Is anyone else having problems with poor sound quality output for headphones from the new Macbook...

This is common with many computers because the DAC chips are rarely isolated away from all of the EMI and other suppliers of noise within the PC itself.  This includes the various clocks on the motherboard, the mouse, and the power supply.  An external USB DAC is an affordable way to really improve the PC audio experience.  I suggest something like the Total Bithead from Headphone.com.  I have owned one for years now and like it for an inexpensive and portable DAC / Amp.

Are you hearing those famous "bleep-bloops" of the PC hardware?  Does the audio sound tizzy with an extreme lack of detail?  Is the bass just not enough?  All of these are symptoms of a bad DAC and poor amplification.

Quote:

Originally Posted by jlesnick 

The computer is fantastic, but it does an absolute **** job of driving my Shure SE 535's, and the sound quality is notably worse than previous macbook pro's.  It's so bad, that my iPhone 4 can drive those iem's better than the mbp.  Anyone else experiencing this problem?

All mobo's come with an integrated ADC/DAC solution, which is compromised.

Secondly, the audio out is not exactly suited for IEMs, its a multi-purpose audio-out. I'm not even sure its a line out or headphone out, or somewhere in between. I've tried my Shure SE425 with my laptop, they sound kinda bad.

Get a USB dac, and an amp, or use the Shures with a portable source, and use a headphone with your mbp.

Quote:

Originally Posted by NA Blur 

This is common with many computers because the DAC chips are rarely isolated away from all of the EMI and other suppliers of noise within the PC itself.  This includes the various clocks on the motherboard, the mouse, and the power supply.  An external USB DAC is an affordable way to really improve the PC audio experience.  I suggest something like the Total Bithead from Headphone.com.  I have owned one for years now and like it for an inexpensive and portable DAC / Amp.

 

Are you hearing those famous "bleep-bloops" of the PC hardware?  Does the audio sound tizzy with an extreme lack of detail?  Is the bass just not enough?  All of these are symptoms of a bad DAC and poor amplification.

Not to hijack his thread but I'm having a problem with my front headphone jack as well, not my rear which is fine, being basically what you described; I can hear my PC working harder. Any tips?

I'm glad your "rear" is fine .  You should probably plug your headphones in there.  In all seriousness given that many manufacturers have not exactly put audio quality at the top of the heap when designing you may have two different circuits involved with the two hp outs.  Could one be a line out?

Sorry about the semantic humor, couldn't resist

Yes that's pretty much correct. External DAC's are typically designed for computers. Some end up working with the iPad and Android devices on 4.1. 

There are DAC's for iPhones though, such as the CLAS or iStreamer.

The only way an external DAC would help with a portable device is if you could guarantee that you are bypassing the portable devices internal DAC.  Otherwise you are still getting the processed signal from the portable device.  As I remember it the DAC chips in most i-devices are typically pretty good and designed with audio quality in mind.  In order to bypass the DAC on a portable device you often have to use a Line Out Device ( LOD ), but with almost every i-device I have tested I cannot hear the difference between the internal DAC and my portable DAC indicating that the DAC inside most i-devices is actually pretty good.

An amp can help not only by making the sound louder by increasing the voltage to the headphone driver, but an amp can also provide a much needed boost in the control of the headphone driver.  This is because most quality amps have really low output impedance ( Ohms ).  Basically if you portable device has an high output impedance say something above 5 Ohms then it is not going to be able to properly damp the driver leading to distortion.  This distortion can lead to other undesired effects because of the transforming nature of harmonics.  Then there is the issue of power.  If you portable cannot provide enough power to the headphones then you are going to have poor control over the driver again.  This includes power to the driver and voice coils.  Amps are almost always a good way to better control a headphone / speaker driver.  For me I first replaced my music with higher quality files, then I replaced my headphones with a pair of Denon AH-D2000, and finally I replaced the DAC.  This all made a very significant leap in fidelity.

See headphone damping here:

http://en.wikipedia.org/wiki/Headphone_amplifier

Also reference Ohm's law and Joule's law for how an increase in voltage / power can help a headphone.

Of course a poorly implemented amp can make the signal worse.  The same goes for any component of an audio system which is why so many people recommend you upgrade up music / music rips to higher quality.

Quote:

Originally Posted by ocstew 

Not to hijack his thread but I'm having a problem with my front headphone jack as well, not my rear which is fine, being basically what you described; I can hear my PC working harder. Any tips?

This is not an uncommon problem. The front panel interface in many PCs is prone to interference, because of the long unshielded cable, and more importantly because the front panel is often poorly designed and the audio ground is connected to the ground wires of the other connectors and buttons on the front panel, and even the chassis of the PC. A correct implementation does not share the audio ground with anything, otherwise a ground loop is created and the digital noise can leak into the audio signal. I had this same problem on my machine, after fixing the grounding issues on the front panel PCB (it took a few cuts and some soldering), the noise was gone.

Quote:

Originally Posted by NA Blur 

The only way an external DAC would help with a portable device is if you could guarantee that you are bypassing the portable devices internal DAC.  Otherwise you are still getting the processed signal from the portable device.  As I remember it the DAC chips in most i-devices are typically pretty good and designed with audio quality in mind.  In order to bypass the DAC on a portable device you often have to use a Line Out Device ( LOD ), but with almost every i-device I have tested I cannot hear the difference between the internal DAC and my portable DAC indicating that the DAC inside most i-devices is actually pretty good.

 

 

To help clarify, Regarding the LOD or line out doc, it never will bypass the dac in an i device.  It does what it says, it provides a line out signal.  This signal is like the one coming from a preamp and allows a fixed voltage signal to exit the i device and go to another device like an amp.  The digital file has already been processed by the dac inside the i device.

 I know of two devices that are made to get the signal from an ipod or i device prior to it being decoded to analog by the idevices dac, one is the ALO Cypher AlgoRythm Solo and the Wadia 170i and 171i.  Correction:  Apparently I was not home when the memo was sent about the ipad and the camera connection kit. So sorry!

Correction:  There may be others but I do not know of any dock cable that I know of that gets a digital out from an idevice ipod so you can send it to an external dac.

I'm pretty sure some DAC's have been confirmed to work with the iPad.

yep you are right the ones I mentioned might, as well as the Fostex might.

Sorry, I was referring to normal USB DAC's. There's a thread documenting it here.
 

http://www.head-fi.org/t/507559/list-of-dacs-that-work-with-ipad

I stand corrected, see my amended prior post.  Who knew?