Author Topic: Snake oil  (Read 779389 times)

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Offline jh15

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Re: Snake oil
« Reply #975 on: March 01, 2018, 06:47:13 am »
I thought bone conduction was only good into the 3khz or so. I played with transducers and found that so.

If you can tell me how you can get 10's of khz through bone conduction, tell me.  Maybey your cochlea still has to work there?
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Offline helius

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Re: Snake oil
« Reply #976 on: March 01, 2018, 06:54:07 am »
 

Offline djos

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Re: Snake oil
« Reply #977 on: March 01, 2018, 07:05:24 am »
I thought bone conduction was only good into the 3khz or so. I played with transducers and found that so.

If you can tell me how you can get 10's of khz through bone conduction, tell me.  Maybey your cochlea still has to work there?

You could well be correct, I'm no expert on the subject but I did read it somewhere on the internetz once, so of course it must be true.  :-DD

Offline McBryce

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Re: Snake oil
« Reply #978 on: March 01, 2018, 07:56:58 am »
It might be true for some types of floor.

The wrong sort of floor could turn the cables into inductors and that would wreck the sound.

Have you seen the Cables AudioPhools use? Those things use more shielding than what you'd find in state of the art RF / EMP hardened Military gear!

FWIW, here's the review: https://www.stereo.net.au/reviews/review-krix-esoterix-altum-bookshelf-speakers

and the cables in question!  :palm:


Fools, don't they know that hard, shiny surfaces like that floor for instance actually colour the sound and so they are not actually listening to the pure sound but slightly distorted sound. Secondly, the quoted frequency response of those speakers is 40Hz to 40Khz, why? I say why because it is a fact the the human ear can only hear frequencies in the 20Hz to 20Khz. That means that only animals can appreciate the upper infrequence between 20KHz and 40Khz. So not only are they missing out on 20Hz of pure joy, deep bass but the speakers are also supposed to to be able to produce sounds 20Khz above the human capability of hearing, why???

Thats proof enough to demonstrate that there are people around who are clearly deluded  and are easily parted from their money. And that cable and the fancy stands for the cable is another clear example.

9 out of 10 fruit bats said they preferred these speakers. :)

<Pedantic_rambling>
@Fungus: The cable would have inductance no matter what floor it was lying on, just some floors might increase the value.
</Pedantic_rambling>

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Offline Specmaster

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Re: Snake oil
« Reply #979 on: March 01, 2018, 09:03:39 am »
Fools, don't they know that hard, shiny surfaces like that floor for instance actually colour the sound and so they are not actually listening to the pure sound but slightly distorted sound. Secondly, the quoted frequency response of those speakers is 40Hz to 40Khz, why? I say why because it is a fact the the human ear can only hear frequencies in the 20Hz to 20Khz. That means that only animals can appreciate the upper infrequence between 20KHz and 40Khz. So not only are they missing out on 20Hz of pure joy, deep bass but the speakers are also supposed to to be able to produce sounds 20Khz above the human capability of hearing, why???

Thats proof enough to demonstrate that there are people around who are clearly deluded  and are easily parted from their money. And that cable and the fancy stands for the cable is another clear example.

Lol, I personally have carpet in my HT room simply because I dislike the reflections created by hard floors. My system (w/400w, 300mm active sub) goes down to 16Hz which you can definitely feel more than hear (which is kinda the point with movies).

but yeah the 40Khz top end response is pointless considering the only way to perceive frequencies above 20khz, is via bone conduction ... which would require you to strap the speaker to your head! :palm:
That's just the point, in the demo room they have wall to wall carpet and the other speakers on test are huge. In that case it is easy get the audience to select which ever set of speakers you want them to by selecting the audiences by their preferences. Take my wife as an example, she hates deep bass and large speakers preferring small unobtrusive ones, find similar people to make your test audience and you get the smallest speaker picked as the winner. Simple as that, big speakers get written off from the get go purely on sheer size and then because they will also produce the heaviest and deepest bass, bingo ladies and gentlemen your winner was predetermined. [emoji41]
« Last Edit: March 01, 2018, 09:06:50 am by Specmaster »
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Offline IanMacdonald

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Re: Snake oil
« Reply #980 on: March 05, 2018, 03:38:08 pm »
There is also a world of difference between bass and boom.  Boom, is when the speaker just makes a nondescript noise whenever a note below 100Hz or so is played. In the worst cases it's not even possible to tell what instrument played the note.  :-//

The audiophools dote on boom though. Especially the car audiophools.
 

