Just listened to some Fostex T50RPs today... WOW!
Apr 3, 2013 at 8:36 AM Post #10,081 of 11,345
Quote:
My Q701 usually gets a lot more use than my T50rp, but tonight I've been using the T50rp for several hours sampling a good deal of my music library. I use to think that my T50rp didn't really have that much more bass than my Q701, but I've changed my mind. They bass is plentiful and big. There is still one thing that I can't place my finger on though. I can't tell if my T50rp has too much in the lower mid-range and upper bass region or if it's just the smaller soundstage that sometimes makes them sound congested. Either way, sometimes they sound a bit congested to me, not really muddy or slow, just congested. If I cut out about 3-5db from the 250-500hz area with an EQ they sound cleaner to me. Anyway to fix this without resorting to EQ?

 
I've noticed this routinely with Shure 840 pads. While they improve overall bass, they seem to overdo it between 70-250 Hz by +3 to +5 dB, depending on the rest of the damping scheme used. Try EQ'ing down by 3 dB, then by 5 dB, between 70-250 Hz, leave 250 to 500 Hz alone, and then take a listen. If this solves the congestion (good description, BTW) you hear, an easy tuning method is to make a "modified bass port" using tape on the outside of the cup vents.
 
A "modified bass port" does not increase bass, it *controls* bass bloat by lowering the FR from about 300 Hz all the way down to 10 Hz. Make sure you completely cover all 4 slots with tape, with no gaps at the corners. I do this by placing/aligning a piece of masking tape over one of the "top" sides of the cup adjacent to the vents (on the cup area where the logo and jack are located), press the tape down onto the cup vent "side wall," and smooth it out all the way across the vent slots, back up the opposite "side wall" and over the back of the cup using the edge of a mini-screwdriver. Next, use an X-Acto Knife to trim off 1/2 of the tape along each "side wall" and peel off those sections of tape. Use the screwdriver to press the tape down along the bottom edge of the "side walls" right next to the edge of the cup vent slots. This method makes a complete seal over the vent slots with no gaps.
 
Listen/measure with the cup vents completely sealed. You will notice the congestion disappears but you *may* also notice you lost too much bass quantity. If so, use your X-Acto Knife to cut open a 3 mm wide opening in the tape overlaying the middle of one of the vent slots; the height of the "modified bass port" is 1.5 mm because this is the height of the slots. Re-test. Depending on what your hear, try increasing/decreasing the width in 1 mm increments until you dial it in for your particular mod configuration. Believe it or not, 1 mm either way makes significant difference in measured FR. Typically with my mods, I find 4 mm is the sweet spot but this varies from one modded set of 'phones to the next, no matter how careful I am when implementing the same configuration on two sets of headphones.
 
Once you've determined the size that works best for you, you can transfer the "modified bass port" to the inside of the cup vents for a permanent fix. I described this method, with photos, in the tuning section of Incremental Mods and Measurements, located just before Graph #56. Alternatively, you can keep the modified bass ports on the outside so you can change the Bass FR "on the fly" as may be needed with certain music genres and when using different amps and DACs.
 
Hope this helps. Please report back with your results if you try this method.
 
FWIW, I've also noticed that after installing/removing the pads many times, the FR deteriorates. I think this is likely due to the flaps stretching out too much and losing pad-to-cup seal. This is where Aleene's Fabric Fusion double-sided tape comes in handy, but only after the tuning process is complete; it's hard to remove once installed.
 
Apr 3, 2013 at 12:14 PM Post #10,082 of 11,345
Just finished my starter mods last night and am listening at my desk this morning...amazing what a little plasticine and Silverstone with some new pads will do. Going to mess with bass ports and cotton filling in a week after giving this configuration a good going over.

They respond remarkably well, un-amped, to my Cowon J3 as well...
 
Apr 3, 2013 at 12:40 PM Post #10,083 of 11,345
Wow, thanks for the long response. Unfortunetely i am already using a modified bass port and i still feel there is to much in the upper bass/lower mids. Im really not sure what else to do. Right now i have the outside taped off and then in each side i have two small pen tip sized holes in the tape.
Quote:
 
I've noticed this routinely with Shure 840 pads. While they improve overall bass, they seem to overdo it between 70-250 Hz by +3 to +5 dB, depending on the rest of the damping scheme used. Try EQ'ing down by 3 dB, then by 5 dB, between 70-250 Hz, leave 250 to 500 Hz alone, and then take a listen. If this solves the congestion (good description, BTW) you hear, an easy tuning method is to make a "modified bass port" using tape on the outside of the cup vents.
 
A "modified bass port" does not increase bass, it *controls* bass bloat by lowering the FR from about 300 Hz all the way down to 10 Hz. Make sure you completely cover all 4 slots with tape, with no gaps at the corners. I do this by placing/aligning a piece of masking tape over one of the "top" sides of the cup adjacent to the vents (on the cup area where the logo and jack are located), press the tape down onto the cup vent "side wall," and smooth it out all the way across the vent slots, back up the opposite "side wall" and over the back of the cup using the edge of a mini-screwdriver. Next, use an X-Acto Knife to trim off 1/2 of the tape along each "side wall" and peel off those sections of tape. Use the screwdriver to press the tape down along the bottom edge of the "side walls" right next to the edge of the cup vent slots. This method makes a complete seal over the vent slots with no gaps.
 
Listen/measure with the cup vents completely sealed. You will notice the congestion disappears but you *may* also notice you lost too much bass quantity. If so, use your X-Acto Knife to cut open a 3 mm wide opening in the tape overlaying the middle of one of the vent slots; the height of the "modified bass port" is 1.5 mm because this is the height of the slots. Re-test. Depending on what your hear, try increasing/decreasing the width in 1 mm increments until you dial it in for your particular mod configuration. Believe it or not, 1 mm either way makes significant difference in measured FR. Typically with my mods, I find 4 mm is the sweet spot but this varies from one modded set of 'phones to the next, no matter how careful I am when implementing the same configuration on two sets of headphones.
 
