Time Alignment and Me.

[Sir-Lancelot 216]

LOL @ this thread.

To throw it more off topic, I like Boobies.

[cobra93 47]

LOL @ this thread.

To throw it more off topic, I like Boobies.

[johnecon2001 82]

Rather than measuring right to your ear, measure to a common spot in the middle of the vehicle.

How would that help?

If the speakers are located at the same locations in the vehicle (i.e. doors), and you measured to a point in the center of the vehicle.....the speakers would measure equidistant

You would have to measure the differences at the listening position. Then again, I've never set time alignment with measurements.....I've always set it by ear.

Because your head moves.

You can't account for how you sit or if you're leaning to the left or the right. You also can't account for passengers being in the way of the waves.

Better to just pick a common open spot in the space and aim for that. As close to your natural spot as possible of course.

You can do timing by ear, or measuring, the only real way to get it right though is with mic and computer that can measure down to the .001 ms.

[Randal Johnson 544]

With correct, accurate, planned, tested speaker positioning, all that time alignment stuff should not be needed ... Its almost like bandaiding a problem in your system ...

Aim and adjust all you want ... Your center channel should be in the center of the dash and out toward your hood, regardless where the listener is in the vehicle ...

[///M5 2,833]

Rather than measuring right to your ear, measure to a common spot in the middle of the vehicle.

How would that help?

If the speakers are located at the same locations in the vehicle (i.e. doors), and you measured to a point in the center of the vehicle.....the speakers would measure equidistant

You would have to measure the differences at the listening position. Then again, I've never set time alignment with measurements.....I've always set it by ear.

Because your head moves.

You can't account for how you sit or if you're leaning to the left or the right. You also can't account for passengers being in the way of the waves.

Better to just pick a common open spot in the space and aim for that. As close to your natural spot as possible of course.

You can do timing by ear, or measuring, the only real way to get it right though is with mic and computer that can measure down to the .001 ms.

If your head moves, why do you care about .001ms?? I'd never T/A a car to do it, but always for a purpose. Being I only build a system for me then I'd exclusively use it to make things sound better in MY seating position. Other people may have different prerogatives on what they want their vehicle to do, but it makes absolutely no sense to T/A to a center point in a vehicle. Hell, it sure looks like in his case by default that is pretty much already done anyways as his drivers ARE equidistant from the center. If he were to do what you suggest, then he should just pick a center point of the mids and tweets and only adjust the difference between them to the center for one set not both the mid and tweet, but there will be no sonic gain from doing that.

Your center channel should be where it sounds best to you and out toward your hood

Fixed and another reason why "to the center of the vehicle" makes no sense.

[diablo_331 23]

Anyone care to go more into using a PC and a mic? I'm curious as to what type of software and hardware this would take? Also can any go into more why Drew could not TA three tweeters per door? Is it because they are all in a slightly different position? Is it because the HU can't TA that many drivers? Just curious to hear someones take on this.

[kirill007 52]

It's because the drivers are all in a different position and have a different distance to where it should meet.

And cancellation can occur or other acoustical problems.

Atleast that's what i think i don't know that much about time alligment.

(So please correct me, if i'm wrong)

[Adrian_D 520]

Rather than measuring right to your ear, measure to a common spot in the middle of the vehicle.

How would that help?

If the speakers are located at the same locations in the vehicle (i.e. doors), and you measured to a point in the center of the vehicle.....the speakers would measure equidistant

You would have to measure the differences at the listening position. Then again, I've never set time alignment with measurements.....I've always set it by ear.

Because your head moves.

You can't account for how you sit or if you're leaning to the left or the right. You also can't account for passengers being in the way of the waves.

Better to just pick a common open spot in the space and aim for that. As close to your natural spot as possible of course.

You can do timing by ear, or measuring, the only real way to get it right though is with mic and computer that can measure down to the .001 ms.

So, if you measure from the center of your car what will you find out other than the fact that you don't need T/A ?

And what relevance doest the fact that you move your head to T/A or even how you set up T/A ? I don't stare left and right and behind me when I do critical listening...

This measurement of the center of the car is similar to people pointing all speakers to the center of the car and up, to get a "centered and high sound stage". I find it pretty amusing actually...

Anyone care to go more into using a PC and a mic? I'm curious as to what type of software and hardware this would take? Also can any go into more why Drew could not TA three tweeters per door? Is it because they are all in a slightly different position? Is it because the HU can't TA that many drivers? Just curious to hear someones take on this.

I believe the only viable solution of doing it by a computer + mic would be to have the software output certain impulses and count time from when the output was sent to receiving it back.

