to much hiss - what do you suggest I look at

jwl

I am hearing what appears to me to be a loud hiss from my speakers (Polk Monitor 40 Series II). The level is same from all cones on all speakers. Changing the volume on the AMP or sound card does not seem to make much difference. I understand hiss is normal, but this is load enough where it is a very noticeable sound when playing softer music. It can be heard with music at all levels. The louder the music, the less of an issue it is.

Hear is what I have HT Omega eClaro connected to a Klipsch Promedia DD 5.1 which is connected to an AT ATI602 which drives the Polk Monitor 40 Series II speakers. The Klipsch is also connected to a PSW10.

Nothing I change on the sound card seems to matter. All components are plugged into a UPS where appropriate.


Polk Monitor 40 Series II
http://www.polkaudio.com/downloads/manual/Monitor2_MN.pdf

Polk PSW10
http://www.polkaudio.com/downloads/manual/PSW10_12_MN.pdf

Klipsch ProMedia DD-5.1
http://www.klipsch.com/promedia-dd-5-1
I have the manual if you need it

HT Omega eClaro
http://www.htomega.com/filedown/eclaro.pdf

BlueFox

Is it new? Hiss is electronic noise, so it isn't the speakers. Maybe something went bad. I had that happen once with an AVR. I was watching a movie, and I thought it started raining outside, but it was the AVR generating hiss. Or a bad cable connection can also cause strange effects. Other than trying to unplug things, and using the process of elimination, I'm not sure what to try. Is it possible to play music without the computer sound card? Or is the computer the only source?

newrival

Lasareath wrote: »

The to in your heading should be spelled too

And you're missing a bunch of punctuation. :rolleyes:
Get over yourself.

newrival

jwl, Do you get the hiss when you disconnect the soundcard from your processor? It is important to try and isolate the hiss to the component. Computers can occasionally be a hostile place for audio signals and impart noise from the power supply (or from hardware or software issues). If the hiss goes away after disconnecting the pre/pro from your pc, you will know whether ii is the pc or downstream. continue to disconnect down stream until the hiss disappears. If you get to your amp and you've still got hiss, well then, that is likely where the issue is.

Try that and then get back to us.

jwl

newrival - There are two things I noticed that might help. The hiss gets less noisy after playing music for a while. If I turn off the pre-amp, the sound goes away completely.

Syndil

Newrival's advice is sound, but I have a question. How is your eClaro attached to the Klipsch? Are you using analog connections or an optical digital cable?

newrival

Good point, Syndil, I had not considered the connection.
I think It is important to turn on the system with only the soundcard disconnected. If there is no hiss, it could be as simple as a cable, or something more complicated in the computer.

SDA1C

Lasareath wrote: »

The to in your heading should be spelled too

There should be a period at the end of your sentence.

SDA1C

Sounds connection oriented to me. With it going away when the pre is off it has to be between the source and the amp right? I'd guess that somewhere in the plugs there is an issue.

jwl

Syndil wrote: »

Newrival's advice is sound, but I have a question. How is your eClaro attached to the Klipsch? Are you using analog connections or an optical digital cable?

It is an analog connection - male 3.5mm to "Green" jack on card to RCA jacks (red and white) to line-in on Klipsch (using PCM setting).

The cables are from monoprice

Cable from eClaro to Klipsch

5602 35ft Premium 3.5mm Stereo Male to 2RCA Male 22AWG Cable (Gold Plated) - Black

Cables from Klipsch to AMP

5347 10ft Premium 2 RCA Plug/2 RCA Plug M/M 22AWG Cable - Black

Syndil

In your configuration the Klipsch is unnecessary. When you use the eClaro's analog outputs, you are using the eClaro's preamp section. There is no need to add another preamp section, which is what the Klipsch is doing in this setup. Simply hook the eClaro directly to the amp using your 5602 cable.

