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post #136 of 783
Quote:
Originally Posted by drez View Post

What is the real world?

"Real World" is what human beings can actually hear.

Welcome to Sound Science. Sorry about your misconceptions.
post #137 of 783
Quote:
Originally Posted by hifuguy View Post

Hi Everyone (again),

I don't run a subwoofer with my BM5A and am fully satisfied on the bass side. I'm not a bass head, but I like solid, tunefull, tight bass as much as the next guy. I borrowed a subwoofer once, and decided that the pros versus cons were not worth it to me. Placing them and adjusting them isn't child's play,

Can we please stop going around and around with the USB cables all sound like they came from Monoprice thing. I don't believe that is true and saying the same thing 10 times doesn't change anything. That is what I believe...

You shouldn't dismiss subwoofers entirely. The setup on them can be a little complicated, but it's totally worth the trouble. Especially with smallish mains like the ones you have. The trick is that the lower a speaker goes, the more power it requires and the more expensive it is to get a good one. The Pieso supertweeters in my system cost $50 for the pair, and they spit out oodles of clean, loud super high frequency sound. But my Sunfire subwoofer cost thousands. But the ability to have a smooth response below 100Hz makes a LOT of difference. The bass carries a lot of the rhythm and fills up a room with sound. It's actually more important than the treble.

As for saying all USB cables sound the same... You're right that me simply repeating the truth over and over isn't going to change your mind. The way for you to change what you believe is to take the time and trouble to set up a nice level matched blind comparison. When you spend $100 on a wire that comes with your hard drives for free, there is a huge temptation to justify the expense to yourself by convincing yourself it sounds better. Just like you've convinced yourself that a subwoofer won't improve your speaker system. But it isn't true. It's perfectly fine to spend big money on simple wires if you have a c note to burn and you really like the color of the insulation on the fancy cable. But it doesn't make any difference to the sound at all. Not even a little bit.

It is very easy to make wires in China. If high end cable manufacturers had really stumbled across a scientific breakthrough in cable design, it wouldn't take two weeks for the five dollar Chinese knock offs to arrive at the Port of Los Angeles and do the exact same thing for pennies.
post #138 of 783
Quote:
Originally Posted by drez View Post

Me personally I know enough to know that I in fact do not understand everything to do with digital audio, and to trust my ears and judgement instead of my limited understanding of the technologies at hand, or what studies I have not actually closely studies might be used to make claims about what will or will not affect sound quality.

Based on your comments, it's clear that you'va actually invested a lot of your time absorbing papers on this subject... But the problem is, it's the papers written by high end cable manufacturers to justify buying their products. And those papers leave out the simplest and most meaningful data of all...

What is the size of the error relative to a natural benchmark we can understand?
And what is the generally accepted threshold of audibility?

Jitter is generally measured in picoseconds. Now the average person has no clue how big a picosecond is. A little googling will answer that. Try to imagine the difference in scale between 24 frames a second in film, or how far a car will travel in a picosecond if it's going 100 miles an hour. Or even the speed of sound, or a bullet being fired from a gun. It's actually a fun little exercise and you'll learn something about time. Once your head is wrapped around how *infinitessimally small* the errors we're talking about really are, it isn't that much of a leap to realize that this stuff *just does not matter*.

Jitter is a marketing ploy. It isn't a measure of sound quality.
Edited by bigshot - 8/15/12 at 10:48am
post #139 of 783
Quote:
Originally Posted by Lorspeaker View Post

dang, jusr realised my mcbook air doesnt hv usb3.

It doesn't need it for this. You have optical out.
post #140 of 783

Also, USB 2 is quite robust, if you don't want to use the optical. 

post #141 of 783
The big problem I've found with optical is that it's a bit delicate. Optical cables don't work well with kinks. Better for installation in fixed systems than portable.
Edited by bigshot - 8/15/12 at 10:49am
post #142 of 783
Quote:
Originally Posted by bigshot View Post


"Real World" is what human beings can actually hear.
Welcome to Sound Science. Sorry about your misconceptions.

Gold.

post #143 of 783
Quote:
Originally Posted by ultrabike View Post

 

Dude, you are right! The paper was done to partially fulfill the requirements for a BS degree!

See....I TOLD YOU!!! I KNEW IT!!!! wink_face.gif

post #144 of 783

USB audio can suffer less from jitter (depending on how it's implemented) than toslink optical audio, but it's more susceptible to line noise. This is why the better USB cables that are made for audio have the power transmission component of the cable broken out or heavily shielded from the data transmission component. The type of USB cable does seem to make a difference to my ears, although I haven't tried to the ridiculous (>$150) high-end ones. This is just what I have noticed from playing around with different DACs and cables, so my findings are 100% unverifiable but that's my experience. I have also noticed improvement using a modest real glass toslink cable compared to a cheap plastic toslink cable when using optical.


Edited by grokit - 8/15/12 at 2:12pm
post #145 of 783
If you guys don't stop talking about college, I'll show you all my BA!
post #146 of 783
Quote:
Originally Posted by bigshot View Post

Quote:
Originally Posted by Lorspeaker View Post

dang, jusr realised my mcbook air doesnt hv usb3.

It doesn't need it for this. You have optical out.

