[wje]

Purpose: To discuss driver alternatives that are being used within the Grado headphone cups.  This would apply to both custom wooden cups, as well as the standard plastic Grado or Alessandro cups, as well as Mahogany cups made by Grado. Again, the emphisis is on non-Grado manufactured drivers.
 
Driver Synopsis: (Added: 10/21/2014)
 
There are direct links below to many drivers.  However, the non-Grado modder would be best to stick with the following drivers, which I've arranged in order of preference along with affordability.  Finally, this thread is dedicated to non-Grado drivers that have been tested and tried.  Input from all members is always welcome based on their impressions.  If a member comes across a noteworthy driver, please PM me with some details on your listening experience and a bit of background of the driver - cost, what type of cup you tried them in, genres of music tried, etc.  It wasn't necessarily myself that found that utilizing non-Grado drivers in wooden cups is a very good possibility.  Stratocaster has been one such individual who has done a lot of trial and error testing with many drives and also pioneered the famed "StratoKossTer" closed headphone cup with he Koss drivers.  It is contributions such as those that inspired me to take it a bit further and to institute a thread for us DIY-ers to get inspired on taking time, a few bucks to build a headphone that would or could be more custom to their listening desires and needs.
 

• Sennheiser PX-100 II Drivers: Basically since this thread was started and the other drivers were tested, the PX-100 II headphone drivers remain one of the best choices at this point in time for this project.  Often they can be purchased as a refurbished pair or even a used pair for as low as $25.00 up to $70.00 (New).  But, one can find a pair of new PX-100 II headphones at times in the $40 range.  It just depends on the vendor, the time of the year, etc.
• Sennheiser PX-95 Drivers: I've placed these drivers into the 2nd place slot because when they can be found for a price about $10 lower than the PX-100 II when looking into the used / refurbished market.  I'm eager to see what other members involved in this thread might come up with their impressions of the PX-95 driver.  To me, I thought there was just a slight bit extra mid-range over the PX-100 II drivers.  But that was just my perception and I didn't have two sets of cups at the time to test the drivers in the headphones back-to-back.  If you find that the PX-95 is harder to find, it might be because the headphone appears to have been released in the summer of 2014.
• Koss KSC-75 Drivers:  These drivers can be found for approximately $15.00 (US$) per pair.  Shipping may be included at that price depending on the vendor.  To my ears, these drivers had a bit more emphasis on the upper frequencies.  I wouldn't really call them bass-light, but the bass presence seemed a bit less than my experienced with the Sennheiser drivers.  Part of that sound signature could have been possible due to the prevalence of the upper frequencies covering up the lower frequencies.  Again, just a very subjective view where I tested the drivers in wooden cups designed for Grado drivers.
• Sennheiser PXC-250 II Drivers:  For this pair of drivers, I placed it into 4th place.  However, it didn't land here because of horrible performance.  When new, the PXC-250 II sells for about $199.  For more modders, that could be a costly set of drivers.  I've done some checks on Ebay and can see a good source of used offerings in the $40 to $60 range; in reality, the are within reach.  A second reason for placing this driver down into this position was due to a small bit of extra work required to remove the small noise cancelling device that was added into / onto the top of the driver protection grill.  Removal is relatively easy, but takes a few more minutes of the modding process for the task.  Now when it comes to sound, I feel that the position where I've placed this driver surely deserves to be pushed up a couple of notches.  While this driver appears to have a slight bit less bass than the other Sennheiser drivers, it still isn't anemic sounding.  The bass is present, balanced and enjoyable.  The upper frequencies are not overwhelming, but really add details into percussion and when those higher frequencies are called for in music passages.

 
****
 

Direct links:
 

