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View Full Version : New to CA, new tweeters, how do I know...



Staynlean
06-19-2013, 06:12 AM
So I bought new tweeters for my truck, they replaced some existing tweeters that the factory had in place. I got Memphis whatever so so brand they were about $75 and they came with the crossover box thing for each of them.

I'm not sure if these are wired correctly and if they are in alignment with each other. How can I tell? I did not look at the factory wring to make sure each side was hooked up the same because at the time I did not see it as a concern.

After reading on here a bit I see that they could be out of phase and after I listen to them more and more I am convinced they are. Don't get me wrong, they made a huge improvement in the overall SQ of the vehicle.

Tweeters are not amped, just hooked straight to the factory wiring that came off the factory tweeters.

Some body please lead me in the right direction, def new at this...

Off to bed, back tomorrow night to check thread guys.

Silverado SS
06-19-2013, 06:27 AM
Check polarity or wires

Staynlean
06-20-2013, 12:58 AM
How?

Staynlean
06-21-2013, 12:51 AM
Really, nobody can tell me this?

Kingstroker
06-21-2013, 01:39 AM
one of the wires should have a line or spots on it denoting -negative

Staynlean
06-21-2013, 01:41 AM
one of the wires should have a line or spots on it denoting -negative

thank you for the help, I will look back under the dash. But how do I "check polarity"

Kingstroker
06-21-2013, 02:26 AM
polar is - or +. Make sure the lined(-) wire is connected to the neg post on each speaker and anywhere else you've added wire

Staynlean
06-21-2013, 02:56 AM
Thanks, will look for the lined wire tomorrow

Silverado SS
06-21-2013, 03:58 AM
Thanks, will look for the lined wire tomorrow

Been told use a AA battery to check it also if wires arent marked

Staynlean
06-21-2013, 04:17 AM
Been told use a AA battery to check it also if wires arent markedOK, how does this work? i've heard something about this, like watching which way the cone moves or something...

Silverado SS
06-21-2013, 04:34 AM
OK, how does this work? i've heard something about this, like watching which way the cone moves or something...

Forward or back I just actually noticed you want to find out for tweeters which I'm not sure who work so I would hold off for now

Go2Sleep
06-21-2013, 04:47 AM
OK, how does this work? i've heard something about this, like watching which way the cone moves or something...

+ BATTERY -

+ SPEAKER WIRE -

Touch the wires to each side of the battery. When the Speaker pops OUTWARD then the polarity is correct. Mark which wire is touching which side of the battery and move onto the next speaker.
Make sure all speakers move in the same direction.

Silverado SS
06-21-2013, 05:07 AM
+ BATTERY -

+ SPEAKER WIRE -

Touch the wires to each side of the battery. When the Speaker pops OUTWARD then the polarity is correct. Mark which wire is touching which side of the battery and move onto the next speaker.
Make sure all speakers move in the same direction.

This works with tweets? I know mids but I thought it may affect a tweet different

Go2Sleep
06-21-2013, 08:59 PM
This works with tweets? I know mids but I thought it may affect a tweet different

It's the same. Look closely

Staynlean
06-22-2013, 01:07 AM
So I will actually see some movement in my little 1 inch tweeter with a grill on it? I 'm not buying it...

calebkhill
06-22-2013, 09:24 AM
Phase issues aren't a concern with tweeters. So don't worry about polarity.

Why?

Frequencies are so high it doesn't matter.

Only with mids should you worry with this.

Staynlean
06-23-2013, 03:18 AM
Phase issues aren't a concern with tweeters. So don't worry about polarity.

Why?

Frequencies are so high it doesn't matter.

Only with mids should you worry with this.
Sounds like great news to me considering my individual situation, however why is everyone else arguing that i need to check polarity. Sometimes my music in the truck sounds like it is coming from 1 speaker fine and then it sounds like i am hearing an echo at other times. The only speakers I have messed with from the factory are the tweet so they could be the only reasonable answer to this.

It's honestly like they are out of phase, or one is playing a little delayed if that makes any sense. This could all be in my head and I have yet to check the wires to see if they are wired correctly.

