Altec compression drivers questions

[George Roland]

Hi,

I write with some questions about Altec compression drivers. I bought a pair of 290-16K drivers because they were rated down to 300Hz rather than the 288 variety that are rated at 500Hz.

Near as I can tell, the 288 drivers are far more popular and costly. The 288-16G has the alnico magnet and a 3-slot phasing plug. The 288-16K has a ferrite magnet and tangerine phasing plug.

I would be interested to hear discussion from those who know these drivers well, particularly used as a K-horn squawker.

Are alnico magnets better than ferrite magnets? If so why?

Is the radial phase plug preferable to the tangerine? If so, why?

Are the 288 drivers better than the 290 for music reproduction, even on a K-horn where the bass extends only to 400Hz? If so, why?

Thanks,

George

[Duke Spinner]

don't give the alnico/ ferrite thing a moment's consideration

phase plug questions are for guy's that own Testing Equipment, we can't hear the difference

I have 290's, great driver, but the top falls fast at 8khz

[djk]

"The 288-16G has the alnico magnet and a 3-slot phasing plug. The 288-16K has a ferrite magnet and tangerine phasing plug.

I would be interested to hear discussion from those who know these drivers well, particularly used as a K-horn squawker.

Are alnico magnets better than ferrite magnets? If so why?

Is the radial phase plug preferable to the tangerine? If so, why?

Are the 288 drivers better than the 290 for music reproduction, even on a K-horn where the bass extends only to 400Hz? If so, why?"

Lansing originally made anular slot phase plugs, got sued by WE, and then developed the radial slot type. After they broke the WE patent, they went back to the anular slot type (they sounded better). Fast forward 40 years and they re-introduced the radial slot type (Tangerine), made out of orange plastic, and much cheaper to make.

JBL has a new design phase plug that uses machined metal next to the diaphragm, and plastic in the throat area. Best of both worlds?

For a mid driver there is little difference.

The 902 sounds OK with the plastic. The 288 sounds better with the metal, that's why the 288G brings much more money than the 288H (alnico with plastic plug).

Ferrite magnets were 2.5X as heavy for the same energy, but cheap as mud. For best performance they do require a shorting ring, alnico does not (it's electrically conducting).

The 288 will go to 300hz on the right horn, but power handling will be very limited with 6dB crossovers. The 290 will handle 100W with 6dB at 300hz on the right horn. Buying used you could try both, and only be out the freight cost when you re-sell the pair you don't like.

My general rule-of-thumb: two-way above 800hz = 288, three-way = 290.

[jwc]

That very well may have been the most informative post I have read all week.

Thanks Dennis

jc

[ZAKO]

The new Anular JBL phase plug is shaped like a lazy S, And is a anular phased array...Ive listened to the old Altec tangerine plus anular types one was to try to extend HF better. The Latest JBL phased array to me sounds cleaner.( I tried aluminum and Titanium phrams) Clarity was still evident.

[pocket.change]

Where would the JBL 2480/82/85 fall in this?  

Maron,  

Which horn would be the preferred horn with one of the above?

Also added the EQ you suggested ...  does help & thinking of aquiring a pair of 

Andrews' horns as funding allows.

p.c

 

[Joe Auwen]

"The 288 sounds better with the metal, that's why the 288G brings much more money than the 288H (alnico with plastic plug).

Is there a big difference in the sound of the 288G verses the H version and what is the difference in sound?