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View Full Version : 1-bit vs 24-bit DAC???



kenstewart
03-16-2006, 12:00 AM
I'm about to purchase a HDD-based HU (Pioneer), but it says the DAC is 1-bit while I see several newer HUs w/24-bit DACs ... will this make that much of a difference in sound quality/power? Basically, will I regret purchasing this instead of a 24-bit DAC system?

neomagus00
03-16-2006, 12:36 AM
i believe that this is a bad case of marketing - one of the worst audio-related diseases to ever affect our world...

i've searched for a definitive answer to this in the past, because it's come up repeatedly... there are many examples of "24-bit resolution, 1-bit DACs" out there (search the string "1-bit" AND "24-bit" in google)...

i have come to the conclusion that marketers are retahded... the '24' part is, i'm almost positive, the sample resolution... that is, at any particular sample (in a CD, there are 44,100 of them per second), there are 2^24 possible positions for the signal level... a normal CD has only 16-bit resolution, or 2^16 possible positions... the up-sampling to 24 bits is intended to provide a smoother sound, and i imagine the '1-bit' part of that spec is related to the interpolation there...

upshot - they are one and the same... either you get a normal 16-bit DAC, or a 24-bit/1-bit DAC... the 24 will probably sound a little better, depending on your other equipment, and will probably cost a lot more...

kenstewart
03-16-2006, 01:03 AM
Thanks neo ... I did a search as well where some people asked the same question then all of a sudden it started getting into debates between engineers :)

howie777
03-16-2006, 01:46 PM
This is a Delta Sigma converter. The resolution is 24 bits plus a 1 bit DAC for feedback into the input from the output. This puzzled me so that is what my hardware guys at work told me. You can google Delta Sigma Converter for more information.

Howie

neomagus00
03-16-2006, 01:55 PM
update, for those who care:

This (http://www.24bitfaq.org/) site says that in order to convert from 24-bit to 16-bit resolution, one must add 'dither' to make it sound right, and that the dither can come in several varieties, including 1/2, 1, or 2 bit. This is confirmed with an easy-to-understand analogy here (http://www.earlevel.com/Digital%20Audio/Dither.html) (the 'least significant bit' this document speaks of is, I'm fairly sure, the 1/2, 1, 2 of the first document). Combined with howie777's reference to ΔΣ converters, I think what they're talking about is upsampling the 16-bit CD to 24 bits, then doing all the processing at 24 bits. I know that doing processing at 24 bits is good, because then you don't need to dither at all (I think the second reference discusses this).

anyone care to add? modify?

MacLeod
03-16-2006, 06:06 PM
Doesnt matter, you wont hear the difference between them anyway.

1996blackmax
03-16-2006, 09:55 PM
I was able to tell the difference in sound between the units I have owned with 20Bit Burr Brown DAC's PCM 1702's (Alpine) and 24Bit Burr Brown DAC's (Eclipse) over the units with 1Bit DAC's. I think the HU's with the multi bit DAC's also had other internal components that when combined together with the premium DAC's helped produce more detailed sound over the 1bit DAC's.

There are several companies right now that use 1bit DAC's that upconvert the signal into 24bit word. Some companies that use this DAC are Pioneer and JVC (both use the one from Burr Brown). The unit I have uses 24bit Delta Sigma DAC's from Burr Brown.

AustinKP
03-17-2006, 01:09 AM
you know, I bet nobody can hear the difference between a 20 and 24-bit d/a converter. This is, of course, my opinion, but the only reason you'd want to pay more for a deck w/ 24 bit, is that the other components used in conjuction with it are probably also higher quality.

1996blackmax
03-17-2006, 06:08 PM
I actually liked the sound from the unit with the four 20bit Burr Brown DAC's more. Not using it anymore because it did not like to read CD-R's. Once in a while I scan Ebay to see if maybe I want to pick that setup again :D.

kenstewart
03-19-2006, 12:47 AM
Well, thanks for the info guys but it seems to me it doesn't make that big a difference after seeing responses here and other sites. Delta Sigma, Burr-Brown, Starsky-Hutch, so on and so on ... too advanced for me I guess :) I ended up purchasing an Eclipse CD-8445 HU which does have the 24-bit DAC.

For those that hate the Sony HUs ... are you proud of me for moving up to Eclipse? :)

1996blackmax
03-19-2006, 12:52 AM
That is a nice HU you have there, and that 24bit Burr Brown DAC isn't too shaby either :D.

kenstewart
03-19-2006, 01:00 AM
lmao ... ty :)

MacLeod
03-19-2006, 11:10 AM
I like Sony. If they had a model with high voltage pre-outs, time alignment and a good EQ I probably wouldve bought a Sony over my Alpine.

cam5860
03-19-2006, 07:08 PM
If sony had there mobile es stuff like they had in the late 90's I would jump on it in a heart beat. In my opinion they had some of the best cd players you could buy back in the day.

1996blackmax
03-19-2006, 08:45 PM
Very true, so did Alpine.........

MacLeod
03-19-2006, 10:15 PM
Yeah, I wish Sony would come out swinging in car audio. Theyre capable of such unreal products I dont understand why theyre satisfied with Xplod!

1996blackmax
03-19-2006, 10:32 PM
I totally agree. It is sad to see where they are now.......