below 32 Khz

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alexone

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below 32 Khz
« on: 23 Apr 2011, 02:53 pm »
a question for anyone who knows:

what if some songs on a hdd are 11025 hz and 22050 hz? the lowest frequency of the BDA-1 is 32000 hz...would the BDA-1 detect and 'play' them? :scratch:

al.

srb

Re: below 32 Khz
« Reply #1 on: 23 Apr 2011, 03:42 pm »
You have posed a question I've never heard asked before, because a sampling rate of 11,025Hz would have a theoretical frequency response up to 5,512.5Hz,  which is closer to the range of telephone/speech than music.
 
The 22,050Hz files would have a frequency response up to 11,025Hz, and would be closer to music range.
 
Although I don't have the BDA-1, most DACs have a similar lower specification, so I will have to try that and see if anything plays.  I assume you are using a music player, OS and driver that are bypassing any internal upsampling?
 
Steve

alexone

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Re: below 32 Khz
« Reply #2 on: 23 Apr 2011, 05:55 pm »
Steve,

a friend of mine came over and gave me his hdd and we had a nice evening with the sound of the BDP-1 :thumb:. then i showed him the several music-players which can control the BDP and we noticed that some of 'his' songs had these sample rates (11.025 & 22.050)...
i haven't tried these files yet as they are only a few among a huge amount of songs. when I'm back home I will try to find the files and play them through the BDP/BDA combo.

al.

alexone

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Re: below 32 Khz
« Reply #3 on: 24 Apr 2011, 06:56 pm »
hi, guys!

now here are some pics of the songs with 11.025, 22.050 and 24.000 hz. the BDA shows 44.1 khz when these songs are played with the BDP/BDA combo...
the interface is BrystonMax.




al.




srb

Re: below 32 Khz
« Reply #4 on: 24 Apr 2011, 07:21 pm »
I guess it doesn't matter if the front panel UP-SAMPLE switch is on or off, as the indicators are supposed to indicate incoming sample rate.
 
Since there is no indicator for anything less than 32K, it wouldn't surprise me if 11,025Hz and 22,050Hz were indicated as 44.1KHz, as it is a multiple of those frequencies. But by that logic, I would expect 24KHz to be indicated as 48KHz - and it's not!
 
You got me, but I don't have (nor expect to have) any files of those sample rates. I would probably prefer to hear some minor artifacts of MP3 compression of 44.1KHz sampled files, than lower sample rate files with limited upper end frequency response. Of course your files in question are both low sample rate and MP3 compressed - there's not a lot going for them!
 
Steve

alexone

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Re: below 32 Khz
« Reply #5 on: 24 Apr 2011, 07:32 pm »
correct, Steve! it doesn't matter if the upsampling button is on or off. and it's also right that 44100 is a multiple of 11025 and 22050...but WHY and HOW should the BDA-1 convert the 11025 and 2050 into 44100?? maybe I'll find some more files with different and lower sample rates than 32000...would be interesting if anything that goes into the BDA-1 with less than 32khz will be automatically 44.1khz?!? :scratch:

al.

brucek

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Re: below 32 Khz
« Reply #6 on: 24 Apr 2011, 07:38 pm »
Quote
Since there is no indicator for anything less than 32K, it wouldn't surprise me if 11,025Hz and 22,050Hz were indicated as 44.1KHz, as it is a multiple of those frequencies. But by that logic, I would expect 24KHz to be indicated as 48KHz - and it's not!

I suggest the soundcard in the BDP upsamples anything less than 44.1K to that sample rate.

alexone

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Re: below 32 Khz
« Reply #7 on: 24 Apr 2011, 08:09 pm »
yes, i think it is the soundcard... :icon_lol:

al.