N800 hiss problem

[johnnybravo]

I've had my N800 for a while now and I have recently tried connecting it to my car radio using a standard jack-jack cable. To my suprise the sound I got is very hissy. The hiss is so bad that I can't listen to any speech podcasts, piano music etc. The hiss is only audible when a sound is played, for example when I click the screen and the click sound is played I can hear the hiss and then after 2 seconds there is complete silence again. It's the same when I play a music file or a film of course, I mean I get constant hiss when music is played.

There's no hiss when I connect an MP3 player with the same cable and there's no hiss when I use headphones or computer speakers so it must be something to do with the tablet itself.

The funny thing is that the only thing I can listen to is the radio. When I click the 'play' button on the radio applet I can hear the background hiss and the radio station and after 2 seconds the hiss goes away leaving me with clear radio sound.

Can anyone help please?

[urnass]

I'm getting aloud hiss also when I connect my Bose Headphones, but not the cheap Nokia supplied headphones. I'm thinking it's a cable/connector issue, but I have yet to pinpoint the exact cause. I'll post more when I get time to resolve this.

[tso]

sounds similar to something i have noticed on and off from the internal speakers of my N800, and i recall having it there even before i upgraded to diablo.

its not loud, but when in a silent environment, its noticeable...

[qole]

I have an interesting problem, it may be related, it may not be... Occasionally, my N800 will make a very high-frequency "hiss", even when it's not playing music. This hiss seems to have something to do with the processor working... The frequency is similar to the sound that an old-style CRT TV makes when operating. Most people can't even hear it, so probably that's why I've never seen it mentioned here... Hmm, I'm probably off topic. Whatever.

[chrisak]

I'm not sure if my hissys are (ooo neat, modest just died inside, anyway) the same as everyone else's... but my thingy always hiss'es for a second or two when contact is made on the touchscreen. It's always done this, but you don't hear it unless your ear is to the speaker. Reminds me of the sound an audio cassette player makes when you hit play. Wow, no double keypresses; Diablo is coool. <grin>

[johnnybravo]

Chrisak, you probably won't hear the sound when you disable 'touch screen sounds' in the sounds options. The thing is that the hiss only occurs when a sound is played. I presume the internal amp goes into 'standby' mode when not in use and that's why the hiss is only audible when it is activated.

[Dpdallas]

I also "just" started to hear the Hiss. I know that it was not there before I updated to diablo. Any ideas?

[jaysin22]

Im with Dpdallas, I noticed the hiss after upgrading to Diablo on my N800. Gonna try the touchpad trick and see what that does.

[jaysin22]

johnnybravo, Thanks for the tip! I disabled touch screen sounds and that annoying hiss is now gone. If anyone is noticing the noise try disabling the touch screen sounds before you try any hardware changes.

[johnnybravo]

I started this thread a few months ago. Since then I have been trying different cables and 3 other car radios so probably there is nothing you can do with the hiss on the N800I have recently bought a N810, mainly because of the sunlight readable screen and 'pocket-friendliness' and to my big surprise there is no hiss. Well, there is some but only audible if I really crank up the volume in my car radio. I strongly recommend getting the N810 to those who listen to music in the car.

My N810 was bought in England whereas my N800 was bought in America but probably it doesn't matter, or does it?

[urnass]

I'm thinking this hissing problem has something to do with the 4 conductor 3.5mm jack on the N800. When you look at the Nokia supplied headphones, they have 4 bands - ground, right, left and mic/antenna/button input. Since the last two bands on the 4 conductor 3.5mm jack land on the a single band on a 3 conductor 3.5mm jack, a bit of static/noise is getting introduced by that extra band/contact. This noice/static probably messes with the electronics in noise canceling headphones, causing it to be amplified/heard.

I'm thinking if I get one of the iphone adapters like this (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370153143753&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fse arch.dll%3Ffrom%3DR40%26_trksid%3Dm37%26satitle%3D 370153143753%26category0%3D%26fvi%3D1) or a headphone & mic breakout adapter like this (http://www.electronicproductonline.com/catalog/product_info.php?products_id=1996).

Does anyone have any experience with these adapters?

To clarify, I hear the hiss/static for about 1-2 seconds on the Bose headphone after any sound event on the N800. The hiss/static stays relatively constant even if the system volume is turned up or down - so your less likely to hear it at high volumes, but it become very annoying at low volumes.