Kirill pretty much nailed the second question.

You would need time alignment for each of the drivers if you want to "do it right".

Drew, have you tried only one pair of tweeters, mounted on the dash / a-pillars ? You are probably loosing a lot of output because of their position.

[BanginGMC 23]

Drew, have you tried only one pair of tweeters, mounted on the dash / a-pillars ? You are probably loosing a lot of output because of their position.

I think he really only needs one component set and a really good 2 channel amp for his front stage. then again, just my suggestion bro ...

One set of tweeters, or one component set isn't going to work, even if they're positioned perfect. 150+dB on music will drowned it out like there not even there.

[Randal Johnson 544]

One set of tweeters, or one component set isn't going to work, even if they're positioned perfect. 150+dB on music will drowned it out like there not even there.

Are you sure about this Bro ???

I think he really only needs one component set and a really good 2 channel amp for his front stage. then again, just my suggestion bro ...

After posting this ... I gave it alot of thought, talked to a few people, then gave him this reccomendation ...

here again, just my suggestion ...

2 tweeters in each A-pillar (off axis to the listener) ... and 2 6.5s in each door on passive RD crossovers on that 100.4 ...

This should put your stage somewhere up in the dash and should sound loud and clear as hell ... possibly no need for any processing/time delay ...

And if needed extra midbass, a pair of 6.5s in the kick pannels (on a separate amp) ...

[johnecon2001 82]

I sincerely doubt each one of those drivers outputs sound at the EXACT same instance as the others. Hence the reason you align the drivers to themselves. Then add time alignment L/R.

[Randal Johnson 544]

I sincerely doubt each one of those drivers outputs sound at the EXACT same instance as the others. Hence the reason you align the drivers to themselves. Then add time alignment L/R.

are you talking about the setup Drew has now or a new set up with a-pillars, door pannels ??? ar any type of setup ???

[Sir-Lancelot 216]

One set of tweeters, or one component set isn't going to work, even if they're positioned perfect. 150+dB on music will drowned it out like there not even there.

Wrong.

You just have to install more efficient mids and tweeters. I am over 150 and my vocals and highs are anything but drowned out even with the gains set as low as they will go and another -7 on the tweeter gain at the HU.

Now midbass ........thats another story.

[Impious 1,476]

I won't touch on the center of the vehicle thing for delta time alignment as Adrian already hit the nail on the head.

I sincerely doubt each one of those drivers outputs sound at the EXACT same instance as the others.

I'm pretty sure they all do output sound at the exact same instant as the others, unless he is using miles of speaker wire or has already applied time delay.

Now when that sound arrives at the listening position, that's more important. You still wouldn't want to measure to a center point in the vehicle to determine parallel time alignment, as the distance between speakers on the same channel is going to depend on the speaker placement and measurement axis. And for delta time alignment, as already covered, you absolutely must measure at the listening position.

I do not believe he has control of time alignment for each individual driver. So parallel time alignment is a moot point anyways.

[///M5 2,833]

And classically the OP still hasn't told us why he wants to use it even.

[Impious 1,476]

Anyone care to go more into using a PC and a mic? I'm curious as to what type of software and hardware this would take?

For measuring T/A ?

You'd need a microphone, and microphone preamp, a sound card (with fixed time latency), and an MLS software program. MLS software generates the test signal then takes the measurement of that signal via the microphone, which allows it to provide impulse response measurements. Fixed latency is important in the sound card because if there is a variance in the time it takes for the soundcard to generate the sound then begin measuring, the impulse response will be different every time you measure. To solve some issues, some people (like myself) go with a single external unit that is both a good quality soundcard and a mic preamp.

I just got my PC based measurement system working tonight......like, an hour ago (issues with my M-audio driver). I have a Dayton EMM-6 microphone, M-Audio MobilePre external soundcard/mic preamp, and am planning to use HOLMImpulse for my measurement software. Hopefully this weekend I'll get to play with it some.

Also can any go into more why Drew could not TA three tweeters per door? Is it because they are all in a slightly different position? Is it because the HU can't TA that many drivers? Just curious to hear someones take on this.

For one, in order to T/A individual drivers, each driver would need to be on it's own channel both at the processor/HU and at the amplifier, and each channel has to have a time delay adjustment. He more than likely doesn't have this capability as he would need 12 individual channels (both preamp and amplifier) just for his front stage.

