[Noshtero]

It's the best way I can describe it. They sound decent on music, but when I run them out of my headphone jack on my bass guitar combo amp, the bass guitar notes sound like farting. Like someone is doing Raspberries in my ear.

I figure either:
A) I got busted headphones
B) My headphone jack isn't pushing enough power to the headphones

Thoughts? I'm pretty worried about getting a $200 pair of headphones that sound absolutely horrible.

 

[dye1337]

try it with another pair of headphones, is it possible the amp sounds bad?

 

[philodox]

"They sound decent on music"

What are you plugging them into for listening to music? It sounds like they aren't getting what they need from your guitar amp.

 

[Kabeer]

Most likely the headphone jack doesnt have enough power. Or the headphone jack is just rubbish all together.

The headphone jack on my guitar amp is useless, it sounds nothing like the speaker, distortion sounds horrible, and its not my headphone (even happens when I use a portable amp in line)

 

[vvanrij]

Hahaha!!! Great thread title

!!!!

 

[Noshtero]

The combo amp headphone jacks powers other cheaper headphones I have just fine. I'll play around with it tonight on a few different sources and see what I find. If I'm not mistaken, the k240 MKiis should have a 55 ohm impedence, which I think should be fine on just about anything. I mean, I would think an Ipod should power them decently. Or am I way off?

I'm reluctant to buy a headphone amp just to find out the headphones themselves were crap.

Maybe I could take them to a guitar center and try them on their equipment.

 

[Dorder]

the akg studio phones are very hard to drive because they're low impedance and low efficiency, which means they need lots of current

 

[Seidhepriest]

K-240S does have an impedance of 55-ohm, true, but... It also has a low efficiency, and just about anything except stationary amps or the better portable amps can't "fill" them quite well. Even a player that can supply enough current may not be able to modulate enough current with enough power at higher frequencies, so the headphones will sound dark.

Oh, and AKG stock cable is a bottleneck too. Though shouldn't affect sound to such an extent, sounds like the amp is distorting and slipping notes.

 

[Noshtero]

So what's the fix? Headphone amp? Recommendations? I'd like to keep it as cheap as possible.

 

[MaZa]

Quote:

Originally Posted by Dorder /img/forum/go_quote.gif the akg studio phones are very hard to drive because they're low impedance and low efficiency, which means they need lots of current

But they still shouldnt sound farty at the bottom end. Just bit round and undefined/muddy at worst. (I own K240S, isnt MKII same headphone but facelifted?) Sounds like a problem with headphone itself to me.

 

[Seidhepriest]

Guitar amp>stationary amp>K-240S might work...

Or, it could be a physical problem, sometimes as simple as a hairline on the diaphragm (blowing might work).

 

[Noshtero]

New data:

I plugged them into the 1/8" headphone out on my computer subwoofer. I can play treble stuff as loud as I can stand and they sound great. The bass notes, however, distort really bad. You get that distorted muddy "Rawp, rawp" instead of "Boom boom". I plugged in a pair of cheaper AKGs, and they did similar things.

I plugged them into the 1/4" headphone out on my very high end digital piano and I was unable to get them to distort. I patched it to a bass guitar, and I could slam the low notes on the piano as loud as I could, and it did not distort at all.

Could I just get a portable headphone amp and go right from my bass guitar to the headphone amp to my K240 MK IIs? I really am only going to use these for bass guitar playing and recording. I prefer inner ear phones for travelling and general listening.

Is there a headphone amp that I can run both my bass guitar and my Ipod into? Is it a gaurantee that a headphone amp will have enough juice to power these things properly?

 

[Seidhepriest]

Looks like the guitar and sub headphone amps aren't powerful enough. They usually aren't, makers cust costs wherever possible.

A portable amp - sure, the cheapest (under $50) would be a CMoy amp or something like a Headphonia or R2V2 amp. A really good pairing would be the Minibox-D (a major delight with the recabled K-240S here), $100 plus shipping for Minibox-D+silver mini-to-mini cable from Head-Direct. Or, a CMoy amp could be built at home (projects over at HeadWize - Breaking News ), or, for something more detailed than a CMoy, a Mini-cubed amp: The Mini³ Portable Stereo Headphone Amplifier

 

[Noshtero]

More info.

The Headphones are 55 ohm

The book for the amp says it outputs at 8 ohm

I was told that you want your source to be 1/10th your rated load or less... so I would want something that outputs at 5 ohm or less. Does that sound right?

 

[tomb]

Quote:

Originally Posted by Noshtero /img/forum/go_quote.gif More info. The Headphones are 55 ohm The book for the amp says it outputs at 8 ohm I was told that you want your source to be 1/10th your rated load or less... so I would want something that outputs at 5 ohm or less. Does that sound right?

You have some of that info confused. One quality of an amp is its output impedance, but it's not published much - if at all. That's the quantity referred to when you state "source to be 1/10th your rated load or less ...".

On the other hand, an amp designed to output into an 8 ohm load is just a fancy way of saying it's a speaker amp.

Back to the issue at hand - you want a Mini3, something similar, or something better. I don't think a CMoy would cut it if you're truly having current issues, but then I haven't heard that the K240 low impedance version is that difficult to drive. You've just been plugging them into the absolute worst choices available (a subwoofer?).