Topic: iriver H1xx Tapers FAQ (beta)

[whatboutbob]

well with an external pre the noise floor issue is essentially a moot point.

shielding the remote might help some if you managed to take it apart and maybe replace the wire with a better shielded version. 

Sanjay: That doesn't sound like a silver bullet.  It may improve things, but I'm guessing it won't fix the underlying problem (main unit not grounded properly).  Any ideas how I could ground the unit better.  I doubt using an external pre will prevent cell phone interference...but I'll do some testing tonight.

hyperplane: looks like your unit is ok, as long as you're not confusing hdd noise with the remote interference?  I didn't just test the quiet part (me paraphrasing).  I recorded a sample, pulled the remote, then checked the resultant peaks in audition.

[hyperplane]

well with an external pre the noise floor issue is essentially a moot point.

shielding the remote might help some if you managed to take it apart and maybe replace the wire with a better shielded version. 

Sanjay: That doesn't sound like a silver bullet.  It may improve things, but I'm guessing it won't fix the underlying problem (main unit not grounded properly).  Any ideas how I could ground the unit better.  I doubt using an external pre will prevent cell phone interference...but I'll do some testing tonight.

hyperplane: looks like your unit is ok, as long as you're not confusing hdd noise with the remote interference?  I didn't just test the quiet part (me paraphrasing).  I recorded a sample, pulled the remote, then checked the resultant peaks in audition.

whataboutbob - I don't think I'm confusing the two... there is the same noise intermittently with, or without, the remote control plugged up. 

[whatboutbob]

Well lucky for you then!  All of my 3 H1x0's have similar issues. :-(

[udovdh]

What is the exact test to see if my H120 is vulnerable to this noise issue?

[whatboutbob]

Set source to line in, don't plug a mic in, set your gain to ~20dB, plug your remote in, record for about 15 seconds, pull the remote out, keep recording for another 15 seconds.  Stop recording.  Transfer file.  View the resultant file in audio software that allows you to monitor levels closely (eg Audition).  If your unit is dodgy you'll see it the levels increase around the 15 second mark.

[kuba]

My noise test:

http://taperssection.com/index.php?topic=62469.15

[hyperplane]

does anyone know what each line on the meter scale corresponds to dB wise? 

Here's what i do, raoulduke. (This is by no means the "best" method, it's simply how I set my iriver for recording.)

I go to Settings > Display > Peak, and set the Minimum to -21 dB, and set the Maximum to -3 dB. Then I *know* the midpoint marker on the LCD is -9 dB, and I adjust the levels such that levels hover between the midpoint and the maximum shown setting (-9 to -3 dB). Yes, I run my levels conservatively.

That's juat how I have it set up... I don't see much need in having the Peak Minimum set to -60 dB (default setting). I suppose one could set the levels to Min = -12 dB and Max = 0 dB, and then you know the midpoint is -6 dB.

[kuba]

does anyone know what each line on the meter scale corresponds to dB wise? 

I used sine generator in soundforge to create a file with -3dB -6dB -9dB -12dB and -15dB each for ten seconds, I set the meter scale acording to this (set, play the file, set again if necessary, play the file and learn what dB amount the marks stand for). Hope it's understandable 

[china_rider]

OK... so I've been slacking and have not done any remote measurements myself... But if I'm following what you all are posting with 0 analogue gain the noise from the remote should not really even be a factor compared to non-remote.  So if I'm running a pre before the 120 like my PA-3SX and I never touch the gain on the iRiver the noise should be a non issue?  Correct?  Charging now... maybe I will play with it tonight... have a few shows coming up and the remote is so tiny I would love to be able to use it.

[hyperplane]

OK... so I've been slacking and have not done any remote measurements myself... But if I'm following what you all are posting with 0 analogue gain the noise from the remote should not really even be a factor compared to non-remote.  So if I'm running a pre before the 120 like my PA-3SX and I never touch the gain on the iRiver the noise should be a non issue?  Correct?  Charging now... maybe I will play with it tonight... have a few shows coming up and the remote is so tiny I would love to be able to use it.

As I had posted before (either it was this thread or another one), I measured the iriver hard drive noise hit around the -64 dB level.

