tweeter too loud

121rickie

Member
2010-12-10 5:05 pm
can anyone help. i have a 3 way crossover and the output from the tweeter is too loud. i have bought some different value resistors to put in the line to the tweeter but dont know how to wire them. do they go in line or across from positive to negative. thanks for looking
 

kbgl

Member
2010-04-03 1:25 pm
can anyone help. i have a 3 way crossover and the output from the tweeter is too loud. i have bought some different value resistors to put in the line to the tweeter but dont know how to wire them. do they go in line or across from positive to negative. thanks for looking

Depends on how much too loud it is. If it's alot, use a 4 ohm in series, with an 8 ohm across the terminals. That assumes the tweeter is an 8 ohm. If it is now not loud enough, swap the 4 with a 2 ohm, and the 8 with a 20 ohm. If you need something inbetween, use a 3 and a 12. The charts can give you more fine tuned values, these are just to find a starting point.
 

xykapec

Member
2020-02-24 9:24 am
I am very beginner in audio field, take it into account.

Just wanted to share my experience with "too loud tweeter".
I have 30 years old Morel speakers. Their tweeters are Morel MDT27.
When I bought them their high frequencies were too loud compared to mid and low frequencies. I opened tweeters and saw that ferrofluid there became very thick and old. I don't do any measurements, but can say by ear that after replacing the ferrofluid (130uL for each tweeter) tweeters started to sound much more inline with mid and low frequencies.
 
When I bought them their high frequencies were too loud compared to mid and low frequencies. I opened tweeters and saw that ferrofluid there became very thick and old. I don't do any measurements, but can say by ear that after replacing the ferrofluid (130uL for each tweeter) tweeters started to sound much more inline with mid and low frequencies.
Where did you get the ferrofluid? Not every kind is suitable.
 

xykapec

Member
2020-02-24 9:24 am
Where did you get the ferrofluid? Not every kind is suitable.

I got it off ebay, some seller from Greece.
I think guy is pretty much serious.
Saturation Magnetisation of this fluid is 200 Gauss (+/-5%). Looks like suitable for tweeters.
Stupid me did not contact Morel guys for an advice :)
Sure it is not the very same as original one, but I like the result.


When I inserted the coil back into the gap I had a feeling that coil tries to center itself inside. So I don't think I had big centering error there.
But membrane itself had an adhesive on the boundary and I guess I damaged this adhesive a bit while peeling it off the surface it was glued to.
You need to be a real pro to do the job right.

So I am worried about these mechanical issues more then about quality (or suitability) of ferrofluid.
 
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If using a single resistor, it should go in series with the tweeter, in line with the positive wire.

If it's an 8 ohm tweeter, then a 3.3 ohm resistor will give 3dB of attenuation, a good starting point for experiment.

I have found just adding a resistor will reduces damping and shifts the crossover frequency. It was more satisfactory
to parallel another low value resistor on the tweeter to improve damping and reduce ringing. In other words, an L-pad.

 

xykapec

Member
2020-02-24 9:24 am
Maybe we should stop buying tweeters without proper disassembling possibilities...

Sure, before buying its better look first if membrane is easily replaceable.
Still modularity can present for some extent, so for example tweeter will have 2-3 easily replaceable parts and not 17 :)

Today's Morel tweeters are modular and their membranes are plug and play type. Even for my 30 years old MDT27 they have replacement membrane R-37, which also fits CAT378. But in my country pair of R-37 costs about 75$, so I first tried to replace ferro fluid.