Carver woofer experiments

Hi all,

I thought you might find it interesting about my Carver woofers experience.
These drivers are the only one on the market that are able to reproduce the deep bass all the way down to 30hz, but not lower. I listened to music examples test tracks containing frequencies below 30Hz but they were inaudible, below that point.
The woofers themselves do have a real 22Hz extension though, I have verified that with my measurements (done at 1m).
I have a tried 4 and 6 woofers per side, but 4 woofers were way better in sonic terms.













I tried quite a lot open baffle/dipole configurations, see here:

http://www.loudspeakers-by-miro.com/

but eventually I went on with these:

http://www.soulsonicspeakers.com/

Cheers,
miro

So, that's a B&G ribbon and Amazing Original woofers from Orevox, yet the woofers on your site look like the cone ribbons, not they ones with the honeycomb fronts.

B&G doesn`t make ribbons but planar magnetic drivers and no, there are no B&G drivers on my photos, just true ribbons I built myself. I said that I went to use different woofers.

more on differences between ribbons and planar magnetic drivers here:

http://www.snippets.org/audio/library/ribbonFAQ.htm

http://en.wikipedia.org/wiki/Tweeter

These look a LOT like James' AL-Vs:

Well, BG calls Carver ribbons line source transducers, so it's a matter of semantics, I guess.

These are some SEXY looking speakers!

They are very cool looking speakers. Bet they sound good also.

Yeah, they're sexy enough but.....do they dispense toilet paper through a tight orifice???

Those are some pretty sweet and juicy like these nutz. looking units! In most cases I'll go along with the whole "form following function" thing, but not this time. If function was first in this case I'm pretty sure those woofers would be in some type of enclosure for the purpose of having them function much better than their current form.......... Those things still look pretty bad A$$ though!!!

Rainman

Hi all,

I thought you might find it interesting about my Carver woofers experience.
These drivers are the only one on the market that are able to reproduce the deep bass all the way down to 30hz, but not lower. I listened to music examples test tracks containing frequencies below 30Hz but they were inaudible, below that point.
The woofers themselves do have a real 22Hz extension though, I have verified that with my measurements (done at 1m).
I have a tried 4 and 6 woofers per side, but 4 woofers were way better in sonic terms.


....
Cheers,
miro

Miro,

I'm curious about your statement of below 30 hz being "inaudible"...is it possible you don't hear below 30 hz or your electronic equipment cut off below that frequency for some reason?

Also, on your site you have this FAQ listed:

Q: What is a Planar Magnetic Transducer ?

A long strip of thin material is impregnated/coated with several conductors which act like the voice coil on a regular speaker. This assembly, typically a kapton or polyester film with aluminum strips, is suspended between continuous rows of bar magnets. When energy passes through the ribbon/voicecoil sandwich, it is repelled and attracted by the surrounding magnets. A planar magnetic driver is capable of seamlessly reproducing almost all of the sound spectrum, from highest highs to mid bass, almost 8 octaves. This eliminates crossover distortion, phase distortion and avoids the different "voicing" of the various cone speakers necessary to cover the same frequency range. The voicecoil has typically no reactive component which makes it an easy, almost pure resistive load for any amplifier. This contrary to cone speakers and ESL's. Impedances are in the 2.5-12 ohm range

Q: What is a "Real" Ribbon Transducer ?

A "real" ribbon driver has a "voicecoil" made of a aluminum strip or strip assembly suspended between continuous rows of magnets. The principle is the same as a planar magnetic transducer other than the ribbon being stretched between the extreme points. A planar magnetic has its voicecoil assembly stretched along the short axis, typically horizontally. This makes the planar transducer mechanically sturdier than a real ribbon. Real "ribbon" drivers boast an extended performance in the high end of the audio spectrum. Planar magnetics show a drop off in the high end caused by the film material weight, mechanical properties and also subject to the horizontal tensioning forces. Because of the "fluttering" suspension, real ribbons need practically a higher low end crossover point as compared to planar magnetic drivers. Impedance of a ribbon transducer is mainly resistive, similar to a planar magnetic driver. True ribbon transducers however have an extremely low impedance, typically between 0.1 and 0.4 ohm, requiring a transformer to be useful with a practical amplifier.

After reading this, I STILL don't understand the difference between "real" ribbon transducers and planar magnetic transducers....do you have any illustrations to explain?

thx~

Since Rabbit brought up your statement which was: "These drivers are the only one on the market that are able to reproduce the deep bass all the way down to 30hz, but not lower." My question is did I read this right? I'm just curious. Thanks,

Rainman

I belch lower than 30hz.....and my lovely wife hears EVERY ONE !

I can fart at 30 hz, but it hertz....

I once farted the theme from Bonanza in 8th grade history class...... Mr. Robinson had to hide his LOL behind a textbook and the class roared in approval! I can't "trust" farts like that anymore!

I`m sorry TNRabbit, I haven`t checked this forum for a while.

What I meant to say was that dipole bass is inaudible below 30Hz, not a boxed one. In fact, I believe all those great dipole loudspeakers,
including Carver Amazing, could benefit below 40-30hz with some boxed subwoofer assistance. My electronic equipment, amps and source, are perfectly flat down to a few Hz, 100%.

The planar magnetic and ribbon descriptions are not from my site, I`ve just included it to help clarify the difference between these two driver types.

Planar magnetic is a transducer that has a mylar (or alike) foil stretched like the Carver Amazing unit, the voice coil is glued or deposited onto this foil and the magnets are either in a "single ended" arrangement (one side only, at the back) or in the "push pull" arrangement, which means the magnets are on both sides of the foil.

Ribbon has a aluminum foil which is clamped only at the top and the bottom, while the magnets are located at the sides of the ribbon membrane.

Since you are most likely familiar with the carver Amazing planar magnetic unit (magnetostat), I`ve included a few links about true ribbons:

http://www.soundfountain.com/amb/ribbon.html

http://www.magnetostatic.com/

http://ldsg.snippets.org/ALSR/RibbonCon ... ns_01.html

Rainman, these loudspeakers have no box on purpose, they`re dipole loudspeakers just like Carver Amazings were or the Gilmores, remember? I have verified the low frequency reproduction with test tones and listening.

http://www.glacieraudio.com/new%20Glaci ... audio1.htm

Nice farting discussion guys!