Offline Specmaster

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Re: Snake oil
« Reply #981 on: March 05, 2018, 06:04:13 pm »
Real quality bass is well defined and not just a one note samba that you tend to get the car audio lot whose main aim in life seems to be moving as much air as they can with their sub woofers. Anyone who has been in a large church/hall/theatre where a pipe organ is playing will of course know that part of the deep bass is also the ability to feel the bass in your body and the lower the note, the greater the feel and less actually hearing the note.

Now to my mind, the job of hi-fi and speakers is to try and reproduce the sound and the feeling that you get by being there and if the equipment is not capable of such reproduction then it is not true hi-fi and in the case of these speakers referred above, how can they be classified high end hi-fi speakers when they are incapable of giving you that lovely spine tingling deep bass that you can actually feel?

I've had the sheer pleasure of being in a theatre when a Wurlitzer pipe organ was being played and some of the bass notes are really deep and prolonged and down in the infrasonic range and speakers that cut off at 40Hz just don't cut the mustard.

https://en.wikipedia.org/wiki/Infrasound
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Offline Cyberdragon

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Re: Snake oil
« Reply #982 on: March 05, 2018, 10:35:02 pm »
Real quality bass is well defined and not just a one note samba that you tend to get the car audio lot whose main aim in life seems to be moving as much air as they can with their sub woofers. Anyone who has been in a large church/hall/theatre where a pipe organ is playing will of course know that part of the deep bass is also the ability to feel the bass in your body and the lower the note, the greater the feel and less actually hearing the note.

Now to my mind, the job of hi-fi and speakers is to try and reproduce the sound and the feeling that you get by being there and if the equipment is not capable of such reproduction then it is not true hi-fi and in the case of these speakers referred above, how can they be classified high end hi-fi speakers when they are incapable of giving you that lovely spine tingling deep bass that you can actually feel?

I've had the sheer pleasure of being in a theatre when a Wurlitzer pipe organ was being played and some of the bass notes are really deep and prolonged and down in the infrasonic range and speakers that cut off at 40Hz just don't cut the mustard.

https://en.wikipedia.org/wiki/Infrasound

Those speakers are total trash. They look like cheap podiums from the 1970s, and they have little horns (an absolute no-no for modern speakers) meaning the drivers are weaker than bluetooth speakers making the sound "hollow". (this would explain the terrible frequency response) I bet those damn things sound like crank phonographs. :-DD
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Offline Canis Dirus Leidy

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Re: Snake oil
« Reply #983 on: March 13, 2018, 11:35:31 am »
Audiophools don't cease to surprise and bring joy. Vacuum tube clock generator for CD-player. Just for $30, without shipping: http://www.abbasaudio.com/miniatjurnij-lampovij-klok.html
 

Offline Cyberdragon

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Re: Snake oil
« Reply #984 on: March 13, 2018, 06:24:05 pm »
Audiophools don't cease to surprise and bring joy. Vacuum tube clock generator for CD-player. Just for $30, without shipping: http://www.abbasaudio.com/miniatjurnij-lampovij-klok.html

I want one of those (if it actually works). ;D More of a "because it can be done" novelty than anything practical. At least it's cheap, unlike most audiophool crap. Although it would probably be more fun to DIY.

We should send one to Paul Carlson and see if he can figure out what it is. >:D
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Offline Brumby

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Re: Snake oil
« Reply #985 on: March 13, 2018, 09:27:07 pm »
Real quality bass is well defined and not just a one note samba that you tend to get the car audio lot whose main aim in life seems to be moving as much air as they can with their sub woofers.
... and not just the air, but the boot lid, windows and door panels.

While a few car owners have addressed this, there are so many that drive by and all I can hear is some muffled music (at least I think it's music) from within the vehicle accompanied by the dominant metallic buzz of the boot lid as it alternates between the boot imploding and exploding.

Considering the money put into such systems, I just laugh to myself.
 

Offline McBryce

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Re: Snake oil
« Reply #986 on: March 14, 2018, 12:54:32 pm »
These are the same people who install gold plated battery contacts to connect to lead battery posts, so nothing suprises me in the Car-audiophool world :D

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Offline Specmaster

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Re: Snake oil
« Reply #987 on: March 14, 2018, 01:29:29 pm »
Real quality bass is well defined and not just a one note samba that you tend to get the car audio lot whose main aim in life seems to be moving as much air as they can with their sub woofers.
... and not just the air, but the boot lid, windows and door panels.

