The DIY'rs Cookbook

johnjen said:

This in part helps to explain why headphones tend to have 'Better' resolution, inner detail, and why in some cases the results out of a system can be 'intolerable'.
We are about as close to the acoustic source we are hearing as you can get.
And this also helps to explain why IEMs are, or can be even more engaging, since they really are as close as we're ever going to get.

But then I spied that the graph in this one paper mentioned 30% relative humidity…
That darn light bulb had stopped flashing, now it was strobing…

I have mentioned that it seems to take ≈ 1/2 hr for the SQ to take a mother may I step up after 'strapping on the cans'.
And then in ≈ 1-1.5 hrs is when the SQ kicks into overdrive.
 

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sheldaze said:

 

bigro said:

  I envy Those Who do not hear much a a difference between DACS or other gear. your wallets must be fat and happy. Bimby vs Modi, Modi 2u and even Bifrost Uber was a very noticeable improvement for me. I did my comparison with speakers, there is a lot that you miss with headphones in my opinion.

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Excuse me if I repost - there are a lot of threads.

 
Yes!

 
My upgrade from Bifrost Uber to Gungnir Multibit - let's just say I'm glad I was using a good set of headphones at the time. Per my amplifier, I could not discern the difference using any of my 3-most common usage (then): NAD VISO HP50, Sennheiser HD650, and another headphone (I am forgetting now). Only through my Denon AH-D2000 was there a noticeable improvement between the two DACs.

 
However through my speaker system, the difference between the Gungnir Multibit and the upgraded (better and closer sounding) Bifrost Multibit was incredibly dramatic.

 
At a recent mini-meet, I could tell the difference between Audio-gd DAC-19, Gungnir Multibit, and Yggdrasil at the first note - and the difference was not strictly related to volume. It was like they moved my chair, changed the room treatment, (Gumby and Yggy compared) and in the case of the DAC-19 put the players into a box.

 
Speakers add more layers to the deltas between DACs.

 
Yes!

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landroni said:

Two questions. These past days in another thread several users seemed to be suggesting the complete opposite when it comes to speakers vs headphones, in the context of comparing DACs:
http://www.head-fi.org/t/782824/schiit-fire-and-save-matches-bifrost-multibit-is-here/1830#post_12276723

Is it possible that what it really comes down to is the specific characteristics of the chosen transducers and the synergy (or absence thereof) they create in a given system?

I'd say yes.
The overall state of tweak of a system can heavily influence the net results.
Most systems will benefit from removing/ameliorating what I call 'choke points', but all I can do is speculate since I know nothing of the setups that those comments are based upon.

Also just as a perspective to consider, the amount of detail from individual instruments that are close mic'd is usually easy to distinguish from a group of instruments where the mic is further away.
For instance big band music is one venue where this is easier to hear.

Secondly, interesting hypothesis on the humidity. Might explain why long-term listening may provoke different effects in people rather than short-term instantaneous comparisons. One way to test this hypothesis (although I admit it's limited) would be to leave the headphones running for say 2 hours, then strap them on and check how long it takes for the SQ to kick in. If it's instantaneous, then it's simply a matter of the wires reaching thermal equilibrium. If however it still takes 30 min until SQ goes live, then the humidity hypothesis would... err... sound very appealing indeed. (Although some could still argue it's placebo.)

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johnjen said:

  I'd say yes.
The overall state of tweak of a system can heavily influence the net results.
Most systems will benefit from removing/ameliorating what I call 'choke points', but all I can do is speculate since I know nothing of the setups that those comments are based upon.

Also just as a perspective to consider, the amount of detail from individual instruments that are close mic'd is usually easy to distinguish from a group of instruments where the mic is further away.
For instance big band music is one venue where this is easier to hear.

 
My 800's run more or less 24/7 and it still takes this amount of time before they step up and then later begin to fully 'sing'.
And it could be that my brain just takes this long to fully acclimate, or whatever it does, but I'm not alone in noticing this time to peak level of experience so it would seem that either we all (or at least a bunch of us) need this time for things to synch and 'click', or it 's a function of the thermal/humidity stabilization, but probably both are involved to some degree.

