[Acix]

Quote:

Originally Posted by love2listen /img/forum/go_quote.gif I promise, thanks!

Start your mod and the sound will change every 100 hours and you will need to change the mod too...

 

[love2listen]

Quote:

Originally Posted by Acix /img/forum/go_quote.gif Start your mod and the sound will change every 100 hours and you will need to change the mod too...

Hopefully you are joking

 

[Acix]

Quote:

Originally Posted by love2listen /img/forum/go_quote.gif Hopefully you are joking

Try and see...

 

[love2listen]

Hello Kwkart,

Thanks for all the very interesting information and experiences!

I am about to do your mods, but still waiting for the Dynamat to arrive and the PL 650 to burn in. Could you pls. advice me a bit on the principles of your mod?

I understand the Dynamat takes out resonance mechanically, and I guess thats is allways a good thing. Markl has a similar mod for Denon's where he also applies Dynamat to the butt of the driver and the ring around it. Would you think this would further improve the 650, or would you recommend to stay with dynamat on the inside of the cup and the baffleboard?

Regarding the acousting dampening material (foam, felt and fabric), what is the most important factor and what does it achieve? I am asking because i don't have excatly the same materials, and would like to get a rough target. My goal is to get a tighter bass and bring out/remove the coloration from the midrange.

Thanks a lot!

 

[kwkarth]

Quote:

Originally Posted by love2listen /img/forum/go_quote.gif Hello Kwkart, Thanks for all the very interesting information and experiences! I am about to do your mods, but still waiting for the Dynamat to arrive and the PL 650 to burn in. Could you pls. advice me a bit on the principles of your mod? I understand the Dynamat takes out resonance mechanically, and I guess thats is allways a good thing. Markl has a similar mod for Denon's where he also applies Dynamat to the butt of the driver and the ring around it. Would you think this would further improve the 650, or would you recommend to stay with dynamat on the inside of the cup and the baffleboard? Regarding the acousting dampening material (foam, felt and fabric), what is the most important factor and what does it achieve? I am asking because i don't have excatly the same materials, and would like to get a rough target. My goal is to get a tighter bass and bring out/remove the coloration from the midrange. Thanks a lot!

You can certainly try the additional dynamat and see if it further helps. The driver is very well mechanically coupled to the baffleboard, so damping the resonant qualities of the baffle board will have a direct effect on damping the driver as well, but I would say it's worth a try to see if you can achieve further improvement. The midrange coloration seemed to be caused by standing waves inside the cavity of the earcup, which is why I added the foam/felt. In retrospect, a single piece of wool felt should do the trick. Damping the mechanical resonances will tighten the bass.

Best of luck!

 

[love2listen]

Quote:

Originally Posted by kwkarth /img/forum/go_quote.gif You can certainly try the additional dynamat and see if it further helps. The driver is very well mechanically coupled to the baffleboard, so damping the resonant qualities of the baffle board will have a direct effect on damping the driver as well, but I would say it's worth a try to see if you can achieve further improvement. The midrange coloration seemed to be caused by standing waves inside the cavity of the earcup, which is why I added the foam/felt. In retrospect, a single piece of wool felt should do the trick. Damping the mechanical resonances will tighten the bass. Best of luck!

Thanks a lot for your very helpful answer!

I really look forward - with more confidence - to do the "surgery" now.

Thanks

 

[love2listen]

Just an update: I have now performed the mod to the Proline 650 in this version:

* Dynamat on inside of the cup, back of the driver and back of the baffleboard (last two only a dab of Dynamat relatively to the area).
* Felt inside the cup, one layer

The operation
The screws for the baffleboard was extremely tight and not easy to unlock. Care has to be taken when re-mounting that the screwsholes are oriented properly, when the baffleboard is remounted, take note of this when you take it a part. The rest is easy as long as you are careful and precise.

The sound
My first observations on the sound: I mainly hear that the bass is better controlled and seems less loud. This makes room for more details in the sound picture. Regarding the mid tone coleration I am not sure if this is cured completely: I have a single tune where the male singer and the whole sound of this exactly tune sounds a bit honky on the PL 650 and only with them, and it still does after the mod... Hmmm. Maybe the mod also take a bit of volume/sound pressure; I find I turn the volume a bit more up now than before, but it could be the battery, 9V, that needs replacement soon.

That's it for the first impressions. Pls. comment!

 

[mfaughn]

I have proline 650s. I just put dynamat on the back of the cups and added a small amount of polyfill. I tried adding a couple layers of felt but they added too much thickness behind the driver, put pressure on it, and the bass evaporated. I am too lazy to open them up again right now but I might felt thicker in the area where the driver isn't and try to get one this layer right behind the driver. I'm surprised that kwkarth could get all those layers in there.

I'm pretty sure that doing this mod was/is a good idea. Obviously I can't A/B with an unaltered version. All I can say is that I had put these on the shelf intending to cycle them to someone else. I was looking for a distraction tonight after a rough day so I decided to play with them. I agree with love2listen that the midrange thing isn't totally solved. Still not enough mids for my taste but not as honky as they were before. I previously felt that there was a lot to really like about these cans and a lot to not like also -- not a ho-hum sound at all. I now feel like there is less to not like. To me, they are a very colored HP but I am finding them very fun to listen to (radiohead at the moment). I EQ down about 7db at ~7.5 kHz and it helps a lot. It is a sound that I get used to quickly. If nothing else I am now really interested in the potential that other Ultrasone's may hold.