SR MBP, do you have audio hiss?

[Sopranino]

it only happened once to me while playing a game with loud voice under bootcamp..

Can you provide a little more detail please? Are you able to confirm if you are hearing the audio artifacts while running Windows? At the time that you heard the sound were you listening with headphones?

Not being picky but you're the first person to respond that has been running Windows so more detailed information would be quite informative.

I believe that because the issue is probably hardware related that if you experience the problem in OSX that you will probably have the same problem in Windows. Getting this confirmed will strengthen the argument that it is a hardware problem.

Thanks

Sopranino

 

[lauph]

yea there is a slight hiss in the background of the R2D2(nice way of describing it). But i think that level of hiss, way way way lower than tape hiss, is acceptable, because i THINK if u plug in the same ipod earbuds into super high end studio professional equipment, there will still be this hiss. Comeon, this hiss is only audiable when my my room is completely quiet(aircon off, fan off). And maybe its lousy wires in the earphones.. i am not expecting silver wires inside this ipod earbuds.

R2D2, on the other hand, can be heard even with the fan on, so i will take the R2D2 as a problem, but the hiss i will let it pass. (cos i owned a toshiba laptop that had FREAKING HELL lots of Static+hiss+tones+everything crappy so this standard i get on my MBP now is way better than expected)

BUT, when playing music, but super soft, (putting itunes volume to 1 pixel to the right from 0, master volume at 1 square), the R2D2 is still present, so this proves that when the audio chip is running, the "extra stuff" is still there, unlike how many other people say. AND when audio is playing at this super soft volume, there is some hum in the background.

so to summarise,

audio idle:
R2D2 keeps randomly generating a tone, then stays a tone finally, with an unnoticable hiss at the background

audio active:
a constant tone+hiss+hum+audio

 

[vicious7]

Thanks vicious7. The buzzing from your cell phone is caused by RF interference and is actually not a flaw in the design of the computer, just about anything with an amplifier and a speaker attached will pick up a cell phone 'handshake' just prior to the phone ringing. You shouldn't have that problem with the phone moved a few feet away.

As for the hiss that you are hearing that is a flaw in the computer audio hardware. I suspect that the impedance at the output jack is a bit too low. Are you also getting the 'R2D2' noises? (sort of random tones)

Sopranino

No R2D2 noises but it is a constant hiss with the ear buds connected directly to the computer. I do have a set of cheapo Logitech R-10 speakers that seem to work fine with no hissing. However, when I connect the ear buds to the R-10's, the hissing returns. I've read on the forums that the mid-range to upper-range priced headphones should not experience the hissing, so I might just go with that.

 

[Sopranino]

No R2D2 noises but it is a constant hiss with the ear buds connected directly to the computer. I do have a set of cheapo Logitech R-10 speakers that seem to work fine with no hissing. However, when I connect the ear buds to the R-10's, the hissing returns. I've read on the forums that the mid-range to upper-range priced headphones should not experience the hissing, so I might just go with that.

It is not necessarily the mid-upper range headphones that don't experience the audio artifacts, it is the impedance of the headphones. So if you are out looking at new headphones you would want them to be at least 36 ohms impedance (based on another commenters statement that he didn't hear the sounds with a 36 ohm headphone). I personally have found that my 55 ohm AKG headphones are crystal clear.

Sopranino

 

[bobcan]

I hear it w/ Shure E4 IEM Buds...

I definitely hear the Exact Same noise regardless or the Volume Level setting... I am using a "Pro" Mid-Level set of Shure E4 Ear Buds (about $200.00 USD) and they are Quite Noise Free with other Pro Audio Devices!!

Things sound quite good but the Noise makes me a bit Crazy... not really a Pro sounding device with that noise as a constant...

My new Comp is a Week Old 2.4/ 2GB/ 160 HD!!

 

[Sopranino]

I definitely hear the Exact Same noise regardless or the Volume Level setting... I am using a "Pro" Mid-Level set of Shure E4 Ear Buds (about $200.00 USD) and they are Quite Noise Free with other Pro Audio Devices!!

