I have an engineering challenge- need to prove the benefit of headphone amps/etc. - Page 2

Your dad is right to be skeptical. This site makes young people want things they don't need. What you get are high school students who spend a lot of time and money listening to the gear instead of the music. I'll help you convince your dad to buy you an E7 on one condition: invite him to watch you take a level-matched blind test. Bring your iPod Nano and your cans. I'll bring a Sansa Clip+, an E7 (or E9), and a voltmeter. Be warned: unless your iPod is malfunctioning, the differences could be subtle at best. I'll even give you a hint on what to listen for, but you might not figure it out unless you brush up on your basic electronics.

Edited by yuriv - 6/4/11 at 12:23am

hmm..a voltmeter is a must if you're trying to do something like that. You may also need information such as what i like to call the "golden operating voltage". The idea with the "GOV" is that every pair of headphones has a specific voltage range where they will put out the best sound. Anything above that will either cook the headphones or cause no discernible difference. Even though something may be underpowered, it doesn't mean that it can't play. It just means that it's not playing at the best it can be.

Have you heard of Fletcher-Munson curves before? They basically describe our ears' loudness sensitivity over the whole frequency range for various sound pressure levels.

 

At low sound pressure levels it is normal that bass frequencies are perceived to be a lot softer, so what you describe doesn't necessarily have something to do with the ipod.

Buy a fiio e5 it has bass boost, it can increase the output of your ipod and it is cheap.

The dac in the e7 isn't really much better than the one in the ipod, you most likely wouldn't notice a difference.

The fiio e5 is an excellent amp it is pretty much perfectly neutral an will add/subtract nothing from your ipod's line out (bass boost off of course)

 

If you want a dac to go with the e5 get a uca202, this combination will perform as well if not better than the e7.

http://rmaa.elektrokrishna.com/Various/FiiO%20E7%20vs.%20E5.htm this shows that the e5 performs pretty much as well as the e7.

I realise people will start yelling "Graphs tell you nothing" but in all honesty they provide a very good idea of how neutral something is and the e5 is perfectly neutral.

 

To tell you the truth differences between amps and dacs is ridiculously overblown and in a blind test almost no one could tell the difference between a decent $50 amp/dac and a $1000+ amp/dac.

But with bass boost on the e5 there is definitely an audible difference (frequency graph).

 

Edited by jackmccabe - 6/4/11 at 1:53pm

Have your father listen to the pre and post sound himself. I'll say that the control of the diaphragm will bring better details at lower volumes with an amp. In this respect, you would listen to your music at lower db because the details needed for satisfaction is present. An amp controls the starting and stopping of that diaphragm as well as providing the audio signal. Without enough power, a headphone will sound boomy and tinny and not very nice to listen to. How much that performance cost vs (subjectively) SQ becomes debatable.

Maybe another angle is to order an inexpensive DIY amp to be your first experiment. Implement the science into a lab. Nerds love labs.
Edited by Happy Camper - 6/4/11 at 2:35pm

I'd say if any of you and your dad can do a half decent soldering job then just get parts and build you own amp. I have a feeling that it won't only only give you better SQ than those Fiios but also you'll get some nice father and son experience. If he is a science guy then theres a good chance that he'll take buying parts into his own hands. Keep in mind that most likely your old man is not trying to argue that amps for headphones are rubish but rather trying to get his son to do some science. Also bonus points to you if things go the tubey way.

 

As Cave Johnson said- "Science is not about why, it's about why not!"

If you run across the proofs for why there are differences in cables, please pass them along.

Well, ever since I was strong enough to hold a screwdriver, I always have known that the best way to get acquainted with your (or anyone elses) things is to dismantle them! Then a few tweaks here and there and honestly- what is the worst that could happen? If some thingies (if they're small then probably not important) are left over after putting it all together, then just pour them in and screw on the lid!

Edited by RudeWolf - 6/4/11 at 4:14pm