What would happen with capacitors on headphones? - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems

Headphone Systems Everything to do with Headphones

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th April 2012, 01:30 AM   #1
Nazo is offline Nazo  United States
diyAudio Member
 
Join Date: Nov 2010
Location: Alabama
Default What would happen with capacitors on headphones?

So I have HD280 Pro headphones in addition to my other headphones (a modified HD555.) I mostly use the other headphones, but every now and then I have to use the HD280 Pros (particularly if doing things out in public.) As anyone who is familiar with them must surely already know, the bass is terrible on them. I've already done the so called BluTak mod which absolutely helps, but it still leaves some of the fundamental problem -- the bass response itself. It's kind of a pain relying on equalizers -- especially since many devices lack a proper equalizer or even one at all. (Not that it occurs to any of them to ever actually LOWER bass, lol. There just aren't presets for this sort of thing and only graphic equalizers can cut it really.) Plus it's a pain on those that do have real equalizers since I have to switch back and forth for use with my normal headphones (especially since my normal headphones are some modified HD555s so this sort of bass reduction is only going to hurt, lol.)

I have no clue if you can really use a capacitor on headphones, but first as a test I tried to simulate the effects of a first order filter using the foo_dsp_xover filter (set to only do one highpass filter at about 60Hz to get it kind of close to where that ugly hump starts based on the frequency response graph from HeadRoom) and I'd say the results were excellent. It definitely took the edge off the bass and got rid of the worst of the distortive effects in some of the more bass-heavy music that I tried. It's not perfect and some careful equalization settings could of course do better, but it does a great job and would be perfect for keeping these as universal and portable as possible without having to fight with equalizers and such just to deal with the bass. The only catch is, as far as I can tell I'd need a fairly odd value capacitor (about 41uF according to the calculator.)

So I have this question: what would actually happen if I actually tried to use a capacitor on headphones? As I understand it, many amps apparently actually use capacitors on their outputs mostly to protect the DAC or something. I'm also using them with lower quality outputs like my PSP and I don't like using an external amp with these (they don't really benefit all that much anyway) so there's a bit of a range of devices they are used with. I never really fully understood how things like capacitors really work as it is, but how they would work (or not work) together especially is something I'm unsure about. Would this work, or would it just go very wrong or be a waste of time if I tried it?

Also, obviously I don't have capacitors like that just lying around and would have to order some. IF this would actually work, I'll still need to actually get the capacitors. Because it's such an odd value, I don't really get a huge selection available even if I just go by some that are fairly close (like 40uF for instance.) I don't want the filter to go too high since there's already a bit of a dip in the upper ranges of the bass (and more importantly, the mids are a bit recessed as it is, so I don't want to hurt them any) and if it goes much lower than 60Hz it starts to lose its usefulness. Besides places like Mouser, is there anywhere else I should be looking? I think I'm not going to get any real options as far as quality is concerned but it would be nice to have options at all at least and I'm not seeing many promising ones in that range on Mouser at least. I may just make a small part for the headphones to plug into that would hopefully not be too inconvenient (I'll probably do this first as a test,) but it would be nice if I could actually put the capacitors in the headphones directly if this works. Either way, I definitely can't use some of the positively gigantic capacitors that showed up in my initial searching at least. (Also, I have no idea what sort of voltage requirements it might have. These are fairly low power headphones so I can't imagine it would take a lot, but perhaps they still need to be of a certain minimum voltage rating?)

Is the whole idea just crazy, or is there maybe some chance it might actually work? If so, it could really do a great job of "fixing" these headphones so to speak.
  Reply With Quote
Old 9th April 2012, 02:13 AM   #2
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Looks like the nominal impedance is 64 ohms. If you want a first order high-pass at 60Hz, a 41.4uF (microF) capacitor series will do the trick. Closest standard value is 47uF, polarized. I would use that.
You could put two 90uF polarized in anti-series to create a non-polarized 45uF if you think the output device doesn't have capacitors.
  Reply With Quote
Old 9th April 2012, 03:24 AM   #3
Nazo is offline Nazo  United States
diyAudio Member
 
Join Date: Nov 2010
Location: Alabama
Quote:
Originally Posted by SoNic_real_one View Post
Looks like the nominal impedance is 64 ohms. If you want a first order high-pass at 60Hz, a 41.4uF (microF) capacitor series will do the trick. Closest standard value is 47uF, polarized. I would use that.
You could put two 90uF polarized in anti-series to create a non-polarized 45uF if you think the output device doesn't have capacitors.
I have to assume that the output device probably does have capacitors though.

47uF does appear to be too high. That's pretty close to 50Hz rather than 60 and when I tested it in Foobar2000 originally, 50Hz seemed to be too low. It's better than nothing I guess, but it's definitely best to aim for 60Hz as much as possible even if it means dealing with trying to find non-standard capacitors.
  Reply With Quote
Old 9th April 2012, 03:51 AM   #4
djQUAN is offline djQUAN  Philippines
diyAudio Member
 
Join Date: May 2004
Location: manila
Send a message via MSN to djQUAN Send a message via Yahoo to djQUAN
I would guess the voltage would be low as any higher on headphones and you'll be deaf. A cap rated at 10V should still be fine.

