General Forum

Re: The Futurist: Why You Should Buy Middle-End Products

Flappo The Grate — Fri, 30 Nov 2007 13:49:16 GMT

i always loved that silly hi fi mag called hi fi review in the mid 80's that actually openly advertised such rubbish as red strips you put on your mains leads to reduce interference ( yes they were made out of REAL plastic ! ) and the utterly daft notion that scratching 1 inch marks on the 3 pins of the mains lead would increase the purity of the sound

Re: The Futurist: Why You Should Buy Middle-End Products

nobby — Mon, 24 Sep 2007 08:25:29 GMT

Can someone add a description on how the ear works? i.e. spectrum analysis and the way in which any waveform is broken down into its spectral content and as such the phasing of waveforms is irrelevant (from a monoaural perspective).

Re: The Futurist: Why You Should Buy Middle-End Products

Puncher — Mon, 24 Sep 2007 06:11:19 GMT

Alex:

Okay, imagine you have two sawtooth waves (for those of you who don't know, a waveform which looks like a saw), and you combine them together, and move one very slightly out of line with the other. What you end up with is two very sudden peaks INCREDIBLY close to each other, and as a result, a short burst of incredibly high frequency. Now, if a speaker cannot reproduce that frequency correctly, the harmonic formed by those two close-by waves will be destroyed and the waveforms will lose their definition as two seperate waveforms, and begin to form into a single, poorly defined waveform. You aren't losing any direct information above 20 KHz, because you can't hear that high. However, you are losing information which affects lower frequencies as well.

I don't think this is true - adding the same signal to itself but delayed in time produces a comb-filter effect which nulls (or emphasises) certain frequencies present in the signal but does not add any new frequency content. In your description you are describing the changes to the waveform in the time domain, which may appear siginificant but these visual changes do not translate directly into the frequency domain and therefore what you hear. The human ear cannot hear absolute phase (only changes in phase) and so the "shape" of a waveform can vary considerably if the relative phase of its constituent harmonics are adjusted but all will sound identical.

Re: The Futurist: Why You Should Buy Middle-End Products

soundproof — Mon, 24 Sep 2007 05:59:32 GMT

wirralsimon:
soundproof:

Which is interesting, though I haven't been able to get a good answer to this question: If we accept this, why do we need a supertweeter? Can't we just filter off said distortion without connecting it to a supertweeter? As part of the loudspeaker design ...
That was my first thought, part of the answer lies in the fact that without the supertweeter nobody is being sold anything expensive.
I suspect anyone who says their system sounds better with a supertweeter would be unable to tell you if the supertweeter was connected or not when blindfolded, expensive solutions to problems you didn't know you had and the placebo effect are rife at this end of the market. Likewise I would be very, very surprised if there was anyone in the world with hearing sensitive enough to tell you what colour the PVC on the cable was, even if there was a slight measurable effect using instruments.

Simon

I quite agree. I'm having a lot of fun rooting out high-end hi-fi canards. The Audiocritic has been doing that for decades, of course.

http://www.theaudiocritic.com/

Re: The Futurist: Why You Should Buy Middle-End Products

wirralsimon — Mon, 24 Sep 2007 04:58:32 GMT

soundproof:

Which is interesting, though I haven't been able to get a good answer to this question: If we accept this, why do we need a supertweeter? Can't we just filter off said distortion without connecting it to a supertweeter? As part of the loudspeaker design ...

That was my first thought, part of the answer lies in the fact that without the supertweeter nobody is being sold anything expensive.

I suspect anyone who says their system sounds better with a supertweeter would be unable to tell you if the supertweeter was connected or not when blindfolded, expensive solutions to problems you didn't know you had and the placebo effect are rife at this end of the market. Likewise I would be very, very surprised if there was anyone in the world with hearing sensitive enough to tell you what colour the PVC on the cable was, even if there was a slight measurable effect using instruments.

Simon

Re: The Futurist: Why You Should Buy Middle-End Products

soundproof — Mon, 24 Sep 2007 01:33:34 GMT

wonderfulelectric:
I think it is not the sound of the supertweeter that matters but the reduction in breakup modes in the tweeter during the production of high frequencies. In the case of a seperate supertweeter, I think it filters off the distortion inducing super high frequencies from the normal tweeters.

Which is interesting, though I haven't been able to get a good answer to this question: If we accept this, why do we need a supertweeter? Can't we just filter off said distortion without connecting it to a supertweeter? As part of the loudspeaker design ...

Or do we need the supertweeter "waves" in the room to retroactively modify the same that are emerging from the tweeter?

Which seems a little weird to me.

Re: The Futurist: Why You Should Buy Middle-End Products

wonderfulelectric — Mon, 24 Sep 2007 01:28:13 GMT

I think it is not the sound of the supertweeter that matters but the reduction in breakup modes in the tweeter during the production of high frequencies. In the case of a seperate supertweeter, I think it filters off the distortion inducing super high frequencies from the normal tweeters.

Re: The Futurist: Why You Should Buy Middle-End Products

soundproof — Sun, 23 Sep 2007 17:28:26 GMT

jandyt:
soundproof:
David:

For instance, Kimber cable is now attempting to convince customers that there's a difference in the sound experienced through cables depending upon the COLOUR of the cable, and they recommend using a clear cable for the negative and a white cable for the positive connector.
Gosh! I've heard it all now!
Andy T.

