Bluetooth tempo and pitch issues?

Interesting artifact I'm hearing streaming my iPad over a Bluetooth connection. I'm hearing slowing and speeding pitch! Subtle, but it is almost like a turntable with a finger on it some moments. Anybody?
I think the best individuals to ask about this phenomen are Rick Thomas or Dave Cooperfield.
yeah i guess not a lot of experience with this in AG world. Not quite magic though :) When they originally developed bluetooth, I'm wondering if they were taking us listeners into consideration or just the typical background music types..........(said like a snob)
I have been using a Chordette Gem (from Chord Electronics) for a number of years now with very satisfactory results. I can stream music from my iPad, iPhone or iPod Touch with great ease. I have never experienced anything remotely similar to what you describe.

The Chordette employs an A2DP (Advanced Audio Distribution Profile) Bluetooth decoder, and is perfectly suited to all but the most critical listening. It is clearly not quite as good as my Wavelength Brick fed by computer via USB, but the difference (while readily discernible) is certainly not dramatic. I suspect it is largely a result of the difference in quality between the two DACs, although the transmission method (Bluetooth vs. USB) may play a small part.

When I first brought up the topic of streaming music via Bluetooth on the 'Gon some years ago, it landed with a great big thud. Nevertheless, I still think the ability to use an iPad or similar device for both storage and playback of audio (especially now with iPads available in 128 GB capacities) borders on the magical. Perhaps, one day, other 'philes will come around and deign to give it a try.

To my mind, the (very) slight loss in quality is easily outweighed (most of the time) by the tremendous increase in convenience. Certainly anyone looking to assemble a high-quality, compact (or portable) system (e.g., iPhone, Bluetooth receiver, powered speakers) ought to give this approach some serious thought.
There isn't a 'very slight loss in quality', there's a HUGE loss in quality.

But I do agree with you, it is very convenient. And I use it sometimes when cooking or doing some other activity, but never for serious listening.

Bluetooth involves WAY too many sonic compromises for serious listening.

M_snow: "There isn't a 'very slight loss in quality', there's a HUGE loss in quality."

While it would be foolish to deny your experience, I would be very interested to learn what equipment you are using that allows you to come to such a dramatic conclusion. I'm going to guess it is NOT, for example, the $10,000 Chord CPM 2800 digital integrated amplifier (with Bluetooth capability).

And yes, I realize that this is essentially an "argument from authority" (I've never heard this unit), but I find it very difficult to believe that a highly respected manufacturer of high end equipment would be foolish enough to offer a $10,000 amp that includes a feature that represents a "HUGE loss in quality."

What I CAN say (with complete conviction) is that my far more modest Chordette Gem (at less than one-tenth the price) offers a quite satisfactory musical experience--though one not quite as good as my twice as expensive Wavelength Brick. And I'm pretty sure that if you stopped by for a listen you would be unable to honestly maintain your rather extreme position.

Jmacinnis: It would be interesting to know what equipment you are using in your Bluetooth setup. Maybe these are the source of your problem.

While hardly an expert on this issue, I do know that Bluetooth comes in a bewildering array of "flavors," some of which are completely inimical to high-quality audio transmission. The A2DP profile that my Chordette Gem and various iDevices use seems to work quite nicely. Current iDevices are, in addition, Bluetooth 4.0 compliant--which means they use less power, and pair almost instantly with their receivers.

If you've got a couple of days to waste, you can read all about the various Bluetooth specifications here. I suggest taking a couple of aspirins before you start in order to ward off the blinding headache you're almost guaranteed to end up with after the first few paragraphs.
Rel - I didn't even know such an item existed, so I certainly haven't heard it.

Think about this: any codec used by Bluetooth has to be lossy in order to fit within the available bandwidth. Additionally, a CD player needs a bit-rate of at least 1.4 megabit-per-second for stereo, and A2DP allows for a maximum of 512 kilobits-per-second for stereo.

I'm not saying Bluetooth can't offer a 'quite satisfactory musical experience', but even you admit it's not as good as your Wavelength. I LOVE the convenience of Bluetooth music, but not for serious listening -- in MY opinion, & from MY experience.






M_snow: You seem to be throwing a bunch of stuff at the wall in the hope that something will stick.

