[goodyfresh]

  So basically at this point I am stuck between the ATH-M50Xs and the HD 598s so I am going to list the pros and cons relative to each other here:
 
Audio Technica ATH-M50X ($169):
 
Pros:
Subtle
Leather earcups (Comfortable, look nice)
Easily portable if needed
 
Cons:
Closed
Leather earcups (Not very breathable, sweat)
Extra Bass
 
Sennheiser HD 598 ($150):
 
Pros:
Open
Valuer earcups (Breathable, comfortable, look nice)
Wider soundstage
Better treble
 
Cons:
Valuer earcups (Collect lint, dirt, etc.)
Ends in a 1/4" plug instead of 3.5mm (need to buy another cable)
Flashy/gaudy (Not too important since these would stay by my computer at home)
A little lacking in bass (?)

If I'm not mistaken, while the cable that comes with the HD598 does end in a 1/4", it is packaged with a 1/4"-to-3.5mm adapter you can screw onto the end, so THAT at least shouldn't be an issue!  Quite honestly though yes, the HD518, 558, and 598 do mids and treble VERY well, but are all somewhat lacking in bass, which tends to be a more common issue in mid-range open-back hp's than closed-back ones.

Also, if you're using your computer's onboard sound-card, then yeah, it's probably bottom-of-the-bucket crap like most computer manufacturers use, and poorly isolated and implemented to-boot.  And so rather than JUST an amp, it would probably be a good investment to get a good USB-plug-and-play DAC/AMP combo, which should give a VAST improvement over your onboard sound.  If not that, at the very least learn how to use a player like Foobar2000 to send WASAPI or ASIO output (the latter by downloading something  like ASIO4ALL) directly to your listening device, rather than allowing things to be muddied and crapped-up by the internal windows mixing in your soundcard.  If you want to learn more about things like Foobar2000, WASAPI, and ASIO, you can search for them in the forums here.  Basically, WASAPI or ASIO, in a player like Foobar that supports them, will send bit-perfect output directly to your device, without any software mixing along the way to muddy-up the sound which tends to be the main issue with sound quality in Windows computers.  Anyway, supposedly some of the very best cheap ones (all can be found for under $100 on Amazon, and a couple of HiFiMeDIY's can be found as cheap as 50, although you don't want to totally cheap-out and get their so-called "Tiny" DAC model that costs like 25 bucks, you def want to spend 50 bare-minimum) are the Fiio E10, Fiio E07K, the various offerings from HiFiMeDIY, the Schiit Modi, and the SMSL SD793-II.  In the audiophile world, it seems as if external sound-cards are frowned upon as compared to external DAC units without a full-blown sound-card.  Also, a buddy of mine and I had a poor experience with one of Creative's external Sound Blaster cards. . .it pooped out and stopped sending proper sound to the left channel after a few months of use.

 

[goodyfresh]

  I think this amp might work for me, correct me if i'm wrong: Polsen HMA-41

4 Channels is more than you need.  If I were you, as I said in my above post, I'd shell out an extra 25 to 60 bucks beyond something like that, on a combo Amp/DAC, to not only drive your headphones better, but get some real noticable improvement over the sound-quality from your computer.  Trust me, it's wroth investing in.  I have the Fiio X3 2nd Gen music player, which doubles,j conveniently, as a USB DAC.  The MOMENT I started using it as a DAC for my laptop's sound, I decided then and there that I would NEVER AGAIN use my laptop's onboard sound to run speakers or headphones, because the difference is like night-and-day.

Also, incidentally, the Fiio X3 2nd Generation which I mentioned is pretty much the best budget digital music player for audiophiles.  Costs 200 bucks or less (I got mine, which was previously a store-display model, for 170) although you need to separately purchase a micro-SD card for storage on it, gets FAR better sound-quality than Smartphones, iPods, and the like, can play FLAC, ALAC, and other lossless files (if you're not familiar yet with lossless formats. . .they are SUPER DUPER important), and is able to double as a USB DAC   Of all my audio-related purchases so far, it is by-far my favorite, even more-so than my V-Moda M-80 headphones which I loveeee.

