You end up with kind of a funky trust relationship where IASCA has to trust empeg to properly calculate and display the hash (and keep the user from tampering with it) and has to trust the user not to have modified the empeg software to display the hash for one song and then play another. I don't see this happening until IASCA is forced to deal with the reality of mp3 players which probably won't happen until all the common stereos by all the big manufactures play digital audio files.

Exactly. Except I don't see this happening EVER. IASCA can't trust the user about anything (otherwise they might as well trust the user to play the right song in the first place). They can't trust the empeg to display the correct hash unless it's a closed and tamper-proof platform. In fact, the empeg is the exact opposite of that.

Borislav

Surely if they can make an approved master CD, they can also make a master CD-ROM of MP3 tracks, which they can shove into the laptop, verify a checksum on, download to the empeg, then after the verification, see the loaded checksum on the target machine?

The fact that the empeg displays the correct checksum doesn't mean anything. If you can change the player software (or the kernel) then you can have it display the checksum of the judge's file and still play your modified copy.

For any checksum based scheme to work, the following needs to happen:

1. Empeg must disallow all changes to the player software. No custom kernels or developer images;
2. IASCA must audit all of the player hardware and software to make sure there are no backdoors and the checksum is calculated correctly.

I hope 1. never happens and 2. sounds highly unlikely.

Borislav

OK, so how about the judges having one empeg of their own, pre-loaded and verified by themselves?

They are, after all, trying to test the audio quality of your system, not your empeg.

One of the few remaining Mk1 owners... #00015

Reading throught this lot reminds me in a way of the history of cycling.

About 80 years ago there was the safety bike with it's diamond frame and upright ineffiecent cycling position and then some bright spark invented the recumbant bike with a low centre of gravity and effiecent cycling position and superior aerodynamics.

This then went onto wipe the floor with the safety bikes so it was banned by the cycleing authorities from competion because it was fundamentally better.

And now in this day the most popular form of bike is the good old diamond framed safety bike. And recumbants are still banned from cycling races.

Just because it is better doesn't mean that they are going to accept it

If i ever decide to take my cars to competions in the UK i will have my mates Alpine 7909L on standby in the boot if they don't like the Empeg.

The alpine only plays one CD but it sounds great must be the Burr Brown DACs just like the empeg

OK, so how about the judges having one empeg of their own, pre-loaded and verified by themselves?

what about your eq settings?

seems like a great expense just for the current few people who have an empeg.

____________________
Murray 06000047

..you give the competitor enough time to set up. I am sure given a bit of practice, Doug could set up his EQ in no time.

Just think how good an ad it would be if the empeg did win a few competitions in this way - any swing with marketing at SBl, Rob?

One of the few remaining Mk1 owners... #00015

or if emplode let you store and mangae things like EQ, you could just save your EQ then sync up onto the 'regulation' Empeg.

____________________
Murray 06000047

I suspect I am somewhat naive about the reality of a contest,

Uhhh, yeah. Think about the majority of people who enter these contests... these are not computer geeks. These are people whose idea of a good time is to put a dozen 15" subwoofers in the trunk of their car and scare the neighbors. At a typical IASCA contest, there are no computers. Period. Not with the contestants, not with the judges. These contests are music contests designed to see whose CD player can (A) play the best reproduction of the music, and (B) play the loudest. The judges are trained to operate just about any weird CD player on the planet, and to have really good ears and to know just what a particular track is supposed to sound like. But that is the limit and extent of their knowledge! They will not be even the least bit interested in in process that requires them to lug around a piece of equipment (i.e. laptop computer) and IASCA is certainly not going to change the way they do things just so the half dozen lunatics in the whole world such as myself can enter their contests with something that is not a CD player.

The only hope would be a completely non-intrusive, no-additional-workload solution, such as the empeg being able to display undisputable verification that the file currently playing has not been tampered with, but is in fact byte for byte identical to the file provided by IASCA. Apparently a simple checksum or hash is not sufficient to this purpose. I don't understand how these things work, but several people on this bbs who are a lot smarter than me (yeah, I mean you, Frank!) are saying that this is not a trivial undertaking.

When digital music players become mainstream, rather than the 1/100 of 1% of market share currently commanded by empeg, then IASCA will have to address the situation.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"

You can argue forever as to what constitutes a "copy" for example

Well, not really. The issue here isn't whether the competitor is playing a copy of the file or not, but whether he is playing the same original source as the other competitors.

Yes, you can argue that the whole purpose of the stereo system is to modify the original source at every step of the way right up to the point where the sound waves come out of the speakers. But you have to define a starting point someplace where everybody begins on an even footing. IASCA has defined that starting point as the original IASCA CD. Unless I or someone else can convince them that my music source is either the original CD or some other media that is functionally identical in every aspect to the original CD, IASCA is not going to allow digital music players.