There will always be those who will attribute it to placebo or an equivalent.

I personally trust my hearing, as it's been with me for quite a while now and I have come to know it quite well.
And also having it get 'calibrated' and being able to utilize that ability thru time lends a fair amount of experience to support my trust.
And until this degree of trust is attained it is an easy claim to make about placebo or any number of other rationalizations.

I have a couple upcoming 'Better' posts which go more into these subjects.
I call one Subjectivist vs the Objectivist ‘duality’, and another Auditory Memory
 

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My 800's run more or less 24/7 and it still takes this amount of time before they step up and then later begin to fully 'sing'.
And it could be that my brain just takes this long to fully acclimate, or whatever it does, but I'm not alone in noticing this time to peak level of experience so it would seem that either we all (or at least a bunch of us) need this time for things to synch and 'click', or it 's a function of the thermal/humidity stabilization, but probably both are involved to some degree.
 

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landroni said:

Actually I think there is a way to check if it's a matter of the brain kicking in, or something else. But you need two identical pairs of headphones. Keep both pairs running for 1-2h, but keep listening only to one of the two. Once you're feeling the SQ kick in and got used to it, switch to the other pair of headphones. If the SQ is still there, then this would suggest evidence for brain burn-in; if SQ is lacking and it's still taking >30 min for it to kick in, then we could with some certainty reject brain burn-in and isolate humidity as a potential factor (possibly in interaction with temperature).

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johnjen said:

 
And the bass detail, definition, impact, extension (in both directions) is simply unbelievable, at first, then later it becomes mandatory, when you realize just how far up the frequency spectrum these tweaks extend.
When the ‘Real’ subsonic bass hits, I can feel it in my chest and head, out of headphones.
I have no idea how this is even possible.
 

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Originally Posted by Jason Stoddard /img/forum/go_quote.gif
 
Open Loop Gain, THD, Frequency Response, Slew Rate. These are the same as the gain, THD, and frequency response measurements outlined in the “what we publish” section above, but applied to the gain stage without feedback, or “open loop.” Since we do primarily discrete designs, and primarily designs that have open-loop bandwidth greater than 20-20kHz, it’s important for us to characterize the designs in an open-loop state. This helps us optimize them for their particular usage. Note that these are early-stage measurements.

 

1. So, how hard is it to get great open-loop numbers? Not too hard with inherently linear stages—from complex multistage solid-state amps to simple tube designs that are run with proper voltages.

 

1. What do we shoot for? Great numbers for both linearity and bandwidth. And by “great,” we mean less than 0.1% THD, greater than audio bandwidth, etc.

 

1. Do open-loop numbers correlate to audible differences? According to some of the Pundits That Be, unless the slew rate is insanely low, no. However, we have noted sonic correlations between a constant -6dB per octave falloff outside the flat passband to infinity (no lumps, humps, bumps, or other weirdness going on.) Of course, pure objectivists will say we’re fooling ourselves on that one. But hey, maybe if we can convince ourselves that there are differences when there aren’t, maybe they can convince themselves that there aren’t differences when there are. Neener.

 

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johnjen said:

What and how do we know what IS ‘Better’?
or
It’s all in our heads, or is it?

Part 11 Mighty Impressive/Mandatory Tweaks.


This is a long post (one of, if not the longest to date) and involves a whole series of topics.
My suggestion is to go slow and read it a few times to wrap your head around all of the little details, and there are a veritable plethora of them…
Also you don’t need to use all 3, as in any combination will also yield impressive results, but if you have HD650/HD800 or any of the rest of the headphones on the sonarworks list, this is a cheap (21 day free trial period) and easy set of tweaks to experience and see if these work for you.


Mighty Impressive/Mandatory Tweaks - Are…
#1. EQ done correctly, an example is Sonarworks, which is what I use, there are others.
#2. Phase Reversal Tweak (PRT). Fuss with your Fase For Fun… aka. Phase em, Phil
#3. SubSonic Bass Boost (SSBB). Boom, Chucka Lucka

These 3 tweaks when implemented together in a system that is capable of delivering low frequency without distortion, can and will deliver a degree of SQ that once experienced is near impossible to give up.
And I do encourage all those who implement these tweaks, in any combination, after getting used to them and fully noticing the differences (i.e. listened to lots of different music you are already quite familiar with) then, disable all of these tweaks and go back to the setup previous to this.

