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Home Theater Hiss

Old 01-29-05, 04:15 PM
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Home Theater Hiss

Right now my current HT setup is a panasonic ht-920. Its making a hiss is noticable at -20dB but when I watch movies I listen to them at -10dB and ths hiss is even worse. I got a new surge protector the other month and i don't think it's the power even though it's 1000 total watts. Can it be the monster 16g speaker wire that I'm using?! HELP ME PLZ!
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Old 01-29-05, 06:37 PM
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I have bad news for you. The hiss is probably in your amp. It is not your cable.
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Old 01-30-05, 02:30 PM
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no i can hear the hiss through all of the speakers though
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Old 01-30-05, 03:08 PM
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Front: 100W x 2 (120Hz-20kHz, 6 ohms, 1% THD)
Center: 140W (120Hz-20kHz, 4 ohms, 1% THD)
Surround: 45W x 2 (120Hz-20kHz, 4 ohms, 1% THD)
Subwoofer: 150W (45Hz-120Hz, 4 ohms, 1% THD)

The 1% THD (Total Harmonic Distortion) sure aint helping. This is what is usually is associated with speaker hiss and is more than likely what you are hearing.
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Old 01-30-05, 05:05 PM
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Distortion is not hiss, and hiss does not come from THD, though you want to avoid both.

I'm not optimistic that any actual useful information -- such as that posted by Brian -- will be well received in this thread.
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Old 01-30-05, 05:37 PM
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Originally Posted by SaigonaZn69
no i can hear the hiss through all of the speakers though
Exactly and it is the amplifier that provides power to the speakers. A 1% THD is an abyssmal spec.
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Old 01-30-05, 05:57 PM
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Originally Posted by Brian Shannon
A 1% THD is an abyssmal spec.
All this tells us is that they measured the people who decided what this amp's specs would be measured the output when the amp was putting out 1% THD. Obviously, this has the benefit of making the WPC rating higher than if they had measured it at a lower THD.

But it tells us nothing about how this amp sounds and -- in and of itself -- has nothing to do with the problem the OP is having.
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Old 01-30-05, 06:16 PM
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Obviously, this has the benefit of making the WPC rating higher than if they had measured it at a lower THD.
. . . at the cost of making amp unlistenable at the customers desired volume level.
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Old 01-30-05, 07:20 PM
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Two useful specifications -- "residual noise" and "signal-to-noise ratio" -- are not given for this unit, AFAICT. (THD is not a measure of noise level.)

Normally, the way to evaluate the "noise floor" of a receiver is to disconnect the source (the DVD player, say), and turn the volume up to normal levels. If there's audible noise, then the receiver has problems.

With an integrated unit you can't disconnect the player, but you could switch to an unused Aux input and try the same test.

Hiss is not a product of speaker wires, and if there was a problem with the AC it would be more likely to cause hum than hiss.

The evidence points strongly at the electronics as the source of the hiss. With an integrated unit trying to isolate it further is pointless. The question that remains is whether it's a defective sample or a design shortcoming. In the latter case, any sample should evidence the same level of hiss, and you should be able to go to a store and hear it in the floor sample. If your unit is noisier than the one in the store, then it's defective and should be repaired or replaced.

You're right about one thing: audible hiss at normal listening levels is unacceptable.

RichC
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Old 01-30-05, 10:08 PM
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Originally Posted by rdclark
Two useful specifications -- "residual noise" and "signal-to-noise ratio" -- are not given for this unit, AFAICT. (THD is not a measure of noise level.)

Normally, the way to evaluate the "noise floor" of a receiver is to disconnect the source (the DVD player, say), and turn the volume up to normal levels. If there's audible noise, then the receiver has problems.

With an integrated unit you can't disconnect the player, but you could switch to an unused Aux input and try the same test.

Hiss is not a product of speaker wires, and if there was a problem with the AC it would be more likely to cause hum than hiss.

The evidence points strongly at the electronics as the source of the hiss. With an integrated unit trying to isolate it further is pointless. The question that remains is whether it's a defective sample or a design shortcoming. In the latter case, any sample should evidence the same level of hiss, and you should be able to go to a store and hear it in the floor sample. If your unit is noisier than the one in the store, then it's defective and should be repaired or replaced.

You're right about one thing: audible hiss at normal listening levels is unacceptable.