When using the remote and full analog gain setting (24 dB setting on the iriver), the remote only added around 6 dB of noise, making the noise floor hit around -81 dB.

So I guess my point is, even if you use the analog gain on the iriver while using the remote control, does it really matter that it adds approximately 6 dB of noise? My reasoning: the hard drive is already raising the noise floor by over 20 dB, and the hard drive noise is much greater than the remote control added noise... so again, I pose the question, does it really make a difference that the remote adds around 6 dB of noise (at maximum analog gain setting on the iriver)?

[George]

does anyone know what each line on the meter scale corresponds to dB wise? 

Here's what i do, raoulduke. (This is by no means the "best" method, it's simply how I set my iriver for recording.)

I go to Settings > Display > Peak, and set the Minimum to -21 dB, and set the Maximum to -3 dB. Then I *know* the midpoint marker on the LCD is -9 dB, and I adjust the levels such that levels hover between the midpoint and the maximum shown setting (-9 to -3 dB). Yes, I run my levels conservatively.

That's juat how I have it set up... I don't see much need in having the Peak Minimum set to -60 dB (default setting). I suppose one could set the levels to Min = -12 dB and Max = 0 dB, and then you know the midpoint is -6 dB.

Never noticed that feature!  Thanks bro!  +T

[whatboutbob]

OK... so I've been slacking and have not done any remote measurements myself... But if I'm following what you all are posting with 0 analogue gain the noise from the remote should not really even be a factor compared to non-remote.  So if I'm running a pre before the 120 like my PA-3SX and I never touch the gain on the iRiver the noise should be a non issue?  Correct?  Charging now... maybe I will play with it tonight... have a few shows coming up and the remote is so tiny I would love to be able to use it.

As I had posted before (either it was this thread or another one), I measured the iriver hard drive noise hit around the -64 dB level.

When using the remote and full analog gain setting (24 dB setting on the iriver), the remote only added around 6 dB of noise, making the noise floor hit around -81 dB.

So I guess my point is, even if you use the analog gain on the iriver while using the remote control, does it really matter that it adds approximately 6 dB of noise? My reasoning: the hard drive is already raising the noise floor by over 20 dB, and the hard drive noise is much greater than the remote control added noise... so again, I pose the question, does it really make a difference that the remote adds around 6 dB of noise (at maximum analog gain setting on the iriver)?

I get similar RMS measurements.  To  be honest, I have no idea what they mean.  I do know, however, that I can hear the impact the remote has on my recordings.  It may not be noticeable to others, but it has always bugged me...I just chalked it up to shortcomings of my mics.

Here's a sample with 20dB gain...don't bother analysing the file (though of course you can if you want)...just play it w/ headphones on and volume up...have a guess when I pull the remote:

http://www.yousendit.com/transfer.php?action=download&ufid=C0E886B753F9DC2B

Having said that, this is all moot with an external pre/adc (which I often haven't used to date).

And yes, while the hdd noise is there, to my ears the noise is usually covered by the signal.

...now that just leaves me with cell-phone interference to drive me batty.

I've got a Jason Mraz recording up on archive.org where you can hear both the cell interference and the remote problem (highlighted because the gain was set to ~30dB for this very quiet gig).

[Todd R]

I was talking to Michael Grace awhile back about noise floors.  He was really just amused that everyone was so gung ho about 24 bit recordings.

He said he had recently been doing some piano recording.  His measurements of the really pretty damn quite recording hall showed a noise floor at -67db (iirc, on that order).  I can't even imagine how high the noise floor is in one of the concert venues we tape in.

The extra noise with using the remote is just going to be, well, lost in the noise.

[whatboutbob]

The extra noise with using the remote is just going to be, well, lost in the noise.

If you're talking about using an external pre, then I agree.  The problem comes when you use the iriver pre and it amplifies the tick.  Its definitely noticeable during recordings then.

On a different note, I think I've cleared the iriver of any wrongdoing in regards to cell phone interference.  Looks like its something higher up the chain.  Still trying to figure it out.

[whatboutbob]

Interestingly the local aussie Ratshack equivalent (Jaycar) just started selling the ipod batteries (same model # as I've bought from ebay in the past).

So if you're looking at a battery upgrade, you may be able to pick them up locally soon (if not already).  Just remember to swap the wires!