To Tune or Not To Tune?

[Kermit]

Hi Sarong1,

 

No leh .. I beg to differ.

 

Even hardcore enthusiats like me but without kungfu become indifferent liao cos given up.

 

Hobbyists like yourself, bro kermit etc. are a dying breed.

 

Sad to say but just take the death of once active sgcaraudio group and taking into considering current much cheaper headfi option especially with tiong gears like latest dsd dsc for sgd100 that can sound much betta without mentioned paying big $ to installers for equipment, installation and tuning .. their young ears are also appreciative of higher sound quality.

 

Imho, unless there are formal "social" classes with practical hands-on lessons like in usa on both repeatable and reproducible "science and art" that can be payable for sustainability, it is a futile attempt with only pockets of success.

 

http://installerinstitute.com/

 

Cheers.

 

Richard

Come come....open school...employ us...hahaha

Hi Sarong1,

 

No leh .. I beg to differ.

 

Even hardcore enthusiats like me but without kungfu become indifferent liao cos given up.

 

Hobbyists like yourself, bro kermit etc. are a dying breed.

 

Sad to say but just take the death of once active sgcaraudio group and taking into considering current much cheaper headfi option especially with tiong gears like latest dsd dsc for sgd100 that can sound much betta without mentioned paying big $ to installers for equipment, installation and tuning .. their young ears are also appreciative of higher sound quality.

 

Imho, unless there are formal "social" classes with practical hands-on lessons like in usa on both repeatable and reproducible "science and art" that can be payable for sustainability, it is a futile attempt with only pockets of success.

 

http://installerinstitute.com/

 

Cheers.

 

Richard

Come come....open school...employ us...hahaha

[Sarong1]

Yes, Richard. That is why I retreat to my room of head-fi and enjoy the aircon and eat tidbits to my joy.

 

I left the scene long ago but returned intermittently to still see ICE still very much alive. Go by any audio ws and you can still see cars installing system.

 

It seems instruments can already do the job. No need Kungfu Panda liao la...

[richard_crl032]

 

 

It seems instruments can already do the job. No need Kungfu Panda liao la...

 

Hi Sarong1,

 

You know I know cannot lah ... but making it reproducible and repeatable with available tools as much as we can should be the approach to keep this alive ...  documentation and training then become necessary.

 

Better nowadays for Buddhism and lesser for Taoism but let's take a look an analogy of a much bigger aspect of life of religion in Taoism/Buddhism vs Christianity and Islam ... then go to Church and see the no. of Chinese and Malay there but enough said since this is a sensitive topic .... suffice to say that the practice which my mother asking me to burn and pray died long time ago without the documentation and training aka teaching ... that is kungfu in our discussion.

 

Cheers,

 

Richard

Edited October 9, 2018 by richard_crl032

[richard_crl032]

Come come....open school...employ us...hahaha

Come come....open school...employ us...hahaha

Hi Kermit,

 

Cannot lah ... your hourly rate too high liao.

 

Also need your training program and materials for biz case feasibility study and equipment capital investment consideration ... send to me for possibility ?

 

But dun wait too long cos resching 60s and cannot hear properly liao with little motivation :(

 

Cheers.

 

Richard

Edited October 9, 2018 by richard_crl032

[Kermit]

Hi Kermit,

 

Cannot lah ... your hourly rate too high liao.

 

Also need your training program and materials for biz case feasibility study and equipment capital investment consideration ... send to me for possibility ?

 

But dun wait too long cos resching 60s and cannot hear properly liao with little motivation :(

 

Cheers.

 

Richard

 

Aiyo....if you remain active in using your ears, it won't deteriorate so fast one....

 

You can't be serious in opening a school?  Hahaha.... 

 

Btw, you can try out what I wrote.  Try to understand by actually doing it.  I've been doing it without understanding it for the longest time....

[richard_crl032]

Aiyo....if you remain active in using your ears, it won't deteriorate so fast one....

 

You can't be serious in opening a school? Hahaha....

 

Btw, you can try out what I wrote. Try to understand by actually doing it. I've been doing it without understanding it for the longest time....

Hi Kermit,

 

Hard de ... cannot fight time :(

 

Dream is foc but never say never .. see if I go usa for toilet paper after retirement then you know liao ..keke !

 

You are too humble ... you say like that liao I how to try :(

 

Cheers.

 

Richard

Edited October 9, 2018 by richard_crl032

[Kermit]

Richard, since you like Kungfu, here's my take. 

 

1. A Kungfu Master did not become a master overnight.  There are 2 requirements.  Talent and hardwork.  This is assuming passion is there in the first place.

