Aurum CantusG2 ribbon tweeter w/Fostex full range driver

Brad · « **on:** 24 Oct 2003, 12:39 am »

Wonder if this might be a good match, crossed over at 8-10khz or so.
Or is it a waste of the tweeter?

The efficiency and the impedance are pretty good matches 96 & 8 ohm.
Thinking out loud.........

DrDave · « **Reply #1 on:** 24 Oct 2003, 01:11 am »

Which Fostex.

I'm wondering the same thing. Just got FX200 drivers and have been wondering if I should add a ribbon tweeter to it. Also would cross high.

In addition to the G2 there are other moderately priced ribbons.

G2Si from Aurum,
Fountek JP-3.0
ATD LeRibbon

Anyone have opinions on any of these?

KevinW · « **Reply #2 on:** 24 Oct 2003, 01:43 am »

I'm using the G2Si crossed over at 7.5k with a Jordan JX92S. The improvement was astounding. I don't think you'll find any problems at all. A 4" driver does wonders for midrange clarity in the 70Hz to 8kHz region, but it usually gets ragged above 10kHz. Crossing over with super tweet ribbon gives the best of both worlds. Neither the ribbon or the woofer stressed at all in those freq's.

beat · « **Reply #3 on:** 24 Oct 2003, 03:20 am »

Sorry I cant add any input other than...DANG that tweeter looks sweet!

_scotty_ · « **Reply #4 on:** 24 Oct 2003, 05:05 am »

I found another pretty tweeter. Fountek JP-3.0 at Madisound
http://www.madisound.com/ Go to the catalog and scroll down. A true ribbon for $81.00.

beat · « **Reply #5 on:** 24 Oct 2003, 06:07 pm »

wow, that fountek jp3 looks like a real winner for the money! Makes me want to send back my hivi rt2-2..well almost. Does anyone know what goes on inside that would cause them to be so much deeper than others? mine is barely 3/4 inch deep and those are like 2 1/2?

Brad · « **Reply #6 on:** 24 Oct 2003, 06:14 pm »

That Fountek is pretty cool.
Nice impedance curve!

KevinW · « **Reply #7 on:** 24 Oct 2003, 06:48 pm »

I hate to dissent, but I think the Fountek looks pretty cheap. It uses a molded plastic front plate, whereas the Aurum Cantus uses aluminum, and the housing on the back looks cobbled together from the pictures. Maybe this doesn't affect sound quality at all, but it does make me wonder.

_scotty_ · « **Reply #8 on:** 24 Oct 2003, 07:30 pm »

beat I am guessing here, but I think it may have something to do with focusing the necessary magnetic flux density in the gap where the ribbon is. Every true ribbon monopole driver I have seen has had a similar structure. I am not to concerned about the plastic face plate or housing.
If it is strong enough to contain the neodymium magnets and not fly apart it might be okay. Don't know until we try it. Dr Dave thanks for mentioning that driver in your post. I had no idea that there was an affordable entry into this type of technology.

beat · « **Reply #9 on:** 24 Oct 2003, 07:31 pm »

Hmm,
didnt realize that about the plastic. Does make ya wonder, though the proof would be in the punch. Even the 30.00 Partsexpress pt2 has an alumnium face and good power handling.

ErikM · « **Reply #10 on:** 25 Oct 2003, 02:30 am »

I've been working with the G2 ribbon over a PHY wideband driver. Running the PHY unfiltered, I highpassed the G2 at 9Khz with a steep slope. The ribbon is certainly underutilized crossing so high, but initially I liked what I heard.

Time, however, is not always kind.

The PHY beams like a laser and gets kind of ragged as it approaches 9 kHz, which made the transition to the ribbon less than ideal. There was also a lot of treble content I just wasn't getting. This would probably not be as big a problem with the fostex.

Recently, I have been playing with a first order series crossover at 4500 Hz, which shows much promise. Crossing here allows the PHY to handle most fundamental tones and the ribbon to handle most harmonics. Imaging and depth actually improved over running the wideband driver unfiltered.

I'm still tweaking and time willl once again tell, but consider using the wide bandwidth of the the drivers for a shallow order crossover.

_scotty_ · « **Reply #11 on:** 25 Oct 2003, 03:18 am »

Erik M, you might try this xover topology at http://www.geocities.com/kreskovs/Series-1.html

Leave out R1 and calculate the cap and coil values using 12db/oct Butterworth values. This is the starting point for a quasi-second order series network. If the woofer has a rising output with frequency a hole can
be engineered into the overlap region between the two drivers by rolling the woofer off earlier and you will still have a flat response curve in the transition region. The initial slope of this type of network is 12db/oct for the first octave and 6db/oct for remaining octaves. You might be able to go as low as 4000Hz with the tweeter with this network. It is also phase coherent.

Bemopti123 · « **Reply #12 on:** 15 Oct 2004, 02:44 am »

What sort of cabinets are you using for your PHYs? Which model do you have? The 8" or the 12" with the coaxial tweeter?