Klipsch H700 Heresy Replacement Woofer

[tlann]

Hi all! I bought some Klipsch H700 Heresys that, according to the serial numbers, were made in 1970. Unfortunately, I discovered upon opening them up that they do not seem to have the original woofers. Instead, they have these woofers (pictures attached) with illegible serial numbers and "Cletron" written in permanent marker on them. From my research, Cletron stands for Cleveland Electronics, a company that made organ speakers and were cheaper competitors to Jensen back in the day.

But I digress. My main question is this: if I were to spend the money to replace these woofers, what should I look for? The crossovers are Type C. Would any K-22 woofer work with this crossover (without having to modify it)? Would it be more worth my while to invest in the Crites woofers, and if so, would those work with the Type C crossovers? Or, lastly, would you recommend the Eminence Pro 12a woofers?

Of course, I would imagine people will have different opinions — and that's fine! I'm primarily interested in (1) which woofers will actually work without further modification to the existing components, and (2) what sound characteristics I might expect from the different options.

Thanks for any insight!

 

[THD+N]

You could go with a K22, but you may want to consider changing the crossover to accommodate the woofer. The capacitors are more than likely out of spec and should be changed as well. See link below for a primer;

Heresy Type "C" Crossovers

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/re...

community.klipsch.com

 

[ClaudeJ1]

Hi all! I bought some Klipsch H700 Heresys that, according to the serial numbers, were made in 1970. Unfortunately, I discovered upon opening them up that they do not seem to have the original woofers. Instead, they have these woofers (pictures attached) with illegible serial numbers and "Cletron" written in permanent marker on them. From my research, Cletron stands for Cleveland Electronics, a company that made organ speakers and were cheaper competitors to Jensen back in the day.

But I digress. My main question is this: if I were to spend the money to replace these woofers, what should I look for? The crossovers are Type C. Would any K-22 woofer work with this crossover (without having to modify it)? Would it be more worth my while to invest in the Crites woofers, and if so, would those work with the Type C crossovers? Or, lastly, would you recommend the Eminence Pro 12a woofers?

Of course, I would imagine people will have different opinions — and that's fine! I'm primarily interested in (1) which woofers will actually work without further modification to the existing components, and (2) what sound characteristics I might expect from the different options.

Thanks for any insight!

I have 4 pairs of K22's with Klipsch names on them. I also have C crossovers with new top of the line capacitors. Message me if there's an interest in a "easy peasy" replacement. I can take your C's in exchange. The sound characteristic is then to original factory spec.

 

[geezin']

A slight diversion but I don't want to start a new thread for it. Can someone tell me what this does?

​

 

[ClaudeJ1]

dampens an impedance peak an increases the drive voltage to compensate for the loss.

 

[geezin']

Which does what to the sound?

 

[ClaudeJ1]

Which does what to the sound?

don't know. Never done it.

 

[geezin']

Worth a try just to see?

 

[ClaudeJ1]

Not a gov. mandate, go for it, as a free man.

 

[eiraved]

Not a gov. mandate, go for it, as a free man.

Not yet at least!

 

[geezin']

I really should know better.

 

[Invidiosulus]

A slight diversion but I don't want to start a new thread for it. Can someone tell me what this does?

View attachment 3113386​

The resistor across the squawker output is supposed to dampen the impedance peak and allow for a smoother response towards the cutoff frequency of the horn.

The change in taps on the autoformer is actually reducing the output of the tweeter and squawker to bring them closer to the output level of the woofer.

 

[Invidiosulus]

That type E mod was discussed in depth over on the K forum.

Heresy Crossover Mod - Less Bright

The attached file is a schematic of a Heresy Type E crossover with modifications (in red) to reduce the output of the squawker and tweeter. the woofer's output rating is a fraction below 95 dB/w/m, but the squawker is run at a nominal 98+ dB/w/m and the tweeter is run at a nominal 99dB/w/m. Movin...

community.klipsch.com

 

[THD+N]

A slight diversion but I don't want to start a new thread for it. Can someone tell me what this does?

View attachment 3113386​

The 16 ohm resistor "flattens out" a rising impedance characteristic of the T2A and provides a constant load for the driving amplifier. This resistor is more commonly a 10 ohm resistor. This connection topology also has the benefit of being able to change the dB tap without having to reconfigure the 2uF going into the T2A each time you want to attenuate the midrange.

Soundwise, there is no sound difference so to speak of, except for a slight signal loss which may or may not be perceptible.

 

[GainFactor99]

My main question is this: if I were to spend the money to replace these woofers, what should I look for? The crossovers are Type C. Would any K-22 woofer work with this crossover (without having to modify it)? Would it be more worth my while to invest in the Crites woofers, and if so, would those work with the Type C crossovers? Or, lastly, would you recommend the Eminence Pro 12a woofers?

Curious to hear any thoughts on OP's original question about which woofers would be suitable replacements for the non-stock ones he found in the cab.

 

[ClaudeJ1]

Curious to hear any thoughts on OP's original question about which woofers would be suitable replacements for the non-stock ones he found in the cab.

If you have cash to spare, I like the KappaLite 2512 II I recommended for the original CaB. The K22 use as an alternative to original spec.

 

[geezin']

There's some discussion about that here.

 

[THD+N]

@tlann, since you are in the honeymoon stage with your new found Heresy's and you need to spend money to get them sounding like something from this century, just go ahead and buy woofers that lend themselves to the "porting mod". You can easily make a new rear panel so the mod is reversible.

You may resist this urge at first, but once you think it through, it is a good decision to make. No one has ever regretted porting the Heresy.

 

[Gigantic]

@tlann, since you are in the honeymoon stage with your new found Heresy's and you need to spend money to get them sounding like something from this century, just go ahead and buy woofers that lend themselves to the "porting mod". You can easily make a new rear panel so the mod is reversible.

You may resist this urge at first, but once you think it through, it is a good decision to make. No one has ever regretted porting the Heresy.

True story. My only regret from porting my H700 was that after I did that, I had to do the rest of the Super heresy mods. Then I had to build another from the ground up. Of course, a second set of super heresy wasn’t enough, so I played with bass extension chambers and passive radiators. Naturally, I had to mess with bigger and better horns. Ultimately, I ended up building a pair of LaScala from scratch, all because I ported a 1971 H700 Heresy a year and a half ago.

 

[tlann]

@tlann, since you are in the honeymoon stage with your new found Heresy's and you need to spend money to get them sounding like something from this century, just go ahead and buy woofers that lend themselves to the "porting mod". You can easily make a new rear panel so the mod is reversible.

You may resist this urge at first, but once you think it through, it is a good decision to make. No one has ever regretted porting the Heresy.

Which woofers lend themselves to that mod? I’m sure there is a thread, so forgive the question! Maybe a better one would be: which woofer would you recommend?