Yes, the mind occasionally does get something to chew on when it comes to high-end hi-fi:

Ready for a stunning revealation? The COLOR of the PVC will affect the dielectric coefficient! Black colored PVC is worse than white colored!
When you stop to think about it, the addition of coloring agents to any pure plastic will tend to cause the dielectric proerties to degrade, as the plastics purity has been compromised and altered.

From this link, go down to Dielectric constant vs. Frequency. http://www.audioasylum.com/audio/cables/messages/2341.html

Re: The Futurist: Why You Should Buy Middle-End Products

soundproof — Sun, 23 Sep 2007 17:05:32 GMT

Does not compute.

Here's one expression of the sawtooth harmonics. In digital synthesis, they are summed over k with respect to the Nyquist frequency, which means that for CD reproduction you would have to obey the limitation of half the sampling frequency of 44.1kHz, thus not allowing for anything above 22050Hz. Which means that even with electronica as source, as long as your medium of distribution is a CD, you wouldn't be able to produce any sensible "ultraharmonics" such as the ones you are claiming.

I seriously doubt whether it matters how many discrete sources you are "juxtaposing" in the manner you describe, there's a ceiling you can't burst through which is dictated by the medium of dissemination.
When we get music at significantly higher sampling rates as standard, then we may be able to create ultrasound content -- though I'm still wondering why we would desire to do so. (Yes, I know I'm flying in the face of a lot of hi-fi supertweeter theory here, but I really do think a sampling of skepticism is justified. If I ever see someone telling me that a new video format is preferable because it contains ultraviolet information that is essential to true colour perception, then I know that I'm going to have to put on sunscreen and sunglasses when watching TV, but my eyes aren't able to "see" the added info. Same with ultrasound and our hearing barrier).

But I'm more than willing to be informed otherwise as it's always fun to learn something new.

Re: The Futurist: Why You Should Buy Middle-End Products

Alex — Sun, 23 Sep 2007 16:17:17 GMT

Okay, imagine you have two sawtooth waves (for those of you who don't know, a waveform which looks like a saw), and you combine them together, and move one very slightly out of line with the other. What you end up with is two very sudden peaks INCREDIBLY close to each other, and as a result, a short burst of incredibly high frequency. Now, if a speaker cannot reproduce that frequency correctly, the harmonic formed by those two close-by waves will be destroyed and the waveforms will lose their definition as two seperate waveforms, and begin to form into a single, poorly defined waveform. You aren't losing any direct information above 20 KHz, because you can't hear that high. However, you are losing information which affects lower frequencies as well.

Re: The Futurist: Why You Should Buy Middle-End Products

Puncher — Sun, 23 Sep 2007 15:21:09 GMT

Alex:

Soundproof, you're forgetting the harmonics formed when two separate sounds from two microphones are combined, which reach way beyond 20 KHz if the audio in the individual channels reaches above 2 KHz. Otherwise both will not be reproduced faithfully...

Explain

Re: The Futurist: Why You Should Buy Middle-End Products

Alex — Sun, 23 Sep 2007 14:08:37 GMT

Almost as stupid as that guy who was selling special rocks which when placed in the right shape around your amplifier, reduced the resistance on all internal components.

Re: The Futurist: Why You Should Buy Middle-End Products

Jandyt — Sun, 23 Sep 2007 13:40:01 GMT

soundproof:
David:

For instance, Kimber cable is now attempting to convince customers that there's a difference in the sound experienced through cables depending upon the COLOUR of the cable, and they recommend using a clear cable for the negative and a white cable for the positive connector.

Gosh! I've heard it all now!

Andy T.

Re: The Futurist: Why You Should Buy Middle-End Products

Mr10Percent — Sun, 23 Sep 2007 09:19:21 GMT

I’m guessing that the essence of this debate is actually defining the standard you set yourself as to what you can call ‘faithful’ reproduction. To explain, I remember back to my first set of loudspeakers – a pair of Ross amplified desk-top speakers. With my Discman, I thought they were great. My next set of loudspeakers were a pair of Beolab 6000’s and they just blew anything away I had heard before. Crisp, clean decent bass etc….

These in-turn were blown away by the Beolab5’s and that is where the bar is now set.

For those in the industry, i.e. those who can regularly listen to and audit high-end gear, and for those of us who are fortunate to own instruments like the BL5’s, we know that high-end gear really does sound a whole lot better than lesser products. Of course, this high-end gear is subjective like everything else and one could argue that a GBP10,000 loudspeaker set could sound better than a GBP20,000 set. However, either are likely to sound very good indeed as the threshold of what does sound good generally passed by several thousand pounds before.

Where some of this hi-end gear does get questionable is when manufactures manufacturer their own unique selling point for the sake of selling rather than true innovation in the product. i.e. 50khz super-tweeters argument below.

For the majority of us, we make a number of basic rises in the world of hi-fi. We usually buy the best we can afford whenever we upgrade. We buy on the basis of sound, hearsay, style/looks, value for money or a combination of all and usually our next pair of loudspeakers sounds better than the previous. In my case, I bypassed the Bose product stage after the Ross and when straight to the Beolab 6000 stage. Simple as that.

10%

Re: The Futurist: Why You Should Buy Middle-End Products

Alex — Sun, 23 Sep 2007 06:30:43 GMT

Soundproof, you're forgetting the harmonics formed when two separate sounds from two microphones are combined, which reach way beyond 20 KHz if the audio in the individual channels reaches above 2 KHz. Otherwise both will not be reproduced faithfully...