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Post by acuevas1206 on Feb 14, 2012 22:17:06 GMT -5
Hello,
Currently I am using my XDA-1 connected via optical to a sonos. I've been reading that some users have used the unit attached via USB to their mac. I was thinking of trying this out, but when I connect mine I am unable to use the mac's volume control, is this normal? I prefer to leave the xda-1 at 80.
Thanks for your help in advance!
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Post by jackfish on Feb 15, 2012 12:47:26 GMT -5
What kind of Mac?
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Post by wcparks on Feb 15, 2012 19:47:01 GMT -5
Can you adjust volume on a digital signal?
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Post by acuevas1206 on Feb 15, 2012 22:34:58 GMT -5
13inch Macbook Pro Current model
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Post by garbulky on Feb 17, 2012 1:19:01 GMT -5
No, I dont think you can control the master volume, (I can't - PC) but you should be able to control the volume using the software volume control on the player application like foobar or youtube flash videos. You may lose some audio info though because of the algorithm. But I don't know if it would be audible.
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Post by knucklehead on Feb 17, 2012 1:26:11 GMT -5
Can you adjust volume on a digital signal? The XDA-1 does not use your Mac's sound drivers so using the system volume won't affect volume. Any player you have running should be able to control the volume signal going to the XDA-1.
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Erwin.BE
Emo VIPs
It's the room, stupid!
Posts: 2,260
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Post by Erwin.BE on Feb 17, 2012 2:43:52 GMT -5
Can you adjust volume on a digital signal? Ofcourse. There's a little white remote delivered with every Mac, it looks like a small iPod without screen. I never use it, since digital VC is inferior, especially when not properly "dithered". If you want to find more about dithering, google Weiss digital volume. OP, why don't you use the optical out from the Mac?
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Post by bobbyt on Feb 17, 2012 3:41:48 GMT -5
Digital volume control is possible, but you're truncating (or rounding) the values.
Imagine you have signal levels 1-10, and you want to listen at 30% full volume. Your range is now 0-3, and on top of that you lose information because everything not evenly divisible is rounded/truncated.
For instance, from the original signal, a 3 would become a 1, but a 4 can't become a 1.2 -- you have to choose between 1 and 2. If you always round it to 1, you'll hear quantization distortion, so you have to dither it, meaning sometime choosing 1 and sometimes 2.
The "proper" way to digitally control volume (what Erwin.BE is talking about above) is basically adding extra digits to keep from losing the fractional values. You turn the 16-bit signal into a 24-bit one and then can keep more information. BUT to really do this you'd want to send a 24-bit signal, not use 24-bit for the volume scaling and then round it back down to 16-bit.
If we use our 1-10 example from above, it would be like adding a digit. So instead of 1, 2, ...9, 10 as signal values, we have 10, 20, ...90, 100. Then we can scale it down to 30% (or whatever) and still keep more of the original information (4 would be 40 at full volume, 12 at 30% volume).
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Post by lvdude on Feb 17, 2012 6:08:46 GMT -5
I agree with wcparks. You are sending a digital stream to the xda-1, and not an analog signal, hence there is no volume control on the stream coming out of the Mac. Volume control happens at your preamp/amp stage. Also, here is a little known tip for Mac users. If you are streaming higher resolution lossless FLAC/ALAC files, make sure the Mac is set up for that. Go to Applications > Utilities > Audio Midi Setup and increase the sample rate and the bit rate to a higher setting. Typically it is set for CDs at 44kHz and 24 bit. If you do not bump it higher, then your high res lossless files will be down sampled to this lower resolution. Here's a good article about this: www.macworld.com/article/160651/2011/06/how_to_find_and_play_high_resolution_audio_on_the_mac.html.
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Post by emotifan on Feb 17, 2012 13:50:13 GMT -5
The USB output only supports up to 16 bit, so if you're listening to any HD audio it's being down sampled.
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USAFRetired
Sensei
New Receiver onboard Denon RIP
Posts: 651
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Post by USAFRetired on Feb 17, 2012 13:56:01 GMT -5
I find this post most interesting and want to follow even though at this time I have nothing to offer. By posting I can continue to follow and use this as a means of playing FLAC and others from my MacBook Pro. I like Airplay for the convenience, but the quality is lacking.
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Post by jackfish on Feb 17, 2012 14:27:13 GMT -5
The USB output only supports up to 16 bit, so if you're listening to any HD audio it's being down sampled. The USB 2.0 output of the MacBook Pro supports up to 24 bit depth and 192kHz frequency. The XDA-1 USB input supports up to 24 bit depth and 48kHz frequency.
