Flatline Design

[Charivari]

So, shipping is out of the question? :sigh:
I might consider getting a bank loan...
Jorge

Well, it'd be a lot cheaper for you to find a pair for sale in the UK and have those brought over. You might even be able to find a pair of Westminsters that way for only a few times more than a plane ticket this way would cost.

Dnewma04, thanks much for that link. While the BG drivers aren't ribbons, the principle behind the crossover remains the same. So, that funky addition in my crossovers must be a notch filter.

kfa888, yep, they're probably the best speakers to ever be purchased out of the back of a white van. :thmbsp:

- JP

 

[Damage]

So because the Carver metal part of the ribbon forms a sort of rectangler... what's the word... crop circle (hence a voice coil)... and is mounted on a Mylar backing it isn't a "true ribbon?"

But in fact, a "true ribbon" is a single strip of aluminum (or whatever) foil without backing and suspended in front of a rare earth magnet?

 

[kfa888]

But in fact, a "true ribbon" is a single strip of aluminum (or whatever) foil without backing and suspended in front of a rare earth magnet?

..and suspended from only two opposing ends I believe.

 

[Charivari]

So because the Carver metal part of the ribbon forms a sort of rectangler... what's the word... crop circle (hence a voice coil)... and is mounted on a Mylar backing it isn't a "true ribbon?"

But in fact, a "true ribbon" is a single strip of aluminum (or whatever) foil without backing and suspended in front of a rare earth magnet?

First question, yep, but you could call it a "quasi-ribbon" or at least a borderline quasi-ribbon if you'd like since that term is pretty vague in definition. Second question, the metal foil is actually suspended between two columns of magnets.

Top view looking down on a ribbon driver:

Typically, the back is open for the complete dipole effect with just some braces across to resist the very strong attraction between the magnets. The ribbons for the Flatlines were fairly strongly attracted to the various body panels of my truck when I tried to unload them.

- JP

 

[Charivari]

Here's an even better picture of a true ribbon cut-away from Magnepan, the originators of the first commercially viable true ribbon driver:

- JP

 

[Charivari]

Ok, I'm going to have to ask for some reasonably priced amplifier options. The ribbon driver on these Flatline Designs measures a DCR of marginally over 1Ω, perhaps 1.3Ω at best and my amps know it. All of the amps I've tried on these speakers have choked as soon as there's a significant amount of midrange information at moderate levels. For the one that holds out the best, when a crescendo hits, the meter lights dim and the sound just drops out, which isn't an issue even with very impactful bass transients for the rest it's nearly constant at volume -- which is fairly low compared to others out there. While it may be possible to get away with low impedance with tweeters, it isn't with a nearly full-range true ribbon like those in these speakers. So, any suggestions would be greatly appreciated.

As to the sound, I was able to fix much of the lower midrange depression by repositioning the speakers closer to the back wall. The back of the cabinets are now just 2' from the wall, but that puts the ribbon 3' away, which appears optimal. The midbass driver still has some integration issues that I'd like to work on. When I powered it separately and set it to the same output at my listening position as the ribbon, it noticeably mismatched. Yet, it sounds like a better match when slightly lower in level than the ribbon. I can't help but wonder if this may have been intentional in the design to better blend a cone to a ribbon. :scratch2: Of course, the new position has resulted in a sonic imbalance thanks to my rack being to the side of my TV. Such is the fun of dipoles, trying to get this all sorted out, but they are worth it.

- JP