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Keep blowing tweeters!! Ideas and suggestions, please!

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blowing ideas
8K views 60 replies 8 participants last post by  AEIOU 
#1 ·
I built two towers, each using four 5-1/4" mids and 8 tweeters. Here are the tweeters http://www.parts-express.com/goldwood-gt-302-1-2-mylar-dome-tweeter--270-170

Maybe my thinking is off...?? They are supposed to handle 30 watts each, so 8 in each tower should handle 240 watts. Add that to the mids (70 watts times 4 speakers) handling 280, gives me 520 watts per tower. I am running both towers off of one channel of an EP4000 at around 6 ohms. Shouldnt be anywhere near 1000 watts.

I have one of these inline with the tweeters and it audibly cuts out all but high frequencies, but maybe they are still moving enough to blow up? http://www.parts-express.com/dayton-audio-dmpc-22-22uf-250v-polypropylene-capacitor--027-415

Mids handle the power fine, but I am constantly blowing tweeters.

I really like my simple little design, so I'd like to know if I'm doing something wrong. If they are just junk, I'll change the faceplate and go with something else. Thanks for any input! :)
 

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#42 ·
Very! Honestly, since I have 4 sets of tweeters, I never really notice when a group quit working. Only when they all have. Since each set is wired in series, it only takes 1 blown one to break the circuit.

If my math is correct, the mids are at 4ohms and the teeeters are 16. Does that mean the tweeters are getting 1/4 the power the mids are getting?
 
#43 ·
I don't know... I would think that it would depend on where they music is in the frequency range. Do you know how much power your amp puts out at 16 ohms (I am thinking it will be considerably less)? If i was doing this... I would make a faceboard for one tweeter, and one midrange, and then hookup the crossover, and see if the tweeter still blows... My reasoning is that the amp will be seeing closer to 8 ohm load. By going this route you can figure out what a single tweeter can actually handle. I am wondering if the high impedance load is causing the amp to clip (possibly the clip indicators don't work under such a high ohms??).
 
#45 ·
Does your amp like a 1.6 ohm load? I am wondering if the load is that low if the amp might cause a problem that could blow your tweeters.
 
#46 ·
Unless I read the drawing wrong the mids are wired - two in series then the two series networks are in parallel. Making the total impedance of the mids 4-ohms. In parallel with the 16 ohm final for the tweeters that makes for 3.2. divide that by 2 and, Yup, 1.6 ohms.

That iNuke 6000 isn't rated for less than 4. You won't clip (won't develop enough voltage to do that) but it'll no doubt act wonky. Try wiring the speaker boxes in series for a total of 3.2 ohms but that'll still be in the twitchy range. If you rewire the mids all in series for a total of 16 ohms the total for the box would be 8 ohms and the two boxes would be 4 if wired in parallel. That'd be in spec for the amp.
 
#47 ·
By "wonky" does this mean the amp could be sending frequencies that the tweeter can't handle or can't handle at rated tweeter power?
 
#48 ·
For me "wonky" means you can't be sure what it'll do so it's best you don't try. Down that low, outside the design spec envelope that far, I wouldn't bet against it flaking out and sending DC down range. That's extreme, I know, but it's like trying to get cutesy with a grizzly bear - just not advisable and will most likely end badly.

My $.02
 
#49 ·
When you mentioned "wonky"... That is exactly what I was thinking could happen (DC current to the tweeters).
 
#51 ·
But you are at 1.6 ohms, correct? Another thing is the Ohms are usually an average as I recall. It might be 8 ohms at a certain frequency and 4 ohms at another. Where I would think it might be a problem is if you are already at 1.6 ohms, and it might go to a dead short at a certain frequency. :T

If I am wrong please correct me.
 
#52 ·
My mistake, sorry.

Still I think you'd be better off doing the rewire on the mids. 1.6 ohms is nominal. Full range it could hit lower. Bumping the final up into a more stable range could help till you iron things out. You'd still have 950w RMS to work with 1400 peak, plenty for your boxes as long as you don't try to blow the windows out.
 
#53 ·
Ok. Im going to try to figure out another wiring possibility. Id rather not have the highs be the same load as mids, as theyd be way too loud, right?

And I did look of the ohm wiring/power ratio. Simple as it seems. Twice the ohms, half the power. Quadruple the ohms, quarter if rhe power
 
#56 ·
I think it would depend on the efficiency of the Tweeters compared to the Mids... If they were to high you could always EQ them lower with a MiniDSP.:T
 
#54 ·
That being said, IF I'm getting 900 watts out of this thing @ 1.6ohms, that's only about 11 watts going to each tweeter. The other 720 watts is going to the 8 mids(which are handling more than rated power quite nicely!).

I'm going to get the total ohm load in check, then do a second order HPF and see what happens.

A quick way to get the load in check is wire my towers in series, giving a 6.4 ohm load.
 
#55 ·
That being said, IF I'm getting 900 watts out of this thing @ 1.6ohms, that's only about 11 watts going to each tweeter. The other 720 watts is going to the 8 mids(which are handling more than rated power quite nicely!).
The issue would be that the tweeters may not be able to handle power outside of their range... Which might be happening if your amp is being asked to go down to 1.6 Ohms or less. I think you are on the right track to check the total system Ohms and to possibly re wire to raise the Ohms overall.:T
 
#58 ·
Please let us know what happens when you re wire them to get the Ohms up over 2 ohms. :T
 
#59 ·
Will do.

In the meantime, today(almost 2 years later!), I just realized I never checked the dip switches on the back of the EP4000 and I have had the 50hz HPF enabled this whole time! Now I have to rewatch all my movies for the new found low bass haha!! I had always wondered why it seemed to roll off on the low end. :(

It's like having a BRAND NEW setup! haha
 
#60 ·
I dont know if you are still trying this current design but if you are put this filter on your set of tweeters. This will get them down 20 db at FS, and it takes an ultra steep LR6 rolloff to do that which is what this filter is doing. I cant tell you if the polarity needs to be flipped, and honestly with your speaker I'm not sure it matters. Try it connected to the positive and then try it on the negative and see which one you like
 

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