While a few car owners have addressed this, there are so many that drive by and all I can hear is some muffled music (at least I think it's music) from within the vehicle accompanied by the dominant metallic buzz of the boot lid as it alternates between the boot imploding and exploding.

Considering the money put into such systems, I just laugh to myself.

I myself have an upmarket sound system fitted to my car, not an after market option but manufacturers option on the particular model I have and sometimes the bass on it can cause various parts of the car to vibrate and rattle on really deep and high energy bass and thats to be expected. However to go to the extents that some people go to with the whole car being in effect a mass of speakers and huge great power amps in the boot which effectively turns the car into a music system on wheels and thats all its all its good for as there is often no passenger space either, is simply ridiculous.

These nerds will be stone deaf before long...

https://youtu.be/xt8Oe8zq3cM
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Offline bd139

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Re: Snake oil
« Reply #988 on: March 14, 2018, 01:46:08 pm »
Got one of these. No dancy stuff required :)

https://www.amazon.co.uk/gp/aw/d/B0787T8SZD/
 

Offline Specmaster

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Re: Snake oil
« Reply #989 on: March 14, 2018, 02:11:24 pm »
That's a really cheap unit and I bet it would struggle to deliver the quoted power output and has sky high distortion figures and has poor frequency response to boot.  :popcorn:
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Offline bd139

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Re: Snake oil
« Reply #990 on: March 14, 2018, 02:59:49 pm »
It's got a class D amplifier which makes that a perfectly credible specification. I cracked it open - has a Chinese IC in it. Possible to get THD down to 0.03% easily with those. Haven't measured it but it sounds pretty excellent even with shitty Fiat default speakers. And I'm throwing Ralph Vaughan Williams' Lark Ascending performed by the Royal Philharmonic Orchestra through it which has an excessively large dynamic range and no compression.  :-+

The thing is regardless of the promises, it delivers 99% of the performance of something 1000% of the cost which makes it a good value proposition. Good job China  :-+
 

Offline Specmaster

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Re: Snake oil
« Reply #991 on: March 14, 2018, 03:06:50 pm »
It's got a class D amplifier which makes that a perfectly credible specification. I cracked it open - has a Chinese IC in it. Possible to get THD down to 0.03% easily with those. Haven't measured it but it sounds pretty excellent even with shitty Fiat default speakers. And I'm throwing Ralph Vaughan Williams' Lark Ascending performed by the Royal Philharmonic Orchestra through it which has an excessively large dynamic range and no compression.  :-+

The thing is regardless of the promises, it delivers 99% of the performance of something 1000% of the cost which makes it a good value proposition. Good job China  :-+
Pink Floyd, The Division Bell, Dark Side of The Moon etc?
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Offline coppice

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Re: Snake oil
« Reply #992 on: March 14, 2018, 03:54:19 pm »
That's a really cheap unit and I bet it would struggle to deliver the quoted power output and has sky high distortion figures and has poor frequency response to boot.  :popcorn:
OK. How much are you prepared to bet and lose?

Class D amps are an area where Chinese silicon vendors hit a home run. They came up with some really good performers which are very cheap to make. Sometimes these devices get integrated into very poor amp designs, but there are other very respectable performers which are still quite cheap. Maybe in the long term their electrolytics won't prove to have the best longevity, but on day one they work well.
 

Offline bd139

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Re: Snake oil
« Reply #993 on: March 14, 2018, 04:16:19 pm »
It's got a class D amplifier which makes that a perfectly credible specification. I cracked it open - has a Chinese IC in it. Possible to get THD down to 0.03% easily with those. Haven't measured it but it sounds pretty excellent even with shitty Fiat default speakers. And I'm throwing Ralph Vaughan Williams' Lark Ascending performed by the Royal Philharmonic Orchestra through it which has an excessively large dynamic range and no compression.  :-+

The thing is regardless of the promises, it delivers 99% of the performance of something 1000% of the cost which makes it a good value proposition. Good job China  :-+
Pink Floyd, The Division Bell, Dark Side of The Moon etc?

Been there done that. Division Bell sounds good. One of the best pieces of recording in history is the first few seconds of Lost for Words.

That's a really cheap unit and I bet it would struggle to deliver the quoted power output and has sky high distortion figures and has poor frequency response to boot.  :popcorn:
OK. How much are you prepared to bet and lose?

Class D amps are an area where Chinese silicon vendors hit a home run. They came up with some really good performers which are very cheap to make. Sometimes these devices get integrated into very poor amp designs, but there are other very respectable performers which are still quite cheap. Maybe in the long term their electrolytics won't prove to have the best longevity, but on day one they work well.

