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Is a bluetooth DAC just a waste of time?


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Morning all.

 

See that this question has been asked a few times in different ways when I search the forums, but with no real answer.

 

Is the data streaming via bluetooth sufficient to play 128-256kb MP3s with good quality? Would it be able to support higher such as FLAC?

 

Is the loss via bluetooth such that even bothering with a DAC is redundant?

 

Basically we have our house set up with a NAS box, have two ipad minis which my wife and I use for work for dermatology, my wife's Asus tablet an HTC one XL and an HTC M8.

 

We have an outdoor audio system which uses a pair of concrete Audiosphere cabinets using carbon-fibre Focal speakers (for the weather protection) and all powered by an akai AM2800 amplifier which sits nicely in a cabinet above our refrigerator.

 

I would love to be able to sit outside and listen to the music and select songs using any one of those devices without running a cable and using the headphone jack.

 

The distance it would be transmitting would be ~3m to the amplifier.

 

If I'm going down the wrong path thinking DAC or bluetooth for this, I'm open to suggestions.

 

Have looked at the rblink and it talks about devices being limited to 40-50kbps..

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I am not an expert on this and maybe wrong.  However the the following text taken from this article(s) suggests quite high limitations on quality

 

http://stereos.about.com/od/portableandpersonalaudio/tp/Which-Of-These-5-Wireless-Audio-Technologies-Is-Right-For-You.htm and

http://en.wikipedia.org/wiki/List_of_Bluetooth_profiles#Advanced_Audio_Distribution_Profile_.28A2DP.29

 

The key points:

  1. Definitely seems to be no better than average quality mp3
  2. will require lossy compression to transmit lossless audio
  3. there doesn't seem to be any consistency across products, e.g. may or may not support mp3 natively

 

 

For audio enthusiasts, the downside of Bluetooth is that it almost always reduces audio quality to some degree because it uses data compression to reduce the size of digital audio streams so they'll fit into Bluetooth's bandwidth. The standard codec (code/decode) technology in Bluetooth is called SBC. However, Bluetooth devices can optionally support other codecs, such as AAC, apt-X and the various MPEG codecs (including MP3).

If both the source device (your phone, tablet or computer) and the destination device (the wireless receiver or speaker) support a certain codec, then material encoded using that codec does not have to have the extra layer of data compression added. Thus, if you're listening to, say, a 128 kbps MP3 file or audio stream, and your destination device accepts MP3, Bluetooth does not have to add an extra layer of compression, and ideally results in zero loss of quality.

I say "does not have to" and "ideally" because we really have no way of knowing exactly how Bluetooth is implemented in any particular product. In most cases, the Bluetooth product is built not by the company whose brand it wears, but by an Asian ODM (original design manufacturer), often using a Bluetooth module purchased from yet another manufacturer. Given such a complex supply chain, it's tough to know if a Bluetooth receiver actually accepts MP3 signals as-is without forcing the source device to first transcode them into SBC.

Is the reduction in quality that can occur with Bluetooth audible? On a high-quality audio system, yes. On a small wireless speaker, maybe not. Bluetooth speakers that offer AAC or apt-X audio compression, both of which are generally considered to outperform standard Bluetooth, will probably deliver somewhat better results, but only certain phones and tablets are compatible with these formats.

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It occurred to me, and I realise that this may be a change in thread topic, but its my thread so I ?think I'm allowed

 

Are there devices which would be able to access a NAS and then be controlled remotely via bluetooth / wireless / magic?

 

Presumably then if that device was going by wi-fi, then there should be no loss only possibly delays?

 

i.e rather than the media being supplied by the phone / ipad / tablet they are mere remote controls?

 

edit: I would still be wanting to select the song by more than a forward/back/skip type function on the phone

Edited by bobbly_bob
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I think you just described a Squeezebox Touch ;)

 

Hard to find but sometimes appear in the classifieds.

 

Well... and to think that my musing might have resulted in a new invention (jk)

 

They aren't cheap though are they. I'd be buying another device the same price as an ipad to run on the network.

 

Their sell is pretty good though, high quality connections rather than a headphone jack, works well with a DAC, a device that I could hide from the children...

 

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I am not an expert on this and maybe wrong.  However the the following text taken from this article(s) suggests quite high limitations on quality

 

http://stereos.about.com/od/portableandpersonalaudio/tp/Which-Of-These-5-Wireless-Audio-Technologies-Is-Right-For-You.htm and

http://en.wikipedia.org/wiki/List_of_Bluetooth_profiles#Advanced_Audio_Distribution_Profile_.28A2DP.29

 

The key points:

  1. Definitely seems to be no better than average quality mp3
  2. will require lossy compression to transmit lossless audio
  3. there doesn't seem to be any consistency across products, e.g. may or may not support mp3 natively

 

 

For audio enthusiasts, the downside of Bluetooth is that it almost always reduces audio quality to some degree because it uses data compression to reduce the size of digital audio streams so they'll fit into Bluetooth's bandwidth. The standard codec (code/decode) technology in Bluetooth is called SBC. However, Bluetooth devices can optionally support other codecs, such as AAC, apt-X and the various MPEG codecs (including MP3).

