New Heathkit AS101 owner - First post.

[alancohen]

So...I'm willing to make a bet that no one has actually installed 802Gs in a Heathkit AS101 cabinet before.

See, they do not fit. They are too deep by exactly this much:



The 806s press right up against the insulation on the back. The back will not attach with the 802s.

Better curves though:

[Earl K]

Bummer , about that .

Some older Altecs had a plastic top-hat extension to allow for deeper horn/driver setups .

OTOH, GPA may have a solution for you ( if they still sell those plastic loading caps for diaphragms, as found on some 802/902s ) .
- Then the metal back-cap isn't used .

[voice of the theater]

So...I'm willing to make a bet that no one has actually installed 802Gs in a Heathkit AS101 cabinet before.

See, they do not fit. They are too deep by exactly this much:



The 806s press right up against the insulation on the back. The back will not attach with the 802s.

Better curves though:

Come to think of it--even the 806's didn't fit in Valencia 846a cabinets. The back panel of Valencias (at least the 846A's that I owned and others I've seen) had a hole "cut out" in the back panel (where the h.f. driver was) that was covered on the outside of the back panel by a very thin piece of wood to allow enough depth for the h.f. driver to extend. The 806-8A drivers do fit in AS-101 cabinets without the hole cut out in the back panel because AS -101 cabinets are a little deeper so maybe this kind of setup would work to get 802-8G's into your AS 101 cabs depending on how much more distance you need. If you add the thickness of the (compressed) insulation and the thickness of the back panel itself, does that total equal the difference in depth between the 806-8A and the 802-8G? If so, rather than cutting a hole in your two back panels, you could (fairly easily) make two brand new back panels with the holes in them for the h.f. driver to extend--and you cover the hole from the outside of the back panel. If you need even more room for the 802-8G, you could use thicker wood for your back panel. Either way, I recommend saving the original back panels so you can return your speakers to original condition someday. Here's a photo of how 846a Valencias allowed for the depth of the h.f. driver....

[alancohen]

VOTT: So I'm not crazy...excellent!

They only miss by about 3/8" with the insulation removed. I think I can get away with a 3/8" strip of wood around the perimeter. The back panel would protrude by that much, but no biggie, it's the back of the speaker anyway. A project for another day. I suppose I could route out a 3/8" deep depression in the existing back panel. That would be about 1/2 the total thickness.

Earl: Thanks for the tip. I'll ring up Bill and see what he has to input.

As far as the sound, they are a little harsh right now. They sound more metallic. The 806s were creamier, if less bright. Is there a break-in period for HF compression drivers like there is for LF drivers?

[voice of the theater]

VOTT: So I'm not crazy...excellent!

They only miss by about 3/8" with the insulation removed. I think I can get away with a 3/8" strip of wood around the perimeter. The back panel would protrude by that much, but no biggie, it's the back of the speaker anyway. A project for another day. I suppose I could route out a 3/8" deep depression in the existing back panel. That would be about 1/2 the total thickness.

Earl: Thanks for the tip. I'll ring up Bill and see what he has to input.

As far as the sound, they are a little harsh right now. They sound more metallic. The 806s were creamier, if less bright. Is there a break-in period for HF compression drivers like there is for LF drivers?

A 3/8" strip of wood around the perimeter would work as long as you can still achieve a (relatively) air tight seal. Otherwise, it will affect your cabinet tuning and it may actually be quicker and easier to make two new back panels with (covered) holes if you find there's a lot of monkeying around required to get a good seal with a wood strip around the perimeter. You may have to adjust your port size anyways as increasing the depth of your cabs by (at least) 3/8" by using wood strips around the perimeter will have a significant effect on their tuning. On the other hand, using new back panels with (covered) holes in them for the h.f. driver won't really affect your cabinet tuning because the hole will be filled with the end of the driver and the internal cabinet depth remains unchanged.....

