First meaningful A/V topic

[Ken McDaniel]

Alright, let me kick this off. I'm in the Army and currently attending the Command and Staff Service School at Ft. Leavenworth, Kansas. I am tasked to perform a decision paper. My topic is which is the best receiver to purchase. I know it's vague, but hey, it's the Army.

I need to break down criteria into two realms. The first is screening criteria, i.e.: What are the minimum requirements out there in selecting a receiver? A minimum price is definately required to keep some of the riff-raff out.

Next I need to come up with some evaluative criteria. There are hard, quantifiable numbers that we can associate with a receiver (watts, # of inputs, etc.) I need 5 or 6 evaluative criteria and I must order them according to priority so they can be mathematically weighted.

Suggestions? I know this is purely empirical. Numbers are not usually an indicator of quality. Remember, it's for a class and not a true indicator of what makes a truely great receiver. Thanks for the help in advance.




Ken

[Lexman]

First off, it must be Dolby Digital with equal power to all 5 channels. It must be remote cotrol driven and have both coaxial and tos-link inputs. 6 channel analog inputs is another requirement for future proofing your purchase. (5.1) I would specify 100 watts as the minimum power per channel. Look for bass management features as a selection criteria as well. THX is a nice to have, Re-EQ required.

quantifiable criteria:
# analog and digital inputs
wattage
Sound modes
RE-EQ? THX?
Warranty?
crossover settings available?

That's it, I am sure I left something out.

Lex

[David Meek]

Ken,

What about Signal-to-Noise ratio? That's always been a fairly important one for me.




David - HTGuide flunky
Our "Theater"
Our DVDs on DVD Tracker

[Digital Bob]

Ken,

A good list so far. I'd add current capability to it. Sometimes known as " real power" , this can often give you a sense of how dynamic and full sounding a receiver will be. Especially in the bass region.

It's a hard number to qauntify and many manufacturers won't share it with you. So here's a rough guideline... look at the wattage specs and look for both the 8ohm AND 4ohm rating. A " perfect" amplifier doubles it's power into 4ohms but those are few and far between in the receiver world. So look for one that puts out signifigantly more power into the lower impedance; this is an indication of big current capability. If the unit puts out about the same (or in some cases, less!!!) it usually means the unit is " currnet limiting" to protect itself from blowing up. A sign of a fair, but possible enemic power supply or output stage. BTW- if the 4ohm spec isn't available at all, I'd be very careful.

Maybe you can put this ratio of 4ohm wattage to 8ohm wattage on a scale for your purposes of creating criteria. Perfection being 100% more power and unacceptable being 0% more (or less) with everything else ranging in betwwen; the higher the better. Does this help?




dB

[Ken McDaniel]

Bob, good question. How would I work the math on that? I majored in History.




Ken

[Digital Bob]

Math...uhhh...like with numbers and stuff? h:
I'd be willing to bet mine is worse than yours but here goes.

If you are looking to " score" this product, I might consider assigning a variable value to each of the criteria you decide upon. The variable might be how well it meets (or exceeds) your spec. For example: If you decide that 5 digital inputs is the right number to have on a receiver you might decide to score as follows...

5+ inputs = 10 points
3-4 inputs = 5 points
<3 inputs = 0 points

or...

6-7 inputs = 10 points
5 inputs = 5 points
3-4 inputs = 3 points

or something similar.

Then you could decide the unit must meet a certain point score overall (all points simply added together). Or you could mofdify that by saying the overall score determines the winner but you must score at least 5 in every category to qualify or something of that sort. This would insure your basics were met but reward units that excelled in some area. You can adjust the scales and or point values for each criteria to place emphasis on the criteria you feel is most important.

In answer to the specific question about how to &#34; spec&#34; the current...
if you use the scoring sytem (or one like it) above then you could assign a point value for every 10 percent (or 25% or whatever) above 0% more power into 4ohms. And you could even establish a &#34; baseline&#34; of acceptable current (ie 40% more power into 4ohms).

if you decide not to score the criteria, then simply decide that a certain amount more power is the accepatble minimum to make the grade.

Your projest is a cool idea and I&#39;d be interested in what you come up with so please feel free ask me for more of my opinons. I&#39;m always glad to share them




dB

[SiliGoose]

Ken,

Buy one of those shoppers guides and just plagiarize an article. It&#39;s just the Army!

Seriously though, these shopper guide magazines (Home Theater mag and SGHT both put one out) run comparison type articles that can be a model for your paper. Follow their structure and form and you too can cater to advertisers.

-Sili

[Ken McDaniel]

I&#39;m creating a weighted-multiplication decision matrix. I think we have a pretty decent amount of screening (exclusion) and evaluative (quantitive). My next question is this:

What are the priorities for the evaluative criteria and by what degree? i.e. cost is more importat than power which is more important than input which is the same as .......

You get my point.




Ken