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Discussion Starter #1
Trying to get some good music to my car audio from my Bluetooth device(phone). It seems like in general the quality of signal is degraded when sent wirelessly.

Also, even when plugged in using supplied cable, music on iPod is worse than CD. These observations are probably obvious. My question is, how can I improve the quality of sound through my stereo utilizing these formats?

Thanks
 

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what bitrate have you encoded your music at? higher bitrates will give you better sound. you can also use lossless formats.
 

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Yeah, I've recently been getting music in .flac and converting it with dbpoweramp to .m4a. Huge difference. I doubt you would want to play that over bluetooth. Just use the USB.
 

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Achieving true SQ with an iPod or Android wirelessly is impossible...
The playback quality could be good for background listening(at best)...
The only way to get SQ from an iPod is to have lossless format and going digitally through a very high quality head unit for the d/a conversion...
I am sorry, this is the truth...

Gus1111
 

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Achieving true SQ with an iPod or Android wirelessly is impossible...
The playback quality could be good for background listening(at best)...
The only way to get SQ from an iPod is to have lossless format and going digitally through a very high quality head unit for the d/a conversion...
I am sorry, this is the truth...


Gus1111
mmmm nope.

http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/77343-iphone-3gs-unloaded-headphone-out-measurements.html

Don't take my word for it, I'm no professional.

These should be more credible.

Apple iPod portable music player Measurements | Stereophile.com

Cheapy Sansa clip+ and iPod 3G
NwAvGuy: Sansa Clip+ Measured

^ And please note that the second link's results are into a simulated headphone load, which is many times harder to driver than any high impedance AUX/Line/RCA input. Yet results are still excellent with regard to audible degradation.

Of course the input of the head unit needs to be of good quality also, but that won't be a problem unless the head unit is of the REALLY cheap POS variety.

And as for USB inputs. Yes they bypass the iDevice "crappy" DAC but most of them don't send the signal to the DSP in the digital form. They convert to analog with their own DAC and then source select that now analog input among the other analog sources like FM to go into the main ADC for DSP work further down the signal chain. Also a quality ipod DtoA plus a good headunit AtoD (AUX in) is easier and cheaper to get right than a head unit USB DtoA plus head unit AtoD. Reason being is that it is more complicated and costly and there is not need for it since the portable source is already doing half the work for you, ie an excellent line output.

So essentially, USB inputs in general are actually a degradation to sound quality and are primarily only beneficial to those with REALLY poor performing USB portable players, digital media drive, or for better noise performance which should not be a problem when a device is installed properly.
 

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there is a hack where you can modify ipods to have true line out through the ipod connector and use RCA's. you cannot control the ipod from the deck anymore if you do this i believe. haven't looked at the hack for a while cause it wasn't worth it IMO.
 

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Achieving true SQ with an iPod or Android wirelessly is impossible...
The playback quality could be good for background listening(at best)...
The only way to get SQ from an iPod is to have lossless format and going digitally through a very high quality head unit for the d/a conversion...
I am sorry, this is the truth...

Gus1111
I am sorry it is not the truth. my alpine does all the D/A work and I can use AAC lossless if I want. no different than a CD
 

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there is a hack where you can modify ipods to have true line out through the ipod connector and use RCA's. you cannot control the ipod from the deck anymore if you do this i believe. haven't looked at the hack for a while cause it wasn't worth it IMO.
They already have a true line out from any available LOD. The line out is already an excellent one in fact and one that sounds as good as any CD source, at any price. See my post above.

The mod you are talking about is likely the iMod. Which is pointless, unless someone hears an improvement, albeit an imagined improvement. Then by all means they should limit themselves and spend the money on one.
 

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Not you, the OP. :p
:D Ah, my mistake.

For what it's worth, I'm no expert by any standard but, the .w4a format into my (meager) HU through the iPhone shows a palpable difference in sound quality.
 

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:D Ah, my mistake.

For what it's worth, I'm no expert by any standard but, the .w4a format into my (meager) HU through the iPhone shows a palpable difference in sound quality.
Not clear on what you mean. That that format sounds better than another one? That that format through the phone sounds worse/better than the cd transport?
 

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so basically what this means is I need to go back and rerip all my music in lossless and convert to m4a to get the best quality? pfft. I don't care that much.
 

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so basically what this means is I need to go back and rerip all my music in lossless and convert to m4a to get the best quality? pfft. I don't care that much.
On the topic of lossy compression quality. 99% of people could not tell a lossless rip from a 256kbps or higher properly encoded lossy rip, in 99% of the music out there. And in a car, the percents are even higher.

I've seen correctly performed blind testing using many dedicated enthusiast from these boards and NOT ONE got any better than if they closed their eyes and picked randomly.

Something to think about when someone tells you that their iTunes store bought track obviously sounds like **** compared to their CD version.
 

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On the topic of lossy compression quality. 99% of people could not tell a lossless rip from a 256kbps or higher properly encoded lossy rip, in 99% of the music out there. And in a car, the percents are even higher.

I've seen correctly performed blind testing using many dedicated enthusiast from these boards and NOT ONE got any better than if they closed their eyes and picked randomly.

Something to think about when someone tells you that their iTunes store bought track obviously sounds like **** compared to their CD version.
I am not doubting your claim and hope this doesn't sound that way. Do you have links or copies to the blind tests. I would love to see this, I could get all my music on one Ipod maybe. I have been to a few meets now and have had two people point out from one album to the next when I went from flac>m4a to flac>mp3 320kbps music using dbpower amp to convert. I have always been curious about this because it took me about a year to re encode all my 250gb's of flac to m4a after I had it all in mp3. I have really ****ty ears and thought I could tell the difference, but then again I thought I was gonna be an astronaut too. Could my set up have something to do with this?
 

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Not clear on what you mean. That that format sounds better than another one? That that format through the phone sounds worse/better than the cd transport?
That the .m4a music on the iPhone sounds better than the .mp3 stuff on the phone. I would put it equal with CD.
 

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I am not doubting your claim and hope this doesn't sound that way. Do you have links or copies to the blind tests. I would love to see this, I could get all my music on one Ipod maybe. I have been to a few meets now and have had two people point out from one album to the next when I went from flac>m4a to flac>mp3 320kbps music using dbpower amp to convert. I have always been curious about this because it took me about a year to re encode all my 250gb's of flac to m4a after I had it all in mp3. I have really ****ty ears and thought I could tell the difference, but then again I thought I was gonna be an astronaut too. Could my set up have something to do with this?
The experiment was conducted in a private car audio forum made up of members from this site and others. I'll PM you.
 

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Discussion Starter #19
what bitrate have you encoded your music at? higher bitrates will give you better sound. you can also use lossless formats.
Music was encoded at whatever rate was available from back in the days of music sharing. Im guessing the highest bitrate is aprox 300. I have quite a few songs on my ipod touch (2009). Preferably if I could use my existing music in its current format would be ideal. This holds more appeal than converting it to some other format then read in another way, then altered again.

Can I convert all my existing music collection to a lossless format?
 

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Discussion Starter #20
Yeah, I've recently been getting music in .flac and converting it with dbpoweramp to .m4a. Huge difference. I doubt you would want to play that over bluetooth. Just use the USB.
Why do you recommend against bluetooth to m4a?
Where do you get music in .flac format?
 
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