3.5mm Analog Audio vs. Bluetooth Audio Quality

Option 1: Bluetooth audio.

Option 2: 3.5mm TRS analog audio connector (wired).

Facts about Bluetooth:

Bluetooth audio protocol is lossy, meaning that some of the data is lost. However, it is digital, meaning that the audio reproduction in the headset is bit-exact the same data that was transmitted.
The data is encoded to a digital format that is compressed in a way that loses some of the source data (but hopefully not enough that you can perceive it); but the data stream is much more resilient to interruption, due to buffering, which means that you are unlikely to notice even if some other electromagnetic frequency transmission interferes with your bluetooth (temporarily).
See A2DP at Wikipedia for more information about Bluetooth audio. To put it simply, there are more than one supported audio codec, and they have varying pros and cons in terms of bandwidth consumed, energy consumed, compatibility across devices, and quality. Some of the newer codecs such as apt-X produce what many consider to be superior audio quality, but device support is limited compared to the older codecs, or SBC which is required by the A2DP standard.

Facts about analog audio:

Analog audio over a standard 3.5mm headphone jack (technically called a "TRS" connector) can be very high quality if the audio playback device has a good DAC. An amplifier (separate or built-in) can make the signal sound even better.
A "good pair of cans" (good headphones) can sound amazing with this dated analog mode of transmitting audio down a cable. If you are using a very high quality DAC on the source audio device, chances are it's better than the DAC that has to be in the bluetooth headphones to convert the bluetooth digital data to analog, because the in-headphones DAC is limited by battery power and size constraints -- but a sound card in a computer is much less constrained. Even sound chips in smartphones are great these days.
All analog audio is subject to interference with the audio cable. Most audio cables are not shielded from external electromagnetic interference, and certain models of computers (especially Core 2 Duo era CPUs with on-board graphics) have been known to spew electromagnetic frequencies that are picked up as a "grinding" or "buzzing" noise on the analog headphone wire, if it is near enough to the computer. Some LCDs can do the same. Depending on your situation, this interference can be even worse than the loss of audio quality of bluetooth's lossy encoding.

The answer is that it heavily depends on your situation, and exactly how sensitive your headphones are, and exactly how good the Digital-Analog Converter (DAC) in the bluetooth headset is, and which codecs the bluetooth headset supports, and........ (many other things). If you're using the headphones in a way that a wire would get near certain models of LCD or computers, the analog signal quality may be terrible due to interference. If you're using the bluetooth in a way that it's in a heavily saturated 2.4 GHz environment (e.g. lots of WiFi signals, microwaves, cordless phones around), it may drop out due to heavy interference and crosstalk. Also you have to be able to live with the quality loss of lossy encoding for one of the bluetooth A2DP codecs, if you go that route. You probably can't detect it if you listen to lossy audio vs. lossless, but some people like to fake themselves out and say that they can tell ;)

allquixotic

Posted 2012-08-21T13:48:01.347

Reputation: 32 256

With BlueTooth there are many quality differences between versions of the protocol. Also the construction of the mainboard is important, limiting the output by resistors and/or caps (limited bass reproduction) to increase battery life is bad for the richness of sound. I have done some test with several BlueTooth devices comparing to analog audio and differences in quality can be huge, some of them add hearable artifacts to the audio (result of compression). You can easily test it by playing compressed audio (mp3 for example). Another thing is delay (by buffering), visible when play a video – Codebeat – 2016-08-02T13:18:39.307

1Sorry but how can you argue as a benefit of Bluetooth that "the data stream is much more resilient to interruption, due to buffering" as an advantage over WIRED 3.5 mm AUDIO when it cannot be interrupted nor need to be buffered, as it is sent in continuous, analog form and not over the air? That's a nonsensic claim. – Pere – 2016-12-19T21:49:45.820

@Pere: I suppose he compares to a hypothetical losslessly compressed bluetooth stream that requires much more bandwidth. – klaar – 2018-04-12T15:23:44.050

@Pere: While an analog signal can't be interrupted, it certainly can suffer from EM interference - you hear it all the time. With digital streaming, instead of hearing such interference, there is a buffer (cache) of audio pre-loaded so that the music can continue to play for some seconds while the devices re-establish their connection. – hardy – 2020-02-10T05:26:15.690

@hardy, you are comparing different concepts - buffering and interference, which are not the same. There's no "interference" over cable analog transmission provided there are no other sources connected, "superimposing" their signal over the purpotedly transmitted one. Of course, interference also affects digital over-the-air transmission. It can affect in many ways, depending on how strong is the interference, from just a slight "dropout" in data, that maybe can be recovered depending on the correction methods or the strength/duration of the interference burst, or too much for that. – Pere – 2020-02-10T16:25:13.667

@hardy to little space for explaining properly, though. An interference in a digital wireless audio transmission can result in a drop no matter how big the buffer if the offending signal is strong and long enough. It can also simply result in degradation in audio quality, without drop-outs, even without having a buffer. As I said, it depends on the concrete situation and technology. – Pere – 2020-02-10T16:31:10.637

1+1 Nice answer and you skirted the "shopping" issue quite nicely – Dave M – 2012-08-21T14:18:17.087

2+1 For the good answer and you were able to turn the question into something useful for SU. – N_Lindz – 2012-08-21T14:41:38.297

I've been trying to figure this out for a long time. Maybe this should be a separate question, but I have RF headphones that do 20-12000Hz and I stopped using them because the frequency response wasn't good enough. How do I select a set of bluetooth headphones that will sound as good as my analog ones do? – Joe – 2012-08-27T19:09:54.090

That's a separate question, though it sounds more like a shopping recommendation question... TBH it's hard to find detailed specs about the freq response of bluetooth cans, even on the manufacturer's website, sometimes you have to dig deep or just pass up the ones that you can't find any info about. – allquixotic – 2012-08-28T13:36:52.820

16To reviewers: Instead of voting to close this question, please feel free to edit the question to remove the shopping recommendation. Look at my answer: there is a general, non-shopping lesson to be taught here about 3.5mm TRS vs. bluetooth audio. It's on-topic for SU when you take away the product comparison and talk about the underlying technologies. If anyone can reshape the question in that light, be my guest. But I'd recommend against voting to close. – allquixotic – 2012-08-21T14:20:19.417

I recently bought a Bluetooth speaker and sound quality is noticeably worse than when using the jack. Also there is about half a second lag, which makes watching videos impossible (lips don't move in sync with speech). Of course this will depend on the codec and device, but overall I would advise against it. – Laurent – 2013-09-01T13:32:24.770

3.5mm Analog Audio vs. Bluetooth Audio Quality

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