Heresy Type "C" Crossovers

[milton10]

I have a single circa '74 Heresy that I am using as a center channel in

my all Heresy HT system (due to its all alnico qualitys). I

swithched the crossover caps to match the type "E" crossover of my

other Heresy's and although the center sounds nice, it sounds slightly

different from the sides/rears.

Should I change the configuration back to the original Type "C"

crossover? Does anyone have a schematic? I don't remember

the configuration of it.

Thanks,

Milton

[Hardhead]

Before you do (or undo) anything else, check to see that the polarities of your center channel crossover and drivers now match exactly with the Type "E" crossover and drivers in your rear or side Heresys. I seem to recall that the polarity of at least one of the Heresy drivers was changed in the transition from the "D" to the "E" crossover, so the "E" polarity may be different from the "C" crossover as well.

[Deang]

Yes, the Type E has polarity reversed on the squawker and tweeter.

Good call.

[Malcolm]

If you changed the values of the capacitors on a Type C crossover to

match those of a Type E crossover, you changed the crossover

frequencies. Ofcourse it won't sound the same. The Type C

crossover was designed for a 16 ohm woofer. Type E was designed

for a 8 ohm woofer. One of the caps in the Type C is

different value than the Type E and autotransformer taps used are

different. IIRC the one feeding the autotransformer should be 1

uF on a Type C and 2 uF on a Type E. If you want it to sound

right, you need to put it back the way it was. New caps of the

original value are alright.

Leave the woofer phase the way it was. The change in woofer

polarity occured after the switch to a 8 ohm woofer. The first

ones had Type D crossovers. Then Klipsch decided the new woofer

sounded better with the phase reversed and changed to the Type E

crossover. There is a Dope from Hope article detailing the change.

[scott0527]

Exactly what Malcom said. I went through a very similar situation. I kept of sketch of the C. PM me and tonight when I get home I'll see if I can dig it out. The autotransformer settings were different as well as the 1uF cap Malcolm mentions. Is there a "red or orange" surround around your woofer?

[milton10]

No, I have no red surround around the woofer. It looks just like

my other pair with gray surrounds. However, it is different from the

others as it is an alnico woofer. I remember that the autoformer

taps were different and that it used 1uf and a 2uf caps.

I want to change the configuration back. Any info or schematic would be appreciated.

Milton

[Malcolm]

Just curious, what is the model number of the woofer, K-22, K-22-E,

etc.? Also, is there an EIA number stamped somewhere on it,

something like 67-xxxx or 137-xxxx? Have you measured the DC

resistance of the woofer voice coil?

The EV and CTS manufactured woofers used through at least 1972 have red

doped fabric surrounds. They are all labelled K-22. There

was an alnico magnet K-22-E used for a while before the switch to the 8

ohm woofers with ceramic magnets. But I don't remember what kind

of surround it had. IIRS I have seem a K-22-R manufactured by

Rola from the same time period.

[scott0527]

This sketch was not meant for human consumption. I scribbled it last minute "just in case".

TypeC.pdf

[milton10]

Thanks for the sketch. It is really helpful.

I'm curious, does the red/orange surround around the woofer mean anything?

[scott0527]

Thanks for the sketch. It is really helpful.

I'm curious, does the red/orange surround around the woofer mean anything?

It's a good indicator that you do in fact have the 16ohm woofer. The 8 ohm's are black.

Edit: See Malcom's post below[]

[BEC]

I have a couple of alnico K-22s here with the red surroumds and they seem to be 8 ohm. Around 6.8 ohms DCR.

Bob Crites

[Malcolm]

All the 16 ohm K22 woofers from EV and CTS used through from the early

60s to 1975 that I have seen had a red doped fabric

surround. It is pretty much a give away that the woofer is

16 ohms if it is original. The later 8 ohm woofers had folded

paper surrounds that were part of the cone itself and therefore the

same color, black. It is certainly possible to have a 16 ohm

woofer with a paper surround, or a doped fabric surround of a color

other than red, but I don't recall ever seeing one in a Heresy.

That doesn't mean there isn't one. Klipsch change woofers many

times in the Heresy. The way to tell for sure what you have is to

measure voice coil resistance. If it is somewhere around 12 or 13

ohms, you have a 16 ohm woofer. If it is around 6 or 7 ohms, you

have a 8 ohm woofer. The difference is important. If

you have a 16 ohm woofer, you need to leave the capacitor values and

autotransformer taps as they came from the factory on the Type C

network. If somewhere along the line someone replace the woofer

with a 8 ohm K-22, you need to change the crossover to Type E

configuration, changing both the capacitor value and autotransformer

taps. Can you post pictures of the front and back of the woofer?

[Malcolm]

Bob,

Are they labelled simply K-22, not K-22-E or something else? What

are the EIA codes on them? Might be under the Klipsch

badge. I am curious as to the year of manufacture. Can you

post pictures of both sides?

[BEC]

They are just labeled K-22.

Bob

[BEC]

Front.

Bob

[milton10]

My woofers are labeled K-22-E. I have attached pictures of them - front and back.

[milton10]

The back.....

[milton10]

closeup of the badge on the back.

[Malcolm]

Milton's woofer is the K-33-E alnico woofer from Eminence I

mentioned. Bob's woofer appears to be the last of the CTS

alnico woofers, the small magnet version. The EIA code is under the

Klipsch badge. I have a pair of 1975 Heresys with these.

They are indeed 8 ohm units and are paired with Type E networks.

I forgot all about these. I have to make a web page with pictures

someday to keep all this stuff straight.

So, to recap and clarify... A red doped surround on a Heresy

woofer is a good indication that it is a 16 ohm unit, but not a

guarantee. Likewise, a paper surround is a good indication that

it is a 8 ohm unit, but not a guarantee. The 16 ohm EV and CTS

woofers used from the early 60s to the mid 70s had red doped cloth

surrounds. The 8 ohm woofers from Eminence and others used from

the late 70s on had paper surrounds. There was some overlap in

the transition years.

I find it interesting that my 1972 Heresys have 16 ohm large alnico

magnet CTS woofers (K-22) , Milton's 1974 Heresy has an alnico magnet

Eminence woofer (K-22-E), my 1975 Heresys have small alnico magnet CTS

woofers (K-22), and my 1978 Heresys have ceramic magnet Eminence

woofers (K-22-EF). And IIRC there was a K-22-R from Rola in that

time frame. Klipsch sure did switch around a lot in the 1970s,

apparently driven by the need to maintain a reasonable price point for

the Heresy and at least in part by the rising price of the cobalt used

in the alnico magnets.

Klipsch also wasn't too consistent about labels for the Eminence

woofers. The alnico one was labelled K-22-E, the ceramic one that

followed was labelled K-22-EF (for ferrite I guess), and a few years

later they apparently later labelled the same ceramic woofer, or at

least one more similar to it than to the alnico one, K-22-E.

Can someone measure the voice coil resistance of an alnico K-33-E and let us know for sure what it is?

[milton10]

Malcolm,

So is my Eminence woofer an 8 ohm or 16 ohm version? If it is an

8 ohm version, why was it paired with a type C crossover network?

Or should I assume that it is 16 ohms? I just want to get the

right crossover back in place.

Thanks!

Milton