Things sound quite good but the Noise makes me a bit Crazy... not really a Pro sounding device with that noise as a constant...

My new Comp is a Week Old 2.4/ 2GB/ 160 HD!!

Unfortunately most earbud or in-ear phones have a low impedance (<20 ohms)

You will need to increase the impedance to the earphones if you want to use them without the hiss. There is a volume control made by Shure (cost is around $15) which plugs in-line between your earphones and the audio out jack on the computer. There is also a similar, but cheaper built, item available from Radio Scrap (er Shack). Everyone who has tried them has reported that they clear up the sound quite nicely.

Sopranino

 

[bobcan]

Noise w/Ear Buds... my "Old School" Sony MDR-V6's...

Unfortunately most earbud or in-ear phones have a low impedance (<20 ohms)

You will need to increase the impedance to the earphones if you want to use them without the hiss. There is a volume control made by Shure (cost is around $15) which plugs in-line between your earphones and the audio out jack on the computer. There is also a similar, but cheaper built, item available from Radio Scrap (er Shack). Everyone who has tried them has reported that they clear up the sound quite nicely.

Sopranino

Very good idea... I have the Funky Little Shure In-Line Resistance device (Originally designed for AirLine High Output Interface I believe!!)... never thought of trying that yet!! Will integrate it and report back; as well I'm gonna "break out" my Trusted Sony MDR-V6 Headphones (which were/ are generally thought of as a Pro Standard) and see how they sound... Still quite a Low Imp Set but will at least let me know the Difference.

Keep up the Good Info!!
Bob

 

[XheartcoreboyX]

Can you provide a little more detail please? Are you able to confirm if you are hearing the audio artifacts while running Windows? At the time that you heard the sound were you listening with headphones?

Not being picky but you're the first person to respond that has been running Windows so more detailed information would be quite informative.

I believe that because the issue is probably hardware related that if you experience the problem in OSX that you will probably have the same problem in Windows. Getting this confirmed will strengthen the argument that it is a hardware problem.

Thanks

Sopranino

well it came outta the speakers..i restarted my computer then go to os x and everything was fine...so i think that it was something wrong with windows..

 

[Sopranino]

well it came outta the speakers..i restarted my computer then go to os x and everything was fine...so i think that it was something wrong with windows..

If you have a set of earbuds or earphones could you test them on your computer under both OSX and Windows? Post back with the results (did you hear any background hiss?) as well could you post the make and model of your earbuds or earphones.

Generally speaking stereo systems have a high enough impedance level that the audio artifacts won't be audible. If you are using a lower end all in one system then it is possible that the impedance is low enough to allow you to hear it. Once again the sounds that you will hear, if you have this problem, will be a low level hiss and 'R2D2' beeps and bloops.

Sopranino

 

[Sopranino]

Just over 50 voters so, far. I'd like to see this poll get to 100 before I consider sending it over to Apple.

By the way everyone I've already sent a post to the Apple Support group detailing the issue, the probable cause, and the repair. I don't actually expect anything much to happen immediately but with some evidence that the problem is probably wide spread maybe they'll look at some kind of in-box repair solution.

Sopranino

 

[lauph]

but wait, have you confirmed that this R2D2 and hiss is only for MBP SR only?

how about MBP before SR, PB? MB? iB?

 

[ToXicWaSTe]

My ear-phones(V-moda Vibes) are with a 16 Ohm impedance and the hiss is very audible. I Normally use a creative Xmod as my sound card, where the hiss is more subtile, but non the less is still there.

 

[Sopranino]

but wait, have you confirmed that this R2D2 and hiss is only for MBP SR only?

how about MBP before SR, PB? MB? iB?

All inquiries made confirm that this issue is present only on the SR MBP. I have personally been able to test a PB G4 1GHz, a MB 2.0 GHz, and a revision a MBP. In all cases, submitted results and personal testing, there were no audio artifacts present.

