Chorus II Passive oddities...Help!

[jimjimbo]

Opened up a pair of walnut Chorus II's for the first time ever....and what I discovered was a bit strange....the passives are different as you can see in the photos, marked the same (although one is a bit more difficult to read) as KD 16.  The speaker serials are consecutive, and everything else is exactly the same....I'm thinking that this is a cause for concern, but, maybe not? 

 

What say you forum techies?  What's the deal?

 

 

 

 

 

 

 

Edited April 15, 2016 by jimjimbo

[jason str]

All the Chorus II's i have seen have the passive style like you have pictured on the right.

 

Must have been replaced at one time would be my guess.

 

The weak spot on the Chorus II is the passive suffering over-excursion.

 

Adding weights will lower the tuning but increase chances of over-excursion, trade off will be taking away some of the tight bass the speaker is known for lower frequency response.

 

If you do happen to blow out the passive cone it would be difficult to find a replacement.

 

I say just add a subwoofer but if you want to experiment go for it.

[mungkiman]

Did they sound different?

[mungkiman]

Passives have magnets?

[mungkiman]

"Passives have magnets?"

Nope, they don't, only drivers do.

 

Hence my question.

[mungkiman]

 Got it!

 

Sorry for the thread hijack...

[oldred]

Kinda looks like it was replaced at one time. I read all about the washer weights. 

Couldn't bring my self to do it.  Did everything else but it to mine. 

Get a subwoofer

 

G.E.M 

[pzannucci]

From the looks of the pictures, they still use the same cone so I would not be concerned.  As long as the frame that holds the code will allow adequate excursion though the cones are the same size and weight (looks like it from the picture), and compliance (of which is very likely because you didn't say the cones looked different), they should tune and perform the same.  It just looks like someone changed the frame at one time or another in manufacture.  The only difference would be maybe at high excursion that the smaller hole would restrict some air flow causing a slight tuning difference but likely doubtful due the volume there.

[jimjimbo]

From the looks of the pictures, they still use the same cone so I would not be concerned.  As long as the frame that holds the code will allow adequate excursion though the cones are the same size and weight (looks like it from the picture), and compliance (of which is very likely because you didn't say the cones looked different), they should tune and perform the same.  It just looks like someone changed the frame at one time or another in manufacture.  The only difference would be maybe at high excursion that the smaller hole would restrict some air flow causing a slight tuning difference but likely doubtful due the volume there.

Thank you for this opinion.  Appreciate the insight.

 

I really shouldn't have even mentioned the "aftermarket" tuning, my mistake, and I am editing that out.

 

I would like to hear some other opinions about this issue if you all don't mind.  As stated in the original post, both of the passives are marked with the same model number KD 16, and actually there are serial numbers on both, and they are not that far apart....  The cones and the basket frames are almost exactly the same, except for what is pictured.  

Edited April 15, 2016 by jimjimbo

[jason str]

The different frames should make very little difference in sound if at all, my guess is you will not hear it.

 

Nothing to worry over.

[jimjimbo]

The different frames should make very little difference in sound if at all, my guess is you will not hear it.

 

Nothing to worry over.

I was hoping you'd say that.....

[mustang guy]

I gotta figure your two speakers were made at the end of stock of the previous style passive frame or something like that. I bet the two cones have the same exact T/S parameters. The smaller of the two former holes looks pretty big, but I know where you are coming from in your question. Even though it is big, it's no bigger than a port would be, and ports that size have air velocity, which in turn means air pressure behind that spider. 

 

Even if the difference is small, and probably not even noticeable, I bet anything it would measure differently because of the air restriction behind the spider.

 

I am with Jason not to worry cause you could never hear the difference. But there is going to be a "measurable" difference, which may still be within manufacturer tolerances.

Edited April 15, 2016 by mustang guy

[CECAA850]

If curiosity eats at you enough, you might PM colter.

[jimjimbo]

I gotta figure your two speakers were made at the end of stock of the previous style passive frame or something like that. I bet the two cones have the same exact T/S parameters. The smaller of the two former holes looks pretty big, but I know where you are coming from in your question. Even though it is big, it's no bigger than a port would be, and ports that size have air velocity, which in turn means air pressure behind that spider. 

 

Even if the difference is small, and probably not even noticeable, I bet anything it would measure differently because of the air restriction behind the spider.

 

I am with Jason not to worry cause you could never hear the difference. But there is going to be a "measurable" difference, which may still be within manufacturer tolerances.

Yes, I was thinking the end of stock for the woofer frames also.  I really don't think these have ever been opened up, so that makes sense.  Just wanted to be careful about this.....grateful for the responses!

[pzannucci]

 

I gotta figure your two speakers were made at the end of stock of the previous style passive frame or something like that. I bet the two cones have the same exact T/S parameters. The smaller of the two former holes looks pretty big, but I know where you are coming from in your question. Even though it is big, it's no bigger than a port would be, and ports that size have air velocity, which in turn means air pressure behind that spider. 

 

Even if the difference is small, and probably not even noticeable, I bet anything it would measure differently because of the air restriction behind the spider.

 

I am with Jason not to worry cause you could never hear the difference. But there is going to be a "measurable" difference, which may still be within manufacturer tolerances.

Yes, I was thinking the end of stock for the woofer frames also.  I really don't think these have ever been opened up, so that makes sense.  Just wanted to be careful about this.....grateful for the responses!

 

Here is a passive radiator calculator that shows what matters from a passive radiator perspective:

 

http://www.mh-audio.nl/PassiveRadiator.asp

[MORE KLIPSCH PLEASE]

Hey jimjimbo, I took a few minutes and took the pass rads out of my Chorusii's this morning....kinda wanted to see what was in mine.
As you can see I have the one that is on the right in your first pic...... just wondering did you buy them new?

I would agree with mustang guy about the "end of stock" in his post...

Also my Chorusii's are not consecutive serial numbers....

Put those back in the cabs and put the watts to em  .....lol lol

MKP :-)

Edited April 16, 2016 by MORE KLIPSCH PLEASE