AR 18 confusion

[Guest Brian_D]

As you may know, I'm looking for a pair of AR18's for my surround speakers in a home theater with 9's as the mains.

I've downloaded the timeline and now I'm a little confused as to what the 18 acutally is. There's the 18, 1977-1982 (which most closely matches the time frame of the 9's, 1978-1982) and then there's the 18s, 1981-1983 and the 18B, 1983-1985 and the 18BX, 1985-1986 and finally the 18BXI, 1986-87. They are all 18" driver and tweeter, but what is the difference, really?

I just want an 18 (of some kind) that matches the timbre of my 9's, and if just any pair will do, fine. But if I need to look specifically for the 18 (NOT s, B, BX or BXI) then I'll do that.

Anyway, if you could lend some help I would appreciate it.

-Brian

[Guest Barrydor]

>As you may know, I'm looking for a pair of AR18's for my

>surround speakers in a home theater with 9's as the mains.

I think this would be a great match

>I've downloaded the timeline and now I'm a little confused as

>to what the 18 actally is. There's the 18, 1977-1982 (which

>most closely matches the time frame of the 9's, 1978-1982)

>I just want an 18 (of some kind) that matches the timbre of my

>9's, and if just any pair will do, fine. But if I need to look

>specifically for the 18 (NOT s, B, BX or BXI) then I'll do

>that.

If it were me (and in fact, I am looking for a set of AR18s), I would look for the original AR18 of 1977-1982. I have owned several sets of these as well as my AR9s. The voicing and timbre of these speakers matches that of the AR9 beautifully.

The original AR18 had the dome tweeters offset to the left on the front panel. Later in the series, the tweeter was moved to the center and surrounded with a plastic baffle. I also understand it was changed to a cone tweeter at some point.

Once again, if it were me, I would try to find the originals to play it safe. I have heard there is little sonic difference between the original version and the later AR18S, but I do not know this to be a fact.

Unfortunately, the original AR18 seems to be a little harder to find than the later AR18S, etc.

Barry

[Steve F]

>>As you may know, I'm looking for a pair of AR18's for my

>>surround speakers in a home theater with 9's as the mains.

>

>I think this would be a great match

>

>>I just want an 18 (of some kind) that matches the timbre of

>my

>>9's, and if just any pair will do, fine. But if I need to

>look

>>specifically for the 18 (NOT s, B, BX or BXI) then I'll do

>>that.

>

>If it were me (and in fact, I am looking for a set of AR18s),

>I would look for the original AR18 of 1977-1982. I have owned

>several sets of these as well as my AR9s. The voicing and

>timbre of these speakers matches that of the AR9 beautifully.

>

>The original AR18 had the dome tweeters offset to the left on

>the front panel. Later in the series, the tweeter was moved to

>the center and surrounded with a plastic baffle. I also

>understand it was changed to a cone tweeter at some point.

>

>Once again, if it were me, I would try to find the originals

>to play it safe. I have heard there is little sonic difference

>between the original version and the later AR18S, but I do not

>know this to be a fact.

>

>Barry

Hi Guys,

Here's the info that I think you're looking for:

The original 18 was essentially an AR-7 with the liquid-cooled version of AR's superb 1 1/4" cone tweeter. It had a crossover frequency of 2000Hz, the same as the 7, but with the new tweeter's greater power handling capability, the 18's power response was somewhat flatter than the 7. The 18 was a truly exceptional small speaker and a great match for the 9.

The 18s was pretty much the same, save for some slight cosmetic differences, and is also highly recommended.

The 18B had a bull-nosed vinyl cabinet , the same 1 1/4" cone tweeter, 2000Hz crossover, but the tweeter was now centered on the baffle above the woofer, instead of being offset as in the earlier 18's. The woofer also changed, and used a shiny black plastic dustcap.

The big change took place with the switch from the B to the BX series. The cabinet got bigger (from 6 5/8" deep to 8 1/4" deep), and the tweeter changed from that great original AR-built 1 1/4" cone to some randomly purchased 1" dome. The crossover went from 2000Hz to 3000Hz, with the expected roughening in power response that physics predicts with an 8" 2-way system.

The BXi was similar to the BX, but the crossover rose to 3200Hz. The BX and BXi had stated LF -3dB points of 52Hz vs. the older 18's 62Hz, indicating a change in the design intent for these speakers to a more full-range design.

The 18 or 18s is the model you want. The 18B is ok, but stay far away from the BX and BXi.

Steve F.