Could we possibly create a refference topic on human hearing or audibility tresholds? I see endless discutions on better or worse thd sources, preamps, amps, dacs fighting their religious wars around -130db of THD +N when Dolby S circuits used on tapes established that below -81db we can't generally hear a damn thing in normal conditions.It might by just an opinion I share...but other than that what would be your scientific proofs of a different world than the one I think I'm living in?
We might probably hear some noise if we'd be living full time in an anechoic room, but with typical 30...60 db ambient noise i don't see anyone in need of more than -81db SNR or THD so why do we keep on proving how stupid everyone else's noise source is once it's past our hearing tresholds?
Why do we pretend to have heard, seen or made better products than others based only on lower numbers when most ears on Earth won't be able to hear it?
I only chose a random Dolby S movie on youtube, but you can google for others if you never heard a good deck with dolby s.I actually never heard a good deck with dolby s in terms of dynamics, but the lack of audible noise was a clear cut thing for me on Sony TC S1.I'm going to work soon on a Pioneer with dolby S...Maybe that will be a bit better in terms of dynamics .
I'm 45 years old and I can't hear any damn noise below 79db in a normal living room. THD and noise are the same thing below the audibility treshold. Can you hear anything lower than what dolby S can provide?!
We might probably hear some noise if we'd be living full time in an anechoic room, but with typical 30...60 db ambient noise i don't see anyone in need of more than -81db SNR or THD so why do we keep on proving how stupid everyone else's noise source is once it's past our hearing tresholds?
Why do we pretend to have heard, seen or made better products than others based only on lower numbers when most ears on Earth won't be able to hear it?
I only chose a random Dolby S movie on youtube, but you can google for others if you never heard a good deck with dolby s.I actually never heard a good deck with dolby s in terms of dynamics, but the lack of audible noise was a clear cut thing for me on Sony TC S1.I'm going to work soon on a Pioneer with dolby S...Maybe that will be a bit better in terms of dynamics .
I'm 45 years old and I can't hear any damn noise below 79db in a normal living room. THD and noise are the same thing below the audibility treshold. Can you hear anything lower than what dolby S can provide?!
Attachments
Two devices with -81dB noise in a chain make -78dB. How many devices in the signal chain? Does SNR or THD change with volume, load, frequency? What is the amplification of the final device in the chain (the sensitivity of the speaker)?
Without getting into any of the myriad other questions that come to mind, that's where I would start.
Without getting into any of the myriad other questions that come to mind, that's where I would start.
Well...if we have a digital source we will only have a -90...-130 db thd+n in series with an amplifier and a speaker following it and -100...105db snr amps are the norm today, while 0.01%(-80db) thd class d amps at low volume are everywhere.Now class d amps can go much higher in both noise and thd BUT ...
The higher the volume output, the higher the treshold cause ear's sensitivity needs to adjust to the new level .If you ever used a machine gun you know what that means...cause i remember experiencing at least 30 db hearing loss for about 5...10 minutes after a few rounds as if my coleagues talking next to me were 50 meters away.
As for analogue sources if you have a -75db phono preamp and a -100db amp you're true limitation is the top -65...-70db snr of the vinyl itself.
That is why they rarely care about tape preamp noise cause tape's noise is 20 db below the worst tape preamp while the noise reducing system takes care of both.
The higher the volume output, the higher the treshold cause ear's sensitivity needs to adjust to the new level .If you ever used a machine gun you know what that means...cause i remember experiencing at least 30 db hearing loss for about 5...10 minutes after a few rounds as if my coleagues talking next to me were 50 meters away.
As for analogue sources if you have a -75db phono preamp and a -100db amp you're true limitation is the top -65...-70db snr of the vinyl itself.
That is why they rarely care about tape preamp noise cause tape's noise is 20 db below the worst tape preamp while the noise reducing system takes care of both.
Possibly...I had a CD304 and a Grundig 7550 with tda1540 and I remember the Philips had a good sound as stock and with unchanged caps for 40 years or so , not exceptional though.I sold them to a guy who made a beast with 4 tda1540 out of both of them that got all the local audiophile claims...Never heard the modded ones, but I do believe the guy who had a PHD in numerics.It's probably that the stock version I owned had just all the caps dried out or maybe the balanced version he built out of the 4 tda1540 had a different presentation...I'll never know .
The quantization noise, dithering and oversampling might have been the stepping stones of those days...
The quantization noise, dithering and oversampling might have been the stepping stones of those days...
Last edited:
Not being a native british speaker I often write the opposite...correction :
the tape noise is 20 db higher than the worst playback preamp noise...
Well those are all different arguments than let's stop at -81dB. All of your arguments there are conditional. Which was my point. "Let's stop at -81dB" on its own doesn't hold up without conditions. You're saying, in the digital realm, let's stop at -81dB for the amp since the DAC will be at least -90dB. Your conditions in tape and vinyl are that the source is so bad who cares.
I don't think your machine gun comment is relevant on the volume front. My comment about volume is related to some systems having different performance at different gain and attenuation, depending on the gain structure. Check THD+N vs input graphs in attached PDF for example. Hearing threshold is a different discussion.
There's a lot of discussion on tda1541 which seem to be both the mother and the father of the late 40 years of cd player modding , but I rarely see any discussion on Tda 1514 chip amplifier which seem to complement tda1541 at some moment but looked more like tda1540 complement if you look at sheer noise...The numbers weren't really a random choice .I heard a few tda1514 and their sound was really really good while the source was a 24 bits computer file...
Attachments
Rated at 50mW output. That's 96dB at the more commonly referenced 1W, assuming noise does not change with signal level.
Ok, then it was made specifically to be paired with tda1541...not 1540, but obviously won't degrade a dac wIth 12 db lower SNR.
93 -12= 81db which is the top SNR of the Sony Dolby S cassette deck 🙂 So tda1540 offer the same snr as the lowest noise Sony cassette deck running metal tape..That's fine for me!
Attachments
Last edited:
