Digital Music File Help

[rpn453]

Originally Posted By: uc50ic4more
Muddiness in the low end is due to the virtual impossibility of properly reproducing good low end in small in a car (small cubic space) or with ear buds (speakers too small to move considerable amounts of air) or poor quality reproduction systems (that have big, fat, flabby woofers that cannot move fast enough to reproduce bass detail, and poor quality amplifiers that cannot supply enough current to do same).


What I mean is, a song that has horrible sounding bass on FM radio - overblown and muddy at around 60 Hz and totally lacking in low bass - can still sound decent off a CD in the same car. A friend once told me that FM is incapable of transmitting the really low frequencies, so they boost what they can to compensate. If true, I guess that would be similar to what you're saying about the high frequencies, but for different reasons. It's unfortunate that they couldn't have put the carrier signal on a higher frequency. Is there a technical reason for that or was it chosen arbitrarily?

Thanks for all the interesting info!

 

[AdRock]

Originally Posted By: rpn453
Originally Posted By: uc50ic4more
Muddiness in the low end is due to the virtual impossibility of properly reproducing good low end in small in a car (small cubic space) or with ear buds (speakers too small to move considerable amounts of air) or poor quality reproduction systems (that have big, fat, flabby woofers that cannot move fast enough to reproduce bass detail, and poor quality amplifiers that cannot supply enough current to do same).


What I mean is, a song that has horrible sounding bass on FM radio - overblown and muddy at around 60 Hz and totally lacking in low bass - can still sound decent off a CD in the same car. A friend once told me that FM is incapable of transmitting the really low frequencies, so they boost what they can to compensate. If true, I guess that would be similar to what you're saying about the high frequencies, but for different reasons. It's unfortunate that they couldn't have put the carrier signal on a higher frequency. Is there a technical reason for that or was it chosen arbitrarily?

Thanks for all the interesting info!


The low frequencies can be transmitted. Below 60 isn't really needed though for most stock car stereos. The systems just won't handle those lower frequencies well at all. The radio stations have EQ's and the signal can will depend on how they are set.

There are a few radio stations that have a much more full sound but are much smaller stations putting out less power than the bigger ones. So it's the quality of the signal, not the power or the frequency of it that can make the difference.

Listen to a rap station. With the right stereo you still get the real low bass.

One other thing. 60hz seems to have a bump because that usually where the kick drum will sit in the eq. When at a concert the 63hz on the eq is the bass that hits you hard in the chest. Once you get down lower than that you feell it but really don't hear it depending on how loud the volume is.

 

[TallPaul]

Originally Posted By: eljefino
battery life should not be a function of memory size so the 2 gb player is better engineered somehow.
I figured it out. The Magnavox player screen goes black after 30 seconds (can set to several time frames). That saves a lot of energy. I can run it for hours on a battery that is showing near gone and it plays fine, soon as I hit a button, which lights up the display, it dies. My other MP2s have constant on display and eat batteries.

Anyhow, here is my solution. Since I almost exclusively listen to a mono earbud, I have converted some of the songs to mono, mainly those with lesser sound quality to begin with. It has opened up quite a bit of space. Only concern is my stereo is 128 kbps wma, which equates to 64 kbps mono, right? But my music editor only offers mono up to 44 kbps. The stuff I converted seems fine though.

I would gladly buy a 4 gig if I could be assured of two conditions: uses AAA (or other standard) battery, and is fairly power conservative. Unfortunately, the industry trend on better models seems to be rechargable.

 

[ARCOgraphite]

I can barely listen to CD after using my R2R and turntable for years. Luckily (or not) my hearing is going and it all wont make a diff pretty soon. MP3 Blechh. Who has a good VBR or high bitrate compression algorithm these days? I have Exact Audio Copy digital workstation on my pC. It seems some MP3 players that have a "SRS type" reconstruction enhancer make the LBR MP3, WMA files somewhat listenable.

 

[Quattro Pete]

Originally Posted By: ARCOgraphite
Who has a good VBR or high bitrate compression algorithm these days?

Ogg Vorbis has always had it. You can also get pretty good results with VBR MP3 if you set the settings right. A quality DAC helps, too.

 

[Win]

Originally Posted By: uc50ic4more

Broadcast regulations in the States state that your audio has to be way down at 15KHz. If I recall correctly, the stereo separation information is broadcast on a 19KHz carrier signal


Sort of. The L - R stereo information is carried on a 38KHz double sideband supressed carrier subcarrier. The 19KHz pilot signal is doubled in the receiver to 38 Khz and then used to demodulate the L - R subcarrier.

So you have the mono L + R channel from 0 to 15 Khz, and the L - R channel from 23 to 53 Khz. When Zenith invented the system, they probably needed this large guard band around the 19 Khz pilot signal. Brickwall DSP filtering could do a lot better today.

Around here, all the FM stations are compressed so bad and have such heavy pre emphasis, that they sound just awful. I don't see how anyone can listen to it.

 

[TallPaul]

One question for you experts.

Apart from the obvious loss of the stereo output, how will my sound quality compare (or suffer) for earbuds going from

WMA 9.2 128kbps 44kHz stereo CBR

to

WMA 9.2 48kbps 44kHz mono CBR

I normally listen to a mono earbud, but occasionally a stereo earbud.