Recently bought a Kanto Syd powered desktop speaker. I'm using it with an iMac (Mojave OS) that I keep updated). The iMac is one of the last models to have optical out, and that's how I've connected the Syd. The Syd also has Bluetooth capability and RCA inputs. For this particular use, I wasn't expecting an audiophile-like experience. That said, the Syd's sound is more than acceptable—truly pleasant and easy to listen to. All that changes when I go to BT (aptX). Although I wouldn't call the BT sound "unlistenable," it's nowhere near the SQ as when optical is used. I'm familiar enough with lossy codecs and expected less. But this is so much less. I was wondering if others have had a similar experience or if it could be something I'm doing or not doing. (I enabled aptX on the iMac and checked dynamically to ensure that it was deployed. I also tried AAC—worse, I thought.) It'd be nice...although not imperative...to go BT with the Syd, but not at this cost in SQ.
I know that could be true for aptX HD, but it's not likely that's what I have, as specs don't mention HD. Qualcomm itself states: "The aptX HD is technically a Lossy codec. However as aptX HD uses a relatively gentle compression ratio of 4:1 it is non-destructive in nature." Debatable, perhaps. In any case, it appears that Bluetooth 4 (which is what the speaker uses) does not have enough bandwidth to support lossless. I may just contact Kanto and get their take on it.
I can give my impressions: At Axpona, I heard Audioengine demonstrating their powered speakers by using BT -- they also use aptX. The sound was flat and dull. I have a pair of their speakers, and I know the sound can be much better than what they were demonstrating -- I use them wired. So my ears agree with yours on this. On the other hand, I have a pair of Sony BT phones that use the LDAC codec, which Sony claims can transmit 24/96 audio data losslessly. They sound great over Bluetooth! It's too bad that more manufacturers can't (or won't) use that.
How exactly did you do that? What do you mean by that? I ask because I was researching AAC vs aptX and some folks had a somewhat involved way of checking what was actually being used. What are you streaming? Apple Music? CD files? It seems for these applications a big component of the quality is not just the original codec (for instance 256k AAC from Apple Music, or various rates of OGG Vorbis for Spotify) but that then the music is re-encoded and re-decoded at whatever format runs between the source (like a phone) and headphone (or speakers in your case). That can make a nasty cumulative effect. I do not understand why Apple, with all their technology and closed ecosystem and purchase of Beats, does not make a headphone which can simply receive the original 256k AAC from Apple Music. Like Sony and LDAC as mentioned by @Mike-48 in fact! Steve Jobs is roiling in his grave... I also wonder if any of these lossy or "gently lossy" codecs employ any lossless compression. Purely lossless formats like FLAC can achieve maybe 2:1 compression depending on the music. So if aptX is 4:1, are they throwing away 3/4? Or losslessly compressing to 1/2 and loosely compressing that by 1/2, throwing away only 1/4 instead of 3/4? (I suspect none of these formats employs lossless compression within the lossy part due to processing power and time requirements, but that's just a guess on my part)
In my experience LDAC and aptX HD are significantly better than all the rest, with LDAC at the top of the heap. Sounds very good but still behind lossless. Here's a interesting comparative article if you care to read it: The ultimate guide to Bluetooth headphones: LDAC isn't Hi-res
@head_unit -- Yes, it's sad. Apple despite its visual design expertise seems to strive for only mediocre audio quality. Their attitude (visual design is everything) reminds me of beautiful buildings one might see that inside don't have proper ventilation or are overly noisy from the mechanical systems or choice of materials. Eye candy but not ultimately satisfying in some respects. I am over-generalizing, but I've known several visual artists, and not one was an audiophile. I wonder if that's a pattern? @Melvin -- Thanks for the additional material on LDAC. I agree, for best performance, one should prefer wired over Bluetooth at present, especially for critical listening. In other circumstances, LDAC is IMO great choice for headphones. When using 'phones outside a room with a closed door, I'll take the convenience of wireless over any slight loss from LDAC -- as we're audiophiles, not everyone will agree.