RichC
So unplug my subwoofer from the dvdplayer/receiver and see if there is still a hiss? Keep in mind it's a HTIB and it does not have seperate av components.
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Old 01-31-05, 01:50 PM
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Do you have a cable box hooked up to the system or TV? If so, try disconnecting the cable from the wall. Sometimes noise creeps in through a ground loop from the AC line to the cable connection.
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Old 01-31-05, 02:19 PM
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Maybe your HT disagrees with your taste in movies?
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Old 01-31-05, 02:56 PM
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Originally Posted by SaigonaZn69
So unplug my subwoofer from the dvdplayer/receiver and see if there is still a hiss? Keep in mind it's a HTIB and it does not have seperate av components.
No, I didn't say anything about your sub. But it's a good idea, like Pete said, to unplug everything from the system except the speakers and sub and see if anything changes.

One question: has it been like this since you got it, or is the hiss a recent development?

RichC
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Old 01-31-05, 07:35 PM
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Originally Posted by rdclark
No, I didn't say anything about your sub. But it's a good idea, like Pete said, to unplug everything from the system except the speakers and sub and see if anything changes.

One question: has it been like this since you got it, or is the hiss a recent development?

RichC
I think its been like this since I got it, but i didnt mind because i thought it was normal for a HTIB that was 1000 watts. People told me it's a natural thing for speakers to have a hiss in the background for something that takes a lot of power. I disconnected like you said, and i don't hear a hiss. I only hear a hiss when playing dvd's, when I watch tv i can still hear the hiss but when tv programs offer 5.1 the hiss is not as bad? Is this normal
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Old 01-31-05, 07:58 PM
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Originally Posted by SaigonaZn69
I think its been like this since I got it, but i didnt mind because i thought it was normal for a HTIB that was 1000 watts. People told me it's a natural thing for speakers to have a hiss in the background for something that takes a lot of power. I disconnected like you said, and i don't hear a hiss. I only hear a hiss when playing dvd's, when I watch tv i can still hear the hiss but when tv programs offer 5.1 the hiss is not as bad? Is this normal
First there seem to be some misconceptions.

Your system's amplifier does not produce 1000 watts. Here are the specs:

Front power 170 Watts x 2
Center power (watts) 260
Surround power 70 Watts x 2
Subwoofer power 260 Watts

Adding up the wattage ratings does not equal output anymore than saying that a 200hp car has 800 hp because it has four wheels.

It is not normal for anything to have hiss in the background "because it takes more power". Amplifiers are made in different ways and the lower quality the amplifier the more electronic noise it produces. As was pointed out in another post this is also an integrated unit so there is undoubtedly some noise from the other parts in the system.

In short, the "hiss" or noise is most likely "normal" for this system. The only way to change this is to either turn down the voulme or save up and purchase better quality electronics.

Good luck.
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Old 02-01-05, 01:58 AM
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Originally Posted by Brian Shannon
First there seem to be some misconceptions.

Your system's amplifier does not produce 1000 watts. Here are the specs:

Front power 170 Watts x 2
Center power (watts) 260
Surround power 70 Watts x 2
Subwoofer power 260 Watts

Adding up the wattage ratings does not equal output anymore than saying that a 200hp car has 800 hp because it has four wheels.

It is not normal for anything to have hiss in the background "because it takes more power". Amplifiers are made in different ways and the lower quality the amplifier the more electronic noise it produces. As was pointed out in another post this is also an integrated unit so there is undoubtedly some noise from the other parts in the system.

In short, the "hiss" or noise is most likely "normal" for this system. The only way to change this is to either turn down the voulme or save up and purchase better quality electronics.

Good luck.
Well, considering I only paid 350 on black friday at fry's, it sounds pretty damn good when playing certain dvd's. The hiss gets worse if I play older dvd's. Watching Phil Collins farewell tour on Voom HD in 5.1, there is no hiss at all.
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Old 02-01-05, 09:52 AM
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Originally Posted by SaigonaZn69
Well, considering I only paid 350 on black friday at fry's, it sounds pretty damn good when playing certain dvd's. The hiss gets worse if I play older dvd's. Watching Phil Collins farewell tour on Voom HD in 5.1, there is no hiss at all.
So you hear hiss only when playing DVDs.

Is there a way to connect a borrowed DVD player to the system? If you do, and you get no/less hiss from the borrowed one, then you know it's the built-in DVD player producing the noise, and not the HTIB's amplifier stages.

I still think you should go to Fry's and listen to one on the shelf and see if it hisses the way yours does. Maybe yours is defective.

RichC
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