I am currently talking to an acquaintance who is an avionics technician. He has said that it should be a relatively simple matter to put together a small metered device to test the output impedance of the audio jack. This should make it fairly easy to test a large number of machines.

Sopranino

 

[Sir Diggamus]

I have had my SR MBP 2.2 since the third week of release and have had no audio issues. I frequently hook up to my Logitech X-230 speakers and the sound is great.

 

[Sopranino]

I have had my SR MBP 2.2 since the third week of release and have had no audio issues. I frequently hook up to my Logitech X-230 speakers and the sound is great.

Thanks for the reply Sir, I believe that you are currently the only one who has left a post who may not have an audio problem.

If you could do one thing for me; could you post back as to whether or not you have tested this out with earphones/earbuds or headphones? And can you post the impedance of them as well? The reason I ask is that the audio artifacts are usually not audible on external speakers.

Thanks for your help

Sopranino

 

[Sir Diggamus]

Thanks for the reply Sir, I believe that you are currently the only one who has left a post who may not have an audio problem.

If you could do one thing for me; could you post back as to whether or not you have tested this out with earphones/earbuds or headphones? And can you post the impedance of them as well? The reason I ask is that the audio artifacts are usually not audible on external speakers.

Thanks for your help

Sopranino

Good morning! I actually ended up using my headphones with my MBP for the first time last evening (http://www.sonystyle.com/webapp/wcs...551&storeId=10151&langId=-1&partNumber=MDRNC6)

Looks like the impedance on this unit is 20 ohms.

The sound quality was great. I only used it for listening to mix of music (dn'b, rock, jazz, house) on Itunes but did not notice any hissing sounds. The lows were clear and crisp with no noticable disturbance. I really wasn't trying to focus on hearing anything other the tunes though.

I hope this helps.

 

[aliquis-]

I wonder if one could convince apple to add a real soundcard for free to help with this ;D

Would an external extra resistance give the same function as a correctly built output or do one lose something else by doing it? Worse sound? Lower effect?

 

[Sopranino]

Good morning! I actually ended up using my headphones with my MBP for the first time last evening (http://www.sonystyle.com/webapp/wcs...551&storeId=10151&langId=-1&partNumber=MDRNC6)

Looks like the impedance on this unit is 20 ohms.

The sound quality was great. I only used it for listening to mix of music (dn'b, rock, jazz, house) on Itunes but did not notice any hissing sounds. The lows were clear and crisp with no noticable disturbance. I really wasn't trying to focus on hearing anything other the tunes though.

I hope this helps.

That's great Sir! This may indicate that the audio problems plaguing the SR MBPs are only on some of them. This could mean that the affected units are from a specific manufacturing date or run, and that there is a good chance that newer builds and/or newer logic boards will have the problem corrected.

Thanks again

Sopranino

 

[Sopranino]

I wonder if one could convince apple to add a real soundcard for free to help with this ;D

Would an external extra resistance give the same function as a correctly built output or do one lose something else by doing it? Worse sound? Lower effect?

Increasing the impedance on the outside of the computer would not be any different than having the correct impedance already installed on the inside of the computer. This, of course, is only accurate if the problem with the audio artifacts is due to the impedance being too low in the first place. An avionics friend of mine has already indicated that it is more than likely an impedance issue.

Sopranino

 

[EdZ]

I too have the problem (VERY evident with my ER-6i's, as they're isolators, but still detectable with my HD-555s). Unfortunately, every on-board sound chip I have ever encountered has also exhibited this, and it's almost impossible to design out without opto-isolating the output. This is because the inside of any computer, especially those with a metal casing (yes, the MPB is aluminium and not a ferrous metal, but there are ferrous structures inside), is a mess of high-frequency RF from busses, fan motors, drive motors and the like, which is audible in the output. The odd little buzzes, clicks and the like are caused my components starting and stopping, or from chance heterodyning of various bits of noise.
The solutions are: raise the impedance of your headphones, or use an external audio device (digital signals are not affected by internal noise).

