Today i was listening to AC/DC Hells Bells when i heard a small pop and the highs seem to lower or quit working all to gether. by the way i have Infinity Kappa 6.5" 90rms and 270peak components with 100watts to each set. I dunno what it is i took it to the shop that installed them and i bought the amp from and it wasnt anything with the amp so i called sounddomain and they said send them the tweeters and thell test them and and if there b roke thell send me new ones and if not i have to pay for shipping. How can i test them unhook the mid from the crossover? I put my ear up to the tweet and it seems like almost all of the sound is coming out of the mid. What do u think it could be? It seems like the mids are still good but the tweets are bad. Got any ideas other than there fried? is that a good way to test them? I dont want to damge them if there not already so whats the best way to go about it?

Thanks,
X

 

Hi-
If you have an multimeter that has an ohm function you can test them yourself. Isolate the speaker from your system and touch/connect the leads from the meter to the wiring posts on the speaker. Assuming that you have 4 ohm tweeters, the reading should be close to that rating. Perhaps 3 to 5 or so, as long as it does'nt go to high or no resistance at all (zero). Let me know.

 

Hey thanks alot ill tetst them when i get time yoday.

thanks,
X

 

A speaker (woofer, mid or tweeter) rated at 4 ohms will NOT measure 4 ohms with a multimeter.

4 ohms refers to the speakers' impedance, which is the speakers' resistance to electrical current flow when subjected to an AC voltage. A multimeter outputs DC voltage and will not be able to measure the speakers impedance, only the voice coil resistance.

If you meter the tweeter, it should read almost a short on your meter. If it is blown, it will most likely read open on any scale of the multimeter.

 

Road RacerX

Using a DMM is a fairly common diagnostic method for checking speakers. See the included link. If a tweeter is bad it's almost always the voice coil.

http://www.eatel.net/~amptech/elecdisc/vomillia.htm

 

B-Man, no flame intended but an ohm-meter or multi-meter in it's impedance measurement setting will give a reading of impedance on a speaker. It will not be dead on accurate but will do the job well enough to determine if the coil is burnt in half or arc welded itself to a dead short. Rule of thumb is when checking the impedance of a speaker allow for 5-15% of inaccuracy. As you will note even in worst case scenario 15% would only amount to .6 ohm difference on a 4 ohm speaker which by all standards is sufficient enough to determine the actual impedance. I have found that my meter actually reads to within 10% of actual impedance. Therefore, when I check speaker impedance on a 4 ohm speaker I typically get about 3.6 ohm reading. Now one thing that needs to be considered here is that if you are trying to measure impedance with a passive crossover in place your meter becomes pretty much useless and will not measure the load.

 

well i took the doors off and started messin around with stuff and i noticed the crossover cover was almost falling off so i looked inside and I found the problem. It shelled it self so hard that the cover came off a little. So im gonna send em back and get new ones. Problem Solved i hope. What could have caused this to happen? Ive never personaly heard of this happening.

Thanks,
X

 

Hey

What do mean by "It shelled it self so hard that the cover came off a little"? Did you mount the crossovers inside the doors? If so that would not be my first choice, too many things go wrong and they are not serviceable without tearing everything apart. I always mounted mine up under the dash or securely under the front passenger seat. Are they destroyed or simply need to be "re-installed"?

Keep kicking

 

The internals exploded! One of the 3 things that kinda look like a battery was about to fall off and other stuff was bent or tweaked on the board. i looked at the other one and it looked ok but im gonna send it back to so i can get 2 new ones. There was this stuff that looked like insilation inside the crossover to, im guessing it came out of the battery like thing. The top is romovable on the crossover so when it blew it pushed the top out a little. What caould have caused this? Just a defect? It wasnt anything but the internals on the crossover.

 

That battery thing you are referring to is the capacitor that is used in a passive crossover. The insulation looking stuff is a the internals of that capacitor. When you first said it made a loud pop I was thinking that it was a possibility the cap popped. Anyway, they explode when one or more of a few conditions occur. a couple are voltage limit is exceeded or rapid polarity change (ie charged cap has polarity reversed). It more than likely was caused by one of two things 1. you exceeded the rated power input of the x-over or 2. you clipped the output signal so badly that you slammed a ton of DC current into it.

To prevent this from happening again I suggest you take a good look at how your gains are set and check ratings on the x-over to make sure it can handle the power you are running through it.

 

Ok thanks. How do i know if it is clipping? I try to never listen to my stuff with any distortion that i can notice. Nothing sounded different when it popped. Like i said i dont like my stuff to ditort at all. I cant find any ratings for the crossover itself but all i can find is 90 rms on the and i have 100 running to each crossover. I have the gain at about 3/4 or 5/8. is tghat to much?b

 

Well the only way to really determine if the signal is being clipped is to look at the sine wave with an O-scope. Since you probably don't have one available the best thing you can do is use your ears. If it doesn't sound like crap your probably not clipping to badly. It is possible that you got a cap with a manufacture defect Although tolerances are usually extremely tight on modern day electronics it is still possible. One way that you could go about protecting the crossover and speaker would be to use inline fuses on the speaker wires. That way instead of popping a x-over or speaker when you get a little on the wild side you blow a cheap little fuse instead. You could use a 20V 5a fuse and it would allow a max 100 watts to flow through but would *pop* if you exceed it's rating. (I used 4 ohm load in my equation) Anyway, it doesn't sound like you have the gains up to high but then again that all depends on what else you have in your system and how it is setup. The way I set gains by ear (really not perfectly accurate but works ok) is set the gains all the way down, crank the stereo up to about 3/4 volume, put in the best recorded music I can find with good dynamics and then slowly bring the gains up to where it's loud and I still have crystal clean sound without the slightest hint of distortion. I am an SQ freak so I typically set my gains way way lower than the average person. I personally like huge amps with really low to no gain added so my curve is always as perfect as it can be. I know it sounds like a waste of amp to many but again that is just me. Best thing I can tell you is use common sense and your ears.