================ How you do it on a Mac is like this: You first ensure that either (or both) aptX or AAC is enabled. There's an app for that, but I just use Terminal. I made sure that only one protocol was enabled during testing. Start playing music. Then, Option - Menu Bar Bluetooth Icon right-click > select device. Among other information, the active protocol is displayed. I'm streaming ALAC files from iTunes. All OS and App s/w is current. I made sure the tested files were ones I had imported from CD and was familiar with how they should sound. Your take on the re-encoding has been mentioned to me elsewhere. I think it's a possibility.
I did contact the manufacturer, who said, in part, "You will always get the best sound quality from optical, and the worst from Bluetooth, I would say what you're hearing is typical for comparing the sound quality of the two inputs. Do you have another audio device to try out the Bluetooth and see what the quality is like? Preferably something with a different OS to the mac." I'm continuing to test. Streaming from Apple Music via my Android phone (Moto Z Force) resulted in, what seemed to me, better sound. Not "great," but noticeably better. I'm going to give it a whirl with different powereds and see what happens.
Some science and measurements, you will be surprised: Audio over Bluetooth: most detailed information about profiles, codecs, and devices
AptX in and of itself is not the problem. I use a simple audioengine b1 (AptX, 25/96 dac) to Bluetooth Spotify to my main rig, and I find the sound to be quite listenable. Your statement that you enabled AptX on your iMac puzzles me. I could be wrong, but I believe it is the Bluetooth receiver that needs to have AptX, not the other way around. Sounds to me like your computer and your speaker might not be talking the same language.
Just to be clear—apologies for not stating this originally—the speaker is assuredly enabled with aptX. Its specs state that clearly and that was confirmed before I bought it. So the iMac and the speaker are compatible in that regard. The iMac is easily set to whatever protocol is desired, by using 'sudo defaults write bluetoothaudiod [aptx|aac|sbc]'. You can have one or more enabled concurrently. I'm testing with just one at a time.
No, it's not. Not even Qualcomm claim it to be. No, not true for any curent version of aptX, not even for aptX HD
Indeed, none of the Bluetooth audio codecs are lossless Codec bitrate (kbps) SBC 328 APTX 352 APTX-HD 576 LDAC (Connection priority mode) 330 LDAC (Normal mode) 660 LDAC (Quality priority mode) 990 LHCD 900 As a reference: The bit-rate of a CD = 2x16*41000= 1411 kbs
How to Enable the Optimal Audio Codec for Your Bluetooth Headphones in macOS This is what I did on my MacBook Pro to enable me to force AptX. As per the above post, AptX is definitely lossy. Using FLAC source files and a Sony NWA45 player / Bowers and Wilkins PX cans, my own experience is that AptX and AAC are both substantially better than SBC, but that AptX HD is better still. None of this is blinded or remotely scientific, granted, but AptX HD is very listenable indeed IMHO. AptX vs. AAC? Can’t make my mind up, personally. AptX may be a higher bit rate but AAC is said to be a newer and more efficient codec. I can happily listen to either without feeling deprived!
Fiddling with the iTunes EQ (so that it matches the kind of music being played) seemed to help...but that is true for other kinds of input, as well. And it still isn't close to optical.
Figured I'd follow up now that testing is complete—you never know when someone might be interested. I tested BT vs. Optical using a variety of configurations. Output was directed to either Kanto Syd or Fluance Ai60. Sources were iMac, MBP, iPad Mini, and Android phone (Moto Z). I often like to use the theme from the Lone Ranger movie for various tests and, among other playbacks, did so here. The phone and mini seemed to produce better results than the computers. Nevertheless, optical was always notably better. I was glad to more or less verify that there was no problem with the Kanto (or Fluance, for that matter). I'm content to stay "wired" in this case.
