Audio frog tuning guide

So anyone that speed tunes and does a lot of cars…. Please read the AF guide

I’m pretty much to the point where I strictly use the guide step by step and it works…

i can get through a lot of muckery quickly by just adhere to the steps…

there’s hundreds of not thousands of things more I can do sure, at some point it’s just collecting too much data and getting very very little back

your the operator, YOU have the say weather it sounds good or not and passes the test tracks or not…. Not a measurement….

stop trying to make a flat line….. it will sound worse if it’s over corrected… you can still get flat enough and great sound… ignore certain dips etc etc….

the guide steps are articulate and they just do what’s needed to get there very quickly…

all the extra stuff you can do on your car… I can’t keep every customer car for a week to fine tune and listen to the environment and runhundreds of measurements

i Never really realized it , but this guide goes quick! You can get through a car in about 15 min if you pay attention and know your equipment (and you can’t be a tard slob slug that can’t think fast and think customers don’t deserve a good tune because your incompetence )… if your a fast thinker, the AF guide actually gets it pretty dang fast….and yes , every customer can get a iasca tune in a few minutes

trying to say that customers don't Know the difference is either lazy or incompetent… period….everyone can get a iasca type tune…. And all that is , is staging and imaging….and spectral balance…. That’s easy…. No it doesn’t have to have gobs and gobs of detail for a 100$ tune on mediocre gear… but for crying out loud give them a strong center and a proper left and right, and stop experimenting on customers cars throwing all pass filters in places they don’t belong…. Stick to the guide and it works pretty much every time.

dlheman said:

Perhaps so, and I do remember he said not to touch the time alignment once is taped measured. Maybe is to do what I did for tuning, but I always have to adjust the delay between speakers to match them at their acoustic centre (assuming LR will always produce flat response) when EQing individual speakers and combining them as one.

Assuming Andy’s way to just group EQ from the get go; Group EQ will eliminate that process, but changed the crossover target/slope even though it is still very much the same at the crossover target if I recall. But does that make the speakers in phase with one another the same as aligning them at their acoustic centre?

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Aligning the centre with ta is not great

Time alignment let’s you have all drivers at your ears at the same time… assuming you’ve just installed your mids and tweeters with no regard to creating a point source left and right… then you will likely have different widths for various speakers

correct time alignment puts the centre exactly between the left and right stage boundary’s when levels match to the ear… so both sides of the car should sound identical…

if left mid and tweeter acoustic centres to the ear (where we put the sound source… not the speaker location all the time) are different, the same for the right drivers (flick between them with a helix using the number keys and see if the stage boundary moves between drivers) then by default the centre with correct timing will be in different locations… correcting this with timing is going to make the timing not perfect, dynamics, timbre and the energy will be reduced at the listening position

I see lots of cars with mids in the corner of the dash and tweeters a foot away in the sails and wonder how they ever get the acoustic centres to line up correctly… until you work out how to line up left drivers to get a point source and right drivers to get the same the centre will always be diffused somewhat…

eq is a better way to correct the centre, but eq throws phase off also but to a lesser degree than timing, and if you use eq to correct the centre you then lose that matching tonality left to right

listen to sone music in mono on left and then right channels… does the tonality match perfectly? I don’t mean an rta measurement, I mean listen with ears… you can swap instantly with hot keys in a helix, does one side have more midbass, less midrange, more treble etc vs the other… if the answer is no you’ve created a unicorn, well done 👏🏼

Yeah that’s actually true , I thought I wouldn’t ever share that but I do something a bit backwards on my center tunes also

They usually are delayd and eq so they reinforce only a psychoacoustic effect that resembles a non center TA car on all seats

and almost always down about 15db less then left and right maybe even 20

just up enough to get the cues to start to take precedence…

Also centers seems to like to make certain frequencies move left or right because glass diffraction and the shape of the glass…
So I’ll Eq that stuff out as no matter what you do it will always sound like it’s coming off center.

i like the sound of center to pick up right where it needs it , and have a little strength around 2000hz …. Give female vocals a strong sense of depth…..

dlheman said:

Actually I was referring to the speaker's acoustic center as in the alignment between speakers at the same side, and not the center image.

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that’s a great HRTF topic , and that’s is one of the bits I’m trying to learn

the acoustic center and how both sides make a deep or wide stage and how to manipulate them

Andy said HRTF has stuff to do with localization of moving things , or you localizing as you move

so that sorta stumped my thinking and I’m currently stuck unti I get a revelation

But the acoustic center has a lot to do with amplitudes , reflections, PLd between drivers as you say and 1st arrival that has the shortest wavelength

I know air is a LPF, so attinuation in the HF can make it sound farther , to a point… it sorta always stops at the HF driver. And the passanger side together can make it go beyond that… again head related or psychoacoustic stuff I just haven’t quite grasped yet on how it all works in our brains

but, TA is only valid at one spot and your alignment of waves at that spot, not where summing happens really….

and I read in an aes paper that waves don’t combine in the air they pass through eachother, and it’s not at all like water waves.

But let’s say you have two speakers and there 4” apart on the dash one is closer to you…

At the passanger pillar there is no PLD let’s say and other angles from the drivers have completely different path lengths, so the angle in where you sit adding TA can actually cause a bit of beam forming ina pseudo sorta way and it may not…

sometimes I get much better summing and acoustic center properties by using the common distance of both drivers as my TA value , then I align my crossover directly between the speakers to have all pass behavior.

doung that I’ve noticed really makes the speakers IN SOME CARS not all (so don’t tard out on me anyone) have better balance between both front seats and also it can make for more even responses between your left and right head…. And I think (best guess here) that it has something to do with the crossovers off axis response and getting them to alignment on an angle that’s even between left and right axis from where LP is…

some is scientific, and some is just me trying to get good summing because the car is a wreck and sometimes doing exacting TA values at my head makes it worse , and sometimes it doesn’t…

The word experimenting has become a little bit evil lately so let’s not call it that let’s call it trading off many of the compromises we have to make and doing what we have to do to get things to work right especially up in it – when you really have many many different arrivals coming at you….

so the whole scientific thing only goes so far and less you can somehow figure out what exactly reflections are doing and where they’re arriving and how there’s coming but I have never ever in my life seen a paper or read or heard of anybody being able to pull that off or even trying so it really does just come down to a good guess and your ears and listening what sounds good what sounds proper and how are the imaging cues working ….

anyway ….

regardless, we almost never have the same axis on all left and right…(like we can in a home where align coils actually makes a lot of sense)

we can try to align to the farthest coil, but again that angular thing and multiple copies can poke its head…..

so , that’s what I was talking about….. the cues AND the coils…. Sometimes it’s a little wiggle of both and it’s wrong in one spot but right in another…. And we hear the delayed copies of the wrong spots and the right spots

so sometimes an average is necessary to make it “close enough “ and the responce to work its best it can and imaging to work its best with the many many compromises that will be made

but sometimes plain tape measurement works the best , and that seems to be the case I would say most of the time….. sometimes it just sucks for crossover alignment, and the off axis vs on axis vs reflected axises ….

You know it’s sorta like I see some make steps in a tune and then backtrack when it gets to crossovers or phase issues….

perfect example, the total and absolute adherence to separate left and right eq

Then , take a listen and it’s badly decorrelated and it’s a big blur ….

so instead of following the proper steps (like in the AF guide) they start looking at phase traces , and turning on APFs because there a DIP????? when that should’ve been done like 5 steps ago when we did the crossover….and probably didn’t need the APF… And then it’s a mess ……

and then lost in their own confusion, come up with some copout like, customers will never know the difference between it and IASCA quality tune they just want it to sound good… and I’m like , “ you have no clue what you’re doing do you”…..

You know there’s lots of different other things to do to make the system work really good like alignment of processors of course there’s much more things that can be done that aren’t in the guide…. But , the AF guide should keep you away from those problems for the most part….

it’s not an expert level tuning guide (there is no such thing, experts just to do it right the way they do it with their gear, you don’t need a max to get a good tune, although it gets you there pretty quickly and easily, there’s different techniques for different measuring systems).

but for someone starting out or even a professional tuner that is speed tuning, the AF guide gets it pretty dang stinkin good