Audio Quality

[4pyros]

I have been looking at dedicated MP3 players that can be triggered to start.
Any thoughts as to the audio quality of this one?
https://www.pricom.com/Trains/DreamPlayerLITE.shtml

 

[tronitech]

It's states CD quality so I imagine it's pretty good. It's probably more to do with the amplifier quality if you want to drive speakers?

 

[audioguru]

Why would anybody buy an audio product that has NO AUDIO SPEC'S??
Frequency response from 20Hz to 20kHz plus or minus a dB or two, distortion at a certain output level at many frequencies? Output hiss level?
It might sound AWFUL (no bass or boomy bass, muffled or shrieking highs with lots of fuzzy distortion and lots of hiss).

 

[4pyros]

Why would anybody buy an audio product that has NO AUDIO SPEC'S??
Frequency response from 20Hz to 20kHz plus or minus a dB or two, distortion at a certain output level at many frequencies? Output hiss level?
It might sound AWFUL (no bass or boomy bass, muffled or shrieking highs with lots of fuzzy distortion and lots of hiss).

That's what I am afraid of. A few of them say CD quality but give no spec's. I need something of high quality for our pyromusicals. Half way thinking of just soldering wires to the play button of a portable MP3 player. We want to trigger two at the same time.

 

[alec_t]

It's states CD quality

..... whatever that is . They could be just referring to compliance with the data sample rate.

 

[Nigel Goodwin]

I would imagine it sounds pretty damn good - it's hardly difficult to make a simple music player sound good - just stick the audio out through a couple of 16 bit D2A's and put low-pass filters on the output.

Looks a pretty handy little unit - now what could I use one for?.

 

[4pyros]

..... whatever that is . They could be just referring to compliance with the data sample rate.

Maybe I will send an email asking what the frequency response is?

 

[4pyros]

I would imagine it sounds pretty damn good - it's hardly difficult to make a simple music player sound good - just stick the audio out through a couple of 16 bit D2A's and put low-pass filters on the output.

Looks a pretty handy little unit - now what could I use one for?.

Ever see the mail box on the side of the street that made crashing sounds?

 

[audioguru]

I agree it is difficult to make an audio product sound bad today, but we do not know if it uses awful LM358 (or LM324) output opamps with crossover distortion, lots of hiss and trouble above a couple of kHz.

 

[Nigel Goodwin]

I agree it is difficult to make an audio product sound bad today, but we do not know if it uses awful LM358 (or LM324) output opamps with crossover distortion, lots of hiss and trouble above a couple of kHz.

Those opamps are used perfectly well in MANY decent quality audio items - however, why would anything even remotely modern use such old devices? (were SM versions even available?).

 

[audioguru]

Here is a photo of the crossover distortion when the output level of an LM358 or LM324 is 2V p-p. When the output level is less then the crossover distortion is much more.
The crossover distortion is caused by the output transistors being starved for bias to keep the power supply current very low. Of course a DC load resistor can bias an output transistor in class-A to reduce the crossover distortion and to heat the IC.

 

[audioguru]

I worked with telephone systems when the Canadian government allowed competition with Bell. A cheap Korean business phone system had horrible crossover distortion in its speaker that caused many complaints. I added a resistor to fix many of its phones.

 

[Reloadron]

Well personally and just my take on this I really don't see where it matters. The specifications mean nothing to me. The very best audio I ever heard was likely during the late 50s to early 60s and was heard on the then new FM radio or vinyl records. Actually as crappy as those were they sounded very good to me. This was all analog sound. They claim the human hearing range is between 20 and 20,000 cycles, which I assume holds true for a young child or adolescent. At 65 years old (in a week or so) I will guarantee you my range is nowhere in that neighborhood. I survived Vietnam and countless explosions and gun shots. I survived Marine and Navy Air around jet engines and while the latter for the most part involved hearing protection the damage continues. I shoot high power rifle as a hobby so more noise. Get real here people, my hearing is not what it once was. My truck has a really cool Boss sound system which sounds good to me the way I set it up. Then again it may sound like crap as to how you would set it up. Matters not anyway as it is all about me anyway, my truck and my sound.

When I set out on a 500 mile road trip to see friends and shove CDs into my trucks CD player all I care about is how they sound to me. Only what I can hear and enjoy. The real world numbers mean nothing. Why should I care? Simply put the very best audio quality is the audio quality that sounds best to the person listening and despite a trail of numbers is the only answer in my opinion. Huh? What did you say?

Just My Take
Ron

 

[KeepItSimpleStupid]

Ron:

Think about the Fourier series necessary to represent a square wave and use that to backtrack bandwidth. At 3kHz. that's like 18KHz of bandwidth for 2 odd harmonics. So, IMHO 20kHz is too low. Slew rate is important.
Some amps choke on high slew rate signals. Slew-rate limiting affects the ability to hear a guitaur pick pluck or the attack of the hammer on a piano.

Tube stuff generally sounds "warm". I used to be an avid FM listener, but not anymore.

Horns can actually sound much louder with a tube amp with a low wattage.

 

[audioguru]

Some people are tone deaf so that all sound frequencies are the same. They do not like listening to music which I guess is simply noise to them.
I am 69 years old, have taken care of my hearing and still hear pretty well. I have always loved listening to music and still do.
I hate distortion and noise and when somebody cuts off all high audio frequencies so that the sound is muffled like an old AM radio or telephone.

 

[Reloadron]

Ron:

Think about the Fourier series necessary to represent a square wave and use that to backtrack bandwidth. At 3kHz. that's like 18KHz of bandwidth for 2 odd harmonics. So, IMHO 20kHz is too low. Slew rate is important.
Some amps choke on high slew rate signals. Slew-rate limiting affects the ability to hear a guitaur pick pluck or the attack of the hammer on a piano.

Tube stuff generally sounds "warm". I used to be an avid FM listener, but not anymore.

Horns can actually sound much louder with a tube amp with a low wattage.

I agree KISS and agree with AG. My only point being when it comes to audio what I can't hear really matters not in any sound reproduction. Rest assured I enjoy my music but to me what sounds like a symphony may not sound quite as good to someone else.

Ron