As far as using loading caps on your 802-8G drivers, there is significant controversy about this option. Yes, they can be used instead of the rear cover for many Altec h.f. drivers and that saves you some space, but many Altec users (here and elsewhere) believe that the loading caps change the sound of the driver and that they are not good for hi fi use. They were mainly used by Altec IIRC for P.A. applications (and later on for cost cutting applications!) to protect the h.f. driver/diaphragm from over extension when exposed to high power levels during P.A. use. Of course, it doesn't hurt to buy and try them--they're not expensive and if you find it doesn't affect the sound to your ears, then it's a good solution.

[VolvoHeretic]

Build extensions for the back cover to screw to, An inch or maybe a lot- nobody will ever know.

So, after loaded with all of this response information, what are we supposed to do with it? Whip out the trusty 15 band EQ and trial and error the what looks like a 20db discrepancy by adjusting the EQ, doing another sweep, adjusting the EQ...? And then finding out we don't like flat response anyway?

Just curious, I didn't pay much attention to the products used in this exercise. How much would it cost to gather all of this stuff. I will probably just keep tuning by ear since every time I am financially ready to send my 416's to GPA in for a recone, some great deal on a set of speakers comes along and blows my budget out of the water.

Also, base and treble responce seams to be very volume db dependent. I bet the responce is very different @110db.

[voice of the theater]

OT post--true story. Volvo Heretic--I used to date a girl who drove a Volvo and she actually said to me that it was embarrassing to drive a car with a name that sounded like a part of a woman's body.....

[VolvoHeretic]

LOL Voice of the Theater! married to her now?

[alancohen]

Build extensions for the back cover to screw to, An inch or maybe a lot- nobody will ever know.

So, after loaded with all of this response information, what are we supposed to do with it? Whip out the trusty 15 band EQ and trial and error the what looks like a 20db discrepancy by adjusting the EQ, doing another sweep, adjusting the EQ...? And then finding out we don't like flat response anyway?

Just curious, I didn't pay much attention to the products used in this exercise. How much would it cost to gather all of this stuff. I will probably just keep tuning by ear since every time I am financially ready to send my 416's to GPA in for a recone, some great deal on a set of speakers comes along and blows my budget out of the water.

Also, base and treble responce seams to be very volume db dependent. I bet the responce is very different @110db.

I had most everything I needed already: laptop, tripods, cables etc. I needed a good mic which thanks to Earl's recommendation was under $100 shipped. The software was free.

As far as bass and treble being volume dependent, I think that depends on your signal chain. My system includes a signal source (TT, computer CD player and cable box) and a very fast and transparent tube based preamp, phono preamp and 15W OTL amp. The preamp has a 3 input selector and a volume knob. The amp has an on/off switch. That's it. No tone controls, let alone an EQ. What comes from the source is what I get. It's uncanny how volume INdependent the frequency response is. I do not have to turn up the volume to hear excellent bass response. Even at very low volumes, heavy bass passages coming by just fill the room. Of course they don't pound my chest like at louder volumes, but I don't feel like anything is missing at low volume. Sparkling high-hats are right there regardless.

Now, a hole at 500Hz and a spike at 1K is another story. I'm not going to be concerned about it until I get everything bi-amped and see what a pre-amplifier active crossover offers. I'm still pondering Earl's suggestion to rebuild the crossovers and eliminate the L-pads. I think every crossover between the amp output and driver is going to have a signature it leaves on the signal. That's why full-range speakers are getting lots of play.

But like you say, all that matters is what it sounds like. I'm just having a little fun trying to figure out why I like some things and not others. My full-range speakers have a gloriously flat response, but sound restricted compared to these. Frequency response curves are two-dimensional. Music and it's successful reproduction are at least three.

[GM]

It's uncanny how volume INdependent the frequency response is. I do not have to turn up the volume to hear excellent bass response. Even at very low volumes, heavy bass passages coming by just fill the room.

Now, a hole at 500Hz and a spike at 1K is another story.

Yeah, with high Vas woofers and compression horns you don't normally need any smiley face 'loudness' control, especially if driven with a high output impedance.

This implies either a poorly done XO or a crapped out one, but my memory says the Heathkits sounded a bit more tonally balanced than the Valencias or maybe we just convinced ourselves they were since we could buy them cheaper due to having a Heathkit store willing to 'deal'.

GM