About 3 months ago I picked up a STR-K750P Home theater system.

I started noticing some hiss at some points in movies coming from my front (and sometimes side) speakers. The best way to describe it is as if you put wax paper over a comb and hum through it. Like the speakers can't handle a certain high point and kind of crack.

I did have the center on top of a pelican powered unit switch and I moved it, but to no avail.

I am using the speaker wire that came with the system and I didn't modify the wires. One thing I do notice is some of the wire (unshielded) is visible after I plug it into the speaker and/or receiver. Not much, just a bit.

I do have monster speaker wire I plan on converting too soon (when I get the time).

Could the wire be part of the problem?

Or is it something else?

Oh yeah, I have 2 DVD players, one uses optical and one uses component. The problem is noticable when playing DVDs on both systems.

Thanks for any help!

-Steve

Is something not clear?

I can try to explain it better if there are questions.

It could be the wires, but from my experience a hissing speaker is a problem with the speaker. Many inexpensive speakers I've heard do this. If you've got another set of speakers you could try out (or borrow) you could hook them up and answer the question right there.

I'm no speaker expert by any stretch of the imagination, but to my ears cheap or bad speakers are either tinny or hiss.

I have an extra center I can test.

Thanks.

I hate to be the bearer of bad news but it is most likely not the wiring. All equipment has a certain noise floor or hiss. In some systems it is more noticeable.

Looking at the specs of this unit you are hearing noise from the systems amplifier. The speakers are grossly inefficient and have limited frequency response. The thd spec is .7%.

I realize you bought this unit for a reason. The quality of the amplifier probably necessitates your turning up the volume for good effect thereby making the problem worse.

I would save your money but not buying cable and upgrading when you are able to.

Good luck.

Specs
http://buyriteelectronics.com/Mercha..._Code=_SYSTEMS

Would buying better speakers fix this, or am I looking at a whole new unit?

Well it would help, however . . .

the thd spec is in the receiver.

STR-K750P Receiver : 100 Watts x 5 (8 ohms 1 kHz, 0.7% THD)

This is part of the problem and my gut feeling is that this line of Sony product is long on features and short on performance. In general even if you got better speakers they would still be driven by this amp.

Not sure what else to tell you, sorry.

Damn.

It's probably too late to take it back, too.

Damn.

The irony is this was one of the first times I checked reviews before buying a product and it got great reviews.

I'm going to test another speaker and hopefully that will get me through until I buy another system.

Thanks for the info!

I am sure it did get great reviews.

In your case you are demanding more from a system than most people. For the most part this is probably a good system. It is lacking in some of the stronger aspects of a better built piece of equipment. In fact ALL equipment will exhibit a certain amount of hiss. I have a demo disc that is all digital with a zero noise floor., ie., there is no recorded material while the track is playing. All you "hear" is the sound of your electronics. Even my system has some hiss.

The difference is in the noise floor and the ability of the amp and speakers to efficiently play a signal without introducing "their noise" into the signal path.

You can try other speakers. You can try several things in fact.

Turn off all bass boost or other "enhancements" to the sound. Keep the treble and bass flat. Turn off the loudness control. Test each connection to be sure it is tight and clean. Try some demo material or get a demo/setup disc to improve your setup.

Good luck!

Just FYI, different groups of people review different types of products. Peopl ebuying low-end HTIB systems (and $250 for receiver, speakers and powered sub *is* low-end!) probably don't expect too much. If you want clear sound at decent volume, chances are you'll need a full upgrade. (Personally, I'd never recommend a Sony receiver, and the low-end ones are even more questionable!)

On the bright side, it looks like a decent bedroom system for moderate volumes. So, you might want to save up for a decent system and move or sell this one. For a decent budget HTIB that probably won't disappoint you sonically, check out the Onkyo systems. They run around $500 and up, sometimes refurbs etc. can be had for under $400.

Take all specs with a grain of salt, especially THD. Also don't trust websites listing the THD unless it's the manufacturer, many stores don't understand the difference between .08% and .8%. For what it's worth, anything below .1% is inaudible. If your system truly is at .7%, then that could be part of the problem.

AR, try the different speaker and see how it goes, and try a decent speaker wire on it. Most of the HTIB's I've seen have speaker wires that are about the same gauge as earbud headphones. That's not good! . Also, on all HTIB's the weakest component is going to be the speaker.

In other words, I'm saying don't start hitting the bottle and crying like a little girl yet. Half way decent speakers, some wire, and adjusting the settings like Brian Shannon suggests could save the old gray mare yet. Let us know what happens, eh?

Thanks again for all of the advice.

I probably won't be able to tear into it for at least 2 weeks, but I have something to go on now.

I already have decent monster speaker wire (got 100' roll for 5 bucks on a sears clearence) and I have a semi-decent (albeit cheap) center speaker I can swap with it. I already planned on buying new speakers anyway, I just didn't want to buy a new receiver--especially so soon.

I'll post what happens.

Thanks again!!

Noted, and thanks.

At least, if worse comes to worse, I can use it in the basement.