Really though, T/A for tweeters is a finicky thing. For one, we don't localize sound in that frequency range by time arrival, we do it by inter-aural intensity differences. So delta (left-right) time alignment itself won't serve much benefit on tweeters. One benefit that T/A can have for tweeters is that it will also basically serve as a phase adjustment (delaying one signal will affect the relative phase with the drivers as well), which can help fix some frequency response issues around the crossover point if the tweeters and mids are at different distances from the listener. To do this we would use parallel time alignment to "time align" (although in this case it's more about phase than actual "time") two different drivers on the same channel (left or right).

[///M5 2,833]

Anyone care to go more into using a PC and a mic? I'm curious as to what type of software and hardware this would take?

For measuring T/A ?

You'd need a microphone, and microphone preamp, a sound card (with fixed time latency), and an MLS software program. MLS software generates the test signal then takes the measurement of that signal via the microphone, which allows it to provide impulse response measurements. Fixed latency is important in the sound card because if there is a variance in the time it takes for the soundcard to generate the sound then begin measuring, the impulse response will be different every time you measure. To solve some issues, some people (like myself) go with a single external unit that is both a good quality soundcard and a mic preamp.

Need phase matched full duplex input/output as well. Any time lag or even minor phase lag will really eff up MLSSA signals. You can also use an analyzer that supports a time selective response to measure the true impulse response, but that is a bit trickier than using a "melissa" analyzer and requires even more smarts with all the reflective paths that occur in vehicle. It is the technique that I'd use, but not everyone has access to a >$30k acoustic analyzer and measurement microphones.

[///M5 2,833]

When doing those measurements for customers, we use a HATS complete with absorbing clothing to simulate the real listener as much as possible. True pinna's with inner ear simulation to make sure what is recorded is as close to real as possible.

http://www.bksv.com/doc/Bp0521.pdf

[bassahaulic 155]

I just want a decent staging. Nothing to be ear cumming amazing, if that is what I was after I would already be in touch with a local guy, and no have 150+ db behind me.

For those saying a single set is enough, I simply cannot believe this. I have NEVER heard a vehicle that is into the 50's on music that can still hear the vocals worth a damn with a single set.

And with using the RD crossovers and the single amp, I did not spend the money to change radios to just use the crossovers. Which I no longer have as they caught fire when I did try to use them.

[Adrian_D 520]

For those saying a single set is enough, I simply cannot believe this. I have NEVER heard a vehicle that is into the 50's on music that can still hear the vocals worth a damn with a single set.

That's not a good reason not to try them...heck, you need a bit of time and some extra wire.

[Randal Johnson 544]

2 tweeters set up on each a-pillar crossed over active on the first 2 channels of your 4 channel amp will set up your stage. I'd be willing to bet on it ... And be loud and clear too ...

2 6.5s standing up as high as possible on each door pannel crossed over active on the other 2 channels of your 4 channel amp should enhance your stage and give you powerfull, loud, and clear midbass ... If needed extra midbass, then a pair of 6.5s or 8s in the kick pannels running fullrange on an extra amp ...

I doudt you would need any processing/time alignment at this point if installed properly. Maybe some EQing set up to your liking ... But this is where the best place in the install to give your processing/time alignment a shot ...

Please note ... All drivers should be (if it was mine) off axis to the listener ... Strong center, deep stage on the dash/hood, and could be very suprising width for that vehicle ...

Again, just my suggestions ... Thanks, Randal ...

[kirill007 52]

Please note ... All drivers should be (if it was mine) off axis to the listener ... Strong center, deep stage on the dash/hood, and could be very suprising width for that vehicle ...

Again, just my suggestions ... Thanks, Randal ...

You do know in some circumstances off axis isn't the best choice.

(depends on the driver, and the kind of sound the listener wants to have.)

[Randal Johnson 544]

Sure bro ... Anything is possible ...

But I'm wondering, aim a driver at a listener, how is the system gonna stage ?? ... Oh yea, I forgot, bandaid it with processing and time alignment ... I guess That's why they came up with single seat judging ... I'd rather a system to sound great from anywhere in the vehicle, playing any kind of music ...

[Adrian_D 520]

But I'm wondering, aim a driver at a listener, how is the system gonna stage ?? ... Oh yea, I forgot, bandaid it with processing and time alignment ... I guess That's why they came up with single seat judging ... I'd rather a system to sound great from anywhere in the vehicle, playing any kind of music ...

It's going to sound selfish ! But no reason to stage bad...for a single seat..

[Randal Johnson 544]

Sounds good to me guys ... Like I said "just my suggestions" ... Its all good ... I'm just trying to help ...

Hey Drew, best of luck with your setup. Hope that wall is done by Scrapin the Coast 2011 !!! See you then bro if not sooner !!!