K55V - new diaphragms installed

[KT88]

 

Technically, my 1977 K55V worked fine. Besides...I had no comparison.
You can accept the sound, but you can also question it. Somehow the sound was a bit sharp and thin. 
Now I have the comparison. The new diaphragm, since yesterday, have a positive effect in two ways. First, the sound is airier, more balanced and much more pleasant to the ear, much silkier. In addition the lower registers of the K400 have become more powerful. With the old diaphragms the low notes of a violin were much quieter. They were overshadowed by other instruments in the orchestra.  Speech Intelligibility has become much better. Easy differentiation of all vowels. With the old diaphragms there were unpleasant overtone resonances on, for example, an A.vowel. 
I read old threads where Bob Crites measurements showed that old diaphragm got weaker below 1000Hz. And I thought that 44 years old phenol might not have the smoothness and internal damping as new material.
It paid off and I would recommend it to anyone who has such old K55V drivers. It's really worth it.
Another step towards the original restoration of my lovely LaScalas after I changed the capacitors. Thanks to Michael Crites who sent the new diaphragms.

[soundbound]

Good job. Thank you for sharing. Enjoy.

[soundbound]

Here’s an old thread about this if you want to read it.

 

 

[KT88]

Thanks for the link, soundbound. I have read it with interest. The measurements vs. the auditory impression is a topic that will always come up.

I read on the forum that it can make a difference to install new diaphragms. So I was curious enough to try it. Nothing more. 
Regardless of any measurement methods, I can say with very great certainty that the fresh diaphragms sound much more pleasant, musical, clearer, transparent and balanced. No one has to tell me that what I hear is wrong. I would pass any blind test in this case. This concerns my wife and everyone who heard the difference in the A/B mono test. The stereo impression amplified it again qualitatively. 
That's how different the sound is between ancient and new. It is more original Klipsch than with the 44 year old diaphragms.

 

I have no objection to any kind of measurements. But as long as we cannot measure everything that can play a role, a measurement is always only a rough guide. If measurements cannot show the difference between very old and new diaphragms, then there is something wrong with the measurement method, but my sense of hearing is fine. The fans of "objective" and "uninfluenced" measurements like to accuse the subjective listeners of bias. They should take the listening experience more seriously.

I look forward to further technical progress. Astrophysics is struggling for methods to detect e.g. dark matter. It can't be measured yet. But some acoustic engineers think they have a complete arsenal of measurements which covers all. Of course, I do not mean all engineers who make audio measurements, there are also those who are really fair.

Bob Crites at least had measured that old diaphragms became dramatically quieter below 1000 Hz. This would give us an indication that both camps can move towards each other. The people who make measurements should try everything to confirm the auditory impression and not to judge the auditory impression as autosuggestion.

[OO1]

On 6/21/2021 at 4:07 PM, KT88 said:

 

Another step towards the original restoration of my lovely LaScalas after I changed the capacitors. Thanks to Michael Crites who sent the new diaphragms.

can you send us actual pictures of the older k55V diaphragms you  replaced -I would have liked to see how these older parts looked after 44 years

[KT88]

I don't know what purpose it should have but here you go, why not. They are not mechanically or electrically damaged in any way, just 44 years of age.

 

 

 

[soundbound]

14 hours ago, RandyH001 said:

can you send us actual pictures of the older k55V diaphragms you  replaced -I would have liked to see how these older parts looked after 44 years

 

Here’s two new diaphragms compared to 27 year old ones that still worked photo for you too RandyH001.

 

[soundbound]

14 hours ago, KT88 said:

Thanks for the link, soundbound. I have read it with interest. The measurements vs. the auditory impression is a topic that will always come up.

I read on the forum that it can make a difference to install new diaphragms. So I was curious enough to try it. Nothing more. 
Regardless of any measurement methods, I can say with very great certainty that the fresh diaphragms sound much more pleasant, musical, clearer, transparent and balanced. No one has to tell me that what I hear is wrong. I would pass any blind test in this case. This concerns my wife and everyone who heard the difference in the A/B mono test. The stereo impression amplified it again qualitatively. 
That's how different the sound is between ancient and new. It is more original Klipsch than with the 44 year old diaphragms.

 

I have no objection to any kind of measurements. But as long as we cannot measure everything that can play a role, a measurement is always only a rough guide. If measurements cannot show the difference between very old and new diaphragms, then there is something wrong with the measurement method, but my sense of hearing is fine. The fans of "objective" and "uninfluenced" measurements like to accuse the subjective listeners of bias. They should take the listening experience more seriously.

I look forward to further technical progress. Astrophysics is struggling for methods to detect e.g. dark matter. It can't be measured yet. But some acoustic engineers think they have a complete arsenal of measurements which covers all. Of course, I do not mean all engineers who make audio measurements, there are also those who are really fair.

Bob Crites at least had measured that old diaphragms became dramatically quieter below 1000 Hz. This would give us an indication that both camps can move towards each other. The people who make measurements should try everything to confirm the auditory impression and not to judge the auditory impression as autosuggestion.

 

You’re welcome and right.

[OO1]

On 6/29/2021 at 12:13 AM, soundbound said:

 

Here’s two new diaphragms compared to 27 year old ones that still worked photo for you too RandyH001.

 

looks quite similar  to mine

[OO1]

On 6/21/2021 at 4:07 PM, KT88 said:

Thanks to Michael Crites who sent the new diaphragms.

Heinz , since you installed the new PD-5VH diaphragms  over 2 years ago , did you test the K-55V drivers after the swap  for the  frequency response  of 110Hz -6kHz 

 

 

 

 

 

[OO1]

On 6/29/2021 at 12:13 AM, soundbound said:

 

Here’s two new diaphragms compared to 27 year old ones 

question for ya   since you installed the new  diaphragms in 2006  , did you test the K-55V  after the swap for the  frequency response  of 110Hz -6kHz  

[KT88]

39 minutes ago, OO1 said:

Heinz , since you installed the new PD-5VH diaphragms  over 2 years ago , did you test the K-55V drivers after the swap  for the  frequency response  of 110Hz -6kHz 

 

 

 

 

 

No I did not but they sound more silky and rounder, fuller.

[OO1]

43 minutes ago, KT88 said:

No I did not but they sound more silky and rounder, fuller.

I had the same impression

[KT88]

What is the difference between Atlas D20G and D20IB diaphragms? 

[Deang]

Looks like the D20GB is for the PD-5VH and the PD-5VT, while the D20IB is for the PD60A, PD60T, and PD60AT.