2x22uF in parallel would yield 44uF. 100uF and 68uF in series would yield 40.476uF.
  Reply With Quote
Old 9th April 2012, 05:08 AM   #5
diyAudio Member
 
Join Date: Jul 2005
Location: Fairfield, IA
Default If you try it...

I'd recommend using very high quality caps. For a moderately inexpensive cap in that range you could try the 40uF caps from Dayton, bypassed with one of their excellent 0.47uF foil caps. Here are some links:

For the 40uF caps
Dayton Audio DMPC-40 40uF 250V Polypropylene Capacitor 027-442

For the 0.47 uF caps:
Dayton Audio DFFC-0.47 0.47uF 400V By-Pass Capacitor 027-458


Of course you could spend more and get these pricier Dayton caps (some people swear by them), also with the foil bypass caps:
Dayton PMPC-40 40uF 250V Precision Audio Capacitor 027-260

I've used them and like them a lot, they really give the uber-expensive caps a run for their money. And with headphones, you're likely to hear the difference these will make, especially inner details the mids and upper registers. If you use these caps and your amp already has coupling caps in line with the headphones, you might want to eliminate those by shorting'em with a jumper wire.

Let us know how this pans out, I'd be interested to know if the impedance bump in the headphone's response doesn't still make it sound a little wooly/slow/fat/bassy.

BTW, it could also be that your headphone amp doesn't handle the aforementioned impedance bump very well, in which case one of the C. Moy headphone amps should help... check on ebay, there are dozens of them.
__________________
Commercial Site: www.HolisticAudio.com

Last edited by Jack Caldwell; 9th April 2012 at 05:10 AM.
  Reply With Quote
Old 9th April 2012, 05:11 AM   #6
Nazo is offline Nazo  United States
diyAudio Member
 
Join Date: Nov 2010
Location: Alabama
Well, on the voltage rating I just wanted to be sure since as I understand it it seems to be used more as a wattage rating or something in audio by most uses. Of course, we're talking about in the milliwatt ranges, so I mostly just wanted to be sure I didn't need to watch out for maybe some extremely low rated capacitors or something.

I was playing around with the filtering a bit more. I was worried that a filter that's too high would be bad, but it looks like I can actually get away with raising a fair bit. That little dip seems to not hurt things as badly as I feared it would. Well, bear in mind that my usual headphones are the HD555s, so some bass rolloff is obviously ok and this still isn't even remotely like the HD555s, lol. Sadly, it still lacks their particular "quality" of bass (I can't really put my finger on it, but to me something about the bass on the HD555s is just amazing to me) even with the filter (and obviously nothing short of some massive equalization will do anything for its weaknesses in the midranges) I was playing around and setting higher is actually ok within reason. So far in just some quick tests, I think I might be ok with as much as 113Hz even (22uF) for me. Though I can definitely tell that it wouldn't be ok for most people like this and they'd have to aim lower. Since a first order filter is actually a fairly light curve anyway (especially at such low ranges) its effect isn't terribly strong. Still, is there any standard value a bit lower than 113Hz (or higher than 22uF I should say) that I should test? If standard values suit me then I'll probably be more likely to find something that I can actually integrate into the headphones instead of keeping external.

This still begs the question of what will happen if the output of the device has a capacitor on it though. I guess what I'm really wondering is how strong the effect might be. If it's just a subtle effect that maybe shifts the curve just a bit, it's no big deal. If it's huge obviously that's a problem. I'm not really clear on just what sorts of capacitors they even use or exactly how they are set up, I just know that I've read that amps sometimes have capacitors on the output. It would be silly to order something and go through all the trouble to set it up on there only to find out that it won't work with the stuff I need it to work with most.

EDIT: Took too long to write my post (my browser keeps crashing due to something on another site freaking out whenever my connection messes up) and you got one in behind me there. First, those capacitors are HUGE. They're meant for speakers, not headphones. Second, I do think I will aim a little higher after all. Finally, while I do want them to be decent, I'm not going to be too fussy over quality since these aren't exactly the best headphones in the world. Just as long as they aren't actually bad it will probably be ok.

