Monitor DAC vs motherboard DAC

geraltofrivia

Limp Gawd
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Jun 12, 2012
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Which DAC will be higher quality, the Realtek ALC898 on the motherboard or the audio out in a Dell 2408WFP monitor (over HDMI)?
 

Seithennin

Limp Gawd
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Jul 30, 2008
Messages
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The audio out on your dell monitor is just pass-through from your computers soundcard, or videocard if you are using a discrete videocard.
You need to compare the sound chip from your soundcard to the audiochip on your videocard... since the videocard more than likely uses a realtec sound chip also, you need to compare those.
If you don't use a discrete videocard, but are using the onboard video on the motherboard.. then the motherboard's audiochip is what you are using, regardless on if you have it running through the lcd monitor or not.
the lcd monitor does not contain a sound chip.
 
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geraltofrivia

Limp Gawd
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I thought that HDMI could only carry a digital audio signal. The monitor still has to convert that into an analog signal right? Also the HDMI audio works when the Realtek ALC898 is disabled in device manager.
 

Seithennin

Limp Gawd
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Messages
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then you are using the audio chip in the videocard, a lcd monitor does NOT contain a audio cpu, the lcd is only passing through the audio from the soundcard..
As for it working with the realtec chip disabled,, it is actually using the "High definition audio device", which is part of the hdmi driver for the onboard videocard.
If you want better audio quality,find a higher quality discrete sound card,or videocard as onboard video AND onboard sound are crap.
as for dac quality.. you would actually have to disassemble the lcd monitor to find out exactly what dac is in it.. but i guarantee it will be low quality, and your onboard dac will be much better.
 
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geraltofrivia

Limp Gawd
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409
I kind of see what you are saying. But I still don't understand this: the signal going through the HDMI cable is digital (wiki HDMI). The signal from the audio out on the monitor is analog (I can plug my headphone in and it works).

How does that digital->analog conversion happen if there is no DAC in the monitor?
 
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Seithennin

Limp Gawd
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the dac on the motherboard's videocard hdmi output converts the signal to analog for the lcd which passes it through to the speakers.(DAC= Digital to Analog Converter)
 
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Medion

[H]ard|Gawd
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The audio out on your dell monitor is just pass-through from your computers soundcard, or videocard if you are using a discrete videocard.
You need to compare the sound chip from your soundcard to the audiochip on your videocard... since the videocard more than likely uses a realtec sound chip also, you need to compare those.
If you don't use a discrete videocard, but are using the onboard video on the motherboard.. then the motherboard's audiochip is what you are using, regardless on if you have it running through the lcd monitor or not.
the lcd monitor does not contain a sound chip.

While the GPU does have an audio chip, it does not have a DAC. The GPU (or mobo) handles the basic audio processing in tandem with the CPU, then sends the digital signal to the monitor, which handles it via the built-in DAC. In fact, when plugged in via HDMI, your monitor will show up as an audio device and can be configured independently. I've used two monitors with these DACs, the Samsung S27B550v, and the BenQ GW2750HM. Both had the same 24-bit, 48khz limit. Technically speaking, the Realtek ALC885 that I own should be superior. However, motherboards and monitors have their own digital noise (neither places priority on the DAC over other purposes), so you'll need to experiment.

In my experience, the Samsung DAC was horrid. It picked up a lot of noise from the monitor if brightness was below 96. It was audible over the built-in speakers, messed with sound over dedicated speakers, and blasted my ears over headphones. It was unusable and I experienced this on both S27B550v models that I tried. The BenQ has no such issues. The audio quality seemed to be comparable over 2xDayton B652 speakers. In this case, I found it useful to disable the mobo audio via the bios, remove the drivers, and then ensure they were cleaned using CCleaner and DriverSweeper. It's a little less overhead for the system.

So basically, plug in your HDMI and try it out. Once plugged in, make sure you open your control panel, go to audio devices, and configure the monitor (as most default to 16-bit, 44.1khz and need to be adjusted). If the sound is good enough for you relative to the onboard, then you can do as I did. If you find it lacking, then don't use it.
 

geraltofrivia

Limp Gawd
Joined
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Messages
409
the dac on the motherboard's videocard hdmi output converts the signal to analog for the lcd which passes it through to the speakers.(DAC= Digital to Analog Converter)

Again, HDMI cannot carry an analog audio signal. There IS a DAC in the monitor! :)


While the GPU does have an audio chip, it does not have a DAC. The GPU (or mobo) handles the basic audio processing in tandem with the CPU, then sends the digital signal to the monitor, which handles it via the built-in DAC.

Thank you for backing me up on the fact that the monitor has a DAC! lol

In fact, when plugged in via HDMI, your monitor will show up as an audio device and can be configured independently. I've used two monitors with these DACs, the Samsung S27B550v, and the BenQ GW2750HM. Both had the same 24-bit, 48khz limit. Technically speaking, the Realtek ALC885 that I own should be superior. However, motherboards and monitors have their own digital noise (neither places priority on the DAC over other purposes), so you'll need to experiment.

In my experience, the Samsung DAC was horrid. It picked up a lot of noise from the monitor if brightness was below 96. It was audible over the built-in speakers, messed with sound over dedicated speakers, and blasted my ears over headphones. It was unusable and I experienced this on both S27B550v models that I tried. The BenQ has no such issues. The audio quality seemed to be comparable over 2xDayton B652 speakers. In this case, I found it useful to disable the mobo audio via the bios, remove the drivers, and then ensure they were cleaned using CCleaner and DriverSweeper. It's a little less overhead for the system.

So basically, plug in your HDMI and try it out. Once plugged in, make sure you open your control panel, go to audio devices, and configure the monitor (as most default to 16-bit, 44.1khz and need to be adjusted). If the sound is good enough for you relative to the onboard, then you can do as I did. If you find it lacking, then don't use it.

Yeah that was basically the crux of my question, the motherboard DAC should be better but there's EM interference inside the case. I wasn't aware that monitors created EM interference too but it makes sense. You're right, in the end it comes down to trial and error.


edit: Did quick swap A/B tests and the realtek alc898 sounded miles better. Also enabled full range speakers in the config and this improved the sound too.
 
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Medion

[H]ard|Gawd
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Thank you for backing me up on the fact that the monitor has a DAC! lol

To be fair, Seth didn't disagree with this, as he stated;

you would actually have to disassemble the lcd monitor to find out exactly what dac is in it..

I think Seth understands exactly how things work, he just didn't to a great job of explaining it. Right now, I'm noticing that some sounds aren't coming in as clear as I remember them, but to a very minor degree. I like the simplicity of having things "just work." With this setup, I can go back and forth between my TV and PC monitor for gaming without adjusting a single setting. If I go back to mobo audio then I have 2 more audio devices on my system as well as the Realtek drivers, which means more (admittedly, negligible) system overhead.

I'm not an audiophile, so I'll leave it as is for now. But, if it does begin to bug me at any point I'll simply go back to Realtek.
 
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