[Varcharz]

Quote:

Originally Posted by scottymac /img/forum/go_quote.gif $180 for a pair of hd650s is a pretty damn good deal

You realise those aren't dollar signs but the symbols for British pounds? Meaning that 180 is roughly $360 USD.

 

[jterp7]

Varcharz, what source do you use with for the move>hd650?

Going by this thread the move would be considered a budget amp since it costs less than the hd650 itself

 

[chris719]

K701 is a lot harder to drive than HD650. K701 has a 64 ohm impedance. It also is less sensitive. Volume control has to be up quite a bit higher for K701 to reach the same level as HD650 on the same amp.

 

[ahamric]

Quote:

Originally Posted by chris719 /img/forum/go_quote.gif K701 is a lot harder to drive than HD650. K701 has a 64 ohm impedance. It also is less sensitive. Volume control has to be up quite a bit higher for K701 to reach the same level as HD650 on the same amp.

Doesn't the HD650 have a much higher impedance like 300 ohms? All things being equal, the K701 with a lower impedance should be the easier headphone to drive. Of course, less sensitivity is probably making a greater difference than the advantage of a lower impedance.

 

[chris719]

No, a lower impedance is harder to drive! Lower impedances require more current from the amp driving the load. The practical exception is where current is not a problem but voltage swing is, which only happens in a battery powered player generally.

 

[Piffles]

Top of the range AKG vs. top of the range Sennheiser.
Which is better, as the situation indicates, is only a matter of taste.

Generally speaking, people's impressions are:
K701:
+ detailed, crisp sound, good textures
- harsh, cold, analytical
HD650:
+ warm, rich, smooth, pleasant for long listens
- lack of edge, slow attacks on instruments, recessed highs

To choose between the two, the only way is to listen to them both.

 

[speakerhead]

Quote:

Originally Posted by scottymac /img/forum/go_quote.gif hmmm i wonder if this is legit, haha http://www.fonem8.com/index.php?act=...&productId=688

that price is in British Pounds

 

[scottymac]

i guess Froogle doesn't convert then... it said $180 bucks. oh well

 

[ahamric]

Quote:

Originally Posted by chris719 /img/forum/go_quote.gif No, a lower impedance is harder to drive! Lower impedances require more current from the amp driving the load. The practical exception is where current is not a problem but voltage swing is, which only happens in a battery powered player generally.

This doesn't seem to match my understanding. The equation is V=iR (Voltage = Current * resistance), which I am sure you know. We know that the resistance of various cans is R. I also thought that you basically get a standard voltage out of the amp. Therefore, at a given voltage, a lower resistance can will be benefiting from a higher current.

Am I missing something? It seems that most folks on the forum are under the impression that higher impedance means harder to drive.

 

[jellojoe]

Quote:

Originally Posted by ahamric /img/forum/go_quote.gif This doesn't seem to match my understanding. The equation is V=iR (Voltage = Current * resistance), which I am sure you know. We know that the resistance of various cans is R. I also thought that you basically get a standard voltage out of the amp. Therefore, at a given voltage, a lower resistance can will be benefiting from a higher current. Am I missing something? It seems that most folks on the forum are under the impression that higher impedance means harder to drive.

Maximum available current of any amp is not infinite so if the impedance of the load is very low, the power delivered to the load will be limited by the maximum amount of current.

 

[465]

Why do you left the Beyer880 out? If Senn is too bassy, and the AKG doesn't have enough bass, then Beyer it is.

 

[tottiflames]

K701 has much lower impedance than HD650, but it is true that K701 is as hard as HD650to be drive well.
And so far, I can't find a amp that is really fit to K701, unlike the HD650 has Lehman.

 

[ahamric]

Quote:

Originally Posted by jellojoe /img/forum/go_quote.gif Maximum available current of any amp is not infinite so if the impedance of the load is very low, the power delivered to the load will be limited by the maximum amount of current.

Current in the circuit will be determined by the voltage across the circuit and the resistance of the circuit. An infinitely small impedance would lead to an infinitely large current at a given voltage, but we know that the wires in the circuit itself have an inherent impedance so yes, there will be a maximum.