 

2. The Master begun by being a novice.  He's first filled passion, because he saw what Kungfu can do.  Then he wants to learn and reach that Master standard.  How?  

 

3.  He becomes a disciple of another Master.  He learns the knowledge imparted to him.  But...he needs to do one thing.  Train hard.  Until the Master is satisifed, the Master will say, you can graduate and go explore the world.

 

4.  He doesn't stop there.  He goes find other Kungfu to learn.  At the same time he keeps training hard.  Then, he finds yet another Master and spends some time learning his skills.  The cycle goes on and never stops.  He keeps learning.

 

5.  How much time he takes to reach what level, really depends on how hungry he is.  If he's talented, maybe he takes a shorter time.  Otherwise, he may take longer.  But, hardwork and passion is always the key.

 

He's now a Master, not because people force him to learn.  But because he is hungry to learn and achieve.

[richard_crl032]

Richard, since you like Kungfu, here's my take.

 

1. A Kungfu Master did not become a master overnight. There are 2 requirements. Talent and hardwork. This is assuming passion is there in the first place.

 

2. The Master begun by being a novice. He's first filled passion, because he saw what Kungfu can do. Then he wants to learn and reach that Master standard. How?

 

3. He becomes a disciple of another Master. He learns the knowledge imparted to him. But...he needs to do one thing. Train hard. Until the Master is satisifed, the Master will say, you can graduate and go explore the world.

 

4. He doesn't stop there. He goes find other Kungfu to learn. At the same time he keeps training hard. Then, he finds yet another Master and spends some time learning his skills. The cycle goes on and never stops. He keeps learning.

 

5. How much time he takes to reach what level, really depends on how hungry he is. If he's talented, maybe he takes a shorter time. Otherwise, he may take longer. But, hardwork and passion is always the key.

 

He's now a Master, not because people force him to learn. But because he is hungry to learn and achieve.

Hi bro Kermit,

 

Thanks but jialat ... I need to go England first before going to USA for tuning class.

 

My england in all my posts on this thread obviously misled you .. no, I dun wish for KungFu on ICE leh .. just need a tailor that I can go to get my tailored pants of right length and look ok and not worry too much if pocket is too small that I cannot put my hands in to play a bit sometime .. lol !

 

Cheers.

 

Richard

[Kermit]

Hi bro Kermit,

 

Thanks but jialat ... I need to go England first before going to USA for tuning class.

 

My england in all my posts on this thread obviously misled you .. no, I dun wish for KungFu on ICE leh .. just need a tailor that I can go to get my tailored pants of right length and look ok and not worry too much if pocket is too small that I cannot put my hands in to play a bit sometime .. lol !

 

Cheers.

 

Richard

Oh...lol

 

Then you'll need to find a tailor that suits you (pun intended).

 

Of cos, not all tailors are hobbyists. And not all tailors who are good would like you to put your hands in the pocket to play.

 

Finding that tailor is tough. You don't have many choices to begin with. This is not like you can fly yourself to Bangkok, England, or USA to tailor that pants. You can't bring the car with you....ultimately, you have to be your own tailor if all the local tailors cannot satisfy you.

[Cycfari]

The “Mysteries Behind Time Alignment in the Car”

 

Hi guys, Kermit here.  Older folks would remember me.  It has been ages since I contributed to this forum.  This is my little “present” to ICE enthusiasts after being in exile for years. Perhaps this would set us back on the thinking track once again and hopefully gain more personal insights.

 

The topic is on “Time Alignment” (TA).  Other aspects such as Crossover settings, gains matching, hardware employment etc, while related, will not be the focus here.

 

There are perennial problems one may often face in TA.  Why is my soundstage slanted? Why is my soundstage not wide/high/deep enough?  Why are there stray frequencies floating and drafting in the car?  Why do I not get a consistently correct soundstage when I switch between tracks and sources?  Sound familiar?  I will attempt to explore these questions here.

 

What is Time Alignment?

 

TA, as its name suggests, is trying to align all the sounds produced by the speakers to reach the listener’s ears (and brain) at the same time. In this way, just like sitting at the sweet spot in home audio, or headphones, or IEMs, one should get a perfectly-synced stereo image of the recording.  The effect is that one would be able to localise each instrument (and overall stage) at its place and space, with the correct focus/size and energy, and the correct tonalities meant to be presented in the recording.

