New Heathkit AS101 owner - First post.

[Alien_Shore]

I did some horn compares that you might find interesting:

Here is a modern HF driver (B&C DE250) on three different Altec horns:


And here is the same driver compared to an Altec 802D on an Altec 511B horn:


All of these are "barefoot" driver measurements (no XO, EQ, etc.)

I also have some 902 and 802-8G graphs here somewhere....

[Earl K]

Alan,


Here's the pic I promised .

My apologies for it's "clutter" ( hopefully the message doesn't get lost in the info ).



The red and teal colored traces shows an 802 ( on a Radial horn ) with a 2-pole HiPass ( similar to the AS-101 values ) coupled with the HF portion of the 30923 "Equalizer Network" . I'd say this network offers 10 to 12db midrange suppression .

[alancohen]

I think I got REW working a little. Here is what I got:

[Earl K]

Put that file into a 60-70 db vertical scale, apply 1/6 ( or 1/12 smoothing ) & then repost the graph.

[alancohen]

Huh???????

[alancohen]

OK...found it I think:

[Earl K]

- A couple things to check out ( to investigate the "suckout" between 800 hz & 1600hz ) .

(i) Replace the horn driver with a single 8 ohm resistor & run another trace ( to see ho high up that woofer is working ) .
(ii) Do the same with woofer ( replace it with a single 8 ohm resistor ) and capture a sweep of the horn circuit on it's own ( to see how low it's going ) .
(iii) Switch the polarity of the horn circuit and then capture a sweep of the horn & woofer together ( to see if the stock polarity is actually "adding" within the crossover region ) .

[alancohen]

I moved the speakers around and centered the mic. This seems about what I have:



It's hard to get a quiet room here. I live on a highway and the roads are wet and cars are going by. That's why I'm moving!!