i know the title says a lot, but that's pretty much it: what makes a head unit better for sound quality than others? we all know about Pioneer's DEX-P9 (w/optional DEQ-P9), and Alpine's F#1 Status DVI-9990, etc, but what makes them so expensive?

and do they (those mentioned, or other expensive decks) really sound better? is it the Burr-Brown, the 24-bit DAC, copper chassis? or is it a high volt pre-out (>4V)? what makes them sound better than others of comparable price? i'm not talking the $50 kragen brand radio vs. the F#1 Status.......

and how about those double DIN units? could they sound good? if not, why? could regular folk like me really tell the difference?

with all the acronyms and techno-gadgetry that are out today, mp3, mp4, wma, aac, ipod, bluetooth, blah blah blah, what happened to a good ol' decent sounding deck? any help would be greatly appreciated....i'd like to hear from as many people as possible.

 

I'm no expert, but I could take a stab.

BTW, electronic music formats like mp3, wma, etc... provide INFERIOR sound quality compared to the uncompressed WAV format that are on CDs. This is why true audiophiles will probably never consider mp3s as a serious audiophile format when compared to the uncompressed formats available through CDs/DVDs, etc. These formats are intended for the masses for portability and convenience.

Features for great SQ:

-Shielding. EMI/RFI from outside and within can add noise. High end decks feature innovative shielding techniques with metal, paint, circuit design, to greatly reduce and or eliminate outside interference.

-Servo Mechanisms. The motor and the mechanical components responsible for holding, spinning, and handling the CD/DVD inside the deck have to be reliable, consistent, precise, and stable as possible. Dampening techniques to isolate the assembly from vibration and other negative mechanical distortion is used.

-Lasers. More precise lasers and the use of multiple lasers to perform various error correction tasks, electronic shock protection, etc. are used to improve performance, increase accuracy, and provide buffer mechanisms to reduce skipping and read errors.

-DACs. Higher bit and higher quality DAC chips allow higher order sound processing similar to the way graphics cards provide high quality anti-aliasing. For example, a 16 bit CD audio sample can be blown up into 24 bit where sound processing is applied and then down mixed back into 16 bit for output.

-Outputs. Higher quality connections improve sound quality by reducing the likelihood of distortion from outside interference. Higher voltage outputs resist distortion than lower voltage outputs. Higher quality metal connectors also reduce this likelihood.

That's all I can think of for now. Hope someone can correct/augment this to make it complete.

 

I think he's looking for specific brands/models that meet those criteria, not the criteria themselves.

 

Having limited experience demoing HUs, I would be at a loss. Perhaps he can use the info to help him rate the HUs he is considering.

 

I would suggest going with a non-amplified, sheilded, high voltage unit ie: Alpine F-1 status.....but no matter what the voltage output of the head unit, usually claimed 4-8 volts, the signal is still not hot enough. It's more like 2-volts rms. Be sure to use a high quality, high voltage (13-volts is plenty) line driver with balanced inputs and outputs(to get rid of any noise). Ie: AudioControl Overdrive or Matrix. This way you can deliver the highest signal to noise ratio and the hottest signal to your amplifiers. Then you can use the least amount of amplifier gain possible. Your amplifiers will still put out maximum wattage. Make sure to find out the manufacturer's specs on input voltage, to further dial-in the gains. ---PeteyPablo---NYC.

 

actually, i was looking for the criteria....what sets high end decks apart. for a true audiophile, i would see why it would make a difference (but i still question whether these "audiophiles" could "hear" things that much better than the normal man). any and all input is welcome. i think this would shed some light for a lot of us who wonder why we spend so much money on our sound systems

 

so a line driver is absolutely necessary? what about balanced input for your amps (such as what zapco amps have)? so would a higher volte pre-out be the overall determining factor?

 

Higher price does not necessarily equate to any better performance. Just look at what it costs to get the Bose system vice the regular stereo... and everyone is replacing that one! That is where the research comes in. Make sure you compare the specs and not just the price.

 

semi-sidenote, but what exactly is the Burr-Brown thing/stuff/whatever? i see it in specs for head units etc. but I really have no idea what it is???