1. Koss 75 drivers: http://www.head-fi.org/t/119314/post-your-grado-mods/4185#post_9948478
2. Sennheiser PX100 II Drivers: http://www.head-fi.org/t/119314/post-your-grado-mods/4200#post_9949100
3. Frequency Charts: Grado RS1 Driver vs. Sennheiser PX100 II Driver: http://www.head-fi.org/t/119314/post-your-grado-mods/4200#post_9950481
4. JVC HAS-400B (Nanotube Drivers): http://www.head-fi.org/t/119314/post-your-grado-mods/4245#post_9963193 and: http://www.head-fi.org/t/119314/post-your-grado-mods/4245#post_9967038
5. Beyerdynamic DT-990 Drivers: http://www.head-fi.org/t/119314/post-your-grado-mods/4155#post_9939990  and: http://www.head-fi.org/t/119314/post-your-grado-mods/4230#post_9959602
6. Parts Express / Mouser Electronics / Lunashops Driver Mentions: http://www.head-fi.org/t/119314/post-your-grado-mods/4185#post_9947911
7. Unknown Make of 40mm Drivers from China: http://www.head-fi.org/t/119314/post-your-grado-mods/4185#post_9948068
8. Kobitone Drivers from Mouser Electronics: http://www.head-fi.org/t/119314/post-your-grado-mods/4185#post_9948089
9. 40mm Drivers from Conrad: http://www.conrad-electronic.co.uk/ce/en/product/541342/LSF-40MF32OHM01W-miniature-speaker-32-150-Hz?ref=searchDetail

  (other names for Conrad.  Conrad Energy - they appear to make quite a few variations of 40mm drivers.  Some down to 8 Ohm, with 86dB efficiency.  Others can have 110dB efficiency with 32 Ohm operation.  Also, they might have 100 Hz or 150 Hz frequency cut-offs, too.
 
New Items: Updated 1/23/2014: While I did purchase these drivers and try them, they did not provide for a good impression.  I still prefer the Sennheiser PX100 II drivers as opposed to these two.

1. Parts Express Headphone Drivers: http://www.parts-express.com/dayton-audio-ce38mb-32-1-1-2-mini-speaker-black-32-ohm--285-131
2. Parts Express Headphone Drivers: https://www.parts-express.com/dayton-audio-ce38m-8-1-1-2-mini-speaker-8-ohm--285-129

 
 

Other Grado Links / Resources:
 

1. Grado Fan Club thread: http://www.head-fi.org/t/530965/grado-fan-club
2. Grado RS1i Appreciation thread: http://www.head-fi.org/t/444439/grado-rs1i-appreciation-thread
3. Grado PS-1000 Appreciation tread: http://www.head-fi.org/t/520884/ps1000-appreciation-thread
4. Grado Modders go Magnum thread: http://www.head-fi.org/t/576717/grado-modders-go-magnum
5. Post Your Grado Mods thread: http://www.head-fi.org/t/119314/post-your-grado-mods
6. SR-60 Mod Part II: http://www.head-fi.org/t/560806/sr60-mod-part-ii
7. StratoKosster thread (Closed Grado Design): http://www.head-fi.org/t/611982/the-stratokosster-a-closed-diy-headphone-based-on-the-koss-ksc-75-driver-and-grado-cup-design
8. The Great Grado Exeriment (4 Tonewoods Tested) thread: http://www.head-fi.org/t/686212/the-great-grado-experiment-4-tonewoods-tested-more-to-come
9. DIY Woody Grado Symphones Magnums - A Build Diary: http://www.head-fi.org/t/626114/diy-woody-grado-symphones-magnums-a-build-diary
10. Woodie Grado Review and Impressions Thread: http://www.head-fi.org/t/558621/woodied-grado-review-and-impressions-thread

 

FAQ:
 
Q: Should all posts in this thread be taken as pure fact?
A: No.  The purpose for this thread is for members who have used non-Grado drivers within Grado, or Grado-sized cup housings (40mm - 45mm).  This thread permits users to share their experiences with the non-Grado drivers and allows them to describe their impressions based on their efforts.
 
Q: Can we share our speculations and thoughts on certain drivers within this thread or suggest other drivers to test for fit, sound, etc.?
A: Absolutely!
 
Questions / Suggestions?  Please let me know if you have any.

 

[bluemonkeyflyer]

wje,

Thanks for starting this thread. This will be helpful as well as specific to transplant donors and methods.

 

[GermanGuy]

subscribed!

 

[fleasbaby]

...subbed as well...

 

[GermanGuy]

LSF-40MF: http://www.conrad-electronic.co.uk/ce/en/product/541342/LSF-40MF32OHM01W-miniature-speaker-32-150-Hz?ref=searchDetail

 

[wje]

  LSF-40MF: http://www.conrad-electronic.co.uk/ce/en/product/541342/LSF-40MF32OHM01W-miniature-speaker-32-150-Hz?ref=searchDetail

 
 
Thanks. As additional links get posted, I will try to keep the original thread updated with them, so we'll have an easy reference.  If you see that I haven't included the link at the top in the 1st post, or if you have other resourceful links, just PM me to remind me.  The door is always open ... 

