MarioD
Head-Fier
- Joined
- Apr 8, 2015
- Posts
- 65
- Likes
- 23
WORD OF CAUTION - If you attempt to do the mods I've described below, there's a very good chance you will break your driver. Even if you don't, there's a potential risk of driver failure over time, as the coil gap will be exposed to the external environment... you know, dust and stuff in the air.
I went to buy a Mac Mini about two weeks ago, and while I was in the store, my eyes fell on a box of HD650. For whatever reason I left the store with the HD650 and this didn't make my wife all too happy. Anyway, I as expecting them to be on the same level as Q701 I used to own (i.e. utter crap), but to my surprise they turned out to be way better. I mean seriously better. The sound wasn't grainy and they had a lot more accurate timbre. After a week of listening to them in the office, I decided they could do better, so I decided it's time for some modifications. I brought from home my TDA1541A DAC and Sygnetics NE5532 opamps, and my Raspberry Pi2 with Volumio. Since obviously I didn't have another 650 pair to compare modded to stock, I also brought over my LCD-2 that I traded back a while ago. So I disassembled the 650. I didn't pay attention to the drivers before that, so I didn't realize how small they were. they are smaller than the ones in AKG k518DJ that I also own. Well, these drivers, as I found, just can't do bass. Due to their size, light-weight membrane (cone), and most importantly their design parameters, they just can't handle bass. When you start cranking up the volume, bass distortion start setting in very early. And in general you can't push them hard. In stock form they sounded generally worse than the LCD-2 (Fazor). However there was this very loverly dynamic pop (as someone described it on Innerfidelity), that is pretty much completely missing in all planar-magnetic headphones. They all sound to me like I'm in flat land
This gave me additional motivation to try make them sound better.
So since I've tried many things over the last two days, I'll just fast forward to the final state of the modifications:
* Removed the foam between the pad and the driver
* Removed the protecting grill in front of the driver
* Removed the silver screens and glued natural cork on the front baffle around the driver
* Covered all holes on the back side with small cork pieces
* Removed the foam behind the driver
* Applied two small pieces of felt on 2 of the 4 holes around the magnet (just mid-range fine tuning)
All this made a pretty decent improvement in the sound. The treble and midrange now sound as a coherent whole, and there's a lot more clarity, no phase distortions or ringing due to particularly the grill and baffle anymore. Comparing the two headphones, the treble of the LCD-2 sounds like broken glass to my ears. On the flip side though, the HD650 simply can't match the bass and juicyness of the LCD-2. However, keep in mind the LCD-2 driver's membrane is 3.5-4 times bigger and it's got more acoustic damping. To my audiophile ears in this modded state, the HD650 is the overall better headphone. However, even if you're willing to risk your drivers, it may not be your cup of tea. My non-audiphile friends love the juicyness and bass push of the LCD-2. They don't seem to care at all about dynamics and treble silkiness
A word of discouragement to everyone eager to mod their headphones. What makes a headphone or a speaker sound good or great or amazing is the driver, particularly the magnetic system and the cone material. You can't mod the driver. You can only make some improvements to the sound by tweaking the damping and solving some common sense issues
The mods I've described above yield some pleasant results but the trade off you face is the risk of ruining your drivers. At 50 bucks per pair though, I personally am happy to take that risk.
Dynamic drivers FTW!!!
Cheers,
Mario
I went to buy a Mac Mini about two weeks ago, and while I was in the store, my eyes fell on a box of HD650. For whatever reason I left the store with the HD650 and this didn't make my wife all too happy. Anyway, I as expecting them to be on the same level as Q701 I used to own (i.e. utter crap), but to my surprise they turned out to be way better. I mean seriously better. The sound wasn't grainy and they had a lot more accurate timbre. After a week of listening to them in the office, I decided they could do better, so I decided it's time for some modifications. I brought from home my TDA1541A DAC and Sygnetics NE5532 opamps, and my Raspberry Pi2 with Volumio. Since obviously I didn't have another 650 pair to compare modded to stock, I also brought over my LCD-2 that I traded back a while ago. So I disassembled the 650. I didn't pay attention to the drivers before that, so I didn't realize how small they were. they are smaller than the ones in AKG k518DJ that I also own. Well, these drivers, as I found, just can't do bass. Due to their size, light-weight membrane (cone), and most importantly their design parameters, they just can't handle bass. When you start cranking up the volume, bass distortion start setting in very early. And in general you can't push them hard. In stock form they sounded generally worse than the LCD-2 (Fazor). However there was this very loverly dynamic pop (as someone described it on Innerfidelity), that is pretty much completely missing in all planar-magnetic headphones. They all sound to me like I'm in flat land
This gave me additional motivation to try make them sound better.So since I've tried many things over the last two days, I'll just fast forward to the final state of the modifications:
* Removed the foam between the pad and the driver
* Removed the protecting grill in front of the driver
* Removed the silver screens and glued natural cork on the front baffle around the driver
* Covered all holes on the back side with small cork pieces
* Removed the foam behind the driver
* Applied two small pieces of felt on 2 of the 4 holes around the magnet (just mid-range fine tuning)
All this made a pretty decent improvement in the sound. The treble and midrange now sound as a coherent whole, and there's a lot more clarity, no phase distortions or ringing due to particularly the grill and baffle anymore. Comparing the two headphones, the treble of the LCD-2 sounds like broken glass to my ears. On the flip side though, the HD650 simply can't match the bass and juicyness of the LCD-2. However, keep in mind the LCD-2 driver's membrane is 3.5-4 times bigger and it's got more acoustic damping. To my audiophile ears in this modded state, the HD650 is the overall better headphone. However, even if you're willing to risk your drivers, it may not be your cup of tea. My non-audiphile friends love the juicyness and bass push of the LCD-2. They don't seem to care at all about dynamics and treble silkiness
A word of discouragement to everyone eager to mod their headphones. What makes a headphone or a speaker sound good or great or amazing is the driver, particularly the magnetic system and the cone material. You can't mod the driver. You can only make some improvements to the sound by tweaking the damping and solving some common sense issues
The mods I've described above yield some pleasant results but the trade off you face is the risk of ruining your drivers. At 50 bucks per pair though, I personally am happy to take that risk.
Dynamic drivers FTW!!!
Cheers,
Mario
