Headphone impedance - high vs. low - educate me...

[napalmdeath]

I'm currently using Audio Technica ATH-M50X headphones with a Cube 20, and previously, with an RP1000 - Both sounded like shit. I know it's not the headphones, they're high quality, and highly recommended for studio mixing and such, but I'm learning they're possibly the wrong impedance.

I have to plead ignorance on this, I had no clue. I'm currently looking at pulling the trigger on a Helix LT, and it looks to be a 12 ohm input on the headphone jack, and if held true to the 1/8 rule, I should look for headphones better than 100? The AT's are 38. I'm guessing that's why they sound like shit with headphone inputs on the past two devices. I don't want to plunk down $999 and have the same ratty, shitty mess through these headphones!

Is there truth to this? Or, is it a matter that the Helix will address with a separate volume for that input. I've seen where Line6 recommends 150 - 600 ohm headphones, yet some say just turn it down! If it's a mis-match, I can't see a volume knob addressing the QUALITY of tone?

 

[Filter500]

Breaking the 1/8 rule for headphone impedance will make the bass a bit sloppier, but won't cause things to sound like shit IMO. The biggest issue with headphone impedance is the ability of a headphone amp to drive the headphones to a desired level without distorting. The M50X is not a hard headphone to drive, so that isn't issue. That said, they're not the greatest sounding headphones either. I have a pair, and the sound a bit nasal and bumpy in the midrange. M50s are popular mid-tier headphones for tracking work more than mixing. I wouldn't trust them for accuracy. As far as the shit sound, I would blame the source first and foremost. The headphone outs on those amps is likely to blame.

 

[Wizard of Ozz]

I'd advise looking at headphones rated at 50 Ohms or less for the Helix. I don't see the Helix (or any gear Line 6 makes for that matter) driving any sort of high impedance headphones (say anything over 100 Ohms). I've got quite a few sets of headphones and in order to drive the high impedance 250+ Ohms phones, the gear in question needs to be some high end high powered studio gear... like a direct AC powered AI, mixing board, tube mic preamp, etc. You can try using a high 250 Ohm rated set of headphones, but you might run out of room on the volume knob with the Helix, then you would need to purchase an additional headphone amp for like $50 and an additional cable.

 

[napalmdeath]

I'd advise looking at headphones rated at 50 Ohms or less for the Helix. I don't see the Helix (or any gear Line 6 makes for that matter) driving any sort of high impedance headphones (say anything over 100 Ohms). I've got quite a few sets of headphones and in order to drive the high impedance 250+ Ohms phones, the gear in question needs to be some high end high powered studio gear... like a direct AC powered AI, mixing board, tube mic preamp, etc. You can try using a high 250 Ohm rated set of headphones, but you might run out of room on the volume knob with the Helix, then you would need to purchase an additional headphone amp for like $50 and an additional cable.

The AT headphones I have now are 38. The Helix output is 12. I've read where Line6 recommends 150-600, as it's the best "match", impedence-wise. They claim there's plenty of juice, and that lower impedance will distort, and get shitty sounding.

Plan B would be to get a headphone amp and run it from the Helix. Many recommend that, I'm just trying to wrap my head around why. Are they optimized for lower impedance, like earbuds and such?? That sounds like the best option. They're cheap, and can clip right to your guitar strap, (and some will run off a 9-volt battery)!

 

[Wizard of Ozz]

I'd advise looking at headphones rated at 50 Ohms or less for the Helix. I don't see the Helix (or any gear Line 6 makes for that matter) driving any sort of high impedance headphones (say anything over 100 Ohms). I've got quite a few sets of headphones and in order to drive the high impedance 250+ Ohms phones, the gear in question needs to be some high end high powered studio gear... like a direct AC powered AI, mixing board, tube mic preamp, etc. You can try using a high 250 Ohm rated set of headphones, but you might run out of room on the volume knob with the Helix, then you would need to purchase an additional headphone amp for like $50 and an additional cable.

The AT headphones I have now are 38. The Helix output is 12. I've read where Line6 recommends 150-600, as it's the best "match", impedence-wise. They claim there's plenty of juice, and that lower impedance will distort, and get shitty sounding.

Plan B would be to get a headphone amp and run it from the Helix. Many recommend that, I'm just trying to wrap my head around why. Are they optimized for lower impedance, like earbuds and such?? That sounds like the best option. They're cheap, and can clip right to your guitar strap, (and some will run off a 9-volt battery)!

Many times companies recommend & claim things... but often times it falls short in-practice.

Usually a headphone amp would be used to boost the signal and volume... where the source unit output signal is too low to drive the headphones... guys have done this on the Fractal AX8 since it lacks a dedicated headphone output for example... but in the case you describe above, it's being used to cut the signal and reduce volume. Either way it should work and give you more room on the volume knob for adjusting.

 

[Filter500]

I'd advise looking at headphones rated at 50 Ohms or less for the Helix. I don't see the Helix (or any gear Line 6 makes for that matter) driving any sort of high impedance headphones (say anything over 100 Ohms). I've got quite a few sets of headphones and in order to drive the high impedance 250+ Ohms phones, the gear in question needs to be some high end high powered studio gear... like a direct AC powered AI, mixing board, tube mic preamp, etc. You can try using a high 250 Ohm rated set of headphones, but you might run out of room on the volume knob with the Helix, then you would need to purchase an additional headphone amp for like $50 and an additional cable.

The AT headphones I have now are 38. The Helix output is 12. I've read where Line6 recommends 150-600, as it's the best "match", impedence-wise. They claim there's plenty of juice, and that lower impedance will distort, and get shitty sounding.

Plan B would be to get a headphone amp and run it from the Helix. Many recommend that, I'm just trying to wrap my head around why. Are they optimized for lower impedance, like earbuds and such?? That sounds like the best option. They're cheap, and can clip right to your guitar strap, (and some will run off a 9-volt battery)!

Your problem is not an impedance problem. I know because I have several headphone amps with different output impedances and have tested various headphones from 32ohm to 250 ohms. I'm currently using a Mayflower Electronics O2, which has an output impedance under 1 ohm. It sounds crisper in the bass, but sounds no better otherwise than another amp I have which has an output impedance of 40 ohms. The 1/8 rule is overrated and applies more to control of transients and low end response in relation to the headphone's drivers. It's not the deal-breaker that some people make it out to be. If you look at some higher end headphone amps offered by Beyerdynamic, you'll see they use a 100 ohm output impedance and violate the 1/8 rule. It will give a different flavor but not turn the sound to shit. On headphones that have peaks in impedance, like the Sennheiser HD 558, a higher output impedance from the headphone amp will give a big bass bump in the low range where the impedance spike exists. My Motu Micro Book interface has an output impedance of 30 ohms at the headphone out, and is slightly inferior the the O2 because of power and distortion in the amplifier section rather than impedance.