LARGE FORMAT DRIVERS 288 ETC.

[JON W]

I KNOW THIS HAS BEEN ANSWERD BEFORE HOWEVER: I WONDER IF SOMEONE IN THE KNOW COULD TELL ME WHAT ADVANTAGES THE TANGERINE PHASE PLUGS HAVE. SHOULD I BUY 288's THAT HAVE THE OLDER STYLE PHASE PLUGS? SHOULD I KEEP LOOKING FOR TANGERINES?
I WANT TO USE THEM WITH 511-B's. ALREADY HAVE AN EXTRA PAIR OF 416-16 Z's AND WANT TO BUILD A PAIR OF SPEAKERS TO GO WITH MY 19's FOR SURROUND.
NEXT I WILL BE ASKING ABOUT CROSSOVERS.
THANKS IN ADVANCE: JON

[Steve Burger]

The 511b can be shortened and modified to be an E.

[John Stover]

stpower: Does the 288G have the tangerine phase plug? I thought it didn't. TIA

[stpower]

Jon,
Before you buy ANY 288 driver, be aware that you can't use it on a 511-b. You will need a 511-E that has the 1.4" throat. The tangerine has better high frequencies. Many feel the 288-g is the best overall sounding of the 288 drivers. I have not A-B ed them so I can't say.

stpower

[Todd W. White]

The Altec 288-G series was the last of the big drivers to utilize the circumferential phase plug.

The "H" was the first to use the Tangerine.

Todd W. White, Owner & Webmaster

ALTEC LANSING'S (unofficial) HOMEPAGE

[RClark]

i believe that the 288-G can be found with both types of plugs-------i had always heard and believed that the HF response of the tangerine was better-------at any rate i did some measurements a while back on about a dozen drivers------the response measurements were done with an Audio Precision and B&k mic with a plane wave tube made according to AES guidelines---------i found that there were quite a few differences in HF response and sensitivity from driver to driver indicating that matching pairs of drivers would be a good consideration if used in a stringent application------since all the drivers were in like new condition but were made over several years (all had aluminum dia's and same imp.) i am not sure just how consistent the original manufacturing was--------at any rate i did an experiment and re-did the test with the same dia in each driver--------the data did not support two things that i had always believed-------i could see no evidence that the tangerine was superior in HF response to the annular ring type-------AND heres the real kicker--------the larger type E/G type drivers did not show the claimed 2 dB sensitivity increase over the earlier C/D types--------i measured the flux density in each of the drivers ------It did measure slightly higher in the larger devices but it didn't seem to relate to higher sensitivity---------anyone else ever actually test this???????-----i always took it for granted...........RC

[RonSSS]

I have measure both early and late (Tangerine) small format drivers and can say that there is a noticible measured improvement in the HF response above 10khz with the tangerine phase plug. My setup consisted of a Tek 7L5 spectrum analyzer with a tracking generator and a SLM with an audio output that I fed back to the SA. A bit crude, but fine for A/B comparisons.
I agree that "pairs" of the same type driver measured differently. Reasonably close however.
Ron

[RClark]

i did not try the test on the small format drivers---------but it seems to me that if it really were superior someone else would have copied it by now---------has anyone?????........RC

[RClark]

todd---------with a measured gauss of over 20KG i don't think aging magnets is an issue--------and since most of my drivers were purchased in the late 70's i doubt they were made in the dark days of bankruptcy-------personally i have felt for a long time the plastic tangerine was a "cost engineered" solution for one of the most expensive parts of the compression driver-------i cannot document any improvement in performance over the previous designs (other than sales literature) and i have a really well equipped acoustic lab..........RC

[Todd W. White]

Several have TRIED.....As I am fond of saying, "Often imitated, but NEVER duplicated....."

That said - there could have been 288-G's with Tangerine phasing plugs, but I don't think so - that was the big selling point of the "H": it was said to be the ultimate big driver, as it had the improved phasing plug....

As for the differences in driver measurements - some of them can be attributed to aging Alnico V motor structures, others to the difficulties Altec had prior to filing for bankruptcy in keeping their manufacturing quality where it should have been...

Todd W. White, Owner & Webmaster

Altec Lansing's (unofficial) Homepage