There is a technique for adjusting your time alignment by ear in this forum. It has to do with playing white noise and listening for the "warble" effect as you adjust the time. That technique has NOT worked out for me as I suck when it comes to listen for the white noise "warble".
I just want to share another technique for time alignment that comes from another field I have an interest. Let me start by discussing the technique and how I applied it to car audio. The technique in question is a method for getting two (or more) microphones in phase. This technique is well known by musicians and recording engineers. It is used for miking guitar cabinets to get a fuller sound and it is also good for noise cancellation. Two microphones in phase record a bigger and fuller sound, specially good for metal (distorted) guitars. Two microphones out of phase are good for spoken word in a noisy environment where one mic will capture the voice and noise and the other only the noise with its phase inverted. when you add up the two signals you get "noise cancellation" and the voice remains intact.
How do you get the mics in phase?
The human voice and the guitar are mono signals, but for this example I will pick on the guitar (no pun intended). We first get an idea of where do we like the mics to be by listening to the signal while we move them around in front of the guitar cab. Then we proceed to fix the first mic in place. Now the fun part, we are going to monitor the signal from both mics in "mono" with the second mic set to 180 degrees out of phase. We are going to start moving the second mic around the location that we liked until the monitored mono signal gets to the thinnest and weakest point. Now we fix the second mic in place and switch the out of phase setting back to normal and your mics are now perfectly in phase.
How do I apply this technique to car audio?
Easy. The only requirement is that you have to be able to feed a mono signal to your speakers and be able to isolate the sound of two speakers at a time. For this example I am going to assume you have a mono sub, so the first speaker pair to time align would be the sub and your right mid speaker. You are going to have to adjust the crossover a bit to get some overlapping frequencies, say 80Hz to 250Hz on both. Also try to keep the levels to sound even as it will make it easier to listen to both speakers at the same time. We are going to start the time alignment of the mid with respect to the sub. The technique only works if you can set the speaker that we want to time align out of phase, you may have to do this manually if you don't have a dedicated switch for it. You don't need white noise, your favorite song actually works best. In my opinion, a recording that has a bit of everything as far as frequencies go works very well (Bass for subs and mids, female voice for mids, guitar solos and cymbals for highs, you get the idea). Start delaying the signal of the mid a little at a time and listen for the signal to start cancelling. You are going to look for the point where it sounds its worst (weak and thin). Once you find it that will be your setting and you can now bring the mid back in phase. Now your right mid and subs are in phase. The next step will be to mute the sub and unmute the other mid. Don't forget to revert the settings on your crossover, both mids should have similar crossover settings now. Now you are going to do the same thing with the left mid, you are going to time align the left mid with respect to the right mid. The only time alignment you are doing at this point is to the left mid only as the right mid is already aligned with the subs. You are going to set the left mid out of phase and start increasing the time and listen for the signal to start to cancel and to sound weak, thin and unfocused. Find the worst sound and that is where you want to be. Now the fun part, bring the left mid back in phase and you will immediately hear the sound JUMP in front of you. That is because your two mids are PERFECTLY time aligned.
Now you are going to mute your right mid and unmute your left tweeter. What you want to try to do is to time align speaker that are opposite to each other (one left and one right) and try to have their frequencies overlap a bit but safely. If you have your crossover set to not overlap you will not be able to align a mid with respect to a sub, nor you will be able to align a tweeter with respect to a mid. If there is no frequency overlap there will be little or no cancellation to listen for when out of phase. Just repeat the process until you are done.
I hope this helps and please post your comments with the results you get.
Derick Veliz, My system may not blow your ears, but it will sweeten your senses. Toyota Yaris Sedan Pioneer P-99, I6SW, - Legatia L6 midbass, - HL-70 3" midrange, - L1v2 Tweeters
Derick Veliz, My system may not blow your ears, but it will sweeten your senses. Toyota Yaris Sedan Pioneer P-99, I6SW, - Legatia L6 midbass, - HL-70 3" midrange, - L1v2 Tweeters
a few quetion...
when we doing this method..., what should the graphic equalizer set....? is it just "flat" ...?
thanks... ...
I don't think the EQ matters that much, mine was pretty much set the way I like it. The trick is to set the crossover to have some overlapping frequencies between the different size drivers to be able to hear the cancellation. Just do it safely and refer to your speaker's manuals to make sure you are playing them within a safe range.
EDIT: Actually, that is not a bad idea. You could use the EQ to boost the overlapping frequencies so you can hear them better.
I don't think the EQ matters that much, mine was pretty much set the way I like it. The trick is to set the crossover to have some overlapping frequencies between the different size drivers to be able to hear the cancellation. Just do it safely and refer to your speaker's manuals to make sure you are playing them within a safe range.