If both the source device (your phone, tablet or computer) and the destination device (the wireless receiver or speaker) support a certain codec, then material encoded using that codec does not have to have the extra layer of data compression added. Thus, if you're listening to, say, a 128 kbps MP3 file or audio stream, and your destination device accepts MP3, Bluetooth does not have to add an extra layer of compression, and ideally results in zero loss of quality.

I say "does not have to" and "ideally" because we really have no way of knowing exactly how Bluetooth is implemented in any particular product. In most cases, the Bluetooth product is built not by the company whose brand it wears, but by an Asian ODM (original design manufacturer), often using a Bluetooth module purchased from yet another manufacturer. Given such a complex supply chain, it's tough to know if a Bluetooth receiver actually accepts MP3 signals as-is without forcing the source device to first transcode them into SBC.

Is the reduction in quality that can occur with Bluetooth audible? On a high-quality audio system, yes. On a small wireless speaker, maybe not. Bluetooth speakers that offer AAC or apt-X audio compression, both of which are generally considered to outperform standard Bluetooth, will probably deliver somewhat better results, but only certain phones and tablets are compatible with these formats.

 

That is the most informative reply I have come across, anywhere, with regard to this subject.

 

There seem to be more and more of these devices available, combined or without DACs. For me that answers the question about a Bluetooth DAC; if the data quality loss is potentialy that significant then in my mind the combination is useless.

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Some NAS can have a DAC (usb sound card) attached to them, and have a audio app for mobile devices. Ive used Synologys AudioStation before, its highly effective if your NAS is close to your amp.

I suspect that even a cheap DAC would be much better than BlueTooth.

Edited by huxmut
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As good forum etiquite, here are photos of the setup. Feel ashamed showing them with the crap around.

 

Apologies for the disgraceful use of vintage audio, but it sounds nice and its 2 year old de-struc-to-proof.

 

So where the amp is, obviously using a laptop would be inconvenient. It needs to be something that can send decent audio and be used remotely / controlled remotely.

 

My NAS is a netgear N3400 series btw, it has usb interface I believe, but how would you then select media?

 

 

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Apple TV is the way to go if you can, brand new $110 gets Airplay into your system.  Then an app on your iPad minis/iPhone turns those devices into the remote control.

 

Question is - can the iPad then control the NAS by sending music to the Apple TV?  Other more tech heads than I should be able to answer, or further research on your part...

 

My set-up - iPad app lists & organises all music in a menu and also controls playback which is actually stored on HDD into USB on my music server (or apps on the iPad/iPhone such as Spotify or Pandora or TuneInRadio etc.), then music to AVR and out the speakers...all over the home wifi/ethernet system...

 

post-134860-0-81983000-1406793541_thumb.

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I bet cranking up that stove is a problem with a two year old around!

Back OT, I reckon you need to look for a Squeezebox or Apple TV.

 See the old axe handle hanging from the post to the right of the stove? That's for keeping the kids away from the stove :P

 

That said, having the little one does mean the stove gets lit less than two monthly

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  • 3 years later...

Hello to the OP,,,,,

 

If I understand your intended use case correctly,,, you would like to drive the outdoor speakers.

 

I imagine outdoor ambient noise of any given environment will outweigh any sonic differences you might hear, by introducing a Bluetooth receiver into the chain.  IMO

 

I would put something economical in, see how it works,,, and enjoy the freedom of passing your mobile devices around and choosing whatever music you please (from home files, or streaming services).

 

Just an alternative view.   I sometimes think we focus too much on some things (like protocol conversions) when environmental limitations are in play and may likely negate any losses anyway.

 

This looks like a pretty flexible device.....

 

Look at this on eBay http://www.ebay.com.au/itm/332285793275

 

Edited by OzMillsy
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Timely, as bluetooth these days (can) allow transmission of audio (MP3 or AAC) without additional compression, which is much better than APTX.

 

Apparently not common yet, but improving - as high rate MP3/4 is certainly transparent for most purposes.

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On 27/09/2017 at 8:24 PM, OzMillsy said:

Just realised I revived a 3 year old thread. ?

 

Has it been that long since my last post?    Moving along.....

Bluetooth running a bit slow??

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