Smaller Advent Fried Egg Green Tweeter

[HiFiGuy9]

I recall reading somewhere that the green fried egg and orange egg are interchangeable. The smaller advent is a 4 ohm speaker, and the green eggs read 3.3 ohms. If they are interchangeable, my replacement cost should be less, as there are more orange ones available.

I picked up a pair of smaller advents that are in pristene condition, except for the one tweeter. It works, but distorted. Anybody have any experience with these?

 

[michiganpat]

I really liked my smaller advents, but for me the top end was a bit lacking...I sold them recently to pay for some Acoustic Research Holographic Imaging M5's that I just couldn't pass up....

anyhoo, one thing I was contemplating was replacing the fried egg with a nice dome tweet that has a low Fs, something like a hivi Q1R, SEAS Prestige 27TDFC, Vifa D27TG35, or dayton reference 1 1/8" tweet, crossing over 2nd or 3rd order in the 1800hz range, or finding some AR17/18 tweets to replace the fried eggs (one of my favorite tweets)

...or I can hear Zilch whispering from above....ewave them....

 

[SPL db]

I have two pairs of the Smaller Advents, one with the green tweets, the other, orange.

What I've noticed is that the pair with the orange tweets seem to have a bit higher output than those with the green.

Higher meaning a bit louder, not extended range.

Neither crossovers had been recapped, so your mileage may vary...

Just stating what I've noticed with the two pairs that I have.

Scott

 

[Doug G.]

The color of the cones doesn't have as much to do with a difference in output from the tweeters as does the size of the magnets.

The Smaller Advents originally had tweeters with 2.5" square magnets while the full size Advent Loudspeaker had 3" square magnets.

The Smaller Advent tweeters had the smaller magnets to match the efficiency of the tweeters to the woofers which were different from the full size model.

At the time, it was felt that the high frequency output would overwhelm the lower frequencies if the larger magnet tweeters were used.

However, later on, Advent apparently used tweeters with 3" square magnets in later Smaller Advents.

Scott, your orange tweeters probably have the larger magnets which would explain the higher output.

I believe the opening in the speaker board would have to be enlarged if you want to use larger magnet tweeters to replace smaller magnet ones.

Doug

 

[audiojones]

There was also a capacitor value change and (I think) and inductor change in the crossover network between the green and the orange tweeter change. IIRC it was around the time that they started using foam cubes in the Smaller Advent instead of fiberglass. If memory serves they went from using an 8 and 4 mfd to using an 8 and 12 mfd, also the inductor coils look different but the mH value isn't written on them so I'm not sure what the difference is (if any).

I have a pair of both green and orange loaded Smaller Advents and I find the green tweeter version to be slightly more laid back than the orange version, but not by very much.

 

[michiganpat]

IIRC my SA's had the green tweets, fiberglass, and 8 & 12uf caps in the xover...the date stamped on the woofers was 1973

 

[audiojones]

IIRC my SA's had the green tweets, fiberglass, and 8 & 12uf caps in the xover...the date stamped on the woofers was 1973

I guess they were using the 8 and 12 mfd crossover first (for the green tweeter version) and then switched to the 8 and 4 mfd crossover for the later orange tweeter version. I've re-capped a bunch of both versions and I can't remember which way it changed, sounds like you've got it right though.

 

[Doug G.]

That would make sense if they started using the larger magnet tweeters as the 4uF cap would decrease the lower range output of the tweeter thus at least partially compensating for the higher efficiency.

Doug

 

[Andyman]

I just opened up a set of OLA's here and they have the foam block stuffing, green tweeters, and a 3 place switch in the crossover with a 8 uf and 16 uf cap. Dates on the tweeters are Sept 25, 1975 and SN on the cabs are A195138 and A193877

 

[ra.ra]

Here are the findings from my two pairs of Smaller Advents, and a pic for comparison of magnet sizes as Doug G has already mentioned.

1972, green tweeter, small magnet, 8uF and 16uF caps, fiberglass fill, soldered connections.
1975, orange tweeter, large magnet, 4uF and 8uF caps, foam block fill, push-on wire connections.