Doubling up on preamps is an almost surefire way to produce hiss, so eliminating the unnecessary Klipsch may take care of the problem.

jwl

Syndil wrote: »

In your configuration the Klipsch is unnecessary. When you use the eClaro's analog outputs, you are using the eClaro's preamp section. There is no need to add another preamp section, which is what the Klipsch is doing in this setup. Simply hook the eClaro directly to the amp using your 5602 cable.

Doubling up on preamps is an almost surefire way to produce hiss, so eliminating the unnecessary Klipsch may take care of the problem.

That is interesting. I asked about the need for a pre-amp in a few different forums (see links below) and the response I got back was "yes". The primary issue seems to be volume control (for different reasons). The Polk forum folks thought that fact that the card sent 2 volts to an AMP requiring .9 volts would essentially be telling the AMP to play at full volume - not good. The folks from Tom's Hardware were concerned that Windows would bump to volume to 100% on its own and blow the speakers. The folks from AVS Forum differed slightly and were thinking that voltage difference would result in distortion.

http://www.polkaudio.com/forums/showthread.php?138092-Do-I-need-a-pre-amp
http://www.tomshardware.com/forum/352183-28-windows-sound-amps#t2686333
http://www.avsforum.com/t/1437044/do-i-need-a-pre-amp

F1nut

The cables are from monoprice

That's the first thing I would change to see if it resolves your hiss issue.

5602 35ft Premium 3.5mm Stereo Male to 2RCA Male 22AWG Cable

That is a very thin gauge.

Syndil

jwl wrote: »

That is interesting. I asked about the need for a pre-amp in a few different forums (see links below) and the response I got back was "yes". The primary issue seems to be volume control (for different reasons). The Polk forum folks thought that fact that the card sent 2 volts to an AMP requiring .9 volts would essentially be telling the AMP to play at full volume - not good. The folks from Tom's Hardware were concerned that Windows would bump to volume to 100% on its own and blow the speakers. The folks from AVS Forum differed slightly and were thinking that voltage difference would result in distortion.

http://www.polkaudio.com/forums/showthread.php?138092-Do-I-need-a-pre-amp
http://www.tomshardware.com/forum/352183-28-windows-sound-amps#t2686333
http://www.avsforum.com/t/1437044/do-i-need-a-pre-amp

I'm not sure what's going on in those threads but it sounds like perhaps some people have misunderstood how the output voltage of the preamp stage works. In general terms, the higher the output voltage of the pre, the less work the amplifier section will have to do to amplify the signal. In other words, higher voltage = good.

It's not going to cause your amplifier to play at full volume all the time, unless of course you turn the volume control on your computer up to 100% all the time.

If you're going to use the analog outputs of the eClaro, ditch the Klipsch. If you want to use the Klipsch, then feed it an optical digital signal, not an analog signal. Or, compare each setup and see which sounds better to you. But using analog to the Klipsch has zero possibility of improving your signal, as its a redundant preamp. It can only diminish it.

If you want to chase the cable dragon, that's up to you. But first resolve the hiss problem. The cable is not the source of the hiss. And Monoprice cables are fine. Most standard RCA cables are 26 or 28AWG, which is of course thinner than 22AWG.

BlueFox

You never did answer the question in post 3 as to whether the hiss is a new issue, or it is there from the start.

dudeinaroom

If the pre has a digital in, use the digital out on the card, and your hiss should disappear. Pc power supplies are not made for sound reproduction, and are shared by all the components in the computer, so any noise made by the power supply, or the computer components will be transferred into the power that is supplying the preamp section on the sound card. Some sound cards have decent filtering, some don't same goes for power supplies, it's a crap shoot. Having the sound card feed a preamped analog signal into a preamp would amplify any amount of hiss. The only issues I would see running an amp directly off the sound card would be the possibility of over driving the amp and/or power supply noise.

jwl

Syndil wrote: »

I'm not sure what's going on in those threads but it sounds like perhaps some people have misunderstood how the output voltage of the preamp stage works. In general terms, the higher the output voltage of the pre, the less work the amplifier section will have to do to amplify the signal. In other words, higher voltage = good.