You admit (now) that Bluetooth can offer a "satisfactory musical experience," but initially stated that it involved a "HUGE loss in quality." When asked why a company like Chord would sell a $10,000 Bluetooth-enabled amp if the use of Bluetooth entailed such a HUGE loss in quality, you replied that you have neither heard--nor heard of--the unit, and declined to comment.

OK, fair enough; but then you say, essentially, that Bluetooth couldn't possibly sound any good, as its 0.5 megabit per second data rate is less than half that of the CD standard (1.4 megabits per second). This spec may have applied to the very first Bluetooth devices, but current (3.0 and above) devices have data rates of 3 to 24 megabits per second--more than adequate for CD.

The data rate, however, in and of itself, is not a very reliable indicator of overall audio quality. The CD standard was not, after all, carved on stone tablets and handed down from on high. It was merely the best that the Sony & Philips engineers had to offer at the time that CD was introduced.

I could just as easily say that CDs represent a HUGE loss in quality when compared to SACDs (which offer a bandwidth 5 times greater than CD) and that CDs are, therefore, unsuitable for serious listening. The fact is that while SACDs are theoretically capable of better sound than CDs, there are many well-recorded CDs that SOUND a whole lot better than many poorly recorded SACDs.

Bottom line, bandwidth is only one of many factors that affect the quality of a recording. How it actually SOUNDS is what really counts. And when I asked what kind of set-up you were using that allowed you to conclude that Bluetooth SOUNDS really bad, I received no reply.

Then you attempt to use my own testimony against me by saying "even you admit it's not as good as your Wavelength," which is true, BUT when I offered that observation it was to illustrate that the twice-as-expensive Wavelength DAC sounds better AS A DAC then the more modest Chordette Gem does AS A DAC. How each DAC receives its input (whether via USB or Bluetooth) probably contributes a relatively small amount to how each unit sounds.

As audiophiles, we are all, no doubt, in search of the best possible sound, but there are many times when something just a notch down will do just fine. So if you are willing (at times) to listen to vinyl rather than master tapes; to digital rather than analog; to CDs rather than SACDs; to AIFF rather than WAV; to ALAC rather than AIFF, then you might just possibly want to consider Bluetooth!
lol...sorry Rel for abandoning this thread for a bit. I'm pretty sure that it is my crap belkin bluetooth adapter that is to blame, but I'm not sure either that I want to fork over for the 600 plus for the Chordette. I do love sitting and being able to browse on the ipad and playback whatever i find through my system, so it may have to happen. I found one by ARCAM for 250, but haven't found any reviews on the quality. I'm not getting into a debate about wireless vs wired. I work in a professional recording studio where wireless is always forbiden. I agree though that in some cases, for convenience, it is nice to use a wireless connection. Just looking for other devices like the chordette around. I really don't want to go down the wifi/sonus route, as they seem to be inserting their amps and routers into a world where we already have all that stuff.
If bluetooth is on that 10,000 dollar amp, I agree, it must have a benchmark far better than what i have I'll keep looking! thanks for the input.

Jmacinnis: I do NOT work in a professional recording studio, but when I listen to some of the recordings produced in such places, I sometimes wonder about those who do! ;-)

Glad that you chimed back in. I'm gonna guess that your Belkin is the most likely source of your problem. I haven't surveyed the Bluetooth receiver offerings of late, but I've been pretty happy with the ARCAM receiver (not a Bluetooth receiver, but a 5 channel all-in-one unit) that I use in a secondary system, so you might want to investigate their offering further.

Bluetooth is becoming more and more common, but primarily on the lower end, which is why so many seem to have such a poor impression of it. Little wireless speakers like the Jawbone Jambox--and others far less capable--have begun to proliferate profusely. I recently discovered my beloved Tivoli PAL (Henry Kloss's Portable Audio Lab) now comes in a Bluetooth version. (OK, now I've completely blown all my audiophile cred).

The fact that wireless is forbidden in your recording studio is interesting, but doesn't really prove anything. Too often, such decisions are made on the basis of inaccurate preconceptions, or other practical considerations that may have nothing to do with the actual audio quality.

Somehow, I seem to be painting myself into a corner as a starry-eyed Bluetooth booster. This is really not the case. All I'm really trying to say is that Bluetooth may not be nearly as bad as you think, and might even be completely acceptable in a particular application.

Or to repeat that most tiresome of audio clich├ęs: Trust Your Ears!