AR18 crossover

[Guest Stevey88]

Does anyone has the crossover schematic for the AR18 and the AR18b ?

I believe they are simple enough to be described in words.

Thanks in advance.

[Guest Stevey88]

Sorry, it is the AR18BXI not the B that I am interested.

[johnieo]

Hello:

The AR-18 crossover consists of a 6 uF cap and a switched 3-Ohm 10-W resistor both in series with the tweeter (0, -3 dB).

The AR-18B and -18s used a 5-uF cap with no switch. both crossed over at 2 kHz.

The AR-18bx and -18bxi used different woofers and cheaper tweeters with crossover frequencies of 3,000 and 3,200 Hz. The -18bx circuit should be in the archives. it has an inductor in series with the woofer and an R-C in series and an L in parallel with the tweeter. I have no information on the -18bxi crossover.

A post from long ago - perhaps by Steve F. - commented that the -18bx and -18bxi speaker quality was compromised by use of successively cheaper drivers.

The -18 and -18s are excellent speakers; the -18b is almost as good. These last three are definitely worth restoring.

Cheers,

[RoyC]

>The AR-18 crossover consists of a 6 uF cap and a switched

>3-Ohm 10-W resistor both in series with the tweeter (0, -3

>dB).

It appears that the AR-18 was essentially the same speaker as the last version of the AR-6, which was described by Klaus in the AR-6 crossover thread as having the same crossover and drivers.

Roy

[KlausDK]

Just for the records, I found the same Cross-over in an AR-17 speaker (6 myF capacitor with a 3 ohm resistor and a switch). AR-17 also had an 8" universal woofer and a 1½" cone tweeter, however, if you look in the pricelists from 79, 81 and 86, the AR 6 (and 7) tweeter versus the AR 17 and 18 tweeter is not listed under the same partnumber.

BRGds Klaus

[Rich W]

My understanding is that the AR-6/AR-7 and the AR-17/AR-18 tweeters exhibit very similar, if not identical, performance characteristics. However, the latter tweeter has greater power handling capability, due to the use of ferro-fluid, and a 3 oz magnet vs. the older tweeter's 2.5 oz.

For all practical purposes, the sound of my AR-7's and AR-18's are virtually identical. In fact, they do utilize the same crossover network, passive for the woofer with a 6uF cap for the tweeter. The same cannot be said of the later incarnations of the AR-18. The AR-18S utilizes an updated version of the AR-17/18 tweeter which is slightly more efficient and crosses over at a higher frequency (this in spite of the specs stated 2000 hz crossover- same as the AR-7/18, it uses a 5uF cap rather than a 6uF). In my estimation, the AR-18S sounds somewhat brighter and not as smooth as the earlier versions (I was a bit disappointed after refoaming a pair).

Rich W