Tone controls are great

1   Mathematics:
Never forget that any filtration in the amplitude domain that is selective in the frequency domain alters timings within the signal.  It's mathematically  impossible to have tone controls that don't alter timing.  Also note that the human ear/brain combination can be amazingly sensitive to timing - it has been shown that (at mid frequencies at least) humans have time discrimination below the Fourier limit.

2   Hearing loss
Hearing loss won't usually be compensated by a 'treble' tone control as it has the wrong operational function.  Hearing loss is usually has much sharper amplitude/frequency curve than is present in tone controls.  It can also be composed of one or more discontinuous band block filters rather than a continuous function.

3   Room correction
Room resonances are usually fairly high 'Q' and so emphasise very specific bass frequencies, with little effect just a few Hz either side of the centre frequency.  A broad bass cut filter won't fix this issue.

Amplitude / Frequency adjustment is a minefield of complexity.  General broadband tone controls are rarely the right answer and graphic / parametric equalisers need a lot of knowledge and work (and measurements) to get the parameters right for any specific circumstances.  Even then you've still got the mathematical issue of the timing changes, and that you can't eliminate.

Innocent Bystander posted:

Harry posted:

Now onto balance  controls.  Who in their right mind would buy an amp with a balance control? Just treat the room, millimetre position the furniture, always sit in the same place and move the speakers about all over the place. No more pandering to this  LoFi rubbish.

And if your room prevents such positioning? 

With the prevalence of remote volume controls these days, whether they be operating motorised pots, or controlling in the digital domain, the potential is presented for individual volume controls on each channel rather than volume and balance controls, so nothing more in the signal path than just having a ganged volume control, while enabling relative levels to be set manually on the amp and operational volume controlled by the remote.

I think Harry was being ironic not serious!

By the way the UnitiQute does have a loudness control, although In my opinion it doesn't improve things at all.

best

David

Harry posted:

Now onto balance  controls.  Who in their right mind would buy an amp with a balance control? Just treat the room, millimetre position the furniture, always sit in the same place and move the speakers about all over the place. No more pandering to this  LoFi rubbish.

I used a balance control once. In 1983 when I got the first Sony CD player the device had a design fault that made one channel 1Db louder than the other.

My Nytech amp doesn't have a balance control, but each channel has a separate volume slider control! Cool!

David Hendon posted:

I think Harry was being ironic not serious!

 

It's OK David. 

The balance control on our 552 has proved to be one of it's most useful practical features.

I don't  remember  Quad getting much  stick for their lift/tilt/whatever-they called-it tone features. Although I expect they did in some quarters. 

Harry, I've moderated/edited this post.  I'm not entirely sure what was mean't in your second sentence but it appeared to be a slight on an other member.  Either way, I've removed it.

Huge posted:

1   Mathematics:
Never forget that any filtration in the amplitude domain that is selective in the frequency domain alters timings within the signal.  It's mathematically  impossible to have tone controls that don't alter timing.  Also note that the human ear/brain combination can be amazingly sensitive to timing - it has been shown that (at mid frequencies at least) humans have time discrimination below the Fourier limit.

.....

3   Room correction
Room resonances are usually fairly high 'Q' and so emphasise very specific bass frequencies, with little effect just a few Hz either side of the centre frequency.  A broad bass cut filter won't fix this issue.

Huge - 1. Indeed detecting timing and pitch are two largely unrelated auditory functions. Pitch is is defined to the range of audible frequencies  - which as you say deteriorates with age - however detection of timing from what I have read (AES library) does not deteriorate to the same extent at all. 

Of course as an aside this is why high bandwidth sampling with a low frequency cutoff makes sense as the timing info is retained but it filters unnecessary  ultrasonic noise frequencies in the pitch domain that are inaudible anyway and will only most likely cause very low intermod distortions within the audible pitches.

3. Yes sometimes the Q can be very high - listen to a double base chord being walked or plucked - and if you hear a note more prominent that its neighbours - you have a resonance - and I find this sort of room/speaker artefact one of the most off-putting - as it instantly shouts ARTIFICIAL  to my brain and it becomes so distracting

Well - prior to having my Naim amps I had an Arcam amp with bypassable tone controls.   I never ever - not once - used them.

Surely if a recording has - say - reduced bass that's the way it is a tone control can't enhance what isn't there?    Without being an expert digital room correction may be an entirely different prospect?

Regards,

Lindsay 

Lindsay - if we were listening to pure sine waves I would agree with you - but we don't we listen to a series of complex fundamentals and harmonics. The tone control is simply slightly adjusting the level relationships of the fundamental to its harmonics across a complex aggregation of sounds - this has the net effect of warming or brightening the sound...

Now as an aside - again the AES library has some interesting info on this - the brain can interpolate the fundamentals from harmonics - i.e. you can hear' sounds that are not there - this is not really related to tone controls - but shows you can trick the brain to hearing things. This technology is used in smart phones and very small loudspeaker designs in some devices.

The Strat (Fender) posted:

Surely if a recording has - say - reduced bass that's the way it is a tone control can't enhance what isn't there?    Without being an expert digital room correction may be an entirely different prospect?

Regards,

Lindsay 

Lindsay

Personally I have only ever used tone controls, on the many Quad amps I used before I came to Naim, to remove or tone down something, not to add what wasn't there.  For example I can think of a particular recording of Strauss's Four Last Songs where the soprano (Elizabeth Schwarzkopf no less) sounds rather strident in what is otherwise one of the great recordings of all time imho.  As it happens the most recent re-mastering from analogue to CD has sorted this out, but before I bought the remastered version, knocking the treble back by one notch allowed me to enjoy her singing all the more.

