Where is the weak link in my setup?

[col_in_belfast]

I have recently improved the sound quality of my setup significantly with the addition of a Cambridge Audio Dac Magic where previously I just connected my Apple TV directly to my amp.

 

I have also re-ripped all of my cd's at 320 kbps (VBR) AAC where previously they were a mixture of 128kbps & 256kbps.

 

I think this has made quite a difference.

 

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I was just wondering where the weak link in my system now resides? Or if maybe i'm not getting the benefits of my changes because of a particular part of my setup?

 

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In detail, I use:

 

-iMac with OS X 10.5.8

 

-Apple TV with 1 TB of external storage

 

- Music collection comprising 256 kbps iTunes plus downloads & CD 's ripped at 320 kbps (VBR)

 

-Apple TV connected to DAC Magic via TOSLINK outputting at 44.1 sample rate

 

- DAC Magic connected to Denon AVR-1907 via QED premium audio cable upsampling to 24/192

 

- QED premium audio cables to 2x KEF iQ7's and Cambridge Audio S90 subwoofer

 

I would appreciate any thoughts or comments.

 

Thanks.

 

[Lakefield]

Well, you should try ripping your CD's to ALAC (Apple Lossless) to get the best quality from your music.

 

The DAC Magic is great, your iQ7 is an awesome speaker. But in your setup, i would say the Denon is the weakest link now.

Are you running a surround setup? Otherwise a Stereo amp should give you a better result.

 

[barrows]

mp3 is your weak link. Rip to at least Apple Lossless.

 

[col_in_belfast]

Thanks for your comments.

 

I am starting to rip a few CD's into ALAC and will have a good listen to compare to what i'm currently using.

 

I'm actually only using the Denon AVR for 2.1 sound, so i'm aware that a lot of video and audio functions are going unused. I am however using in puredirect mode so hopefully I am getting the best that I can out of it. I am going to have a look at some alternative amp's as i'm now confident that i'm only interested in stereo sound and don't need surround.

 

Just one other quick question, if iTunes plus provides a 16/44.1 sample rate which I understand to be the same as a Red Book CD, in what way is this audio inferior to ALAC?

 

Thanks again.

 

[blueixus]

I know very little about Apple TV but Toslink connections are poor. Personally i would play the music out the imac and look at using a Hiface from USB to the Dac.

 

As stated rip at ALAC as a minimum,

 

[bixby]

Just one other quick question, if iTunes plus provides a 16/44.1 sample rate which I understand to be the same as a Red Book CD, in what way is this audio inferior to ALAC?

 

Could you clarify what you are asking?

 

 

And to Blueixus:

 

I disagree that toslink connections in general are poor. Yes, the ATV does have fairly high jitter and only have toslink as a digital output so no other alternative is available that route. As for using a Mac, I prefer a very high quality toslink to a usb to spdif converter like the Halide on 3 different dacs. Just my preference.

 

[bottlerocket]

I agree with Bixby. The ATV only supports toslink and it is fine for your set up. There are certainly better options with a lot of cash output, but the toslink and ATV are not the weak link in your set up.

 

The weak link is your lossy files. ALAC is Apple Lossless Codec. It will be redbook quality 16/44.1 and approximately 900 kbps as opposed to AAC which is 256 kbps or in your case 320 kbps. ALAC matches redbook quality, the 320 kbps files do not. To use ALAC, set your ITunes preferences/General/Import Settings to Import Using Apple Lossless Encoder. Or you could use AIFF which will have the same quality but not be compressed. The confusion you might be having is that Itunes also lists AAC files as 16/44.1. Itunes supports all resolutions from 16/44.1 up to 24/192 and higher as long as your output device supports it.

 

It is possible your Denon's DAC is not that great either (I am not familiar with the Denon at all so not really sure), so it could be the next weak link in your chain after the lossy files.

 

 

 

[Erwin S]

col_in_belfast,

 

Here's my take. Like you, I used a DacMagic to a AVR (Yamaha). But it was feeded from an Airport Express. I am lucky to have a stereo-only set-up now.

 

First, watch out with SW. While the frequencies from 80 Hz and below are indeed directionally undetectable, their relative distance to the ear vs the distance of the main speaker is critical. If different, you get muddy bass, caused by the smearing in time between the arrival of the sound waves. Your AVR might deal with the time delays, but this only works for one listening spot. And if you are like me who wants to listen from various spots in the room, it does not work. Recent software like Audyssey MultiQ XT32 or what's it called use multiple positions, but I'd reserve that for surround sound. So the only good SW for stereo are stereo SW positioned next to the speakers...

 

Second, just go modern and use a DAC with volume control and a stereo power-amp without any pre-amp. For less than $1,000 you get the Emotiva XDA-1 (new DAC with volume control) and a pair of Emotiva UPA-1 monoblocks. Just saying.

 

Now about the AAC. @320 kbps, it's not to bad. But Redbook CD is 1411 kbps! (BTW, kbps stands for kilobites per second). You have to realise that those lost bits can't have disappeared without any loss in SQ, no? The 16/44,1 or 24/192 tell you more about the potential than about the actual SQ. Upsampling to 24/192 is considered pretty useless, but others here are far more savvy than me to explain why. But it has to do with the fact that you can't turn a donkey into a thoroughbred no matter how hard you try.

 

With Apple, you have three viable options that allow decent tagging with album art etc.

 

AIFF: basically the same as the CD you used to rip from, although it's not limited to Redbook, it works also with 24/48 to 24/192 high resolution downloads. It's uncompressed. Same SQ as the CD: also 1411 kbps and more for high res. Only drawback is that it eats more space. You would get about 1,700 hours of CD on 1TB.

 

ALAC: compressed, but without loss in SQ (some disagree). Redbook wasts space because a CD-player is not a computer. If there are ten "1" in a row, ALAC uses 10*1 and not 1111111111. All the info is there with ALAC, just stacked more wisely. That's why ALAC gives you 500 kbps for one song and maybe 1,100 for another. You get about 2,500 hours of CD on 1TB

 

AAC: it dumps some of the info to get to 320 kbps. Its lossy compressed. It's not what we want! And to hear some improvement, you have to at least double the bits. You will hear the difference between 128 and 256 kbps, but not from 256 to 320 kbps. After 256, you need ALAC, which is usually around 800-1000 kbps on average.

 

I chose to keep using ALAC to rip CD's, but use AIFF for high res downloads. If the source is in FLAC, I open it with XLD that converts to AIFF. My current 2TB Iomega MiniMax storage is now about half full with over 2,000 albums (some are 2CD or more and I have about 50 high res albums also). If you have 1TB, there's no need to consider anything less than ALAC!

 

[col_in_belfast]

Thanks so much for your comprehensive and very helpful answers!

 

Currently researching the Emotiva UPA-1 monoblocks.

 

My confusion was that if iTunes Plus offers 256kbps & 16/44.1 then I thought this would be as good as a CD as I thought it was all about the sample rate being the same.

 

I had no idea that while the sample rate is the same as a CD, there was such disparity in the kbps.

 

Thanks again.

 

[mwheelerk]

The major weak link in my opinion is your library in that it is comprised of lossy compressed files. If you have the source material available to rip (CDs) I would highly, highly recommend you recreate your file with at a minimum Apple Lossless files. As your system grows this enhancement will only prove itself more and more worthy even as painstaking as this might seem to do right now.

 

[mstieb]

+1 on your choice of lossy formats being the weakest link.

 

+1 on your amp being the 2nd weakest link.