It's not going to cause your amplifier to play at full volume all the time, unless of course you turn the volume control on your computer up to 100% all the time.

If you're going to use the analog outputs of the eClaro, ditch the Klipsch. If you want to use the Klipsch, then feed it an optical digital signal, not an analog signal. Or, compare each setup and see which sounds better to you. But using analog to the Klipsch has zero possibility of improving your signal, as its a redundant preamp. It can only diminish it.

If you want to chase the cable dragon, that's up to you. But first resolve the hiss problem. The cable is not the source of the hiss. And Monoprice cables are fine. Most standard RCA cables are 26 or 28AWG, which is of course thinner than 22AWG.

That is good to know about the volts. I am assuming than that I would connect the sound card directly to the PSW10 sub? I am asking because the original configuration folks had me try was to connect the card to the amp, the amp to the sub and the sub to the speakers.

Possibly related or unrelated, does it make a difference is how long the speaker cables are for each speaker. I have one 1 foot cable and 1 10 foot cable (the amp is located under the left speaker). Both speakers hiss about the same.

J

Syndil

If you want to connect directly to the card you have two options. You can either connect the sub directly to the card using the card's subwoofer output and another 3.5mm to RCA cable, or you can connect your amp to your card's main stereo output, then run speaker cables in and out of the sub to your main speakers. Both methods have their pros and cons. If you use the card's subwoofer output, that means you are relying on your PC to provide all of your bass management, however flexible or inflexible that may be. If you use the card's stereo outputs -> amp -> sub -> speakers, your sub will provide low end for any sounds the PC produces, not just the ones the PC decides to send out the subwoofer jack. I've not used the eClaro, but in my experience bass management provided by a PC is rather lacking, so I'd probably go with the latter setup.

The mismatched cable length has nothing to do with the hiss. If you still have hiss after removing the Klipsch, then that means either the eClaro or the amplifier is causing the hiss--or possibly each is contributing a bit of hiss. In that case I would disconnect the PC from your amp, turn the amp on, and see if it still hisses. If not, then that would narrow it down to the eClaro causing the hiss. Where to go from there? Optical digital to the Klipsch. If it does still hiss without any input source connected, then the amp is causing the hiss.

jwl

I tried the optical cable because I had one - still produces hiss. I connected the sound card directly to the AMP and still got hiss. So I guess the problem may be the sound card. Working on getting a DAC from eBay to test....need to make sure this is the issue before buying anything else.

blehmbo

Is your pc connected to your audio system in any other way when using optical? If it is try disconnecting the other connections for testing.

When I connect a spdif or hdmi cable from my pc to my AVR it transfers a lot of computer noise (whining with mouse movement and clicks with HDD activity) to my sound system, even if the HDMI or spdif connection isn't selected. My solution was to stick to optical and (isolated) usb for pc audio.

Syndil

Just to be sure, have you tried just having the amp connected to the speakers and turned on without any inputs at all? If it hisses without anything connected to it, it's the amp. If it doesn't, then yes, it could be the sound card, or it could be that both the soundcard and the Klipsch produce hiss.

jwl

Syndil wrote: »

Just to be sure, have you tried just having the amp connected to the speakers and turned on without any inputs at all? If it hisses without anything connected to it, it's the amp. If it doesn't, then yes, it could be the sound card, or it could be that both the soundcard and the Klipsch produce hiss.

I normally turn the sub on, then the AMP (both switches) and then the Klipsch. I just redid this to be sure and heard a slight buzz after getting as far as the AMP which did not change when I turned on the Klipsch....which is the opposite of what I was experience before. What is odd is that the problem I started out with no longer appears to be there. I am wondering if it was a connection somewhere.

Syndil

Might have been... Anyway glad you got it sorted out.

BTW the proper way to turn on equipment is starting with the Pre then working your way out to the speakers. So for you, pre -> sub -> amp. That way you avoid amp thump.