[starscream]

I keep reading on the threads about the D2 having a roll-off. Then that using a headphone-amp recitifies this.

How is this exactly? Is the headphone-amp 'artificially' increasing those frequencies to achieve this, or is just restoring what is originally there somehow? I thought that if the bass is rolled-off going into the amp, then it would be rolled-off on the way out, unless the amp is colouring the sound?

Is this the case for highs too?

 

[wnmnkh]

D2 bass roll off happens due to the limitation of amplification section of D2 by coupling caps when loaded.

With an amp, there is virtually no load to D2's amplification section, so bass roll off does not happen in the first place.

Most solid state amp (a.k.a non-vacuum tube amp), from my experience, hardly color the sound -the players themselves color the sound worse than amps.


Edit : not for high. And a properly made amp does not artificiality increasing any frequency area.... that's what equalizer for.

Plus : of course, not only D2, virtually almost all portable players suffer same problems (one of very few notable exceptions is 1st gen ipod shuffle.)

 

[starscream]

The D2 uses a mini-to-mini from the headphone out when connecting to a headphone-amp right? How does simply the fact that an amp is connected to the headphone out instead of headphones suddenly stop the load going to the D2's amp?

 

[Punnisher]

Because the amp is supplying all the voltage and current to the headphone. The D2 is just supplying the audio signal at that point.

It's true though. The D2's bass rolloff is gone when using an amp. There is more bass impact and quantity.

 

[E.B.M.Head]

The bass roll off only affects low resistance headphones (most portable players are affected by this btw). An Amp or an 120 Ohm Adapter will help.

 

[tessss]

Quote:

Originally Posted by E.B.M.Head /img/forum/go_quote.gif The bass roll off only affects low resistance headphones (most portable players are affected by this btw). An Amp or an 120 Ohm Adapter will help.

Sorry to hijack this thread for awhile.
Then may i ask is the UM1 a low resistance earphone, and will it have serious roll off with the D2.

That means if i connect the D2 to a hi-fi set or active speakers, the bass roll-off would be gone right, since the speakers have amp internally.

 

[RedSky0]

Quick google gives me 25 ohms for the UM1.

I dunno, I've tried a Mini3/FiiO with my previously owned D2 and the sound sig of it didn't change. The bass still didn't extend deep enough, and it was never punchy enough. I mean sure adding an amp helps, but it just boosts certain aspects of the sound. You might be happy with that though.

I mean I've seen the graphs that show the bass roll off seems to dissapear with higher impedance phones, but I don't feel like the player sounds fundamentally different, the bass felt just as absent switching the AD700s with HD600s on multiple players (for me anyway).

 

[E.B.M.Head]

It depends a bit on the used headphone. If it's one with "insane" bass level like the DT-X 50 or the q-jays, then you might still get a decent bass, as the headphone compensates the roll off. But "flat" earbuds will definitely have a hearable bass roll off.
The easiest solution is to add a resistor in line and pull up the volume a bit.

 

[tessss]

Quote:

Originally Posted by E.B.M.Head /img/forum/go_quote.gif It depends a bit on the used headphone. If it's one with "insane" bass level like the DT-X 50 or the q-jays, then you might still get a decent bass, as the headphone compensates the roll off. But "flat" earbuds will definitely have a hearable bass roll off. The easiest solution is to add a resistor in line and pull up the volume a bit.

May I know how do I add the resistor, as in are there other posts or websites which shows how we do the adding of resistor.

Does many head-fiers do the addition of resistors to their Cowan D2


thankyou

 

[RedSky0]

You can buy something like this:

ETYMOTIC ER4P TO ER4S RESISTOR ADAPTOR - eBay (item 300259377942 end time Sep-23-08 18:58:51 PDT)

You can choose the impedance to determine the degree of the effect you want.

Not sure how many people use them or some other resistance adapter but I've seen them mentioned several times.

 

[toughnut]

Freq Response with impedance

hope that help. just try to increase your IEM total impedance to 80+ Ohms

 

[kazakore]

Quote:

Originally Posted by toughnut /img/forum/go_quote.gif Freq Response with impedance hope that help. just try to increase your IEM total impedance to 80+ Ohms

Even with the 80Ohm test the deviation is just 0.5dB, really nothing to worry about! Would of been good if there were more measurments in the range 16 - 80 Ohm, to cover the area most headphoens fall in.

What does surprise me is the amount of crosstalk those tests show the D2 exhibiting.

 

[tessss]

What if lets say I do not want to add resistors, will the fiio E3 do the job of preventing the bass-roll off of the Cowan D2 as effective as the resistors.

 

[kazakore]

I don't know the input impedance of the FiiO but I imagine it would do yes. Amplifiers tend to have high input and low output impedance (for reasons I wont go into here.)

 

[shigzeo]

what bothered me more than the bass rolloff (as most players have it) was the crosstalk which gave me a headache. even with resistance it only performs about as well as most other average performing players.

my nano without resistance puts out 65-70db crosstalk and does not give me a headache but does have a similar bass roll off.

had it been that the stereo performance was better than this audiophile piece had gapless, i might ahve kept it