[KarmAbe]

Hi!

I have been spending much time yet to read and learn on Head-Fi, and I have been given the impression that low impedance phones will permit a higher amount of bass.

Like for the Beyer DT770 Pro 80ohm.
Also been heaaring of less bass in Senns 600/650, which are 250-300ohm.

Is there any relation at all?

I assume also from my reading that low impedance cans a well driven on low impedence sources (soundcards, CD/MP3 players). Am I right?

I also read that high impedance phones needs high impedance amps to feed them properly, and as such low imp cans need low impedance amps.
Does my soundcars/MP3 player has a low imp amp? or is it better said it has unamplified low impedance?

So much to learn!!!

Cya
KarmAbe (

going on

)

 

[smittysan89]

Well, that is not neccesarily true. The DT770/80 are huge huge bassheavy cans. So yes you should hear more bass from them than the 600/650.

Your sound card and mp3 player, will drive lower impendance phones better than higher ones.

 

[grawk]

The additional bass in the 770s doesn't come from the impedance, but rather from the design. The 770/250s have more (good) bass than any headphones available short of the grado PS1s.

 

[South_Korean]

the proximity of the driver can play a part in this as well. the HD6XX's have a driver farther away and are also open. the beyers are closed which produce more bass.

 

[sgrossklass]

Lower headphone impedance only equals more bass when the amp has a non-negligible output impedance. Of course the cans better be identical otherwise, like 120 ohm and 50 ohm HD595s. (*) When you get to very low impedances, you may even get less bass due to the output coupling caps (usually found on portables) getting too small (think highpass). I won't even mention the harsh distorted tinny sound you get out of simple opamp based amp circuits when loading them with low impedance cans. How much bass you can get out of cans is influenced by design (closed/semi-open/open - closed cans can go deeper, but are more difficult to handle at higher frequencies), the drivers you have and who knows what else.

*) BTW, does anyone else think that the current HD5x5s combine features in a somewhat strange way? On the one hand you get this clunky 1/4" plug geared towards home hi-fi equipment - not to forget about their size -, on the other hand the low impedance of 50 ohms would make them suitable for portables but not so great for anything with a moderately high output impedance (think impedance related bass hump). You end up with cans that truly are a jack of all trades but master of none - for a portable, a flexible adapter is needed (OK, exists, at least over the pond), and at home you either need an amp that can drive 50 ohm cans properly or an adapter that basically connects, say, 22 ohm in parallel to each channel. (The latter will reduce the output volume possible, but the impedance curve of the cans + resistor will be a lot flatter.)

 

[Banfi T.]

There is no connection between the impedance of the phone and the bass. At least, this parameter doesn't means anything without a context. As mentioned before the dumping factor (impedance of the can/output impedance of the amplifier) is one factor, but the design of the driver is also very important. To have a real life hi-fi analogy you literally kill out the musicality from a single driver speaker with a low output amplifier and vica-versa, don't dream to drive a Dynaudio speaker properly without high damping factor a lot of power. So there is no overall solution, there is more then one parameter in the equtation here. As i see...

 

[JunktionFET]

Indeed a lower impendance headphone will see a lower damping factor which can sometimes result in a little looser or warmer bass. This of course depends on the amplifier design used. An amp that is essentially an opamp or buffer with large value resistors in series with the output (so as to not overload the poor IC) has a relatively high output impedance and will have almost negligable damping into lower impendance headphones compared to an amp with a very low output impedance. Some headphones "reveal" damping better than others. It is said that once the damping factor gets much above 10 or so, you can't really hear the difference. Your mileage will vary of course

 

[flibottf]

Impedance matching only allow for maximun energy transfert. Sonic characteristics has to do with other factors.

 

[KarmAbe]

Wow, so much learned!

Basically, you match the cans impedance with the receiver/amp/source impedance to ensure maximum transfer of energy. In other words, you ensure this way the cans matche the source.

So I will get better bass of 80ohm phones if I plug them to my soundcard instead of my receiver (>=120ohm) because of better energy transfer.

Therefore eventually, when time to upgrade, I will suite a headphone amp to my 80 ohm cans to ensure max. energy transfer.

Did I get it right?

Now for some details:

sgrossklass: "When you get to very low impedances, you may even get less bass due to the output coupling caps...getting too small...I won't even mention the harsh distorted tinny sound you get out of simple opamp based amp circuits when loading them with low impedance cans"

Banfi T.: "To have a real life hi-fi analogy you literally kill out the musicality from a single driver speaker with a low output amplifier and vica-versa"

Based on those affirmations, would you recommend an impedance minimum for my cans? I don't want to suffer eventually of problems with low impedance amps/cans?
I now plan to run them through my RECEIVER (plugged to my soundcard), until I buy a dedicated headphone amp.

Cya!
KarmAbe

 

[JunktionFET]

Well... without going into a multi-paragraph dissertation, it really depends on the amplifier design used in the soundcard and in the receiver, as well as how you define "better bass". In the end, the only way to know for sure is to try both and pick the one you like better.