Diagnostic Assistants Needed

[The Mad Professor]

**broken link removed** - follow the listen live link

Am field testing a bit of an experiment and am seeing how well an aging PentiumIII computer with some streaming audio freeware for the next three hours on a home broadband connection. swing by and see if we crash lol

 

[Sceadwian]

Could only listen for a few a minute, sorry. The bitrates too low =) It's like listening to good music with water in your ears, just ruins it.

 

[The Mad Professor]

Thank you

Thanx for the feedback , some technical glitches this end during the first hour.
Aging PC here is struggling to handle the number of connections but is still running lol
quality should of settled down now , stream rate is now set at 30+kbps

 

[audioguru]

I listened for a while. It had a very boomy response at about 200Hz so that a male voice could not be understood then "music" was played that was also boomy and had many high frequency shriek noises.

If it is stereo then its separation is very low. At first I thought it was mono.

I listened again and heard a woman talking with such a strong UK accent that she was talking in a foreign language.

The sound quality is much better than a horrible AM radio that outputs only vowels.

 

[Sceadwian]

As audioguru says it's still too boomy. Do you have any pre-emphasis filter or eq set up for your home speakers on it? Unless you're listening from monitor quality headphones or output speakers you may be adjusting the EQ on the machine outside of what other users need (basically a nice flat eq) Might sound nice over there, but here not so much.

 

[Sceadwian]

Although I'm turning it off now, I was listening for the last 20 minutes or so this time. Need something a little more upbeat. Good ambient. I'm getting some serious low end distortion occasionally though, I really think you have a big EQ snafu going on.

 

[audioguru]

I have a real time analyser on my pc's screen and it shows a huge peak at about 200Hz. I listened again and heard a bongo drum that is much louder than anything else.

Some of the songs sound like copies of the songs by the monks many years ago but without their vocals.

 

[audioguru]

I listened on the web to my local FM radio station Z103.5. The sound was crisp and clear without any boominess. When the DJ talked it was so clear that it sounded like he was here. Stereo separation was obvious. No distortion but a little compression was heard.

 

[The Mad Professor]

I listened again and heard a woman talking with such a strong UK accent that she was talking in a foreign language.

Ah.. that would be my devoted assistant Julie, the accent is from Hereford lol
If you think that's bad you should hear what the original dialect sounds like in the "Forest of Dean" just down the road from here in Newent.

Further distortion came from the internal microphone of the iMac and strongly suspect that it also the source of that 200hz hum. Going to have another bash at it this weekend with updated drivers for the sound card and an increased bitrate. Hopefully will have ironed the bugs out of the EQ setup by that time as well.
[9pm till midnight GMT friday or saturday, Rock,Blues,Ambient - hour of each in that order]

Therapy is available for those unfortunate enough to hear me speaking during the 'show'

But seriously .. Thank-you to all who did 'tune in', at our peak we had 35! of you connected at one point during the last hour. The PC half of the setup was struggling to keep up with demand by this time , ditching WinXp in favour of a smaller Linux operating system might be worth a try me thinks.

Regards to all

Jon & Julie

 

[The Mad Professor]

All set this end for another experimental adventure, in fact the stream links are active now and will remain valid till midnight GMT.

That annoying spike in the spectrum of last weeks webcast at 19.5khz appears to have been introduced from inside our iMac Classic better known as as Dewy and is either a D2A issue or fan noise on the supply upsetting the internal op-amp.

Reluctant to go into the case and chase it down as I have only ever been inside an Imac classic once before and that was with the aid of a hacksaw, those cases are not exactly easy to open up...maybe it's just me lol

Starting off with some pre-recorded tracks whose playback quality are known beforehand and we will see how they sound to the rest of the planet. Later on we will engage Dewy again with some filtering and see how he behaves.

 

[audioguru]

Now I hear good old rock and roll. I even heard a saxaphone.
the boosted response at 200Hz is gone but I detect no high frequencies above about 10kHz.
It sounds like mono, not stereo.
Some songs have very distorted high frequencies but maybe that was how they were recorded long ago.

EDIT:
I quickly gave up with the old sounds and switched to streaming from my local FM radio station playing wideband, very low distorted Today's Hits.

 

[The Mad Professor]

Thanks AG, I suppose I ought to set a loop of test tones on both channels to get a clearer picture of what is being lost in transcoding. Have to agree it does sound like mono, high frequency cut off is rather pronounced (practically nothing above 5730Hz) will take another look at the EQ settings.

 

[audioguru]

My EQ at 16kHz has no effect but its 8kHz can be boosted and cut.

 

[audioguru]

Now your sound is horrible. No bass and boosted and distorted highs. My Real Time Analyser is a diagonal line (low levels at low frequencies and high levels at high frequencies). The lows and highs are well balanced from my local radio station.

 

[audioguru]

"La Bumba" a minute ago sounds well balanced but like an AM radio station (no high frequencies).

 

[The Mad Professor]

small hiccup this end with the alternative sound card not talking to the operating system quite the way it's supposed to.. and the microphone input has gone completely to pot in the process..

[apologies for the trance/dance music it's a request from my niece]

have attached screenshot from the analysis software I have here, notches are clearly visible.

 

[audioguru]

I don't see notches but I see and hear AM radio sound (100-4kHz)frequency response.

My local radio station just finished a song that was compressed to death! I looked for the song on Google and found it on You Tube with even worse compression!

 

[audioguru]

Do you have a microphoner in front of a speaker? Horrors!

 

[audioguru]

Sounds good now.

 

[The Mad Professor]

Over last hour we were using an external source of audio from the iMac fed directly into the mic input, software conflicts had rendered the normal 'line input' useless everything said it was connected , played through fine locally but the streaming software would not listen to it. As more logged on problems arose with available RAM and virtual memory so trying it again under a much lighter Linux operating system looks attractive. Most likely DSL or Puppy linux , results in the past have been good with these distros on older Pc's.

ahh yes, did commit unspeakable acts of horrors on more than one occasion,
on the plus side no ear splitting feedback this time

The downside of using the iMac as a source of audio is that it is impossible to turn off the built in microphone entirely using the Mac O/S , we had tried using an external mic with it but no joy [that hacksaw is looking mighty tempting], will probably just use a blank jack and disable it that way.

The quality is not quite as good as hoped for, but it's still early days.. it works and that is half the battle...