 

However, the car has its unique inherent challenges.  The listener is not seated at the centre.  Speakers are not symmetrically facing towards the listener. The car is a confined space and has many surfaces that absorb or reflect soundwaves, e.g. windows, seats, dashboard etc.  All these complicate matters (sound reproduction).  I'll try to be as simple as possible in my explanation, so most people may understand.  Also, note that I’m not addressing issues related to the acoustic environment in the car.

 

But, TA aims to mitigate the above problems.  How?  The DSP can now try to apply a time delay to each channel (corresponding to each speaker) so that the aim is the make each speaker’s sound arrive at the same time to the listener (Driver). In other words, we make sure those speakers that are nearer play a bit slower and therefore waiting for the further speaker to reach us. Sounds simple?  If it is, I wouldn’t be writing this.

 

If we can now imagine a bit.  In home audio or headphones, all the speakers are of (1)same distance, (2)facing the same direction, and even (3)pointing directly at the listener (on-axis).  If we can replicate this environment in the car, we could use no TA.  Perhaps one can defeat all TA and try to sit the back row centre in the car to get a feel.  No need TA.

 

Time Alignment and Phase

 

It is now time to introduce the idea of “Phase”. Back to secondary school physics, remember how a sine wave looks like, with ups and downs cycles?  A complete wavelength goes up from the x-axis, comes back down cut the x-axis, then goes down and back up ending back at the x-axis.

 

There is an intimate relationship between time and phase.  Remember TA is about time?  So, if we delay the production of a sine wave by some milliseconds, at any given same point in time on the x-axis, the Phase of the wave is different.  Can you picture this?  Sorry I can’t draw here….

 

So, by applying delay to sound, you are also introducing phase changes to it.  Do not confuse this with polarity, or phase inversion deliberately applied to the speakers.  In the world of TA, phase changes are applied to all the frequencies in the range so that in relation to each other they are almost phase coherent with each other with respect to time. In TA, you call this group phase or delay. On the other hand, in deliberate phase inversion, e.g. by switching the +- poles of the speaker, all the frequencies are inverted in phase with no respect to time.  

 

Bear with me.  With this technical wisdom, now, you know that each speaker in the car is at different distance, and facing different directions. What does this mean?  For phase changes without time consideration, you already have sound arriving at different phases without TA.  i.e. speakers that are facing their sides at you (e.g. right side woofer in door) already arrives at a 45deg angle out of phase.  Some other speakers could be at other angles and your subwoofer is probably 180deg off.  So, you have all coming at you at difference phases.

 

How to TA?

 

Remember that TA also shift phases?  The aim of TA is therefore to make all sounds arrive at the SAME PHASE.  I emphasize this because, Phase is a relative thing in sound.  They don’t have to be correct; they just have to be coherent.  You can well have all sounds at 180deg out of phase and they will still sound correct because you do not get funny things happening such as phase cancellation and peaks.

 

So in practical sense, what should you do?  Study the angles of the speakers.  Have an idea what the original “phases” are.  When you apply TA values, remember that they are applied with the assumption of speakers being on-axis.  This would be a good start.  You can measure the distances of each speaker and input them according to how your DSP works. At this stage, you should get a rough centre image there.  But sound may still be diffused or drift because they are slightly out of phase due to speaker angles.  Move the TA values for Left and Right channels in corresponding magnitudes up and down such that the delay difference between the L/R channels remain roughly the same.  At some point, sound will become more focused, balanced, and more energy both at the centre and at the sides.  Try it, feel it. 

 

Then, do the same for all speaker sets (Low, mid, highs) in L/R pairs.  Please try to ignore the figures on your DSP and do not attempt to understand them.  Use your ears.  The reason why the figures are so far-off between each range sets is because of speaker angles!  When you now combine all the sets of speakers….here’s the fun part.  Remember they are firing at different angles? This is give you a hint of whether you should apply more or less delays to each set, so that the phases are brought to become all coherent to the listener.  Do this keeping one set constant and work on aligning another set to it.  Do this until u get a nice and focused soundstage.

 

I apologise for the fuzziness in this.  Perhaps hands-on would help in understanding this.  In summary, TA is about getting phases together, with the help of time delays to shift phases so that they all work together.  We need to do this because we have so many speakers responsible in producing different frequency ranges and firing all over the place. So far, this is my humble attempt at explaining the scientific portion of a proper TA in the car.  

 

TA is both an Art and a Science.  The Art is your good ears.  Some people don’t even know what they’re doing with TA but their ears bring them there.  Some people, use scopes and measurements and all….yet they still can’t get it.

 

Cheers! Have fun.

 

Oh….copyright reserved.  I welcome constructive discussions and comments.

 

For TA , EQ & crossover settings, there are a few good software that helps. Checkout APLAUDIO software.

 

I am using this APL TDA software & it helps to get you almost there. Its measurement Accuracy & repeatabilities is perfect.

 

http://aplaudio.com/conc2/products/tda/

 

 

Edited October 11, 2018 by Cycfari

[Kermit]

For TA , EQ & crossover settings, there are a few good software that helps. Checkout APLAUDIO software.

 

I am using this APL TDA software & it helps to get you almost there. Its measurement Accuracy & repeatabilities is perfect.

 

http://aplaudio.com/conc2/products/tda/

Thks for sharing. Have you tried this in the car?

 

I remain sceptical because such softwares would not be able to account for phase differences when speakers are not firing on axis, which is the case in the car.

 

That's why u need to sometimes push TA values to something else which may not be logical. And we also have car acoustics to content with....

[richard_crl032]

For TA , EQ & crossover settings, there are a few good software that helps. Checkout APLAUDIO software.

 

I am using this APL TDA software & it helps to get you almost there. Its measurement Accuracy & repeatabilities is perfect.

 

http://aplaudio.com/conc2/products/tda/

Hi Cycfari,

 

Cool share !

 

Please help further to highlight key differences against dirac-live especially the advantages and disadvantages.

 

Cheers.

 

Richard

[richard_crl032]

Thks for sharing. Have you tried this in the car?

 

I remain sceptical because such softwares would not be able to account for phase differences when speakers are not firing on axis, which is the case in the car.

 

That's why u need to sometimes push TA values to something else which may not be logical. And we also have car acoustics to content with....

Hi Kermit,

 

Certainly no expert and hence many stupid question but fundamental of just plain old TA for a whole specreum of frequencies and range of difference firing angles aka dispersion I believe requires more complex tools now available.

 

Infinite or very high resolution eq and phase to be make sense with all these tools.

 

Sure, kungfu still required for fine tuning, abnormalities etc. Especially since our ears are different from even best stereo or even dual mics tuning setup but I hope it gets many bros to 90% and not struggle with first 90% ..then this will get interesting for noobs and beginners like me.

 

Cheers.

 

Richard

[Kermit]

Like I said...if it gets you there faster....do it :)

[Cycfari]

Hi Cycfari,

 

Cool share !

 

Please help further to highlight key differences against dirac-live especially the advantages and disadvantages.

 

Cheers.

 

Richard

Hi Ric,

 

Sorry, i do not have other software experiences. My audio knowledge is just basic but I have been lurking around diyaudiomobile, learning from sifus there :)

 

My understanding is to use only 24 or 48db slope to minimise phase issues. The TA helps too.

 

Here's some pictures of the results, peaks & dips are still unavoidable. The goal is to get a straight line at 0 time position, ie all frequencies to be in phase :

 

 

Edited October 12, 2018 by Cycfari

[Cycfari]

Thks for sharing. Have you tried this in the car?

 

I remain sceptical because such softwares would not be able to account for phase differences when speakers are not firing on axis, which is the case in the car.

 

That's why u need to sometimes push TA values to something else which may not be logical. And we also have car acoustics to content with....

 

Yes, I am using it, after setting time alignment by measurements & test tones. I still need to do lots of Time adjustments with the software help.

[Kermit]

Using such techniques to tune may not yield the desired outcomes. It is also time consuming and perhaps expensive. There's nothing like good old sensory (ear) tuning, which is more the art part. After all, music is Art. Old school thinking? Maybe. I prefer old school...hahaha

[richard_crl032]

Using such techniques to tune may not yield the desired outcomes. It is also time consuming and perhaps expensive. There's nothing like good old sensory (ear) tuning, which is more the art part. After all, music is Art. Old school thinking? Maybe. I prefer old school...hahaha

Hi Kermit,

 

Understand .. and nobody can be more old school than me on eqpt still holding onto 3 units of >decade old alpine F1 H900 processor.

 

Point is the you can only do so much with old school TA to shift phase of entire audio spectrum .. these SWs on the other hand provides tool for you to have closer to infinite adjustment on phase over the audio spectrum for each driver ... similar situation of 0.1ms TA sensitivity of H900 compared to my other Helix dsp pro at 0.01ms or 10x resolution at just 3.5mm steps as we encountered recently right ?

 

New era and new available tools to hopefully simplify tuning for the masses and get 90% there and believe worth exploring especially for guys like you with already kungfu .. will be like you having the green dragon sword ..lol !

 

I need to put up my H900s for sale at ebay :(

 

Cheers.

 

Richard

Edited October 13, 2018 by richard_crl032