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Tweeter Blown OR Crossover? How to check?

I have a pair of Revel M22 monitors that I suspect one has a blown tweeter (no sound at all).  Am planning to purchase a pair of new tweeters, but dawned on me that I should check "output" at the speaker wires where the tweeter is .... maybe not tweeter and crossover instead?

How can I check that?  Can I clip leads onto those wires and hook into a small bookshelf speaker to check?  Or is that a no-no?

Nothing labeled on the tweeter to say positive or negative .... just one white wire (with blue stripe) and one black wire.  Guessing the white is positive and black is negative?

If it is the speaker, I'd guess I would install the new tweeter same way and hook up wires according to which way they are now (same) since there aren't any indicators on the speaker itself....

Please forgive my terminology if incorrect.

scot_m
18 responses Add your response
scot_m OP
25 posts
 
I called and they said these are $128.70 each.  I'll probably buy a couple of them.  Not sure why cheaper?
Thanks again everyone for the help.
imhififan's avatar
imhififan
2,108 posts
 
The tweeter is dead! Years ago I paid $150 for a M20 tweeter. 
scot_m OP
25 posts
 
Did the 1.5v battery thing ..... no sound.
scot_m OP
25 posts
 
Regarding the amplifier clipping, I really don't think that was the cause.  I have an old Llano 200watt (400 into 4) amplifier driving the speakers only down to 80hz where the subs take over.  It's a pretty solid amp and I don't really listen that loudly .... lot of jazz.
Guess I didn't mention (and you had no way of knowing) that I have a Bel Canto PrePro everything is hooked thru and something just happened to it.  It literally went dead ... no sound from any source or any of the 5 channels.  Although I didn't hear anything, and the other speaker is fine, I'm thinking this did it.  Happened pretty much at same time as tweeter.  I'm trying to contact Bel Canto, but having a hard time getting a response.

Sucks!!!  Blown tweeter and PrePro.....  no listening for awhile!
atmasphere's avatar
atmasphere
11,574 posts
 
Sounds like you have it sussed out- the tweeter is blown and the crossover is good.

The tweeter blew because the amplifier used to drive the speaker was clipping (same as in your son's speakers). If you don't plan to go to a more powerful amp, install a fuse in series with the tweeter so that it blows instead of the tweeter. Fuses are a lot less expensive! I'd put the fuse holder right by the tweeter.

imhififan's avatar
imhififan
2,108 posts
 
You don't need to desolder the tweeter for 1.5V battery test .
BTW, caution on the strong magnet in case you want to do any soldering/desoldering.
scot_m OP
25 posts
 
So, since I believe this tells me the crossover is fine, I will unsolder and then put the meter on the speaker itself and see if it reads anything .... as a double-check.  I will let you know what I see.

As I'm certainly not someone on here often, or very educated about working thru audio issues, I am sure grateful for the input and help you all have provided.  You are a wealth of information.  Appreciate It!

I'll get back on the meter test.
yogiboy's avatar
yogiboy
5,460 posts
 
Yes it sure would!
scot_m OP
25 posts
 
Boy do I feel stupid .... the tweeter I tried from the Polk doesn't work even in it's own enclosure.  They are a set my son used and I didn't test them before I used them for testing.  He must have blown them or something.
Regardless, I pulled the 5.25 inch driver out of the Polk (that is working!) and ran leads to the Revel tweeter connectors and YES, there was sound coming from the 5.25 inch speaker ..... so there is "sound" coming from the tweeter wires of the Revel .... so I would think that tells me the crossover is working?
scot_m OP
25 posts
 
I think I have a meter around, certainly not an expert at using it.  Sounds like I need to unsolder one of the wires and test.
scot_m OP
25 posts
 
Since the connections are all soldered, I haven't undone the connections yet.  I did pull a tweeter out of an old, small Polk bookshelf speaker and ran leads from the Revel connectors on it's tweeter (but they're still connected  /soldered to wires going to it's crossover) to the Polk tweeter itself.
Turned on a source to test and No sound from the Polk speaker.....  Is that a "true" test without unsoldering connections yet?  I would have expected the tweeter to make sound.  Since it didn't I'm not sure it's the tweeter?
I have done a tiny bit of soldering (and unsoldering) before, but since I'm not great at it, I wanted to try to test somehow without unsoldering the nicely done solders from the factory.

Thoughts?
grannyring's avatar
grannyring
6,436 posts
 
Did you test yet?
imhififan's avatar
imhififan
2,108 posts
 
Contact a 1.5V battery across the tweeter terminals, you should hear some popping noise if the tweeter still good.
helomech
1,489 posts
 
The polarity DOES matter - because you could connect the tweeter out of phase with the main driver
Not for testing whether it's blown!

grannyring's avatar
grannyring
6,436 posts
 
Easy to test the tweeter. Get a multimeter and set it for driver resistance. Place one meter lead to one side of the tweeter and the other meter lead the to remaining tweeter terminal. Measure the ohms/resistance  across the driver. If 3-8 ohms all is good. If you get no reading, then the tweeter is bad. 

You must disconnect st least one lead from the crossover to the driver for the test to be accurate.  
scot_m OP
25 posts
 

They're soldered instead of clipped on.  Which is why I didn't really want to take the other one off the other speaker to test.

Thus why I'm asking if I can just hook up another small bookshelf speaker (at speaker inputs) to test the tweeter connection.

Will that tell me if there is power thru there (from crossover) or shouldn't I hook up a whole speaker to the tweeter only wires?

williewonka
3,066 posts
 
The polarity DOES matter -  because you could connect the tweeter out of phase with the main driver - then it would really mess with the phase of the other speaker and they would never sound right.

So make sure you record which wire goes to which terminal.

You could attach the tweeter from the other speaker - that will tell you if the x-over is still functioning correctly or not.

Regards...
helomech
1,489 posts
 
For testing, the wire polarity doesn’t matter because speakers receive an AC signal. Remove the crossover (probably attached to the binding post bracket) and inspect for any broken wires or solder joints. Inspect for any burnt or missing PCB traces or leaking capacitors. If everything looks copasetic, order a new tweeter and install it in the same configuration as the original. Highly doubtful it’s the crossover.
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