 

Burr-Brown is the name of the people who developed a type of DAC (digital-to-analog converter). here's a really technical explanation.

 

An in-car head unit can be thought of as the equivalent of a home CD player, a home AM/FM tuner, and a home preamp, all in one box.

What makes a home CD player sound better? It should be stipulated up front that there are some people who believe that all CD players sound the same.

This is not consistent with my experience, but there are some who say it.

First off, the way a CD player works is, the digital signal from the laser pickup goes to the digital-to-analog converter chip. An analog signal comes out of the converter chip and goes through the pre-amplifier section of the CD player. The preamplifier section sends the analog signal to the amplifiers.

The pre-amplifier section of the CD player - home or car - is the part that has the biggest effect on sound quality. 24-bit D/A or no, 4V or no, this section may sound good or may sound great or may sound poor. Parts quality - capcitors, op amps, resistors, all affect sound quality. Many voltage-controlled-amplifier or preamp-hybrid chips - the ones that allow control of volume from a pushbutton instead of a real potentiometer **** - sound crappy. In the old days, this was all discrete circuitry. Now, the lower and mid-end decks use off-the-shelf ICs, many of which sound bad. There are good sounding ICs, but they cost more.

Can't look at the box and figure out if the deck sounds good just by seeing "4V".

Another thing that makes a CD player sound better is better disc reading in the first place. CDs have digital error correction as part of their operation - but if the CD player is using too much error correction, there is an audible decrease in sound quality BEFORE audible dropouts are heard as such. You will see some VERY different transport systems used in expensive home CD players. It's harder to fit something odd into a DIN size, but Nakamichi, for instance, in the CD 1200, was aiming for improved sound out of the transport.

So the better the transport and laser pickup operate, the better the sound is. How to quantify this? It's hard.

How good a job the CD player does at preventing electrical noise from affecting the analog signal affects sound quality. Related to this is the CD player's ability to supply consistent voltage to the transport and analog section so that fluctuations in the car's system voltage do not affect sound quality differently from momnent to moment. This is where external power supplies - often called DC-DC converters - come in. Having one SHOULD mean that you will have better SQ. Again, how to quantify?

Finally, the quality of the D/A chip makes an audible difference in sound quality. Not as much as the preamp section. Not even as much (in my mind) as the transport section. But it does make a difference, and a lot of the cheapo 1-bit processors do sound crappy. Especially the Alpines.

That said, what makes a CD player sound better? Often it's using discrete analog parts instead of an off-the-shelf chip. Sometimes it's using a chip that costs a lot more since it's made in very low quantities, and to much tighter tolerances (like op-amps or transistors or even DACs).

But also, the equation for profit for very-small-volume high-end parts is very different than it is for volume units. Inventory turns are very different, much slower, and the margins have to be correspondingly higher to pay for the overhead. Basic ROI calculations, unfortunately.

 

Oh, balderdash. Specs tell you so little about sound that it's pathetic.

 

thanks el_duderino....that helps and is exactly the kind of analysis that i'm looking for. i'm sure that post will help others as well!

 

For what it's worth, the best sounding CD player I have ever heard for a car was the Denon DCT-Z1.

Wish I hadn't sold mine.

The guys who used to be at Phoenix Gold did a listening test with the old Alpine 7909, the original Clarion 9255, and the Denon DCT-Z1. The Z1 blew the others away.

 

from what i'm finding out, with the information given, the best sounding units are denon, nakamichi, and mcintosh. they may be ugly, and lack the "expansion" that most people want, but i guess if you want what sounds the best, those are the ones to beat. but what about decks like the Alpine F#1 (DVI-9990) and the Pioneer Premier DEX-P9? those can't be bad either. i believe they too have burr-brown dac's.

as for the system that i am building, it will be small, and will definitely not have one of these high end decks. don't get me wrong, i'm not going to go with a cheapo krager brand or anything, but i am not going to break the bank on a large system which will just weigh the car down and take up so much space in the trunk (which is so valuable to begin with).