Bluetooth speakers. Why so good?

Alan Surrey

Member
Messages
990
Does anyone here know why bluetooth speakers, the whole idea of which seems so unpromising, sound so good?
At my exercise class a little bluetooth speaker, the size of an instant coffee jar, fills the entire church hall with perfectly acceptable sound. I'm not suggesting equivalence to a PA system and you must not confuse it with the system used by your favourite rock band at Wembley but it produced quite enough musical, squawk free, buzz free, largely boom free sound over quite a broad frequency range to do the job so well that it is worth remarking about.
How on earth is this sound quality possible? I have a few ideas, but no actual knowledge of bluetooth speakers.
Mobile phone sending to this little battery powered speaker via bluetooth.

I have heard other bluetooth speakers that sound good too, so the sound quality is not exclusive to this particular speaker. (Wonderboom. Unpromising name isn't it?)
 

mowlas

Member
Messages
1,728
First noticed these in 2015 whilst on a family picnic. Could not believe how this small JBL device filled the open air with bass and treble. I was similarly astounded and impressed!

Have used it in large meeting rooms with up to 100 people - amazing how effective it is.
 
Last edited:

CatmanV2

Member
Messages
48,557
They aren't really but digital amplification, better design technology (computers!) and different manufacturing capabilities in terms of both materials and what can actually be produced have made them wildly better than, say, a set of Sony bookshelf speakers on the back shelf of a Mk1 Fiesta ;)

As for the broad frequency range, I suspect, if actually measured it's not (that broad) and the ensemble is tuned to take advantage of some of the ear <> brain tricks to fill in the blanks as it were. We tend to interpret certain higher frequencies as lower than they are because they are resonances of those frequencies. The difference becomes apparent when you put them up against something that has genuinely broad response.

Probably going to be proved to be a load a ********, now :)

C
 

DLax69

Member
Messages
4,180
They aren't really but digital amplification, better design technology (computers!) and different manufacturing capabilities in terms of both materials and what can actually be produced have made them wildly better than, say, a set of Sony bookshelf speakers on the back shelf of a Mk1 Fiesta ;)

As for the broad frequency range, I suspect, if actually measured it's not (that broad) and the ensemble is tuned to take advantage of some of the ear <> brain tricks to fill in the blanks as it were. We tend to interpret certain higher frequencies as lower than they are because they are resonances of those frequencies. The difference becomes apparent when you put them up against something that has genuinely broad response.

Probably going to be proved to be a load a ****, now :)

C
Nah, Chris; agree. Seems like bottom end/bass is missing...but I generally think that of CDs, streaming, etc. When I want to really hear music loud & proud, I still go to the turntable. That said, though, 90% of the time we are listening to SiriusXM or iTunes through Sonos wifi/bluetooth speakers...
 

CatmanV2

Member
Messages
48,557
Nah, Chris; agree. Seems like bottom end/bass is missing...but I generally think that of CDs, streaming, etc. When I want to really hear music loud & proud, I still go to the turntable. That said, though, 90% of the time we are listening to SiriusXM or iTunes through Sonos wifi/bluetooth speakers...

There's the convenience factor. I have a Volumio and a Cyrus streamer in the living room. The Volumio can be synced seamlessly with other players in the house so if you are having a party, you walk around to the same music in time....

The speakers and amps though.... very different. The ones in the living room often have me getting up to see if someone has pulled a truck up to the front window. The bass extension is significant, but fundamental physics says that you need volume (as in volume of air) and size to do that, and they are not small.......

Compare and contrast with the baby BT speakers.

OTOH I have a little BT amp in the office and it has no right sounding as good as it does, hooked up to a set of Scandyna Minipods. It's about the size of a large matchbox FFS.

As for source, well, I used to love my turntable but fundamentally the science doesn't really support vinyl and a good streamer with good sources is still fab.

C
 

DLax69

Member
Messages
4,180
We have the nicest Sonos in the office/library...it has two speakers in the unit, and does the best on the low end...and another in the bedroom, and one more in the kitchen/dining area, so they all stay synced, all the time, like you mentioned. Which is definitely nice & convenient.

I realize the science doesn't support the vinyl...and I'm not a total Luddite/crank...it's simply, to my mind/ears having a separate subwoofer; excellent Advent cabinet speakers; and a really strong amp go a long way toward rattling the windows...!
 

Alan Surrey

Member
Messages
990
Thanks for replying guys. I agree with all the above, speculative and factual (except for a mild disagreement with the bit about science not supporting the notion of turntables being capable of being excellent - tell me again, what is the sampling rate for CDs? My pick up cartridge goes up to more than 40kHz. Though there is plenty more to it than that, probably much around accuracy of RIAA equalisation in the phono stage of the amplifier.)
I'm glad that I am not the only one astonished by the sound available from these tiny bluetooth speakers.
But I am still interested to know why they are so good.
 

CatmanV2

Member
Messages
48,557
Thanks for replying guys. I agree with all the above, speculative and factual (except for a mild disagreement with the bit about science not supporting the notion of turntables being capable of being excellent - tell me again, what is the sampling rate for CDs? My pick up cartridge goes up to more than 40kHz. Though there is plenty more to it than that, probably much around accuracy of RIAA equalisation in the phono stage of the amplifier.)
I'm glad that I am not the only one astonished by the sound available from these tiny bluetooth speakers.
But I am still interested to know why they are so good.