 

[Meetite]

 
If I'm not mistaken, while the cable that comes with the HD598 does end in a 1/4", it is packaged with a 1/4"-to-3.5mm adapter you can screw onto the end, so THAT at least shouldn't be an issue!  Quite honestly though yes, the HD518, 558, and 598 do mids and treble VERY well, but are all somewhat lacking in bass, which tends to be a more common issue in mid-range open-back hp's than closed-back ones.

That is true, but people say it is a bit bulky and over time will bend the end of the 3.5mm plug
 

Also, if you're using your computer's onboard sound-card, then yeah, it's probably bottom-of-the-bucket crap like most computer manufacturers use, and poorly isolated and implemented to-boot.  And so rather than JUST an amp, it would probably be a good investment to get a good USB-plug-and-play DAC/AMP combo, which should give a VAST improvement over your onboard sound.  If not that, at the very least learn how to use a player like Foobar2000 to send WASAPI or ASIO output (the latter by downloading something  like ASIO4ALL) directly to your listening device, rather than allowing things to be muddied and crapped-up by the internal windows mixing in your soundcard.  If you want to learn more about things like Foobar2000, WASAPI, and ASIO, you can search for them in the forums here.  Basically, WASAPI or ASIO, in a player like Foobar that supports them, will send bit-perfect output directly to your device, without any software mixing along the way to muddy-up the sound which tends to be the main issue with sound quality in Windows computers.  Anyway, supposedly some of the very best cheap ones (all can be found for under $100 on Amazon, and a couple of HiFiMeDIY's can be found as cheap as 50, although you don't want to totally cheap-out and get their so-called "Tiny" DAC model that costs like 25 bucks, you def want to spend 50 bare-minimum) are the Fiio E10, Fiio E07K, the various offerings from HiFiMeDIY, the Schiit Modi, and the SMSL SD793-II.  In the audiophile world, it seems as if external sound-cards are frowned upon as compared to external DAC units without a full-blown sound-card.  Also, a buddy of mine and I had a poor experience with one of Creative's external Sound Blaster cards. . .it pooped out and stopped sending proper sound to the left channel after a few months of use.

the issue is my computer only has 4 USB 3.0 ports and all except for 1 is in use and i occasionally need that one for flash drives and such, but if something can be found for less than or equal to 50 bucks that would be awesome.
 
I just can't shell out any more than like, 50 bucks, i just don't have that kind of money to be spending on things like this

 

[cel4145]

I'm personally thinking of an amp for the ATH-M50Xs and the HD 598s if i need it, but frankly I don't know if I do, I am a bit of a newbie to this.
My sound card has an output impedance of "<24 ohms" if that helps.

Which make/model is it?

Does the output impedance need to match or be greater than the headphone's impedance?

Optimally, the low output impedance of the headphone should be 1/8 lower (or even lower) than the headphone's impedance rating. Then the general impedance range that amps and sound cards give is just a general guide. Might or might not need more headphone amp depending on if headphones are difficult to drive. Notably, the HD598 are not.

 

[RRod]

  That is true, but people say it is a bit bulky and over time will bend the end of the 3.5mm plug

 
Cheap cables are easy to get for the 598. As far as the sound, here is the FR for it, the HD800, and PM-3 as measured by a binaural mic in my left ear:

 

[goodyfresh]

  That is true, but people say it is a bit bulky and over time will bend the end of the 3.5mm plug
 
the issue is my computer only has 4 USB 3.0 ports and all except for 1 is in use and i occasionally need that one for flash drives and such, but if something can be found for less than or equal to 50 bucks that would be awesome.
 
I just can't shell out any more than like, 50 bucks, i just don't have that kind of money to be spending on things like this

Then you should probably just go for the HiFiMeDIY Sabre USB DAC Digital to Analog Audio Converter available for 49.99 on Amazon, it's supposed to be the best "budget" solution among USB DAC's, and supposedly can drive most headphones with impedance under 100 to 200 ohms just fine, even though it's more of a DAC than an actual Amp.  There's also the Fiio E10K and the one frmo SMSL which I mentioned which both go for around 65 if I remember correctly, but you can probably find used for under 50.