Mostly to learn what the results from these 3 mods truly are.
I have found that this is, really, the best way to know what is truly ‘Better’.
IOW, turn off the mods and notice the differences.

And it should be noted that this is a useful tool, that can be used to ‘zero in’ on the optimal settings for you and your system.
Just turn off the mods and notice the differences.

And I’d be willing to prognosticate that they will be turned back on, and perhaps tweaked, just a tad bit more, and in short order.
Because sometimes even 1 or 2 dB, or a center frequency change of only 1-3Hz and everything can ‘click’ and fall into place.
This where the tweaking, the fussing with the knobs takes place.
And this is where the magic happens,
when the compensation curves match to each other AND to the natural curve of the drivers themselves.

YeeeeHaaaawww!!!! BOOM Chucka Lucka

For the first time, on a mass scale, attaining near flat response out of our headphones is now possible, at least for some.
This is whole new territory and we are only at the initial stages of exploring this entire subject of EQ as it applies to headphones.
But the results to date are far beyond most folks wildest imaginations.

And when DSP based EQ is used with these other 2 tweaks, the results are addictive and compelling and IMPERATIVE, with a generous dollop of Superglue tossed into the mix.

As Atomic Bob has stated, he would rather listen to music for his enjoyment on his ≈$1500 system with these tweaks than a top end system without these tweaks and he has immediate access to both at the same time.
And I too would not willingly give up these tweaks, no matter what gear I’m using, as the sum total is far to compelling and necessary in order to hear the music presented this way.

#1. EQ done right…
I prefer the Sonarworks EQ plugin, mostly because it has a compensation curve which is based upon actual HD800 measurements. And it can be further refined for an ever more exacting match.
But many other parametric EQ’s could do a similar job, IF you start with a a known ‘good’ FR curve, and use a good quality parametric EQ plug in.
And then fuss with the dials and knobs a whole bunch to dial it all in.
A ways back I did try this approach but it never ‘clicked’ for me and so I abandoned my efforts and settled on just bass boost.

But for me Sonarworks is Way ‘Better’, and much easier to implement.
And Sonarworks has provided average ‘No Limits” curves for the Sennheiser 800 and 650’s. These “no limits” curves are much preferred and make blending the SSBB settings much easier and less drastic.
These ‘No Limits’ curves essentially extend the compensation all the way down to 20Hz, which is where the SSBB kicks in and extends the compensation down to below 10Hz.
And I must add I am quite satisfied with the SQ of the Sonarworks plug in, in terms of inner details, focus and resolution and more.

#2. Phase em, Phil…
There is however one caveat, the PRT does require a balanced connection to the headphones of your choice.
Those headphones must have a 4 wire cable to the Left and Right earpieces, not a 3 wire.
Also, a 4 wire retrofit of the connector is actually fairly easy if needed, for most headphones.

But if you already have a balanced headphone cable, this tweak is a plug-n-play operation, once you have a phase reversal cable at hand, or are willing to rewire your balanced cable.
We prefer to use the 4 pin XLR connectors instead of the dual 3 pin XLR type as it makes for a simpler and less cumbersome setup.

What is entailed is making one channel of your system reverse polarized with respect to the other. It doesn’t matter which channel, although I normally use the right channel (R - Reversed) just to keep it straight in my head.

So, to activate PRT, in DSP, reverse polarize the right channel and then when the right driver in your headphones is also reversed at either, the end of the main cable, or by adding a Polarity Reversal cable, or by swapping the wires right at the driver, we hear our music in proper polarity.
However all of the analog electronics have the left and right channel polarity out of phase with respect to each other.
What this does is tend to equalize the load on the power supplies. Which in turn means they are ‘stressed’ less so there is less voltage sag during instantaneous transient demand for power.

