ACTIVE - Imaging - Center Image - Center focus

[eharri3 10+ year member]

I would agree with that, this is why I prefer to use both front driver and passenger seat as the listening position in my Pioneer HU's time alignment rather than just the driver's seat. More natural to feel like It's all happening right in front of me but I'm sitting a little left of center than that the soundstage confines me unnaturally.

 

[FoxPro5 5,000+ posts]

So at a concert you'd prefer to sit off the left of center stage //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Ugh, not this again.

So at a concert you EXPECT the band to get up and move in front of you? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

A stereophonic center image is an illusion created by the crosstalk of the L and R speakers. If you want perfect stereo imaging, you have to nail the sweet spot. That means in a car you either put your head at equal vectors and path lengths from the speakers, or buy a McLaren F1, or you compromise in several different ways, OR you don't set up stereo, but panned mono or some other type of replay.

 

[FoxPro5 5,000+ posts]

I wonder if you there was a way to be able to adjust the levels of every speaker seperately. That would be cool.

R/L EQ'ing if you have the processor power. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

IME, adjusting in the power/level domain before the time domain is the first step. This means level matching the L and R sides as closely as possible (.1v for me) per driver pair.

Next up; phase. Independent phase control on all drivers is a must IMHO. And if you don't have to ability to flip phase without moving your head, then build a phase switching ability into your system.

Finally; time domain (T/A). Only after all the speakers are playing their optimal levels should you make an adjustment in the time domain. Again, if you're setting up a stereo, you have to be able to make small incremental changes without moving your head...otherwise the illusion will be lost.

Anyway, this is how I do it and my center is eye level right on Shakira's forehead...width defined by the pillars....and depth a few inches beyond the windshield. I'm sure you could get to this in many other different ways.

 

[Rudy 10+ year member]

Anyway, this is how I do it and my center is eye level right on Shakira's forehead...width defined by the pillars....and depth a few inches beyond the windshield. I'm sure you could get to this in many other different ways.

I'll be ****ed - you're right, she does have a forehead //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

 

[PaulD 10+ year member]

Seriously, though. I'd like to have Jeezy nice and focused in the center of my windshield, and I don't want him to be all over around the stage like his entourage

Most pop recordings do not have a true center image, so maing a system that produces it might be challenging at best.

 

[mcsoul 10+ year member]

Would it be possible to get a center image without time alignment?

not without a couple of hundred foot spools of wire for your left speakers:laugh:

It is really hard to get around the fact that one set of speakers is right next to you.

There may very well be an analog circuit that can introduce delay and

handle the voltages required for a passive crossover. You may have to scrap

it and rebuild a few times to get it right. However dsp's just make it easier.

If you where running a single cab pickup and a sealed sub(s) right behind the

seats, with no rear fill; TA may not be an issue if you sit in the middle:laugh:.

 

[audiolife 5,000+ posts]

propper kicks and horns will center and image well also heard some cars with no processing center well without horns..just well placed and tuned kicks.

 

[pjhabit 10+ year member]

Would it be possible to get a center image without time alignment?

Phase issues are fairly common & can really mess w/ imaging. Reversing the polarity of a speaker can help makeup for phase differences, so try different combinations.

I use pink noise to find a good "focus", then check w/ a phase check track &/or music w/ a good center image. Do each set of drivers individually ie, tweets then midrange etc.. IMO this should be done before time alignment is ever implimented.

 

[James Bang 5,000+ posts]

not without a couple of hundred foot spools of wire for your left speakers:laugh:It is really hard to get around the fact that one set of speakers is right next to you.

There may very well be an analog circuit that can introduce delay and

handle the voltages required for a passive crossover. You may have to scrap

it and rebuild a few times to get it right. However dsp's just make it easier.

If you where running a single cab pickup and a sealed sub(s) right behind the

seats, with no rear fill; TA may not be an issue if you sit in the middle:laugh:.

Are you trying to say it's impossible to get a center image without time alignment?

Phase issues are fairly common & can really mess w/ imaging. Reversing the polarity of a speaker can help makeup for phase differences, so try different combinations. I use pink noise to find a good "focus", then check w/ a phase check track &/or music w/ a good center image. Do each set of drivers individually ie, tweets then midrange etc.. IMO this should be done before time alignment is ever implimented.

I'm a believe of phase. It's good that everybody's system is capable of changing the phase of every speaker via speakerwire. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Also, i'm not sure about that pink noise stuff... that would probably be the last thing i use to try and get a center focus. I would use it to RTA, though.

 

[mcsoul 10+ year member]

Are you trying to say it's impossible to get a center image without time alignment?


I'm a believe of phase. It's good that everybody's system is capable of changing the phase of every speaker via speakerwire. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Also, i'm not sure about that pink noise stuff... that would probably be the last thing i use to try and get a center focus. I would use it to RTA, though.

In my 4-door sedan and setup it would be close to impossible for me, now that I have ingested the red pill of TA.

 

[James Bang 5,000+ posts]

In my 4-door sedan and setup it would be close to impossible for me, now that I have ingested the red pill of TA.

why is it impossible for you? is it impossible for you or for everyone with no time alignment?

 

[mcsoul 10+ year member]

why is it impossible for you? is it impossible for you or for everyone with no time alignment?

I'm just saying that now that I've used time alignment, I can't do without it.

I've tried, inadvertently when I pulled out my HU and everything defaulted.

I being serious when I say that those last few inches of fine adjustment when

I had the T/A close to correct; I could actually move center stage around

the top of my dash in real time with the turn of a knob.

 

[James Bang 5,000+ posts]

so what would you do to get a center image without time alignment?

 

[mcsoul 10+ year member]

so what would you do to get a center image without time alignment?

I'd experiment with axis, phase and balance. Puke twice and buy a new head unit.

 

[James Bang 5,000+ posts]

I know this is the general discussion section, but did you have to be THAT general? //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif