, and it is possible that it may be higher than with the dome. This could contribute to a listener hearing less off-axis performance, but it could be due to greater beaming from the woofer at frequencies higher than 2.7 kHz.

 

[KEW]

FWIW, I heard changes in the cymbals when I did this comparison.

That is not to say that there were not differences in the upper midrange, but the differences at higher frequencies is what stood out.

 

[tom67]

Silly question, but can someone tell me the correct way to pronounce Geddes? Thanks. (For that matter, anyone else run into a person or two who pronounce Denon with the accent on the second syllable: den-ON?)

randyb, I find your subjective blurbs to be very interesting, and so thanks for sharing. It is JMO, but I have the impression that midbass is the hardest thing for the typical speaker in an HT environment. While looks are only looks, I would still perhaps mistakenly look at a Salk as an "audiophile" speaker, and the Geddes as a commercial/HT looking speaker (without knowing anything more, for instance).

But going by your description, I'd opt for the Salks in an HT setting, and I might choose the Geddes for a 2ch classical music rig!

Pronounced "Ged-ease"......Jack Nicholson played Jake Geddes in " Chinatown"