Yes exactly. The implementation is pretty amazing in this if I'm honest. I've got a NAD C340 as well and it pretty much destroys that. Sounds the same, costs and weighs a hell of a lot less :)
 

Offline Specmaster

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Re: Snake oil
« Reply #994 on: March 14, 2018, 04:32:54 pm »
It's got a class D amplifier which makes that a perfectly credible specification. I cracked it open - has a Chinese IC in it. Possible to get THD down to 0.03% easily with those. Haven't measured it but it sounds pretty excellent even with shitty Fiat default speakers. And I'm throwing Ralph Vaughan Williams' Lark Ascending performed by the Royal Philharmonic Orchestra through it which has an excessively large dynamic range and no compression.  :-+

The thing is regardless of the promises, it delivers 99% of the performance of something 1000% of the cost which makes it a good value proposition. Good job China  :-+
Pink Floyd, The Division Bell, Dark Side of The Moon etc?

Been there done that. Division Bell sounds good. One of the best pieces of recording in history is the first few seconds of Lost for Words.

That's a really cheap unit and I bet it would struggle to deliver the quoted power output and has sky high distortion figures and has poor frequency response to boot.  :popcorn:
OK. How much are you prepared to bet and lose?

Class D amps are an area where Chinese silicon vendors hit a home run. They came up with some really good performers which are very cheap to make. Sometimes these devices get integrated into very poor amp designs, but there are other very respectable performers which are still quite cheap. Maybe in the long term their electrolytics won't prove to have the best longevity, but on day one they work well.

Yes exactly. The implementation is pretty amazing in this if I'm honest. I've got a NAD C340 as well and it pretty much destroys that. Sounds the same, costs and weighs a hell of a lot less :)
When I said cheap, I meant at £22, it is cheap, I don't doubt for a moment that it is also capable of putting in a reasonable performance and when taking the low cost into consideration, its incredible really, and I for one would much rather sit and listen to it then I would that stereo in the the YouTube video  :-+ I would like to know about just how that 4 channel sound is measured, peak, music power or RMS and if it is actually capable of delivering that level of power without cooking itself as normally you need some pretty monstrous heat sinks and into what impedance?
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Offline bd139

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Re: Snake oil
« Reply #995 on: March 14, 2018, 04:49:20 pm »
Being class D, it is considerably more efficient than other amplifier topologies. The output is a PWM signal which is stuffed through a low pass filter. The MOSFET that controls the PWM is either on or off so there's as close to no power dissipation going on at all. The LPF is usually a purely reactive network i.e. L/C so there is no power dissipated there. Talking 90%+ efficiency easily. Make the traces thick, fast and low Rds(on) MOSFETs use decent inductors and you're done. Power is quoted RMS on the box into 4 ohms.

If you go back to the distant past of early 1990s, and take a look at the old MOSFET PWM RC speed controllers which are the granddaddy of the class D amps, this little bugger can shift 75A continuous and 300A peak!!! Just over an inch long. No heatsink. A lot has happened since then as well...

« Last Edit: March 14, 2018, 04:51:27 pm by bd139 »
 

Offline Specmaster

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Re: Snake oil
« Reply #996 on: March 14, 2018, 04:58:55 pm »
Being class D, it is considerably more efficient than other amplifier topologies. The output is a PWM signal which is stuffed through a low pass filter. The MOSFET that controls the PWM is either on or off so there's as close to no power dissipation going on at all. The LPF is usually a purely reactive network i.e. L/C so there is no power dissipated there. Talking 90%+ efficiency easily. Make the traces thick, fast and low Rds(on) MOSFETs use decent inductors and you're done. Power is quoted RMS on the box into 4 ohms.

If you go back to the distant past of early 1990s, and take a look at the old MOSFET PWM RC speed controllers which are the granddaddy of the class D amps, this little bugger can shift 75A continuous and 300A peak!!! Just over an inch long. No heatsink. A lot has happened since then as well...


Well there you go, thats my something new learnt for the day  :-DD
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Offline bd139

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Re: Snake oil
« Reply #997 on: March 15, 2018, 01:22:38 pm »
From Radcom this month :D

 

Offline McBryce

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Re: Snake oil
« Reply #998 on: March 15, 2018, 01:40:03 pm »
Very funny, but it's a joke, not a real product.

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Offline bd139

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Re: Snake oil
« Reply #999 on: March 15, 2018, 01:52:09 pm »
Of course it is. But it's better presented than half of the snake oil products are.
 


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