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A better quality ISD (Winbond) chip..anything new ?

Seems like ISD are happy making crappy 4kHz bandwidth chips for
"telephone" grade audio storage. Does anyone know of anything new on
the market of similar simplicity (knocks out MP3 decoders) but of
better audio quality.A single chip solution offering a minute or two of
10kHz bandwidth 60dB or better s/n would be ideal.
cheers
M
 
M

Mike Harrison

Jan 1, 1970
0
Seems like ISD are happy making crappy 4kHz bandwidth chips for
"telephone" grade audio storage. Does anyone know of anything new on
the market of similar simplicity (knocks out MP3 decoders) but of
better audio quality.A single chip solution offering a minute or two of
10kHz bandwidth 60dB or better s/n would be ideal.
cheers
M

If you need playbackl only, you may want to look at using something like a ST serial flash (M25p
series) and a cheap audio DAC (e.g. TI, AKM) It is possible (not trivial, but possible) to stream
audio from the flash to the DAC at 31.25K sample rate with a cheap PIC running at 8MHz.
 
J

Joerg

Jan 1, 1970
0
Hello Moby,
Seems like ISD are happy making crappy 4kHz bandwidth chips for
"telephone" grade audio storage. Does anyone know of anything new on
the market of similar simplicity (knocks out MP3 decoders) but of
better audio quality.A single chip solution offering a minute or two of
10kHz bandwidth 60dB or better s/n would be ideal.
cheers

TI used to give out "retro watches", little experimenter boards with a
high power MSP430 on there. I believe one of the applications was audio
storage. 60dB would be a stretch though, guess you'd have to hang an
external ADC onto it but that should not be a big deal. You also need an
external memory.

Regards, Joerg
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg
Hello Moby,


TI used to give out "retro watches", little experimenter boards with a
high power MSP430 on there. I believe one of the applications was audio
storage. 60dB would be a stretch though, guess you'd have to hang an
external ADC onto it but that should not be a big deal. You also need
an external memory.
I'd be interested to know why the OP wants the performance specified. It
seems like overkill.
 
J

Joerg

Jan 1, 1970
0
Hello John,
I'd be interested to know why the OP wants the performance specified. It
seems like overkill.

It depends on where it'll be used. Automatic PA announcements in upscale
stores, cars, airplane cockpits might make the whole product or location
look quite cheesy if it were done at 4kHz and 8 bits. It wood be like
Naugahide seats in a Bentley.

Regards, Joerg
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg
Hello John,


It depends on where it'll be used. Automatic PA announcements in
upscale stores, cars, airplane cockpits might make the whole product or
location look quite cheesy if it were done at 4kHz and 8 bits.

Yes, although noise from 8 bits might well be a greater defect than 4
kHz. Cars (even top-class) and airplane cockpits are NOISY; 60 dB S/N is
quite unnecessary.
 
J

Joerg

Jan 1, 1970
0
Hello John,
Yes, although noise from 8 bits might well be a greater defect than 4
kHz. Cars (even top-class) and airplane cockpits are NOISY; 60 dB S/N is
quite unnecessary.

On airplanes only after the engines spooled up. And a Bentley or Rolls
Royce shall never be noisy inside, at least not when considering the
money that needs to be plunked down for one of these. Even my rather
modest SUV is surprisingly quiet inside.

Regards, Joerg
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg
Hello John,


On airplanes only after the engines spooled up. And a Bentley or Rolls
Royce shall never be noisy inside, at least not when considering the
money that needs to be plunked down for one of these. Even my rather
modest SUV is surprisingly quiet inside.

You may be surprised, but you may be even more surprised if you put a
sound level meter inside. In an exceptionally quiet room in a
residential area, you may get down to 35 dB A-wtd. I suspect that your
SUV does about 45 dB A unless it's coasting with closed throttle on a
really smooth surface. Step on the gas and all bets are off.

Same with aircraft, even in the first-class cabins that you travel in.
(;-) The meter does not lie, but your ears (and mine) are easily fooled.
 
John said:
I'd be interested to know why the OP wants the performance specified. It
seems like overkill.
--
I make audio systems for museum exhibits, interactives, theme parks
etc.
Depending on the application, I have 2 approaches - if it just has to
make a noise, and the source material is crappy (derived from a
cassette for instance) I use an ISD4004 (or multiples thereof) at 8
minutes apiece (using the fastest available sampling rate). As long as
I apply careful compression to the recording process this is fine for
speech (the s/n of conversations between spitfires and dispatcher
during the Battle of Britain was never the greatest in the first
place). If better quality is called for (like music for instance) I use
a VS1001K MP3 decoder, A CF card and a microcontroller - all the
quality you need at 320kbps. What I'm looking for is a "middle ground"
- better than the ISD but not as complicated as the VS.
Not overkill at all, just enough kill :)
M
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that "[email protected]"
I use a VS1001K MP3 decoder, A CF card and a microcontroller - all the
quality you need at 320kbps. What I'm looking for is a "middle ground"
- better than the ISD but not as complicated as the VS.
Not overkill at all, just enough kill :)

No, really, you won't get any perceived quality improvement by going
from 8 kHz to 10 kHz, especially if you aren't spending $$$$ on
loudspeakers. And think about the acoustic background noise in your
space. It's probably around 45 to 50 dB A. So unless you are putting out
100 dB or so *average*, not peaks, 60 dB S/N is pointless; the acoustic
noise masks it.
 
J

Joerg

Jan 1, 1970
0
Hello John,
You may be surprised, but you may be even more surprised if you put a
sound level meter inside. In an exceptionally quiet room in a
residential area, you may get down to 35 dB A-wtd. I suspect that your
SUV does about 45 dB A unless it's coasting with closed throttle on a
really smooth surface. Step on the gas and all bets are off.

