Roms SQ Diary

[madhouse12]

self edit, (duplicate post)

[roms]

Setting Gains w/o Oscilloscope - DIYMA Car Audio Forum

- - A Mini Tuning Guide for the Active User - - - DIYMA Car Audio Forum

A simple way to tune courtesy of cmusic....... - DIYMA Car Audio Forum

Precision time alignment using only noise tracks and your ears - DIYMA Car Audio Forum

Time Alignment and driver seperation???? - DIYMA Car Audio Forum

How To EQ For Better Sound Staging Without an RTA - DIYMA Car Audio Forum

Flat Response? - Page 3 - DIYMA Car Audio Forum

not for a noob. even i couldnt understand half the stuff they are talking there. some good reads none the less...

i have read almost all of these recently, the best thread i will say is the precision time alignment using noise tracks.
Maddy bhai have u tried setting gains with a oscilloscope.

[roms]

Well, the thing is, each time you EQ a system, or change time alignment, that change is also accompanied by a shift or change in the phase as well. It all depends how a syte is setup, installed and eq-ed. A DSP can certainly give you more control over the phase adjustments. And another important thing to consider is that, what frequencies or what frequency range is effected by the phase? because no matter if you are 0 degrees or 180 degrees out of phase in the higher frequencies (tweeters and upper midrange) you simply just cant hear the phase changes at those frequencies.
Have you ever thought what Time alignment is? Time alignment actually getting your drivers aligned in acoustic phase! so even if your drivers are mechanically aligned ( 0 degree and 360 degree for example) still you have to use Time alignment OR equalize PLD to get the drivers aligned in acoustic phase.

SQ or SPL, phase is phase no matter what. Look up spec sheet of your driver. See a phase graph or curve? is it a straight line? NO, why? because phase ISN'T constant and is changing through out the frequency range Isn't it fun?

The good thing about the phase is that you don't need any equipment to see if it is aligned and can easily be detected by ear in the frequency range that it matters.... In short, play with those settings (Xover point, slope,phase,TA) Ever wonder why even they do include third or first or 4th order slopes?

Shahid bhai you are spot on. I got that but time alignment is to minimize the ITD or to minimize/ correcting the path lengths of sound. No problem we can do that by delaying signal to match the ITD at both ears. But the question is, after the sound is reproduced the reflections, reverberations etc will contribute to the ILD. So can we manage control on ILD's

[roms]

There comes a point in car audio when you cannot move forward and some things become essential or inevitable. To have more control over your system you need to introduce a new friend, and that is a digital signal processor.

Phase, its very important when it comes to audio. I have played a lot with it, first you won't even recognize what phase shifts are doing to your system, then when you start feeling it, it would sound as if its killing the dynamics, for me it was hit and trial in the early stages of tuning, then I started to hear it. Since you're dealing with a 2-way setup you only need to work between your midbass and sub, for now you can try different things like I did once. Bring back your sub the same phase as your midbass, and then change polarity of one of the drivers after the crossover's, first try drivers side, and listen, then try passengers side and listen. I would suggest the passenger's side. An out of phase sub would sound as if its placed in the dash board, try that too. This is all you can do right now. Since I was playing with MS-8, I did not have much controls on the phase, and I had to manually introduce them and re-tune and listen, and my DSP was doing all the magic.

As Shahid bhai stated, reflections, install, and placement are the factors that would always influence your acoustics one thing is for sure, keep experimenting, there would be a time when you would start liking what you hear, but not for a long time..

Interesting point jee, i will try it today and will let you know.

[kzaki]

Rom bhai what i did regarding the phase shift with respect to slope and xover point will explain here: Full range = 0? 6dB slope = 90? 12dB slope = 180? 18dB slope = 270? 24dB slope = 360? or back to 0? There are 2 schools there, some prefer to use 6dB or 12dB and states that the sound is clearly more natural Whereas those that prefer 18dB and 24dB, states that in order to have precise imaging and no wandering, you need to keep interaction between drivers to a minimum - 24dB steep slopes also helps keep phase problems to the minimum. However it all depends upon your car acoustic your placement of Mid, height of tweets along with degree on which they are firing and position. Personally, i like 12db which is best so far as my system is concerned. Although, there's no right or wrong really, you need to try one setting i would suggest 24dB at first and play with T/A until phase is correct @ the Xover point - I use Norah Jones for that and try to get all the sound above the dash (easy way to say it but there's more to that of course). i hope this would help.