Bumping to see if anyone else agrees that out of phase tweeters has no effect, bring me some answers...

hispls
06-23-2013, 04:07 AM
Been told use a AA battery to check it also if wires arent marked


OK, how does this work? i've heard something about this, like watching which way the cone moves or something...

I wouldn't count on popping method with a tweeter. In theory it would work, but it's pretty sketchy IMO.

You have 4 different ways you can hook up the pair. Try each and go with whichever method sounds best. Many people run tweets out-of-phase to the midranges or one out of phase with the other for various reasons (vehicle acoustics, location, etc.). If it sounds good, it is good. Won't hurt them to test each combination

Silverado SS
06-23-2013, 06:02 AM
I wouldn't count on popping method with a tweeter. In theory it would work, but it's pretty sketchy IMO.

You have 4 different ways you can hook up the pair. Try each and go with whichever method sounds best. Many people run tweets out-of-phase to the midranges or one out of phase with the other for various reasons (vehicle acoustics, location, etc.). If it sounds good, it is good. Won't hurt them to test each combination

Thanks for the info I thought it was sketchy too

calebkhill
06-23-2013, 10:36 AM
Sounds like great news to me considering my individual situation, however why is everyone else arguing that i need to check polarity. Sometimes my music in the truck sounds like it is coming from 1 speaker fine and then it sounds like i am hearing an echo at other times. The only speakers I have messed with from the factory are the tweet so they could be the only reasonable answer to this.

It's honestly like they are out of phase, or one is playing a little delayed if that makes any sense. This could all be in my head and I have yet to check the wires to see if they are wired correctly.

Bumping to see if anyone else agrees that out of phase tweeters has no effect, bring me some answers...

are there rear speakers in your truck? Also, the fact that your tweets are most likely playing the same frequencies as your mids is the likely reason your hearing an echo effect.

But, back to your original post. The only thing I see, is that you are worried about polarity based on what you have read. But then you say it made an improvement in your sq.
I wouldn't worry about it.
I'll see if I can find a reference for tweeter polarity.

calebkhill
06-23-2013, 11:02 AM
In the meantime


There is a mountain of stuff to talk about here.


Getting a perfect sound stage for all listeners isn't feasible without a center channel and a lot of processing. getting a nice sound stage for both front passengers is doable without a center channel, but the "center" for each listener will usually be different (closer to them).

For over 10 years I've ran head units or processors that give me T/A presets. I have a preset for myself only. A preset for the passenger only. And a preset for both seats. The first two produce an excellent sound stage with the center being truly center of the sound stage boundaries. The preset for both seats still sounds good and has correct height, but the center appears more in front of the listener which means it's not in the center of the sound stage boundaries. This is fine for daily listening but obviously not going to cut it for world finals.

With a passenger or a demo, I don't mind giving them the preferred sound stage.

Achieving the desired sound stage requires you consider IID, ITD, PLD, and HRTF. You need to know what effect each speaker will have on localization. This is determined by frequency response, aiming, location, and airspace.

Proper time alignment should be done in steps and requires considering the virtual source you are creating.
Step 1 is to align all of the front left drivers so they appear as one virtual source.
Step 2 is to align all of the front right drivers so they also appear as one virtual source.
Step 3 is to then compare left vs right and add more delay to all of the left speakers to center yourself inside the virtual source.
Step 4 is to bring in rear fill (if any). I haven't found a good algorithm for this other than to say good rear fill should meet the following criteria
....a. it should be band limited between 400Hz-4,000Hz
....b. it should be delayed to create the sense of a larger listening space (not just delayed based on path length)
....c. the level should be adjusted so it is not noticeable when it's on, but turning it off is an obvious change.
....d. it should be an L-R or R-L mix to remove center channel information
....e. the goal should be to simulate rear reflections in a larger listening room that has proper acoustical absorption/diffusion.
Step 5 is to bring the subwoofer system into the mix. Again, I don't have an algorithm yet, but in general, you don't want it localized and it should not take away from bass in the soundstage (T/A, crossover, and level play a role)

the concept of a "virtual source" is important to grasp. ideally, we would place/aim all drivers on each side such that their acoustic center axis would converge at some point outside of the car. simply imagine (or draw) a line through the center of the speaker. placement and aiming can work together to allow these lines to converge. we use this concept in pro audio speaker arrays.


You hear people say "swap phase on something" to fix an imaging issue because it is out of acoustic phase with other drivers. . This can be achieved in two ways:
1. reverse polarity on the driver (physically or electronically)
2. change phase by adjusting crossover slope.
The biggest culprit in car audio are crossovers. Passive or electronic - crossovers change acoustic phase. In addition, passive crossovers are influenced by impedance - and impedance is not constant. You need to pay close attention to what your crossover settings are doing to the phase of the speakers. 12dB or 18dB slopes will reverse phase. with modern processing equipment you can choose slopes so that you retain the same acoustic phase for all drivers, which negates the need to change speaker polarity.

phase is relative.
polarity is absolute.

note that running a simple 2-way component set with passive crossovers using 12dB slopes (common) means that both the woofer and tweeter phase are reversed. no problem since the tweeter and woofer are still in phase relative to each other. what if the component system is bi-amp or if you run active? you still have the 12dB tweeter high pass and woofer low pass - now if you put a 12dB slope high pass crossover on the woofer it is now out of phase relative to the tweeter. This may cause harshness and other issues that people attribute to bad speakers/tweeters. reversing polarity on the woofer will return it to be in phase with the tweeter. Now the subwoofer phase relative to the woofer comes into play in a similar manner. if the crossover slope is 12dB then everything is in-phase now. if the sub crossover slope is 24dB/oct then the woofer and sub are out of phase. a simple phase reversal of the sub system will correct this, and the reason most equipment include the phase switch (0/180 deg).

i typically combat this by using 24dB/oct slopes for the tweeter and woofer channels and 18dB/oct slopes for my midrange and midbass channels (since midrange and midbass have bandpass crossovers - phase is reversed twice).

you really need to pay careful attention to phase relative to each driver type and crossover slope. until that is resolved, nothing else can be successful.

the only real mystery is what electronic crossovers are doing to phase. what they should do and what they actually do can vary.


another item i'll touch on is level. level, or volume, is important to consider for each driver. localization of high frequencies is mostly influenced by level (IID). i believe this is the real reason passive crossovers include level adjustment - to allow you to turn down the tweeter closest to you. doing this can help greatly with imaging even without T/A. tweeter aiming also plays a strong role since tweeter response rolls off very quickly as you move off-axis. this is why my tweeters are aimed at the opposite passenger's head rest.

lastly (because it's late), reflections are detrimental. aiming and placement should consider what effect reflections will have on phase interference (when i use the term phase interference, i mean it to include both constructive and destructive). reflections will create additional virtual sources which will greatly confuse the sound stage. sadly, we have a huge reflecting plane next to our ear. that allows information meant for the right ear to be easily reflected into the left ear, a short time later. this plays a role in localization because it has an effect on the HRTF and intended shadowing.

Staynlean
06-23-2013, 11:21 AM
are there rear speakers in your truck? Also, the fact that your tweets are most likely playing the same frequencies as your mids is the likely reason your hearing an echo effect.

But, back to your original post. The only thing I see, is that you are worried about polarity based on what you have read. But then you say it made an improvement in your sq.
I wouldn't worry about it.
I'll see if I can find a reference for tweeter polarity.
They are Memphis audio tweeters, they have there own crossover so I assume they are not playing the same freqs as the mids. Like i said, i'm new to this

Vehicle is a 2010 Pathfinder so yes there are rear door speakers for whoever asked.

Headunit is a new Kenwood DDX370, I know a lot of changes can be made through the hu alone but I don't know anything about that...

pickup1
06-23-2013, 11:24 AM
On your factory tweeter.... is the crossover cap mounted on the tweeter?

Staynlean
06-23-2013, 11:26 AM
On your factory tweeter.... is the crossover cap mounted on the tweeter?
No, it is a separate box

These http://www.memphiscaraudio.com/products/speakers/power-reference-component-speakers/

Staynlean
06-23-2013, 11:31 AM
Oh sorry, on the factory tweeter yes the cap is mounted directly on it...

pickup1
06-23-2013, 11:37 AM
Follow that wire down to the plug..if it had a plug....That's your positive...

Staynlean
06-23-2013, 11:38 AM
Sounds good, thx