New Heathkit AS101 owner - First post.

[voice of the theater]

Hi Alan,

Not mentioned yet is the flipping your drivers 180? to help relieve the downward stress of having sat that way for how ever many years.

Excellent suggestion--I've done that with all of my vintage Altecs--glad you thought to mention it!

Also, I noticed you have wired your L-Pad as a series resistor. Doing that will alter what your XO does. You'll want to correct that. Here is how:
https://www.google.ca/search?sourcei...iring+an+L-pad

And yes I know Altec does it that way also. For the life of me I can't ever sort out why. It makes no sense to have an L-Pad and not use it as one.

Alan, your crossovers/L Pads are currently wired the way Altec crossovers and the AS 101 crossover are designed to be wired. Keep in mind those crossovers are designed to work with your specific drivers and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do. In other words, you wouldn't be "correcting" the wiring of your crossover by doing so, you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

EDIT: In the interest of experimentation, IMHO there is no harm in trying out rewiring the L Pad to see what it sounds like. If you do decide to pursue this avenue, I would recommend rewiring one L-Pad and do an A/B comparison between the two speakers to see if the one with the original wiring scheme sounds/operates "better" or "worse" to your ears than the speaker with the re-wired L-Pad before deciding to re-wire both....

[voice of the theater]

I was wondering if the Zilchlab Econo Wave boards are still available. I came across this video:

Rev Up Your Vintage Speakers, Econowave Style - YouTube

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail. It might be fun to play with them.

Attachment 1586

I just watched the video and it references an Audio Karma thread. I'm not a member there but some of our Altec Users Board members also belong over there so maybe one of them would know about Zilch's Econowave board. If the guy in the video and/or Audio Karma thread is suggesting that this is a "one size fits all" type crossover to be used with any woofer and cabinet regardless of efficiency, frequency response, etc., then I'm very skeptical of that sort of approach. I have a feeling that Zilch would have known better than that......

[alancohen]

Excellent suggestion--I've done that with all of my vintage Altecs--glad you thought to mention it!



Alan, your crossovers/L Pads are currently wired the way Altec crossovers and the AS 101 crossover are designed to be wired. Keep in mind those crossovers are designed to work with your specific drivers and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do. In other words, you wouldn't be "correcting" the wiring of your crossover by doing so, you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

EDIT: In the interest of experimentation, IMHO there is no harm in trying out rewiring the L Pad to see what it sounds like. If you do decide to pursue this avenue, I would recommend rewiring one L-Pad and do an A/B comparison between the two speakers to see if the one with the original wiring scheme sounds/operates "better" or "worse" to your ears than the speaker with the re-wired L-Pad before deciding to re-wire both....

I was assuming that Cal was talking about my other speakers when he mentioned the L-Pad wiring, as they are indeed wired as a series resistor quite intentionally. It happens to fit fit that driver and cab configuration.

DIY Speakers

I will certainly flip the drivers. I never thought of that.

As far as rewiring the crossover, I really don't have much inclination at this point to change anything. I'd be willing to bet $1 that the people that set up this system know a little more than me about speaker design. I want to hear then as intended for a while. Only then will I be able to tell if any changes are helping or hurting.

[voice of the theater]

I was assuming that Cal was talking about my other speakers when he mentioned the L-Pad wiring, as they are indeed wired as a series resistor quite intentionally. It happens to fit fit that driver and cab configuration.

DIY Speakers

I will certainly flip the drivers. I never thought of that.

As far as rewiring the crossover, I really don't have much inclination at this point to change anything. I'd be willing to bet $1 that the people that set up this system know a little more than me about speaker design. I want to hear then as intended for a while. Only then will I be able to tell if any changes are helping or hurting.

It didn't occur to me that Cal was probably talking about your home made speaker system as far as the wiring of the L Pads. I'll bet you're right about that Alan. I agree that the people at Altec (and Heathkit in the case of your crossovers) know a lot more about speaker systems than I do which is why I never re-wired the L Pads on any of my factory Altec crossovers and why I always try to use exact values when replacing caps.

By the way, those are nice looking cabinets that you've built--especially considering they are your first build. The first speaker cabinets that I ever built were in junior high school ("shop" class). They housed 12" full range radio shack speakers and by the standards that I have today they were, in a word, embarrassing (in just about every conceivable way)!

[alancohen]

By the way, those are nice looking cabinets that you've built--especially considering they are your first build. The first speaker cabinets that I ever built were in junior high school ("shop" class). They housed 12" full range radio shack speakers and by the standards that I have today they were, in a word, embarrassing (in just about every conceivable way)!

Yeah, it's been a long time since Jr High shop class for me. But I'm a closet woodworker and keep a few tools and machines around in case I need a new project.

These are still a work in process. The baffles are still just screwed on. I've been playing with the padding type and quantity. Once I'm done, I'll glue the baffle on, fill in the screw holes, sand everything smooth and cover them in a nice paisley fabric . Or maybe some tie dye.

[Old Guy]

and I happen to have these "made for Ovation" Altec VHF drivers and horns in the mail.
Attachment 1586

University, not real Altecs. Okay at best was my opinion. All the Ovation stuff was University AFAIK.

[alancohen]

University, not real Altecs. Okay at best was my opinion. All the Ovation stuff was University AFAIK.

Well that's a bit disappointing. They were billed as "Altec". Oh well, not a big investment.

And it's quite likely I will not need them.

I had noticed while playing an old jazz vinyl this morning that the ride cymbals were shining quite brightly. I'm not sure there is much north of there that I really need to hear anyway.

I might play with them a bit to satisfy my curiosity, but I'm all for keeping things as simple as can be.

Fresh caps should be here in a day or 2. Can't hardly wait.

[Cal Weldon]

and that re-wiring them as mentioned in the Google search will alter what your crossover was specifically designed to do.

Actually it will keep the XO doing what it was does at all L-Pad settings. Having it as a variable resistor will change the XO slope and leave a whole or an overlap at the XO point as you increase or decrease the resistance.

you'd instead be "altering" the design of your crossover. I personally wouldn't recommend doing so......

I don't undertand how it can be called a 'design' if it's wired that way.

[alancohen]

I don't undertand how it can be called a 'design' if it's wired that way.

Did you read this page that I posted earlier?

DIY Speakers

It's wired that way because it achieves the desired result. If you don't agree, you can take it up with Bruce Rozenblit. It's his design. And design is something I'm guessing he knows something about.

[Cal Weldon]

Hi Alan,

I'm not doubting that, I am just confused. Why would you not want to keep the impedance constant? Does the shunting cause an excess heat build-up in the L-pad so you're better off changing the impedance the amp sees?

I am curious.