And when running tubes, with both the left and right channels running in same dual triode or pentode, the common signals between the 2 channels tend to cancel their effect upon each other.
In effect it tends to reduce crosstalk between the 2 channels, and balance out the operation of the tube.

PRT has the effect of reducing the 2 signals ability to ‘contaminate’ each other, which in turn means less smearing and tends to lower tLFF (the Listener Fatigue Factor) among other unwanted factors.
Some of those other sonic effects are increased definition, tonality, and just about all of the terms I have mentioned during this entire ‘Better’ series of posts.
But perhaps it’s largest impact is on the amount of bass the total system can deliver, which usually minimizes the need for adding any more bass.
And sometimes, if this tweak is added last, much of the previously added bass will probably need to be reduced.
So if you’re a bass freq your REALLY gunna love this tweak in particular, but the sum total will probably drop your jaw onto your desk.
So have some bandages handy

#3. BOOM Chucka Lucka
Lastly is the SubSonic Bass Boost SSBB
This bit of EQ when added to (or built into the primary EQ) and properly aligned, should extend the FR response down into the sub 10Hz region (1+ octave below ‘audibility’).
This may sound at first like either an unnecessary tweak or perhaps wishful thinking.
As in, there is nothing down at those frequencies so why bother, why even try to bring this portion of the spectrum up to near flat response in the first place?

My answer to that line of inquiry is…
If you have ever heard a system setup like this and played some of the music you are very familiar with and discover that there truly IS music to be enjoyed down at these frequencies, then you will know the full net effect that this last tweak can have.
And it doesn’t really matter if it’s speakers or headphones, when the entire system ‘properly’ couples, as my friend says, “from DC to light”, AND especially when it reaches down into the sub-basement, there is a whole new appreciation for the music you have heard countless times before but are hearing as if it were new, all over again.
Short of that it’s just words on a screen or page.
Experience is the teacher of merit in this case.

But if you need evidence of these low frequency sounds, you can monitor it using an FFT display.
JRiver has an “Analyzer” built into DSP and you can define both the lower and upper limits of the displayed spectrum.
I set my lower limit to 5Hz and then just watch it while playing music.

This last tweak is the icing on the cake, the pièce de résistance, Le Bomba Supreeze, the BOOM in the Chucka Lucka.
I never suspected I would EVER hear or more accurately feel, in my body, music with this much definition and detail and visceral impact, from headphones.
Like I said bass freqs are gunna love this.
And this will help make converts out of all of you bass freqs who are still ‘in the closet’, so to speak…

SSBB is accomplished in DSP via parametric EQ settings.
Simply add 3-12 dB (or more) of bass boost at 8 - 15Hz with a ‘Q’ of 0.7 to 2.0.
Here are a couple of examples that are in use.
I use 15Hz +4dB and a Q of 1.41
Other user 1: 10Hz +12dB and a Q of 2
Other user 2: 8 Hz +5 dB and a Q of 0.7

Of course these are just guidelines, ‘test settings’ to start with, use these to begin fussing with the knobs, for yourself, to see if you can adjust them to best match what works best for you and your system.
And be sure to use the ’Turn It Off’ test just to see where you are…

Note: it may be necessary to reduce input to, and or the output from the Sonarworks EQ plug-in by 3 – 12 dB to avoid an overload condition that may be produced by this boost.
IOW if either the input or the output ‘leds’ at the top of the dancing ‘VU meters’ inside the Sonarworks main window are red, then those channels have been overloaded and you need to correct this condition.
To start, you can ‘reset’ these indicators by simply clicking on them, so they turn green.
Then every once in a while check them to see if they have turned red again.
If so, either the input to the sonarworks plugin or its output, or both, need to be reduced in order to not overload the resulting signals.

So lets start with the input and adjust it using this method…
Note: if the input ‘leds’ don’t turn red then you can skip straight to the output ‘leds’ section below.
#1 In DSP and inside the Parametric Equalizer (the same plug in used to set the SSBB) Add “Adjust the Volume”.
#2. change the gain to -3dB (minus 3dB) as a place to start.
#3. Make sure this Parametric EQ plugin is fully activated (√’d).