 

[Sopranino]

I too have the problem (VERY evident with my ER-6i's, as they're isolators, but still detectable with my HD-555s). Unfortunately, every on-board sound chip I have ever encountered has also exhibited this, and it's almost impossible to design out without opto-isolating the output. This is because the inside of any computer, especially those with a metal casing (yes, the MPB is aluminium and not a ferrous metal, but there are ferrous structures inside), is a mess of high-frequency RF from busses, fan motors, drive motors and the like, which is audible in the output. The odd little buzzes, clicks and the like are caused my components starting and stopping, or from chance heterodyning of various bits of noise.
The solutions are: raise the impedance of your headphones, or use an external audio device (digital signals are not affected by internal noise).

Interesting post. You have correctly pointed out that there are a lot of items inside a computer that generate RF interference which can be picked up by the audio system. You have also stated that every on-board sound chip also exhibits this, correct again, -sort of-. (Read on and I'll explain)

One thing that needs to be brought up; All sound output systems have a certain amount of 'self noise' inherent in the circuitry, and in some cases compounded by RF interference. There are a couple of approaches to removing or filtering out the 'self noise', they involve either balancing the circuit between the output jack and the actual sound processor or by putting an impedance 'step' in the circuit where the 'step' is just a bit higher than the noise floor.

Generally the manufacturer of the audio product will have designed in the appropriate noise filter and everything works just fine, regardless of the level of impedance of your headphones/earphones. In this case I suspect that the circuit was probably -designed- correctly but for some reason, during production, a too low impedance resistor was put in.

Thanks for the info in your post.

Sopranino

 

[askywalker]

No hiss - using Shure SE210's

I picked up a MBP 15", and a pair of Shure SE210's a few days ago at the Mac store. Reading this post I gave them a try (had been using the 'phones with my ipod). No hiss. Tested a bunch of music with iTunes. Now I don't want to start working again!

The SE210 has 26 ohms impedance according to the Apple store.

I also tested with the ipod stock headphones - no hiss. I will try to do the test again at night - I am in Japan - seems impossible to find complete silence...

 

[Sopranino]

I picked up a MBP 15", and a pair of Shure SE210's a few days ago at the Mac store. Reading this post I gave them a try (had been using the 'phones with my ipod). No hiss. Tested a bunch of music with iTunes. Now I don't want to start working again!

The SE210 has 26 ohms impedance according to the Apple store.

I also tested with the ipod stock headphones - no hiss. I will try to do the test again at night - I am in Japan - seems impossible to find complete silence...

Hello askywalker

You actually don't need to be listening to iTunes to hear the hiss, it will be present in the headphones regardless of the volume settings. In point of fact you can drown out the hiss by playing music.

Sopranino

 

[1ncr3du10u5]

Audio bleeps...

I have a SR Macbook Pro, and when my Creature Speakers are attached, even with mute on, there is an audible bleeping noise. It reminds me of the noise my first computer used to make when loading games from cassette only higher in pitch. I have used these speakers with my previous mac (iMac G4) and also with 2 windows laptops and this is the first time I've noticed the noise. I have also tried 2 sets of headphones (bud-type), one set from my iPod Shuffle (clip-on) and I couldn't hear the bleeps at all.

The noise is simply drowned out when music is played through the speakers at an appreciable volume so it's not a major problem by any means, just mildly annoying that it does it at all.

 

[Kahalu'u Bob]

I hear both the hiss and the tones. Hitting the function button to raise or lower volume will provoke the tones. The tones are very soft, like the tones in a hearing test. I would not be surprised if some folks who think they have pretty good hearing can't hear them. I'm in my 50s, but I can certainly hear them when there is no other source playing (when I hit the volume up or down function keys). Younger folks probably hear them more easily.

Low impedence Etymotic ER-4Ps make it very obvious. High impedence Sennheiser HD 600s don't show it.

Good luck with the survery and notifying Apple!