It doesn't become much more noisy if you step on the accelerator, just
for the brief moment the computer needs to adjust the mixture.
Same with aircraft, even in the first-class cabins that you travel in.
(;-) The meter does not lie, but your ears (and mine) are easily fooled.

Probably true. However, I can notice a marked difference between cell
phone (on the car speaker) and AM radio quality, then another from AM to
FM and if it's a really quiet ride even between FM and CD.

Regards, Joerg
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg
Hello John,


It doesn't become much more noisy if you step on the accelerator, just
for the brief moment the computer needs to adjust the mixture.

1 dB you wouldn't notice. 3 dB you'd just notice. Beg, borrow or acquire
a sound level meter and measure what happens. I'd guess +6 dB.

But you should probably get a 'sports muffler' (i.e. loud), to give you
a bit of a thrill for all the gas you are burning. (;-)
 
John said:
I read in sci.electronics.design that "[email protected]"


No, really, you won't get any perceived quality improvement by going
from 8 kHz to 10 kHz, especially if you aren't spending $$$$ on
loudspeakers. And think about the acoustic background noise in your
space. It's probably around 45 to 50 dB A. So unless you are putting out
100 dB or so *average*, not peaks, 60 dB S/N is pointless; the acoustic
noise masks it.

The ISD chip gives less than 4khz bandwidth, NOT 8 (that is the SAMPLE
rate).
I want 10kHz bandwidth (ie > 20khz sample rate). These things are often
used with phone style handsets and even my ancient ears CAN hear the
difference of both the noise floor and HF response here. I want the
things to sound substantially better than talking Xmas cards. The
producers of the audio tracks put considerable effort into them and it
is they who are the final arbiters, not Joe Punter, who doesn't give a
rats :)
M
 
R

Rich Grise

Jan 1, 1970
0
I read in sci.electronics.design that Joerg


Yes, although noise from 8 bits might well be a greater defect than 4
kHz. Cars (even top-class) and airplane cockpits are NOISY; 60 dB S/N is
quite unnecessary.

I'd even suggest that if he's looking for good intelligibility, that
a high-pass at about 300 Hz could help dramatically, at least for human
voice. They've been doing that for decades in the Ham radio field. (you
throw away the fundamental, so that it doesn't hog all of your transmitter
power - all of the "intelligence" is in the harmonics anyway.)

Cheers!
Rich
 
J

Joerg

Jan 1, 1970
0
Hello John,
1 dB you wouldn't notice. 3 dB you'd just notice. Beg, borrow or acquire
a sound level meter and measure what happens. I'd guess +6 dB.

After a kaboom while at the army I guess it's more like 6dB for me.
But you should probably get a 'sports muffler' (i.e. loud), to give you
a bit of a thrill for all the gas you are burning. (;-)

The Mitsubishi doesn't burn much. 25mpg on California gas, 28mpg on
Nevada gas. I think you guys calculate in liters per 100km and I believe
it would come in under 10. For a car that weighs almost two tons that's
not so bad. I think the automatic version would be worse.

Regards, Joerg
 
C

Clifford Heath

Jan 1, 1970
0
Depending on the application, I have 2 approaches - if it just has to
make a noise, and the source material is crappy (derived from a
cassette for instance) I use an ISD4004

Have you experienced temperature dependent failures with the ISD chips?
 
Seems like ISD are happy making crappy 4kHz bandwidth chips for
"telephone" grade audio storage. Does anyone know of anything new on

Succinct answer: I hate ISD too. There is cause enough for this merely
in their (unstated) datasheet errata, let alone the actual chip specs.

I've been asked recently to do some similar projects (vending machine
applications, mostly). I've chosen to use an SD card (in MMC/SPI mode)
to store raw PCM samples. I use an Atmel ATmega8 with an R-2R on one of
the ports to do the DACing. Using a parallel 16-bit DAC seems to be an
intractable problem on an 8-bit micro because of the impossibility of
updating both bytes at the same time.

I come from a toy background (Winbond's other, larger line... among
other vendors) and the 8-bit 12kHz samples sound pretty good to me.
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg
The Mitsubishi doesn't burn much. 25mpg on California gas, 28mpg on
Nevada gas. I think you guys calculate in liters per 100km and I
believe it would come in under 10.

Not in UK, and we have bigger gallons. Are those figures average, and do
you do a lot of journeys over 20 miles?
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Rich Grise <[email protected]>
I'd even suggest that if he's looking for good intelligibility, that a
high-pass at about 300 Hz could help dramatically, at least for human
voice. They've been doing that for decades in the Ham radio field.

And telephones, but to retain a 'balanced' sound quality, you need then
to restrict the high end as well - 300 Hz to 3.4 kHz is about right -
surprise!

You don't get any significant increase in intelligibility by extending
frequency response above 8 kHz, and if you have 8 kHz, you should roll
off from 80 Hz at the low end. There is an empirical rule for this
'balanced sound quality' in BS 6259 - a straight line on log-log scales
from 20 kHz/20 Hz to 2.9 kHz/400 Hz.
(you throw away the fundamental, so that it doesn't hog all of your
transmitter power - all of the "intelligence" is in the harmonics
anyway.)

Well, not really harmonics, but higher frequencies. 120 Hz to 6 kHz (at
-3 dB) sounds 'balanced' and has high intelligibility, while not
difficult to achieve, and is also acceptable for music (excluding
household hi-fi).
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that "[email protected]"
The ISD chip gives less than 4khz bandwidth, NOT 8 (that is the SAMPLE
rate).

I didn't say that they do. I said that you almost certainly don't need
10 kHz audio, 8 kHz is enough.
 
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