 

[Levictus]

Subbed! Thanks for getting this one together! Gotta say, I'm a bit flattered you added my China driver post up top . Hoping to get them sometime soon. I started turning my first set of cups and they were turning out great it then I realized that the initial cut outs I made with the hole saw were off by 1/4" in diameter! What?! Yep, feeling like an idiot as the measurement for a hole saw is to the outside of the saw cup, not the inner diameter. Scrap that block of Zebrawood. Oh well, this is how we learn. I know this thread is about the drivers, but if you want to see some pics if the cups I would be happy to post them up

 

[pepku]

So replacing sr60 drivers by PX100 II drivers would be good idea? I was thinking about buying TURBULENT X drivers instead but PX100 price is so damn good... Now i have hybrid chamber : driver housing is made from aluminium and the other part is made from mahogany, like in the ps1000, ps500 but reverse. What do you think?

 

[7keys]

Great thread, It might be nice to have a closed cup to test some of those non Grado drivers in, I think I'll work on one.

 

[wje]

  So replacing sr60 drivers by PX100 II drivers would be good idea? I was thinking about buying TURBULENT X drivers instead but PX100 price is so damn good... Now i have hybrid chamber : driver housing is made from aluminium and the other part is made from mahogany, like in the ps1000, ps500 but reverse. What do you think?

 
No comment.  I'd hate for people to get the wrong impression.  

 
Then again, this is the "non-Grado" Grado thread.  

 

[fleasbaby]

Great thread, It might be nice to have a closed cup to test some of those non Grado drivers in, I think I'll work on one.

A classier StratoKOSSter? Perhaps we could refer to it as the Keyster?

Let me know if you need a tester, I have spent a good amount if time buggering around with Koss drivers....

 

[wje]

  Great thread, It might be nice to have a closed cup to test some of those non Grado drivers in, I think I'll work on one.

 
Actually, Sennheiser makes a closed version of the PX100 II, which is noted as the PX 250 II.  I'm not sure what the parameters are like for space requirements in the airspace behind the driver.  Or, not even sure if the driver used is the same as the PX100 II, or slightly different.  The PX250 II seems to run about $40 more -- in the $90 or so range.
 
I don't envision myself opting for the model MX250 anytime soon, though.
 
I would be curious as to how the Koss KSC drivers would work in closed cups, though.  I found them to be a bit "screechy" on the upper frequencies when used in Grado cups.  Also, the bass was falling a bit short of range where I'd like.  I then tried a small dab of Dynamat on the rear shells and noticed some "odd" things happening to the sound.  So, I reduced the amount of Dynamat quite a bit and just a very small amount on the backs of the shells, and then the sound seemed to come back a bit - yet, still a bit weak on bass, with a lot of energy in the upper frequencies.
 
I'm not sure what would happen if I were to just cut the back silver shells off the drivers with a Dremel?  If I were to liberate the drivers from the silver shell, the diameter of the driver would be quite a bit smaller and have trouble filling out the edges to fit into the cup and would have a lot of "slop" that would have to be filled with some other material.

 

[7keys]

A classier StratoKOSSter? Perhaps we could refer to it as the Keyster?

 

 

[wje]

A classier StratoKOSSter? Perhaps we could refer to it as the Keyster?

Let me know if you need a tester, I have spent a good amount if time buggering around with Koss drivers....

 
Classier as in diamonds on the cups?  Or, perhaps more bling as in chrome on the metal and plastic surfaces?
 
I get what you mean, though. A nice cut wooden pair of cups, leather headband, leather ear pad coverings, etc., etc.  It would be pretty classy with all the creature comforts that a headphone could offer.  I think I need to go through that whole thread a bit.  I'm not so sure my impressions of the Koss driver is quite as good as some others may feel.  Then again, I might be a bit jaded by the Sennheiser MX100 II drivers.  However, when it comes to a closed variation, I question how good the Sennheiser PX250 II would be.  It is about $90 and is a closed headphone, so the drivers are meant and built to operate within a closed can.  Then again, Sennheiser might be using the same drivers for the 100 and 250.  Hard to tell without seeing them side-by-side and listening to them.

 

[fleasbaby]

I need to try some of the PX100 II...the KSC75 is technically an open driver, and it performs well closed...perhaps the PX100 would also, and prove to be better.