Gift: Help me replace a Samsung HT-P38 DVD Home Theater
December 20, 2006 2:38 PM   Subscribe

GiftFilter: My brother's Samsung HT-P38 DVD Home Theater receiver is broken. I'd like to fix it or replace it with something equivalent/better/the same thing. Advise!

So the HT-P38 is a 5-disc DVD player and receiver for surround sound. Everything works just fine, except the tray of the DVD player is messed up and makes a grinding sound for 1 minute whenever you turn it on or off (and you can't play DVDs in it).

Repair: I get the impression that repairs on devices like that tend to cost more than replacement. Is this true?

Replacement: Can I just replace the receiver? For less than the price of a whole unit? Looks like refurbished whole units (speakers and all) are going for $150 on Amazon.

Other options: Are there other receivers that would be good, compatible with the Samsung speakers, and play dvds? (And support the HD TV)
posted by anonymoose to Technology (8 answers total)
I'd suggest asking this question over at the AVSForum; all the cool AV geeks hang out over there :)
posted by jacobian at 5:06 PM on December 20, 2006

My dad insists on buying these things (which he can never figure out how to use) over buying components. They do tend to break. If I were you, I would go the component route, but if you insist on sticking with the all-in-one gizmos, do what my dad does and buy them from Costco. That way, when they break three months later, presto! New piece of crap.
posted by Sinner at 5:54 PM on December 20, 2006

Response by poster: Can I replace the receiver with a component and reuse the speakers? (Thereby setting him on the component route?)
posted by anonymoose at 5:57 PM on December 20, 2006

Best answer: You can almost always freely interchange speakers. Technically, you should choose speakers of the appropriate impedance rating (I can dig up links to some old questions if you want, you probably don't want to go there), but odds are you will be fine, especially if your listening levels are moderate. On the other hand, speakers are the most important component for sound quality, so..

I would open up the unit and see how it works. There is probably some simple mechanical blockage interfering with the disc mechanism. Often just playing around a bit is enough to fix this kind of thing. Of course playing around on the inside also greatly increases the chance of more dramatic damage :P
posted by Chuckles at 6:37 PM on December 20, 2006

Response by poster: ...say, would this be a nice upgrade? Would it work fine with our speakers?
posted by anonymoose at 8:18 PM on December 20, 2006

Response by poster: (And why is a seemingly much-better quality Onkyo system advertise 30W/channel and the seemingly cheapo Samsung system 134W/channel? Am I getting the whole picture here?)
posted by anonymoose at 8:21 PM on December 20, 2006

Response by poster: Nevermind..I opened it up and fixed it...NOW what am I going to get him for Christmas? :)
posted by anonymoose at 9:15 PM on December 20, 2006

Way to go on fixing it!

For a gift, better speakers for the left and right channel, of course :P

Power ratings on cheap gear are almost completely imaginary. They get away with this because an optimum methodology for rating power doesn't really exist.

The simplest standard is continuous RMS, which is to say, the power output the unit is capable of producing constantly, over a period of many hours. However, it isn't very relevant to music reproduction.

Most music isn't very continuous. There are loud notes, and even loud passages, but the average level (volume) of a track is very likely to be far lower than the peak level. The measurement of this effect is crest factor. Ideally, a music amplifier should be capable of supplying power for the peaks, as often and for as long as necessary, but since the peaks are known to end in short order, there is no need for that power to be available continuously.

Supplying the most power for peaks is a fairly different goal from supplying the most power continuously. Primarily, it is a lot easier/cheaper to build an amplifier that doesn't have to run at full power all of the time. But in addition, to some extent, achieving maximum continuous RMS output actually conflicts with achieving maximum peak output. Basically, in order to maximize continuous output, the design might compromise in areas that would improve peak output. In the end, all but the most extreme designs are a price/performance trade off, so designing for highest continuous RMS rating is not optimal.

Now, it is all well and good to recognize that continuous RMS isn't a great design goal for a music amplifier, but what do you replace it with? Peak implies instantaneous, like a nano-second, or a pico-second, or whatever.. So, instantaneous peak output is a completely useless rating - that doesn't stop shady manufacturers from using it in specifications. Instead, you need some kind of functional definition for the duration of a musical peak. An optimal amplifier design would be rated for its ability to provide power for that duration, and for its ability to recover and be ready for the next musical peak. As far as I know, there is no common standard for this kind of measurement.

So, you get an Onkyo rated at 30W/channel and a Samsung rated at 134W/channel, where the unit rated at less than 1/4 is probably more capable :)

I spent a couple of years designing subwoofer amplifiers, and in that business it is a little more complicated still.. In a movie, rumbling explosions can last for minutes. You still don't need an amplifier capable of truly continuous output, but compared to music, peaks last a long time.
posted by Chuckles at 11:05 PM on December 20, 2006

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