[roms]

Rom bhai what i did regarding the phase shift with respect to slope and xover point will explain here: Full range = 0? 6dB slope = 90? 12dB slope = 180? 18dB slope = 270? 24dB slope = 360? or back to 0? There are 2 schools there, some prefer to use 6dB or 12dB and states that the sound is clearly more natural Whereas those that prefer 18dB and 24dB, states that in order to have precise imaging and no wandering, you need to keep interaction between drivers to a minimum - 24dB steep slopes also helps keep phase problems to the minimum. However it all depends upon your car acoustic your placement of Mid, height of tweets along with degree on which they are firing and position. Personally, i like 12db which is best so far as my system is concerned. Although, there's no right or wrong really, you need to try one setting i would suggest 24dB at first and play with T/A until phase is correct @ the Xover point - I use Norah Jones for that and try to get all the sound above the dash (easy way to say it but there's more to that of course). i hope this would help.

Thank you Zaki bhai for your input. This thing can be quite easily eliminated and corrected with proper processing. My initial point was the phase correction and proper driver alignment in a passive network without processing.
This science is deep as hell and the only way we can understand is research, discuss and implement.

[madhouse12]

i have read almost all of these recently, the best thread i will say is the precision time alignment using noise tracks.
Maddy bhai have u tried setting gains with a oscilloscope.

i had a friend who was incharge of an electronics lab with many oscilloscopes. never got time to do it though cos he was in fateh jhang

[roms]

i had a friend who was incharge of an electronics lab with many oscilloscopes. never got time to do it though cos he was in fateh jhang

Tell me the useful equipment which i will try to find in Engineering Uni lab

[madhouse12]

oscilloscope and a signal generator. a multimeter as well and a person who can operate em all

[roms]

I need input on this,

180 degrees on comps at the cross over point.
270 degrees on sub at the cross over point which is mutual at 80 hz.

Polarity reversal on comps will bring the signal back to 0 degree shift.
Signal at 3rd order sub stage is already 270 degrees. Dialing in 90 degree from the variable phase knob on mono will take the phase to 360 degrees. Which in real is equable to Zero degrees.

So we will get a Zero degree shift on both cross over points, meaning perfectly aligned.

Who can embrace it or dismiss it.

Tried this and it has gave me the best MB, sub blending. Without time correction, the DLP moves the image best infront and compensates for the distance between MB's.
Guys on passives should try this method at least once.

[roms]

oscilloscope and a signal generator. a multimeter as well and a person who can operate em all

Sir can you do it or shall i bring these and have a go on it together

[madhouse12]

Sir can you do it or shall i bring these and have a go on it together

nah yara. he isnt here anymore... went back to badeen

[kzaki]

Thank you Zaki bhai for your input. This thing can be quite easily eliminated and corrected with proper processing. My initial point was the phase correction and proper driver alignment in a passive network without processing.
This science is deep as hell and the only way we can understand is research, discuss and implement.

Sir It's difficult but not impossible, however you can get it close but not really perfect and this technique I tried when I was using Alpine head unit.

For that I picked up 3 drums (L C R) track on repeat and for that you can download Autosound2000 cd number 2 you would get 3 drums tracks in it.
Now disconnect the tweeters and play the track and try to listen for the levels (loudness) and adjust (on the Head Unit) don't worry about the center drum at this time. Reconnect the tweeters and disconnect the mids try to listen for the levels and adjust (on the passive Xover) and don't worry about the center drum yet now reconnect the mids and listen to the track try to see if you have a phase/integration problem (one side louder than the other), you can have all kinds of combination (Left Tweet, Left MID and right MID in correct polarity & Right Tweet out of phase or Left Tweet & Right MID out of phase & Left MID & Right Tweet out of phase etc) again don't worry about the center drum yet .Now listen to the track, L drum and R drum should sound pretty much the same and adjust on your HU if you feel that your left side is still louder than your right side now adjust T/A to center your drum to the center of your soundstage. That's how I did it and it worked really well for me.
The above is the basic way to do it, your Focal passive has a Xover frequency jumper connector which can help tailor your speakers, you can also play with those 6dB/12dB slope on your Right side and 12dB/18dB slope on your left side and lets see who it works in your car, apart from that you can also tailored bright sound of your tweets by adjusting xover of your amp for that play around with frequencies from 1-5khz and see which one suits the best.

