That is a very good question. And there are many good reasons.
You are right in that it is much easier 'lowering' the voltage in an AC home component than it is to 'step up' the voltage in a DC auto/marine component (especially since transformers do not work in the DC realm). And you have an endless supply of AC power in the home. There is no 'at rest'.
So let's say you are placing a full and biggy 7.1 home theater system along with whole house distribution, including 4 to 8 outside speakers around the pool and pool house, etc. in a converted closet. That either constitutes a ton of amplifier channels or some really huge amplifiers with a matching multi-tap autoformer. Now the 15 amp service capacity is way beyond toast and you place your expensive electronics at risk from sagging voltage. Even twin 15 amp services will get challenged. So enter fullrange Class D for the whole house distribution.
I have some pretty big Sherbourne amplifiers in home that are Class H. So higher efficiency has caught on in the home too.
Several editions ago in Absolute Sound they had a very long feature article about Class D with just about every top amplifier engineer in the home Hi Fi biz. Yep, including the tube and Class A pipe smokin' guys with twead jackets and suede elbow pads. And, you don't get that type of attention unless the technology has come of age.
I see the issue with large whole house audio/home theater all being ran off a single room. I guess I figured that the home theater guys would take to this route as most houses don't have a separate power run to a location and if they did, still lots of other gear plugged into it, but the tweed pipe smokers seem that it's more about a pair of mono amps driving a pair of speakers with a preamp and either a turntable or a high end cd player. in this case, I would think that class d would be perceived as introducing sonic imperfections into the signal source and would prefer class a as there would not be as large an issue with outlets as the "drive 80 speakers and a theater off one outlet" guy.
it's absolutely daunting all the choices out there. want to get into hdmi switching from the receiver for simplistic sake. replacing an Onkyo TXDS-838 that has served me very well. old school, but was hella-expensive when I bought it and sonically, a solid unit(couldn't afford the 939 or the hk signature 2.0 separates that were the competing units).
I miss the golden years of simple two-channel home audio. Like an old school analog dial with a heavy flywheel. I recently got an FM/AM/XM home tuner for whole house and you can tune only as fast as the tuner responds. The menu and functionality is retarted. I actually had to read the manual to figure out how to enter the presets. Bottom line, even though it's from a prestigious brand, it's still a POS.
Speaker value I can definitely see and the good ones for home have gotten super expensive.
A lot of the other esoteric stuff is just placebo effect. And many will cling to things well past their expiration date.
Class D well done has no audible artifacts in the context of what we do in boats or cars. It would be crazy to be listening to an esoteric SACD with D to A conversion talking about how you hear this or that from a top analog switching D amplifier. Kind of the pot calling the kettle black. But again, there are different levels of everything. The difference maker for Class D was the more recent advent of super high speed microprocessors and transistors that keep the switching frequency perhaps 20 times what our audible bandwidth is. It's the same for the evolution of fullrange Class H where the power supply has to track the audio signal super fast. That would have artifacts if the devices were slower. Speed has changed both topologies.
someday I'll get the old man's extra stereo. it's a technics 35wpc old school lighted dial receiver, a bic turntable that has the clear bottom on it and a real wood frame, and an old super expensive pioneer tape unit that didn't have autoreverse, you had to grab the tape out and flip it(no door, the "door" is over the head and roller assembly. he ditched the polk monitor 10b's as they were way old, but I know I can find some "old school" speakers to compliment it. speaker technology doesn't seem as dependent on all the new electronics. it'll find a home in the empty spare bedroom and become a "listening" room. gotta love the old pops and hiss of vinyl..
oh well. I kind of want to spend some cash on a decent preamp and add external amps, but it's real hard to find a hdmi switching preamp that doesn't drain the bank account.. sure it'll be a receiver/amp combo. lots of good stuff out there if you shop.. wish we had a better selection of brands above best buy(nothing worth shopping there), but our single local shop looks down on you if you are not spending krell/martin logan money :(
Hi-Jack Accomplished :)
interesting stuff tho.................
ya, feel kind of bad, but I think he got the right info :)
besides, maybe he's looking for a new home receiver as well :)
I hoped to be looking for one soon but not after this convo. I'm lost.
Originally Posted by sandm
To get you by for the short term, could you depend on the LCD/LED to output the audio thereby acting as the selector? They make digital audio to analog audio convertors...for maybe under $100.
it's hooked up that way currently. everything ran to the tv and then to the receiver. downside is the tv struggles switching between different hdmi inputs with the harmony remote. something to do with sony tv/dvd and a bd setting. it senses the dvd player and will automagically switch inputs for it, but does not sense the wii or dish receiver to switch back to the correct input on the tv. also tough to get ac3/digital signal to the receiver that way(tv not smart enough to switch between digital/analog that I can see). figured it's easier to run hdmi to a receiver, let it use the signal it needs for audio and then run a single component vid or hdmi to the tv. would also allow me to use the receiver as a 2ch straight from the dish unit to play the sirius channels and negate the need for the tv to be on. couple simple macros should get me that result.
really, it's an excuse to upgrade to a new receiver :) the onkyo is a solid unit, but it's only 5.1, no hdmi. I am leary about losing what I percieve is a pretty high quality output setup in that receiver and that it'll take a spendy unit to replace that, but it's time :) I know when I bought it, it has a pretty beefy output and additional dac's that their cheaper lines did not. heck pick it up and it weighs a ton compared to some of the stuff on the shelf today. that used to be a pretty good indicator of quality construction.
Like KG, I am also approaching a potential full home audio install, except..after reading all of this....wut?
David, I may just have to have you come walk thru the house and doodle me up a picture of where all the wires need to come from and go too.