Once you've determined the size that works best for you, you can transfer the "modified bass port" to the inside of the cup vents for a permanent fix. I described this method, with photos, in the tuning section of Incremental Mods and Measurements, located just before Graph #56. Alternatively, you can keep the modified bass ports on the outside so you can change the Bass FR "on the fly" as may be needed with certain music genres and when using different amps and DACs.
 
Hope this helps. Please report back with your results if you try this method.
 
FWIW, I've also noticed that after installing/removing the pads many times, the FR deteriorates. I think this is likely due to the flaps stretching out too much and losing pad-to-cup seal. This is where Aleene's Fabric Fusion double-sided tape comes in handy, but only after the tuning process is complete; it's hard to remove once installed.

 
Apr 3, 2013 at 2:10 PM Post #10,084 of 11,345
Listened last night after taking a week long break from my T50RP.  Still very satisfied with these headphones, and their abilities.  I own a pair of Orca speakers which have a very similar sound to the headphone which is great when I want the same lovey sound without annoying people late into the evening. 
 
Drop Stay updated on Drop at their sponsor profile on Head-Fi.
 
https://www.facebook.com/drop https://twitter.com/drop https://www.massdrop.com/?clickid=3QR3Ib27lyA-VkBRJwyGuQJeUkhUQvX5r0tLzQ0&utm_term=252901&utm_content=VigLink&utm_medium=affiliate&utm_source=impactradius&irgwc=1
Apr 3, 2013 at 2:17 PM Post #10,085 of 11,345
Quote:
My Q701 usually gets a lot more use than my T50rp, but tonight I've been using the T50rp for several hours sampling a good deal of my music library. I use to think that my T50rp didn't really have that much more bass than my Q701, but I've changed my mind. They bass is plentiful and big. There is still one thing that I can't place my finger on though. I can't tell if my T50rp has too much in the lower mid-range and upper bass region or if it's just the smaller soundstage that sometimes makes them sound congested. Either way, sometimes they sound a bit congested to me, not really muddy or slow, just congested. If I cut out about 3-5db from the 250-500hz area with an EQ they sound cleaner to me. Anyway to fix this without resorting to EQ?

 
One of my only complaints with these headphones is how the upper bass does seems to crowd the mids and push them further back than I'd like.  I did add dome cotton stuffing into the cups which help this issue and I might add some more stuffing soon to see if it continues to help bring the mids forward.
 
Drop Stay updated on Drop at their sponsor profile on Head-Fi.
 
https://www.facebook.com/drop https://twitter.com/drop https://www.massdrop.com/?clickid=3QR3Ib27lyA-VkBRJwyGuQJeUkhUQvX5r0tLzQ0&utm_term=252901&utm_content=VigLink&utm_medium=affiliate&utm_source=impactradius&irgwc=1
Apr 3, 2013 at 9:34 PM Post #10,086 of 11,345
Quote:
Wow, thanks for the long response. Unfortunetely i am already using a modified bass port and i still feel there is to much in the upper bass/lower mids. Im really not sure what else to do. Right now i have the outside taped off and then in each side i have two small pen tip sized holes in the tape.

 
LOL! Sorry, I should have asked First.
Quote:
 
One of my only complaints with these headphones is how the upper bass does seems to crowd the mids and push them further back than I'd like.  I did add dome cotton stuffing into the cups which help this issue and I might add some more stuffing soon to see if it continues to help bring the mids forward.

 
Maybe try a little more and/or a modified bass port?
 
Apr 4, 2013 at 3:36 PM Post #10,087 of 11,345
I've finished every mod today but is it normal that i just can't drive them anymore with any of the 3  AVR in my house? the felt on top of the driver seems to have mutten everything by 20db easily!
 
oh i user super thin adesive felt around 1mm
 
Apr 4, 2013 at 4:55 PM Post #10,088 of 11,345
You put the adhesive felt on the driver? That will block out all sound because the adhesive layer is non-breathable.
 
Apr 5, 2013 at 6:26 AM Post #10,092 of 11,345
I picked up a pair of these a month a go at a trip to NYC.
 
So far I've put modelling clay in the baffel, dynamat extreme and cotton balls in the cups, made a treble reflector and replaced the pads with 840's (also tried HM5 and Hfiiman pads but I prefer the Shure's). In addition I had a V-moda cable around home that I'm also using.
I'm very happy witht he result so far and just wanted to say thank you to everyone that has contributed to this thread since I never would have figured out all of this on my own
beerchug.gif

 
Apr 6, 2013 at 12:35 AM Post #10,095 of 11,345
Please don't rip into me too hard here guys.
I've decided to set aside a bit of money from my tax return for headphones, enough for either a fostex t40/50rp and mods or a rock it r50 IEM(and new pads for my mdr-v7). I have a sansa clip zip and a rk3066 based tablet with an unknown but pretty good DAC/amp (for reference it can drive my headphones almost twice as loud as the clip). But budget constraints don't allow for an amp just yet.
Can the sansa clip drive the t50rp well enough to work for now till I gather a bit more for an amp? Or should I skip the fostex for now and go for the IEM instead since they are a lot easier to drive? I want the fostex because from everything I've heard, they can be modded to endgame level in the things I value most in a full sized closed can.
Also, t40rp + alpha pads or t50rp + shure pads? Word is they have the same driver
 

Users who are viewing this thread

Back
Top