[scorpion80]

great hi-level talking !!!

[roms]

Sir It's difficult but not impossible, however you can get it close but not really perfect and this technique I tried when I was using Alpine head unit.

For that I picked up 3 drums (L C R) track on repeat and for that you can download Autosound2000 cd number 2 you would get 3 drums tracks in it.
Now disconnect the tweeters and play the track and try to listen for the levels (loudness) and adjust (on the Head Unit) don't worry about the center drum at this time. Reconnect the tweeters and disconnect the mids try to listen for the levels and adjust (on the passive Xover) and don't worry about the center drum yet now reconnect the mids and listen to the track try to see if you have a phase/integration problem (one side louder than the other), you can have all kinds of combination (Left Tweet, Left MID and right MID in correct polarity & Right Tweet out of phase or Left Tweet & Right MID out of phase & Left MID & Right Tweet out of phase etc) again don't worry about the center drum yet .Now listen to the track, L drum and R drum should sound pretty much the same and adjust on your HU if you feel that your left side is still louder than your right side now adjust T/A to center your drum to the center of your soundstage. That's how I did it and it worked really well for me.
The above is the basic way to do it, your Focal passive has a Xover frequency jumper connector which can help tailor your speakers, you can also play with those 6dB/12dB slope on your Right side and 12dB/18dB slope on your left side and lets see who it works in your car, apart from that you can also tailored bright sound of your tweets by adjusting xover of your amp for that play around with frequencies from 1-5khz and see which one suits the best.

The settings which suit better at the moment are:
Right tweet inverted polarity (180 deg)
Left tweet -3db
Mids 180 degree out of phase
Sub 180 degree out of phase
Digital listening position slightly at right +2
Now the sub perfectly blended and dead centre vocals.

One more thing, do u know that a signal is delayed few ms when polarity is inverted. But how much ms?

Sent from my iPhone using Tapatalk

[moonjee]

Bravo, dead center is possible. This is mainly cause of your DVD player. I heard STJ's car, he had this player, without processing he achieved a great sound stage on his passive system, I was totally surprised. Its indeed an amazing HU. Good luck again. Keep SQing.

The settings which suit better at the moment are:
Right tweet inverted polarity (180 deg)
Left tweet -3db
Mids 180 degree out of phase
Sub 180 degree out of phase
Digital listening position slightly at right +2
Now the sub perfectly blended and dead centre vocals.

One more thing, do u know that a signal is delayed few ms when polarity is inverted. But how much ms?

Sent from my iPhone using Tapatalk

[roms]

Why dont you discuss MS8 tips tricks, reviews? Secret

Sent from my iPhone using Tapatalk

[moonjee]

Haha you're right, I should be talking about JBL MS-8 But I am spending more time motivating people to get a processing unit, once they do, we can have group discussions and meet ups.. Point taken.. Let Mughal sahab get out of bed with his processor, once he starts his install and tune up, we'd start discussions :D..

Why dont you discuss MS8 tips tricks, reviews? Secret

Sent from my iPhone using Tapatalk

[kzaki]

The settings which suit better at the moment are:
Right tweet inverted polarity (180 deg)
Left tweet -3db
Mids 180 degree out of phase
Sub 180 degree out of phase
Digital listening position slightly at right +2
Now the sub perfectly blended and dead centre vocals.

One more thing, do u know that a signal is delayed few ms when polarity is inverted. But how much ms?

Sent from my iPhone using Tapatalk

yes it is 1.0ms

[roms]

yes it is 1.0ms

Nopes zaki bhai, time is constant and the 180 degree shift (Inverted polarity) only shifts the amplitude of wave at certain frequency.