EDIT: Actually, that is not a bad idea. You could use the EQ to boost the overlapping frequencies so you can hear them better.
thanks a lot.. ....
after tweeter out of phase and overlapping frequencies between let say for example right midbass and left tweeter and then the tweeter turn in to in phase again.., should i change the croosover again.., or it's not necessary anymore...? .... and keep crossover overlapping... .....
after tweeter out of phase and overlapping frequencies between let say for example right midbass and left tweeter and then the tweeter turn in to in phase again.., should i change the croosover again.., or it's not necessary anymore...? .... and keep crossover overlapping... .....
once again... thank you very much... ....
Only change your x-over settings when needed for the TA. That is when you are setting the alignment for opposite speakers that don't have the same frequency range. When you are done bring them back to normal.
For example, if you are working on the sub and midbass, raise the sub frequency a little and lower the midbass a little to have them overlap. Do your TA and once you are done bring both back to normal. Now you are going to move to the two mid basses, here there is no need to change the crossover settings as these two speaker should cover just about the same frequency range. When done you are going to move to one midbass and one tweeter, here you will want to adjust the frequencies to overlap again. Lastly, before you do the two tweeters you need to bring the crossover settings back to normal.
In a nutshell, different speaker type, make the frequencies overlap. Same speaker type, bring crossover settings back to normal (same in both speakers) to overlap. Once you are done with the TA revert all your crossover settings to normal.
Only change your x-over settings when needed for the TA. That is when you are setting the alignment for opposite speakers that don't have the same frequency range. When you are done bring them back to normal.
For example, if you are working on the sub and midbass, raise the sub frequency a little and lower the midbass a little to have them overlap. Do your TA and once you are done bring both back to normal. Now you are going to move to the two mid basses, here there is no need to change the crossover settings as these two speaker should cover just about the same frequency range. When done you are going to move to one midbass and one tweeter, here you will want to adjust the frequencies to overlap again. Lastly, before you do the two tweeters you need to bring the crossover settings back to normal.
In a nutshell, different speaker type, make the frequencies overlap. Same speaker type, bring crossover settings back to normal (same in both speakers) to overlap. Once you are done with the TA revert all your crossover settings to normal.
Wwwwwooowwww.....a very nice explain... Thanks a lot... really thank you so very much.... ..., and in about a few more minute..., I'll try this method... ....
Well..... I just did this technique... and "woowwww".... awesome... ....
First I try to set both midbass which left midbass in phase and right midbass out of phase.., then I play the white noise (coz its already nigt and if I play my favorite song it would be annoying my neighboard ) untill I hear the weak and thinnest sound....
And then left tweeter out of phase and right midbass in phase.....
And the last is left tweeter in phase and right tweeter out of phase....
Oke......now put all of them in phase...., and result is the sound of the sub woofer, midbass and tweeter are more detail and more focus...., more loud but not too loud off course... .....
since I learn to hear the noise...., somehow that make me much easier to find the weak and the thinnest sound..., coz if you find that kind of sound, that make you will hear the difference after all speaker are in phase.... ......
Thanks for every share that already gave for us... ....
Will consider this once I go 3 way active.
Which track can you recommend that has "a bit of everything as far as frequencies go "? Thanks for sharing.
Humph umph tsk tsk hump umph tsk
Quote:
Originally Posted by MarkZ
It's not Tchaikovsky. But it's still music that people like and that people want to listen to. Therefore, the goal is to meet that demand. When you let your audio system dictate the music you listen to, you've lost.
left midbass (in phase) ===> right midbass (out of phase) ...
right midbass (in phase) ===> left tweeter (out of phase) ...
left tweeter (in phase) ===> right tweeter (out of phase) ... and final...
right tweeter (in phase) .....
damn...it seems like main vocal like in the center...., and the backing vocal feels like somewhere in the back of main vocal or sometime just like in front me...
yeesss..... the stage are made..... ...
or may be there is something i missed.... please teach me.... ....
left midbass (in phase) ===> right midbass (out of phase) ...
right midbass (in phase) ===> left tweeter (out of phase) ...
left tweeter (in phase) ===> right tweeter (out of phase) ... and final...
right tweeter (in phase) .....
damn...it seems like main vocal like in the center...., and the backing vocal feels like somewhere in the back of main vocal or sometime just like in front me...
yeesss..... the stage are made..... ...
or may be there is something i missed.... please teach me.... ....
.... but really apreciate and many thanks for the time allignment lesson..., that helping much from my car audio sounding... ...
For some reason I think you can get that CD or a similar one here in the forum. I have seen one going around that has test tones created by a member. This member is making it available for free. Ask around or try searching for it.
A better technique for "ear" time alignment?
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) untill I hear the weak and thinnest sound....
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Linear Mode