Similarly I think turning the bass down a little can help remove the bloated sound that speakers positioned too close to the room corners can sometimes produce. Domestic harmony, especially when children are involved, and optimum speaker positioning don't always go hand in hand!

But to pick up and paraphrase a point HH made back at the beginning of this thread, I agree with him (and I think you) that sitting tweaking the tone controls for "sound perfection" is a very poor way to enjoy music.

best

David

Joe x Nai

Out of interest what are you using ?  something Japenese Accuphase,Luxman that sort of brand.

I am not at all technical on the right and wrongs of tone controls its only what suits your ears in your listening room in your system which matters in the end

Thanks for all the replies. Some very interesting comments and technical facts I was unaware of.

I only had to set the tone controls once and they have stayed that way. I worked on the premise that the studio engineers knew what they were doing and ergo, all recordings are the same or at the very least, sound the way intended. Whether this is or isn't correct is irrelevant to me because my room was the beast I was trying to tame not the recordings. Eventually I know there may be further slight adjustments needed to compensate for hearing loss but I haven't had to adjust the tone controls again since I set the amp a year ago.

I too remember the Tone-control amps of the 80's, woeful beasts, but I assumed the implementation of tone controls these days was more subtle? I'm no technician so please correct me if wrong. The controls can be defeated too which is a great feature should someone want to listen to my amp without the settings.

Before the Luxman I was in my own way tone controlling by adding a hi-Cap or trying a different speaker cable, interconnect etc. So it's something that was always an issue for me that isn't any longer.

JoexNaim posted:

Before the Luxman I was in my own way tone controlling by adding a hi-Cap or trying a different speaker cable, interconnect etc. So it's something that was always an issue for me that isn't any longer.

About hi-cap, is this considered to be tone controlling too? My understanding of a hi-cap is that it is taking a certain electrical circuit from the pre-amp which therefore is able to output cleaner sound.

Fair point, but I always found the bass deeper and the treble cleaner when I added a hiCap.

JoexNaim posted:

Fair point, but I always found the bass deeper and the treble cleaner when I added a hiCap.

I have just added an XPS DR to my NAC N-272 and cleaner hf that seems to soar higher and further is my immediate observation, which my wife commented on too.

best

David

David Hendon posted:

JoexNaim posted:

Fair point, but I always found the bass deeper and the treble cleaner when I added a hiCap.

I have just added an XPS DR to my NAC N-272 and cleaner hf that seems to soar higher and further is my immediate observation, which my wife commented on too.

best

David

Is my understanding correct that tone controls affect the same area's (treble / bass) as power supplies, but where tone controls add more or less treble / bass using amplification (linear scale?), power supplies do this by moving distorting components to a dedicated unit and free up capacity of the amp/pre-amp for driving the speakers.

Obviously, the power supply will bring higher quality of sound, especially in complex music.

OP, please add a poll so we can have our vote.

Getting rid of tone controls was one of the more idiotic ideas of high end audio. Losing balance controls even more so. Most people do not have a dedicated listening room. Even if they did and everything were optimized,these controls did and do have a place.Live room,damped room,which is correct.The person "treating" a room is in part putting in place tone controls - no booming bass or tizzy highs. Granted tone controls are only partially effective,but they can make an improvement.As we continue the switch to digital,even the room correction that linn and several others have pursued will seem positively primitive.Tone controls will return as an electronic room correction and at some point (probably a long ways off) all high end will incorporate something to compensate for the"variable" needs of each room. In the meantime, I would welcome some controls!

The problem with conventional analogue tone controls is that they always take information away from the original signal.  This is one reason behind Julian's original decision when designing the first Naim pre-amp, the NAC12, not to include any switched filters, loudness compensation, or tone controls.  He felt that the pre-amp's excellent stability, overload margin and outstanding transient handling capability made such things unnecessary.  Further, he felt that tone controls did far more harm than good; never improving sound and always losing crucial information.

Richard, it's not just analogue controls that cause problems, digital (mathematical) filters operating in the audio band have the same problems; it's just that they can be more specific and more controllable both in action and effects.  The side effects in timing are the same, however digitals can be more specific in the frequency domain, but the side effects are still there.  Also, in mathematical terms, by definition they actually remove data from the signal.

and the digital tone control side effects are as every bit as real as analogue tone control side effects - a filter is a filter and has characteristic response including errors - and this makes no difference whether digital or analogue... other than the more you change the signal the more the errors become.

Clearly non signal related noise in digital will typically be quantisation rounding and numerical errors in convolution etc - where as analogue noise will be typically be heat generated noise though from the components and non linear distortions.

I am not sure why a tone control detracts from the signal specifically - yes it does - but in the same way that any active or passive stage does... sure simplification reduces the number of  stages and therefore distortions - but that is not about tone controls per se. 

After all the magnetic cartridge phono preamplifier has quite a specific and severe tone control - but referred  to as RIAA equalisation - to make it sound more respectable - no one appears to blink  about that - and in the CD, DAB and FM world there is pre-emphasis sometimes used which requires the  use of a specific treble tone control to correct the sound - again no one minds about that - but then Pre-emphasis sounds perhaps more sophisticated that 'tone control'- but its the same thing.

S