[tso]

given how its there in the speakers as well, faint tho, i would say its likely to be of no use...

[qole]

Just a note about that hiss that follows Maemo sound events, and the weird, soft little pops and rumbles that you hear if you are working in Maemo with no background music but with headphones on or in a very quiet room with the speaker volume on high.

I found that when I shut down hildon-desktop and use something else instead (KDE or Debian LXDE) there is no hiss anymore, even though there are still sound events like screen-tap "clicks" etc.

There is something hildon-specific in these noises. I don't believe it is hardware, or if it is, it is not just hardware, but something about how hildon is interacting with the hardware.

[YoDude]

I'm thinking this hissing problem has something to do with the 4 conductor 3.5mm jack on the N800. When you look at the Nokia supplied headphones, they have 4 bands - ground, right, left and mic/antenna/button input. Since the last two bands on the 4 conductor 3.5mm jack land on the a single band on a 3 conductor 3.5mm jack, a bit of static/noise is getting introduced by that extra band/contact. This noice/static probably messes with the electronics in noise canceling headphones, causing it to be amplified/heard.

I'm thinking if I get one of the iphone adapters like this (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370153143753&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fse arch.dll%3Ffrom%3DR40%26_trksid%3Dm37%26satitle%3D 370153143753%26category0%3D%26fvi%3D1) or a headphone & mic breakout adapter like this (http://www.electronicproductonline.com/catalog/product_info.php?products_id=1996).

Does anyone have any experience with these adapters?

To clarify, I hear the hiss/static for about 1-2 seconds on the Bose headphone after any sound event on the N800. The hiss/static stays relatively constant even if the system volume is turned up or down - so your less likely to hear it at high volumes, but it become very annoying at low volumes.


Yup, I was thinkin' the same early on... figuring it was bleed from the microphone circuit. I tried both the single adapter and even the "Y" adapter that provides a separate input for the microphone and an output for the speakers.... With no luck :(

However, what I didn't try was plugging a microphone into the one input to see if it has sumpin' to do with impedance or suttin' scientific like that. :)

I have reduced some, but not all of the noise by turning off the system, key, and Touch screen sounds in control panel...

I don't know how to turn off the microphone circuit on the tablet.

[Benson]

I don't know how to turn off the microphone circuit on the tablet.

Simple: plug in a 3-pole connector; it detects that mic is shorted to ground, and uses the internal mic instead.

I'm quite confident the 4th pole isn't a problem here.

[YoDude]

Simple: plug in a 3-pole connector; it detects that mic is shorted to ground, and uses the internal mic instead...


Via the Firm/Software

...I'm quite confident the 4th pole isn't a problem here.

I agree. However, it still sucks. Until a solution is provided, I'll try anything.

Using this dang thing as a portable, sound server that can be easily jacked into fixed sound systems is one of the reasons many justified it's purchase in the first place.

That hiss is quite annoying and it doesn't matter if it's heard through high end earphones, piped through a venues PA system between sets, or simply rigged up to a cheap iPOD speaker set. :eek:

[tso]

have anyone checked the sound files used by maemo?

[urnass]

have anyone checked the sound files used by maemo?

It's not just the maemo sound files that make the noise - it's any type of sound (MP3, music, videos, etc.) event.

I bought a 4 conductor to 3 conductor 3.5mm iphone adapter at radio hack - it didn't help. In fact, it made the situation even work by introducing a low freq. snapping sound.

Bose sells at $US40 "Mobile Communicatioins Kit". I'm going to try that & see if any of the adapters in this kit help.

I'll hold off buying the "Y" adapter based on YoDude's comments

[tso]

It's not just the maemo sound files that make the noise - it's any type of sound (MP3, music, videos, etc.) event.

in that case i put my money on nokia having a special "kill the audio chip" code in there somewhere, and i suspect no amount of equipment plugged into the headphone jack will fix that.

[qole]

I think someone who is really annoyed by this problem should try KDE, Deblet, or my Easy Debian LXDE As A Replacement Desktop (http://www.internettablettalk.com/forums/showthread.php?t=24761) and see if playing music while not in Hildon has any of the same audio artifacts. My experience has been "no", but I'm not an audiophile.

(Note: running LXDE "on top" of Hildon doesn't fix it...)

[tso]

so it could be something introduced by whatever audio setup thats used by hildon-desktop?

or could it simply be that replacement desktops dont bother with switching the audio hardware off when its not in use?

[johnnybravo]

I reckon there are 2 types of hiss and one of them is only audible in the N800.

1. As I described in the first post of this thread is the N800 produces a very hissy sound when connected to my car radio. It's a really ugly, dirty hiss. It must be something to do with the radio chip with the jack-jack cable possibly acting as an aerial because like I said before:
"When I click the 'play' button on the radio applet I can hear the background hiss and the radio station and after 2 seconds the hiss goes away leaving me with clear radio sound. "
I can only hear this type of hiss in my car, well, I could since I can't be bothered to listen to music with so much hiss :)

2. The other one is not so obtrusive. It's probably not audible to everyone, it's definitely not a loud hiss. This is the one that you can hear when the sound chip is working and about 2 seconds after a sound has finished playing and this hissing sound finishes with a click.
They might have improved it a bit because the N800 produces slightly louder hiss. I,for one, can barely hear it in the N810. This is the one you have been talking about here.

[tso]

the ting is that 1 can be related to 2, unless you get 1 with "touch screen sounds" set to off.

now im tempted to investigate what player hildon-desktop uses for its system sounds...

[johnnybravo]

I don't think they're related. I get 1 no matter if screen sounds are on or off

[tso]

ok, and some quick testing here confirmed to me that 2 is hardware related. youamp and mplayer produced the same hiss as the system sounds, with system sounds off.

still somewhat odd that issue 1 is for two seconds rather then the whole time the sounds are playing (as i would have expected, not that im an expert on audio cabling) if it was related to the plug and so on...

[speculatrix]

I use a 3rd party clone of a Belkin FM transmitter, and I get a bad hiss on the car radio - the hiss volume is constant no matter what I set the media player vol or master vol to, so I end up running media player's and master's volume at max, which tends to produce distortion.
I tend to listen to speech recordings (catch-up comedies from bbc radio4 for example) so the hiss isn't a big problem, but it does spoil it for music.
I don't remember the hiss being there with headphones.

perhaps the relatively low impedance of the headphones sinks the noise signal, but the relatively high impedance of an FM tx or auxiliary jack on a sound system allows the noise level to float quite high?

does anyone have some stereo jacks and sockets, croc-clip leads and 50 ohm resistors to make a "break-out" box and try adding/removing the resistors when connected to the line or aux-input of some active speakers?

[YoDude]

... I
perhaps the relatively low impedance of the headphones sinks the noise signal, but the relatively high impedance of an FM tx or auxiliary jack on a sound system allows the noise level to float quite high?

does anyone have some stereo jacks and sockets, croc-clip leads and 50 ohm resistors to make a "break-out" box and try adding/removing the resistors when connected to the line or aux-input of some active speakers?

^There ya go... now we gettin' si-yun-tiffic! :p

But I think that may be what is needed.

The Nokia supplied earbuds for me, are clear as a bell with no hiss. But then again they do have a mic. Perhaps a "dummy" load is needed on the mic side when connecting to other speakers.

[timsamoff]

https://bugs.maemo.org/show_bug.cgi?id=1040

-T.

[speculatrix]

I dug out some low-impedance headphones - some respectable Sennheiser ones I've had for a long time which are quite efficient (very loud at low power levels) - and there was only a tiny background hiss and the sound quality was excellent (Lord Of The Rings sound tracks which has very wide dynamic range).

I've found a 3.5mm jack extension cable and some croc-clips and resistors, so I'll try my crude hack suggested above and report back.

[Cadabena]

I dug out some low-impedance headphones - some respectable Sennheiser ones I've had for a long time which are quite efficient (very loud at low power levels) - and there was only a tiny background hiss and the sound quality was excellent (Lord Of The Rings sound tracks which has very wide dynamic range).

I've found a 3.5mm jack extension cable and some croc-clips and resistors, so I'll try my crude hack suggested above and report back.

Hmm. I find that the hiss is much more prominent with my Sennheiser CX300s than with anything else. I've had a few pairs of them (nothing beats their bass on the tablet), so I can see that it seems to be just with these earphones. What pair do you use?

[dennylee]

Hello,
I started using the N800 for MP3 and the hissing sound was driving me crazy. I turned off the touchscreen click and now everything sound great. I normally use a set of noise-reduction headset for music and for some reason if I leave the noise-reduction turned off, I do not get the hissing but if I turn the noise-reduction on, I get really loud hissing.

Anyhow, thanks for the suggestion on how to fix hissing.

Denny