 

The Macbook Air does not have the optical/analog combo jack found in all other Macs (except Mac Pro where they are separated), but it does offer HDMI output as an alternative to USB audio.


Edited by grokit - 8/15/12 at 1:58pm
post #147 of 783
HDMI is the slickest of all
post #148 of 783
Quote:
Originally Posted by drez View Post

 

Data transmission over USB and the way in which A DAC streams audio from a computer are different.  Data transfer uses bulk mode which does not care about the timing at all.  Cheaper USB transports and DAC chips use adaptive transfer mode in which the USB receiver is reveives the clock from the computer, and attempts to fix any timing errors (jitter).  Some more recent or expensive USB transports use asynchronous tranfer where the USB device controls the rate at which the packets are tranfers with it's own clock, usually with some sort of buffer to attempt to ensure that if a packet is not sent in time the stream is not interrupted.  The Hiface uses bulk mode transfer which in theory means packets can be resent if they are not received correctly.  Bear with me if I have not described things correctly.

 

Some USB transports draw power from the USB port, so the cable may contribute the the rective impedance of the power being supplied, or pick up noise from the surroundings, or crosstalk between the conductors.  Most USB cables are effective enough to ensure that non-timing critical transfer modes work without error.  At this point people who beleive they can predict how equipment will behave for whatever reason will say "but asynchronous USB is buffered to compensate for variation in the latency between when when the USB transports requests a packet and when it arrives, and they are correct in theory.  In practice things are not that simple in my experience and you may feel free to take my experience with a grain of salt if you think you know everything there is to know about digital audio.

 

Me personally I know enough to know that I in fact do not understand everything to do with digital audio, and to trust my ears and judgement instead of my limited understanding of the technologies at hand, or what studies I have not actually closely studies might be used to make claims about what will or will not affect sound quality.  

So what you are saying is the DAC receives its clock from the computer. How exactly does it work? USB2.0 runs 488MHz and the DAC runs 44KHz. What if I have a USB1 or USB3, won't that really screw up the system?

 

Let's assume if indeed you get your clock from the computer. Let's say my music is recorded at 43KHz (there will be tolerance and I am exaggerating the difference) and you are running 44KHz. Won't that cause buffer under run?

 

People are confused by synchronous transmission and synchronous timing. Synchronous transmission is synchronous to a transmit schedule which gurantees bandwidth and latency that's important in real time communication. Synchronous timing refers to clock synchronization which is necessary to recover data.

post #149 of 783
Quote:
Originally Posted by grokit View Post

USB audio can suffer less from jitter (depending on how it's implemented) than toslink optical audio, but it's more susceptible to line noise. This is why the better USB cables that are made for audio have the power transmission component of the cable broken out or heavily shielded from the data transmission component. The type of USB cable does seem to make a difference to my ears, although I haven't tried to the ridiculous (>$150) high-end ones. This is just what I have noticed from playing around with different DACs and cables, so my findings are 100% unverifiable but that's my experience. I have also noticed improvement using a modest real glass toslink cable compared to a cheap plastic toslink cable when using optical.

Wouldn't it be cheaper simply to cut the power line? It might be interesting to DBT a USB cable with and without the power line since they're the same in every other aspect.

post #150 of 783

Ya know... I really like you guys, but I think I am going to need some therapy pretty soon.  :-0

 

Just for fun.... here's a nice hypothetical question for you guys that believe in your hearts-of-hearts that USB cables don't sound better. Please humor me for just a second here... I'm really curious.

 

What would you say "IF" (note the big, and bolded IF).

 

1 - We all got together at my house... and drank a couple of beers (always a good plan... and maybe a pizza too... I like pepperoni)

2 - We ran a 100% fully legitimate DBT to you full specifications.

3 - The result of said DBT was that, "Yes" the high-end USB cable was identified as significantly better every single time. DBT passed with flying colors (remember the IF).

4 - The beer in step 1 had no influence whatsoever in the results of step 3.

 

What conclusions and thoughts would you have to say, if this were indeed the result?

 

And yes, I really do believe in my heart-of-hearts, that on my system, in my living room, on my music, that I really could deliver this result.

 

But coming back to our individual realities in the real world... I again suggest that unless you have heard a really good cable (Locus Design Polestar and Axis in my case), then I don't think that there is very much that you can tangibly contribute to threads such as this. The same goes for interconnects, speaker cables and power cables. On the other hand, if you really have indeed listened to a specific cable change (USB Cables in the case of this thread), then your experiences (confirming that you can hear improvements or conversely, that you can't) truly are invaluable to the our community and to our understanding of what is worthwhile and what isn't.

 

If a cable does deliver an improvement, then it becomes a simple question of whether that amount of improvement is worth it to you, as you prioritize your short and long term financial situation and goals. If yes, then buy it; if no, then send it back. It's pretty simple really. Therory is great, but in a thread like this where all of us are really pretty much professional amatures at best, the back and forth theory debates fail to bring much real value to the table in terms of a specif cable being considered is worthwhile (or not). And with that... I'll be at the therapist if you need me any further :-)

 

Take Care... Happy Listening!


Edited by hifuguy - 8/15/12 at 4:18pm
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