Which make/model is it?
Optimally, the low output impedance of the headphone should be 1/8 lower (or even lower) than the headphone's impedance rating. Then the general impedance range that amps and sound cards give is just a general guide. Might or might not need more headphone amp depending on if headphones are difficult to drive. Notably, the HD598 are not.

Like cel4145 is saying, the HD598 are not hard to drive.  Neither are the ATH-M50x.  You probably wont' need any amp for them anyway, so I'd focus on a DAC to improve sound-quality out of your computer into the headphones, and just leave it at that.

The thing about an external DAC and/or using bitperfect WASAPI or ASIO output is, that if you DON'T do it, then you're not really getting the available sound-quality from headphones in the class you are looking to buy, and then, what would be the point of spending a couple hundred bucks on the phones, ya know?   You'll believe me if you DO get an external DAC and listen to the headphones with it, and hear JUST HOW MUCH BETTER it sounds than the headphones driven by your onboard sound-card.

Out of curiosity, what soundcard DOES your computer have?  What exactly is the computer, make and model?

   
Cheap cables are easy to get for the 598. As far as the sound, here is the FR for it, the HD800, and PM-3 as measured by a binaural mic in my left ear:

Ahahaha dude, you're comparing the HD598's freq-response to two models that each cost something like five times as much OR MORE than the 598.  That just isn't fair to the poor little HD598s, you shouldn't be having the HD800 and a pair of Planar-Magnetics bullying them like that, it's just mean

 

[cel4145]

As far as the sound, here is the FR for it, the HD800, and PM-3 as measured by a binaural mic in my left ear

Nice tool to have

 

[goodyfresh]

Nice tool to have

Right?  And my lord dude, just LOOK at that frequency-response on the PM3!  That is a thing of true beauty, right there. . .if only it weren't SOOOO far out of my price-range >_<

 

[Meetite]

I don't know exactly what sound card it is but my computer is a late 2013 27" iMac which I dual boot into windows

 

[goodyfresh]

I don't know exactly what sound card it is but my computer is a late 2013 27" iMac which I dual boot into windows

Well then I have no idea how it might sound since I've always been a devoted user of Windows computers, sorry.  But most likely (like 99 percent chance) an external DAC will undoubtedly give a HUGE improvement over its onboard sound.

 

[Meetite]

Well then I have no idea how it might sound since I've always been a devoted user of Windows computers, sorry.  But most likely (like 99 percent chance) an external DAC will undoubtedly give a HUGE improvement over its onboard sound.

Yeah, you are probably right.

 

[Meetite]

I am a little confused, so I know people have given examples of DACs except I don't know what to get, please link me to some which are good for about $40 or less

 

[goodyfresh]

I am a little confused, so I know people have given examples of DACs except I don't know what to get, please link me to some which are good for about $40 or less

$40 or less is not going to happen, honestly.  Literally the cheapest you can get that will actually give good sound will be 50.
 
http://www.amazon.com/HiFiMeDIY-Digital-Analog-Converter-Optical/dp/B00AOH5JTQ

Honestly though man what you really should get is an ASYNCHRONOUS DAC, because with non-async ones you can run into issues and hangups.  This is the cheapest good Async one:
 
http://www.amazon.com/HiFimeDIY-Sabre-U2-Asynchronous-optical/dp/B00EDHC5YU/ref=sr_1_1?s=pc&ie=UTF8&qid=1438365223&sr=1-1

 

[RRod]

  Right?  And my lord dude, just LOOK at that frequency-response on the PM3!  That is a thing of true beauty, right there. . .if only it weren't SOOOO far out of my price-range >_<

 
TBH it's a bit low in the upper range, though all of this is quite dependent upon what your particular ears do to the sound.

 

[Meetite]

Are the behringer UCA-202/222 any good?

I mean how big of an improvement is it? Because it might not be worth getting a DAC for below $50 at all and would be better to just run the headphones off my computer's built in sound card, save the money to buy games.