Oh, and as far as amps go, the fundamental issue is in the headphones themselves just actually having that sort of response curve. I get basically the same results from everything. For the record though, my favorite amp (the one attached to the Alien DAC I'm listening with on this computer) isn't just a CMoy, but one with the Analog Devices AD8620 OPAMP (via an adapter) which IMO blows away all the Burr-Browns and etc. (I actually have an iBasso D3 "Python" which I originally got for different headphones that don't suit me as well and I love the sound of this CMoy with the AD8620 far better in fact. So far as I can tell the only catch is that it eats 9V batteries for a light snack before breakfast. I was burning through alkalines and rechargeables pretty quickly for a while there. I gave up and got an adapter that lets me plug 6xAAs into a 9V plug and now it has been going strong for a very long time indeed. Part of the problem is they just don't make 9V batteries very well anymore since they are so rarely used and mostly just cram cheap Chinese-made AAAAs into the case with most 9V batteries.) As far as I can tell, none of the amps really seem to help with the quality of the bass on the HD280 Pros whether higher end or lower end. In the end, it's just due to their design and the not exactly high volume casing of the headphones themselves (I think before I modded them my HD555s actually had more room inside!)

Last edited by Nazo; 9th April 2012 at 05:23 AM.
  Reply With Quote
Old 9th April 2012, 05:28 AM   #7
diyAudio Member
 
Join Date: Jul 2005
Location: Fairfield, IA
Default If it needs to be small...

Maybe the best option would then be some Elna Silmic, 20 or 22uF. You could probably get away with as little as 6.3V rating, with the signal levels you're generating you'd probably never damage the cap. Heck, even a 3V cap would likely work OK.

Those special CMOY amps should have zero trouble driving the cans with a series cap.

I'm still thinking the impedance bump is gonna make it sound fat and or slow, even with the cap.
__________________
Commercial Site: www.HolisticAudio.com

Last edited by Jack Caldwell; 9th April 2012 at 05:32 AM.
  Reply With Quote
Old 9th April 2012, 05:52 AM   #8
Nazo is offline Nazo  United States
diyAudio Member
 
Join Date: Nov 2010
Location: Alabama
I'm not as worried about the CMoy as the rest. I almost never actually use the HD280s on it, I was just saying that it's among the things I've tested with. The CMoy can't really be very portable (it stays in a fairly large tin along with the Alien DAC) and I can't really afford to make one that is portable just now. Also, I really hate using an amp and try to avoid it when I can. I've actually even mostly focused on DAPs that don't need external amps such as practically everything Cowon makes and I now have an Archos 43 "Internet Tablet" (aka PDA since it's a small one that fits in a pocket rather than a true "tablet.") But my biggest concern are things like the PSP. It has a terrible sound system, but still manages to drive these headphones sufficiently for music games and it's probably these music games where I'm most concerned about the HD280s.

And yeah, nothing will ever 100% fix the bass. I don't even think equalization can get it completely right. I'm just trying to "tame" it so to speak.
  Reply With Quote
Old 9th April 2012, 06:06 AM   #9
diyAudio Member
 
Join Date: Nov 2009
Location: Los Angeles
Quote:
Originally Posted by Nazo View Post
I'm not as worried about the CMoy as the rest. I almost never actually use the HD280s on it, I was just saying that it's among the things I've tested with. The CMoy can't really be very portable (it stays in a fairly large tin along with the Alien DAC) and I can't really afford to make one that is portable just now. Also, I really hate using an amp and try to avoid it when I can. I've actually even mostly focused on DAPs that don't need external amps such as practically everything Cowon makes and I now have an Archos 43 "Internet Tablet" (aka PDA since it's a small one that fits in a pocket rather than a true "tablet.") But my biggest concern are things like the PSP. It has a terrible sound system, but still manages to drive these headphones sufficiently for music games and it's probably these music games where I'm most concerned about the HD280s.

And yeah, nothing will ever 100% fix the bass. I don't even think equalization can get it completely right. I'm just trying to "tame" it so to speak.
If you're using a CMOY why not build active EQ into it? I did that back in '84 at a TV station so the 'talent' wouldn't mess with the LF filters to eliminate close mic proximity effects in the sound booth. It made everybody happy. I added 12dB of low end boost so they thought they sounded 'right' (to themselves of course) and left all the LF cut switches active (except the one new non-switchable filter I added). Of course if the 'talent' REALLY knew what I had done besides giving them new headphones.......

G
  Reply With Quote
Old 9th April 2012, 06:12 AM   #10
Nazo is offline Nazo  United States
diyAudio Member
 
Join Date: Nov 2010
Location: Alabama
Like I said, I don't really use the HD280 Pros with the CMoy. That was just for testing purposes mostly. Also like I said, I hate using external amps with portable devices such as the PSP. Such devices may not drive them perfectly, but low power headphones like these actually do surprisingly well with such headphones.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What would happen if... nguarino Multi-Way 8 13th January 2012 03:34 PM
How did this happen carshateme Car Audio 34 7th October 2011 03:03 AM
what would happen if.........? pointy Tubes / Valves 10 17th January 2010 11:42 PM
what would happen if... aletheian Tubes / Valves 8 14th September 2005 04:34 AM
What happen to my sub! Mikka Multi-Way 22 7th October 2002 02:16 AM


New To Site? Need Help?

All times are GMT. The time now is 07:00 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2