Then make sure the ‘led’s are green and play some music.
If the input turns red again, reduce the settings to a greater amount (say -6dB)
Then reset all leds’ to green and play music and continue until the input no longer overloads.

Note: I’d also recommend turning off the “Avoid Clipping” function just below output ‘VU meters’ so that you can dial in these settings.

Now if the output ‘leds’ still go red, or if the input never did, here’s how to adjust the output.…
And the output is the easiest to adjust as it’s the slider just to the right of the output ‘VU meter’.
A place to start is with a setting of -6dB .

If you need more help you can ask in this thread and between me and others we’ll be able to help you resolve the situation.

As these tweaks become more refined and work more seamlessly together, the degree of focus, the resolution of the sonic information becomes finer and finer with higher degrees of precision and ‘realness’ (think Phase Δ Reduction thought experiment).
And the bass detail, definition, impact, extension (in both directions) is simply unbelievable, at first, then later it becomes mandatory, when you realize just how far up the frequency spectrum these tweaks extend.
When the ‘Real’ subsonic bass hits, I can feel it in my chest and head, out of headphones.
I have no idea how this is even possible.

Indeed the last few newly re-purposed terms I have ‘coined’, are all due, in whole or in part are due to the consequences of these 3 tweaks.
Namely, SEB, IMPERATIVE, SuperGlue, I HEARD.

These 3 tweaks when used in conjunction are much greater than their mere sum.
Yes it may require a bit of doing (converting your HP cable to balanced, and the need for DSP in the s/w player, and fussing with the SSBB settings) but the results are WELL worth the effort, and once experienced it seems they are rather difficult to live without.

They truly are Mighty Impressive/Mandatory Tweaks.

ps. just to say these 3 tweaks can be used on any Single Ended OR Balanced amp.
pps. All of this is completely reversible, well except if you added the 4 pin connectors to your existing cable. And even that is functionally ‘transparent’.

End Part 11

Next up Where is all of this taking us?

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landroni said:

Hmm, is it possible that the brain registers subsonic bass not via the cochlea but, say, via the skin? After all, contrary to supersonic sounds, subsonic sounds must generate quite a lot of (subsonic) energy and move quite a lot of air, quite violently.

I figure it's a combination of our ears, the body, and the brain.

As in the brain will 'fill in' where the input from our ears and body may not get a full strength signal, so that the brain will make us 'feel' the consequences of the low frequency acoustic energy.
It feels that way to me.
IOW the head rattling and chest thumping isn't felt as you would fully expect but it's 'close enough' to feel real.

But then, what components should one use to achieve this? Most DACs, amps and transducers are specced at 20 Hz in the lower bound... Although I notice that the System Synergy components go beyond that:
Bifrost MB: 20Hz-20KHz, +/-0.1dB, 2Hz-150KHz,  
-1dB 

PS-III: 4 Hz – 350 KHz (-3dB) with 32 Ohm load
HD650: 10 - 41000 Hz

My HD800's are spec'd 6 – 51000 Hz (- 10 dB)
The Rok specs at 2 - 180KHz (-3dB)
The PWD has 20Hz square wave response that is as square as the source

I'm wondering if Jason Stoddard's take on Measurements is relevant here, especially the open-loop section:
http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/6990#post_11763661

He also notes that most Schiit "equipment is -6dB at 0.16 Hz and 300-500kHz (without input filtering at 150kHz or so, so it doesn’t reproduce AM radio)". Of course he focuses here on the high-frequency performance, but it's clear that care is shown to frequency response outside the audible band in both directions. 

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landroni said:

Actually I think there is a way to check if it's a matter of the brain kicking in, or something else. But you need two identical pairs of headphones. Keep both pairs running for 1-2h, but keep listening only to one of the two. Once you're feeling the SQ kick in and got used to it, switch to the other pair of headphones. If the SQ is still there, then this would suggest evidence for brain burn-in; if SQ is lacking and it's still taking >30 min for it to kick in, then we could with some certainty reject brain burn-in and isolate humidity as a potential factor (possibly in interaction with temperature).

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johnjen said:

I find that having a paper copy sometimes is easier to refer to, head scratch with, ponder upon, etc.

JJ

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