There is a subtle slant to the purpose of their competitions. They are not trying to find out who can produce the best sounding music. They are trying to find out who can build a stereo that will do the best job of playing their CD. The base intent of this is to then convince other people that, since my Mega-Blaster 8000 with inverse capacitance bias modulation rectifier plays their CD better than your Ear-Killer Mark 7 with Ultra-Bass enhanced tweeters, you'll go visit your Mega-Blaster dealer. This is why Mega-Blaster, along with lesser brands like Sony and Panasonic, give considerable financial support to IASCA.

Hey, it's their game, so I guess they get to make the rules.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"

This is more proof that the empeg Mark III needs to come with digital in and out.

Save the whales. Feed the hungry. Free the mallocs.

Exactly what I said. Attach a CD ROM to the empeg, and have the empeg rip the judge's original CD and play it off the hard drive. Then all the sound would be subject to the empeg. Simple. My argument was not intended to state that running the iasca cd off the empeg hard drive is the same as running it off the judge's cd. My argument states they are different. However, you CAN argue that the hard drive is a distinct audio component in the path, and therefore if given the same starting point (judge's cd) and if you can rip the cd fast enough, then you can get away with it.

Calvin

Calvin

Attach a CD ROM to the empeg, and have the empeg rip the judge's original CD and play it off the hard drive

Never happen. Aside from the fact that there is absolutely no possibility of the Judge hanging around for 30-40 minutes while the music is prepared, there is no reasonable way for a non-technically inclined judge (they're music judges, not computer geeks) to ascertain that the music being played on the empeg is in fact the same music that was just installed. Remember that the majority of judges will have never even heard of an empeg, much less seen one, operated one, or understood how the hierarchical playlist structure works.

I still maintain the only possible way for digital music to be allowed under any semblance of the rules as they are currently written, is for the empeg to have the ability to display a tamper-proof idenfitication of the currently playing file. Hey -- you could make it one of the visuals! Then all we have to do is (a) get empeg to write the software, and (b) get IASCA to understand and accept it.

Don't hold your breath.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"

A feature we have been hoping for for a long time

One of the few remaining Mk1 owners... #00015

Why would it take 40+ minutes to rip a CD? I never said encode the cd as an MP3. Theoretically you can read the cd, store the cd, play the cd in virtually real time.

Calvin

I think the empeg main board is capable of a optical output with the addition of a optical digital audio driver chip. I'm not sure if the chip is bidirectional but it sounds like if you are trying to compete in IASCA with a CD based empeg you should do it right and bypass the D/A's on CD players. Many CD players have optical outs these days. This is more of a solution for future hardware though.

Seems like if you are serious about IASCA, just buy a CD player. The cost of a CD player compared to an average IASCA system is a tiny fraction anyway.

Also, I mentioned a while ago I would analyze the Alpine Ai-Net bus to determine the protocol for controlling a CD changer (only if there is someone that can impliment that control.) Offer still stands.

Alex Lear

Seems like if you are serious about IASCA, just buy a CD player.

Yep. That's what I've decided to do. I have a halfway decent CD player that came out of my car when I got the empeg, and I have room in my dash for both, so I will use the CD player to feed the aux in on the empeg.

Of course the downside is I am adding one more processor to the signal path with some inevitable signal degradation, and I end up using the DAC from the CD player instead of the empeg.

I guess I could do some fancy wiring with switches that would allow me to bypass the empeg completely and run the CD player directly to the amplifiers... Hmmm, I'll have to think about that one. Would need an 8PDT switch, lots of opportunity for noise to leak in. Maybe someone already makes a nice A/B switch that would handle four L/R audio channels? But then I lose the empeg's parametric equalizer. Probably better to keep the EQ and suffer the small amount of signal degradation caused by playing through both the CD player and the empeg before getting to the amps.

I'm open to ideas here.

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"

Greetings!

A recommendation: hook it up through the empeg first, see if you can quantify the noise introduced. You might find that it is very small, or if it is enough to warrant a switch.

I don't know if the voltage differences (empeg input 1V, output 4V) will cause you any problems. If you use a switch, both inputs from to the switch should be the same approximate level. I don't know if the CD you are looking at is adjustable, or what voltage it uses, but if your amp(s) expect 4V from the empeg, you may wind up with a quiet signal if your CD isn't 4V as well. Likewise, if your CD is 4V, running it through the empeg may give you a very loud signal...

Disclaimer: I am a very basic beginner, so I don't know how practical this is for a competition level vehicle.

Paul G.
SN# 090000587 (40GB Green)

but if your amp(s) expect 4V from the empeg, you may wind up with a quiet signal if your CD isn't 4V as well

An excellent point. The CD player is putting out somewhere around 1.0--1.5V so the amp gains would be way out of whack.

Probably better to just run it through the empeg, and at least take advantage of the 20 band parametric EQ.

Thanks for pointing out such an obvious problem that I was too dense to see for myself!

tanstaafl.

"There Ain't No Such Thing As A Free Lunch"