Tweeter is ~10db lower than normal at 3K Hz. Anyway to fix?

Yes, the lower frequencies need a bit more excursion (4x as much per octave), so reluctance of the driver to move from ferrofluid needing restoration can affect lower frequencies more, although it would be unusual, as these speakers seem like they can't be more than twelve years old (and the tweeters are dated as such).

Also, any other problems in the voice coil gap, such as debris or being out of center and touching, or problems with grit getting in the suspension or the suspension being out of the gap can cause such effects. Are you able to record a 1kHz tone (disconnect the woofer for better results) and see the waveform of each tweeter in audio editing software? Measure the impedance of one tweeter vs the other, to detect burned or shorted coil?

 

Good suggestions. My current REW setup is not functioning correctly. I will get a new mic preamp to see if the measurements are more correct. Thanks!

 

Double check your measurements. Consider disassembling the suspect tweeter for a visual inspection, checking if the coil shifted in the gap for instance.

Also check with the manufacturer on whether the unit can be rebuilt for fewer $$$. Maybe do that before disassembly.

 

I have never open up a tweeter before. I will try swap tweeter from my center speaker first, then inspect the bad tweeter when I have more time.

Thanks!

 

You might also have some luck finding a used speaker with the same tweeter on eBay, and harvest the tweeter.

 

Yup. This is an option I am checking too. So far no luck yet.

By the way, I was planning to use the center speaker's tweeter as a replacement, but I just found out it is not the same. Too small. The S2 tweeter is bigger. : (

 

Kind of disappointed with Paradigm tech support. I was told center speaker tweeter can be used to replace the bad tweeter. That is not correct.

I spent the night open up the center speaker from behind, taken out the metal body from the front metal plate, and then finally taken out the tweeter from behind the front metal plate. After I disassembled the S2's tweeter assembly next, I finally find out those are not the same.

The center speaker's tweeter is smaller! And there are no holes to screw onto the front plate assembly of S2 tweeter assembly!

The front of center speaker only show a small tweeter part. Thus no way to know how big until I fully taken apart the speaker!



This is what I found after all the work!

 

Hi All,

Thank you for commenting!

I think I may have solved the 2k to 4K dB dip problem. I did two things this morning:

1. I manually moved the voice coil thing up and down to "exercise" the foam material connected to the dome.

2. I removed the protective metal mesh that was placed on top of the dome. I think the base of the metal mesh is impeding the dome from freely moving around.

The chart below is what I get afterward. Both time with only tweeter terminal connected, measuring from 1K Hz up, with mic 3 ft away. The green trace is with protective mesh removed.

 

If it is truly beryllium then the mesh is on there to protect you from the beryllium as it is hazardous to humans.

And if you can buy one for $165 that is cheap. Any beryllium tweets I've seen are much higher than that including what is available at Madisound.

 

Cheapest dome at Madisound is $291, highest is $546.

 

So hopefully with what you have learned you can shim the screen upward to allow tweeter diaphragm movement. It needs to be on there and you need to be careful in handling!

 

Yeah, I already ask the New Zealand store and they don't export. : (

 

They replied already. They said it would be hard to find anything that would fit the custom front plate to which the tweeter is attached. : (

 

I think the issue of the mesh is the base of it. Shim the screen upwards would not help in this case.

Thank you for your concern. I do know the material is hazadous when being manufactured. But I am not sure how bad a finished product is to human. How would a mesh help protect us? My understanding is dusk and airborne particles that are bad. A mesh would be unlikely to help prevent that.

Looking at the list of beryllium tweeter Madisound sent me at Beryllium Dome Tweeters: Madisound Speaker Components , there are 3 of them without protective mesh? Again, would you please explain to me how a porous mesh could protect me from beryllium health hazards? Would the grill serve the same protective purpose in this case?

Thanks!

 

(none)

Beryllium is very toxic, play at your own risk. I wouldn't touch it with bare hands myself. If you notice all the Be tweeters have something over the dome, you don't see that on most domes and there is a reason that they do this, it's not just for kicks.

Shimming the screen upward away from baffle will increase the space between the dome and the screen in all locations around the dome. It will solve your problem, and it doesn't need to move much to do it.

Based on your test, you don't need a new tweeter, just an adjustment.

 

Or you can just leave the mesh off.

 

It’s the inhalation if berillium dust which is the primary toxicity route. Maybe don’t lick the tweeter.

 

Thanks. I may still need a new diaphragm + coil. In a few hours after initially getting it to work much better, the slope from 4K and below got a bit worse. Still much better than before, but can be better around 3k.

 

That's disappointing.

 

Too bad but...

As a Canadian who has come up against numerous American sellers over the years who "don't export" I came up with a few work-arounds. One of which was to have them ship to a friend in the US. Then I'd either pick it up from the friend the next time I visited, or paid them to slap a new address label / postage on it and send it on its merry way to me.

Now I wonder where one would be able to find a "friend" in New Zealand, who shared a common interest in things audio, and who might be willing to help out? In this internet age how would one even go about doing that? I mean is there a place where such people might meet-up online? A place where you could even ask the question?

Just wondering...



Jeff

 

Haha, yeah, I wonder if there is anyone I can trust....
Actually, now it is not too bad. About 5db off at 3K Hz instead of 10 dB down. I listen to 3khz test tone a couple days ago via both speakers at the same time and I was surprised that I can't detect the imbalance....

 

How can you not trust someone that has a walleroo or baramundi for a pet?

 

I feel your pain.

I had gotten a pair of Focal 1008be2’s demo, and while setting them up pierced the tweeter.
Yup it’s beryllium. Called a few dealers, $800. However the distributor in North America was kind to me and sold me one at a reduced price. Maybe see if the distributor has one that they’ll sell you for less.

Regarding Beryllium, it’s only toxic in dust form, and during manufacturing. Otherwise there would be a lot of dead audiophiles out there.

 

Alrighty then, I'll stop with the scare tactics.....