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Post by thunder240 on Feb 18, 2012 17:51:36 GMT -5
The USB 2.0 output of the MacBook Pro supports up to 24 bit depth and 192kHz frequency. The XDA-1 USB input supports up to 24 bit depth and 48kHz frequency. Jack, timely post! Yesterday I downloaded some jazz studio masters (24/96 and 24/192 versions) along with 16/44.1 CD versions (16/44.1) from Kent Poon's blog, and was looking forward to comparing them using my XDA-1. When I connected it to my MBP using USB this morning, in my Apple Midi Setup the max supported bit depth and sample rate shown is 16/48. First question -- where did you hear that the XDA-1 USB input supports up to 24/48? This isn't mentioned anywhere in the manual. The technical specs listed in the manual read: "• Sample Rate: All standard resolutions are supported up to 192kHz • Bit Depth: Standard bit depths up to 24Bit are supported at clock frequencies up to 192kHz • Inputs: 2 Optical TOSLINK, 2 COAX Digital, 1 AES/EBU, 1 USB" I'm very disappointed, and I feel mislead. Second question -- any idea why my MBP is only giving me 16/48 rather than 24/48? When I select the internal speakers as my output, Apple Midi Setup allows up to 24/96. One possibility is that my USB cable is longer than the 2 meter "maximum length" recommended in the manual (I'm using a 10 ft cable),. I'm not sure why this would matter since the USB is transmitting a digital signal. I'm running the latest release of Snow Leopard, in case that makes a difference. Third/Fourth questions -- is it true that the Mac's built-in mini-optical digital audio out supports 24/96 max? If so, it appears that no matter how I slice it, I'm not going to be playing any music at 24/192 Has anyone out there figured out a way to play music at 24/192 from a Mac using the XDA-1? Thanks.
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Post by jackfish on Feb 18, 2012 18:28:15 GMT -5
From the XDA-1 webpage: •USB hardware support up to 48kHz / 24Bit
To all your other questions - For better and complete answers to computer audio questions I would go to Computer Audiophile and ask there. The realm of computer audio with the Mac is a series of convoluted steps in different areas in the OS and applications. Don't buy 24/192 music, most people can not tell the difference between that and 24/96.
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Post by thunder240 on Feb 18, 2012 21:27:01 GMT -5
From the XDA-1 webpage: •USB hardware support up to 48kHz / 24Bit To all your other questions - For better and complete answers to computer audio questions I would go to Computer Audiophile and ask there. The realm of computer audio with the Mac is a series of convoluted steps in different areas in the OS and applications. Don't buy 24/192 music, most people can not tell the difference between that and 24/96. Thanks. I'm definitely aware of the fact that in all likelihood I can't tell the difference between 96 and 192 khz, but that was the point of the exercise I was embarking on! Three songs, each encoded at three different sample rates, tested blindly with the help of a friend on the same hardware in the same room. If I couldn't hear the difference, I'd put that baby to rest and never look back. Unfortunately the test will have to wait til another day when I get these hardware issues sorted out, and til then, who knows?
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Post by acuevas1206 on Feb 18, 2012 21:51:16 GMT -5
Thank you for all the help! I found some great answers, I will be using the optical out as Erwin suggested. Great info from everyone. Thanks!
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Post by ematthews on Feb 21, 2012 16:26:52 GMT -5
And I was told today by Emotiva that Computer {MAC} music is NOT a good source to feed the XDA. This is the whole reason I purchased the XDA... I am a bit frustrated at the moment with the XDA..If I can not get a good source connected to it, what's the point? I already have the USP-1 pre that is great with my CD player....I think in the end I will just continue with my CD's instead of computer junk
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Post by jackfish on Feb 21, 2012 17:32:09 GMT -5
And I was told today by Emotiva that Computer {MAC} music is NOT a good source to feed the XDA. I don't know who told you that but why have a DAC if you can't use a computer as a source? Bits are bits, just get things configured right and it should work OK. From everything I've read, the XDA-1 works fine with the Mac. How are you trying to implement it the XDA-1 with your Mac? Optical through the headphone jack or USB?
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Post by bd52 on Feb 21, 2012 18:55:37 GMT -5
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Post by musicfreak on Feb 21, 2012 19:01:47 GMT -5
The USB output only supports up to 16 bit, so if you're listening to any HD audio it's being down sampled. The USB 2.0 output of the MacBook Pro supports up to 24 bit depth and 192kHz frequency. The XDA-1 USB input supports up to 24 bit depth and 48kHz frequency. Partially correct. The hardware supports 24/192, but the operating system does not. The best you can do is optical out on a Mac at 24/96. The way around this is by using a USB>SPDIF converter that comes with its own drivers. I use the M2Tech HiFace and can get up to 24/192 out of my Mac Mini.
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