[kboe]

If you remove the foam from the back of the driver, and cur out the felt like material covering the front of the driver, the bass behaves much more.  Unfortunetely it also perks up the highs, which is good for subject detail, but it leaves the mids where they were to begin with, behind the veil.  So this would help the bass and highs, but leave the midrange kinda out there away from the rest of the musical message.     

 

[kostalex]

... then grill the drills to open the mids
... then probably put some front felt back to tame the highs
... then ...
 
Take a look on my PortaGold mod to see the perspective.
You may turn your UR40 to HD650
UR40 comfort and weight + HD650 SQ = champ

 

[kboe]

It simply wont ever reach the sound QUALITY of the 650s, no matter how much modding we do to them.  It can however be shaped to mirror their sound QUALITIES.

 

[jasonb]

looks like i am going to get a set of HD650's and a Practical Devices XM5 or XM6 if they are coming out soon enough.

 

[Zombie_X]

I would also look into a cmoy amp for those. They mate much better with higher impedance headphones than the XM6, but this statement maybe taken with a grain of salt as I am not totally sure. Just not sure on my end as I never heard the XM5 or XM6.
 
Just from experience my $100 Airhead could drive the HD600 well, but the $40 cmoy could drive them much better and also to higher volumes without clipping.

 

[kboe]

Thats impressive to here the cmoy can drive the 600/650s better than the Airhead.  the Headroom and 650s I owned had wonderful synergy, hard to imagine it could be better for less than $100.00. 

 

[Zombie_X]

Well the cmoy I had was made for high impedance headphones as it ran off four 9v batteries. This gives it a higher voltage swing than what the Airhead has.

 

[kboe]

Wow! FOUR 9vs.  Thats a ton of power to tap.  Do you have pictures?
 
Quote:

Well the cmoy I had was made for high impedance headphones as it ran off four 9v batteries. This gives it a higher voltage swing than what the Airhead has.

 

[Zombie_X]

Unfortunately at the time I did not own a camera so no pictures are available. I bought it off ebay about a year and a half ago though, so maybe some are still floating around.

 

[jasonb]

well the xm5 and xm6 have all the bells and whistles i want. i need a DAC and i need crossfeed. i also like the option to have the bass and treble boosts if needed.

 

[jasonb]

so just to confirm before i order the hd650. the hd650 has about as much bass quantity as the ur-40?
 
i'm happy with the quantity of bass from my ur40 and i am hoping the HD650 has about the same quantity.
 
can anybody that has both confirm this?

 

[Zombie_X]

I believe it has more bass, but it's been a long while since I listened to the HD650. They aren't my favorite pair of headphones.

 

[jasonb]

you're saying the HD650 has more bass than the UR40? if so, then sweet!!!

 
can anybody else confirm?
 
Quote:

I believe it has more bass, but it's been a long while since I listened to the HD650. They aren't my favorite pair of headphones.

 

[logwed]

The bass on the PPs is boomier and sounds louder (same driver as the UR40, or something pretty damn close) to me than the HD650. The HD650 is definitely more clearly defined and controlled than the Portapro.

 

[jasonb]

alright, fair enough. also, my father has a pair of new HD280 pro. new meaning not broken in yet. i find them bass on them to be plenty as well and it looks like the overall quantity is about the same between the 280 and the 650. the bass peaks at a much different frequency though. the 650 looks warmer and smoother which sounds like a plus. one thing i am really enjoying on the UR40 is the big wide open soundstage. looking forward to that on the 650 as well.
 
i just want to be sure i am going to like them since to me 300-400 bucks is a lot to spend on a pair of headphones, add an amp on there and it's even harder to swallow. headroom has the nice 30 day return policy though, so i guess if i'm not thrilled with them i can return them. i'm pretty sure i'll like them though.
 

 
Quote:

The bass on the PPs is boomier and sounds louder (same driver as the UR40, or something pretty damn close) to me than the HD650. The HD650 is definitely more clearly defined and controlled than the Portapro.