Umm, didn't say they weren't excellent. I seems to have missed the word 'better' as in 'better than CD's'. But I'd also point out that I explicitly didn't mention CD's either ;)

C
 

Wattie

Member
Messages
8,640
Well they’re Convenient And easy to connect, simple to set up with no wires everywhere and frankly technology is so good nowadays that with all the background noise of real life, the sound quality is excellent and virtually faultless to the normal human non nerd ear.
 

DLax69

Member
Messages
4,180
Umm, didn't say they weren't excellent. I seems to have missed the word 'better' as in 'better than CD's'. But I'd also point out that I explicitly didn't mention CD's either ;)

C
I will. And call me a liar, but CDs have always sounded tinnier. And vinyl fuller. And cassettes had/have a hiss. And 8 tracks are still a source of trauma.
 

CatmanV2

Member
Messages
48,557
I will. And call me a liar, but CDs have always sounded tinnier. And vinyl fuller. And cassettes had/have a hiss. And 8 tracks are still a source of trauma.

I agree with nearly all of that. TBH the science all gets a bit wooly. The 40Hz response (which is probably isn't, at least not meaningfully) certainly won't clearly improve sound given that the average middle age person's hearing tops out at 12-14KHz. Now having said that, it's also not clear that there is no perceptual difference. I'm not aware of any blind listening tests that show any particular superiority or preference.

Certainly early CD players weren't up to much, compared to a decent vinyl system. These days, digital music at 192/24 running through the analogue phase at the same quality <shrug>

C
 

Alan Surrey

Member
Messages
990
I haven't had many opportunities to try 192/24 at home, but they have always sounded good to me.
For what it's worth, I think the significance of a bandwidth of 40kHz or so is probably down to group delay, which, If I recall correctly, is governed by the rate of change of gain with respect to frequency. An octave below 40kHz is 20 kHz so group delay effects are nicely out of the ear's range if the system's bandwidth (3dB point) is 40kHz. And even if we can only hear up to 12kHz, we would still need a bandwidth of 24kHz
You can usually hear group delay when you listen to applause. On your HiFi, it sounds like lots of impulses. On your kitchen audio it sounds a bit more like white noise, hiss, because some frequencies are delayed more in the electronics than others, so that ones that originated at the same time, from the same handclap or impulse, arrive at the loudspeaker and therefore your ear at different times, as if they were not part of the same impulse. reasonably easy to imagine what this does to the sound of musical instruments. This is why I get so locked into group delay.

I suspect that all modern recordings are mastered in studios whose bandwidth far exceeds 40kHz, so as long as the recording engineer knows what he is doing, the recording be it analogue, digital many bits or digital fewer bits, features no discernible group delay effects: they sound good.
What do you think?
 

CatmanV2

Member
Messages
48,557
Well that's one of the other things. Bad recordings will be bad no matter what you play them on. I'm not familiar with group delay, but I have some terrible recordings in my collection. From The Matrix OST (awful clipping) to Dennis Brain Horn Concertos (hideously compressed dynamic range). So, yes. The studio bandwidth may be top notch, but what the engineer decides to do.....

C
 

DLax69

Member
Messages
4,180
I think that's a pretty brilliant explanation! Had not heard it put like that. And perhaps also explains the "flattening" I (mis?)heard in early CDs...? I was a late adopter of that tech for that reason...and never bought an iPod or MP3 player.

Again, not a Luddite. And no musical training, either, per se. I just know what sounded better to my ears...even if I was lying to myself!
 

MarkMas

Chief pedant
Messages
8,796
Does anyone here know why bluetooth speakers, the whole idea of which seems so unpromising, sound so good?
....

A pedant writes:

I don't think this is anything at all to do with Bluetooth is it? Yes, small portable speakers are getting really good, presumably due to better designs and materials. But whether the audio signal gets to them via Bluetooth, some other wireless solution, or wires is irrelevant, surely?
 

MarkMas

Chief pedant
Messages
8,796
I always thought it was pretty interesting how Bose got good audio by making the sound travel around inside the box.

106572
 

DLax69

Member
Messages
4,180
I always thought it was pretty interesting how Bose got good audio by making the sound travel around inside the box.

View attachment 106572
I had the Bose and replaced with Sonos. Think the bottom end in the larger Sonos is better. To the pedantics...the Sonos operates over wifi, where the Bose worked over Bluetooth, as I think about it...!

And agree that, to my ears, the system in the Coupe is dreadful. But the Tubi exhaust note more than compensates...
 

CatmanV2

Member
Messages
48,557
A pedant writes:

I don't think this is anything at all to do with Bluetooth is it? Yes, small portable speakers are getting really good, presumably due to better designs and materials. But whether the audio signal gets to them via Bluetooth, some other wireless solution, or wires is irrelevant, surely?

Well it's another conversion step which introduces the possibility of error and and subsequent possibilities of artefacts introduced by correction (think of your headset or car connection when something interferes) BUT digital stream > bluetooth > analogue really should be no worse than digital stream > analogue (unless someone wants to explain that I'm wrong)


I always thought it was pretty interesting how Bose got good audio by making the sound travel around inside the box.

View attachment 106572

Transmission line. Makes for some very good (and very large) speakers. All about wavelenghts.

C