New Heathkit AS101 owner - First post.

[Earl K]

That makes perfect sense, Earl, but it might not be a good option in my case. The amp(s) I plan on driving my HFs is a pair of 1W 300B OTL monoblocks. At 1W I need as much of the efficiency that a HF CD can afford. If I'm toning down the mids almost 14dB then I think I'm shooting myself in the foot.

FWIW, once I build the 300Bs I will have 3 amps available for tri-amping. That would allow me to boost the above 14KHz range through a tweeter without muting the 800-14Khz mids through the 811.

But that might defeat the gloriousness of the 300Bs by chopping them off at 14Khz and not allowing them to reach higher. And I'm not building 4 300Bs!!

I think the 802-8Gs might be the answer. It will allow the 300Bs to play all the way up, I won't be disturbing the imaging by adding another component and I'll be able to maintain the high efficiency Altec horns are known for.

A couple of things to make note of ( before you pull the trigger on any new drivers or tweeters ) .

(i) You're repeating verbatim ( as if it's somehow gospel , info that can't be substantiated ) that your current drivers are somewhat flat out to 14K .
- I can assure you they are not flat out to 14K / ( almost 15db down at 14K compared to 1K, is not my definition of the word "flat" ) .
- I guess the message contained within this Zilch graph ( that I posted earlier ) simply didn't register with anyone here .
- The existing curve ( on your 811/806 combo ) won't be that much different from the following red trace .
- If you want to use tweeters, you'll want to cross-over in the 6-8K region ( if you go with a raw 811/806 response ) .
- Here's that graph again ;



(ii) If you do get some 802-8G drivers, you'll need to tone down the mids 10 or 11 db to be somewhat flat out to 14K ( according to some testing that I just did with a 802-8T loaded with a 34647 diaphragm / I'll post pics sometime later today ) . The 806 requires even more midrange attenuation .

(iii) I'd suggest you get some measurement gear before buying anything like other drivers or tweeters.

- FWIW, REW is still free & it works well on a Mac ( under some strict conditions that dictate what sort of external soundcard you can use ).

- Also, a USB based test-mic is in the works ( from the MiniDSP people ) which will come with a unique calibration file ( for each & every device sold ) making the mic useful for measurement purposes. It'll be @ $100.00 ( from what I've read ) making the entry cost for getting serious data, cheap as Borscht !