$3 1" dome tweeter.

[johnnyrichards]

MCM 53-1080 often goes on sale for $3 or $4. So what does that get you? Cheap build quality, gotta be careful with the plastic faceplate. It uses a standard 104mm cutout with side terminals, though. It has a weird suckout at 7k that also has a 3rd order distortion spike - it also has a wiggle at 7k on the impedance plot, otherwise it looks good. I have been playing with it with four different 6.5" woofers the last two nights and think it is well worth the price. I have been crossing it over between 2.7 and 3.5k, but it should play a little lower than that if excursion is not an issue. Of course, this was not 100% flush mounted, about 1/8" of the frame sticks out.

Here is a FR grab on a 9.25' baffle, 3.5" from the top and centered:


The broad dip from 1.8 to 4k is probably more the baffle geometry than the tweeter itself:



Here is distortion at ~85 db:


Low sensitivity, I am guessing around 87db or so.

So there you have it, this is the only sample I have so I have no way of knowing if this is a typical unit or not. It was cart filler at MCM one day.

[greywarden]

Re: $3 1" dome tweeter.

Is that suckout/THD spike due to the plastic faceplate, maybe?

[johnnyrichards]

Re: $3 1" dome tweeter.

Is that suckout/THD spike due to the plastic faceplate, maybe?

No idear, maybe I will check

[Pete Schumacher]

Re: $3 1" dome tweeter.

No idear, maybe I will check

Internal resonance due to inadequate rear chamber damping more likely.

[moron#99]

Re: $3 1" dome tweeter.

Probably a dumb question, but I have to ask. Were you actually running 105-110dB during testing?
You guessed 87dB sensitivity. If so, wouldn't that mean it shouldn't be driven over ~100dB? Do you get the same plot if you back off to a 96dB average?

[johnnyrichards]

Re: $3 1" dome tweeter.

Probably a dumb question, but I have to ask. Were you actually running 105-110dB during testing?
You guessed 87dB sensitivity. If so, wouldn't that mean it shouldn't be driven over ~100dB? Do you get the same plot if you back off to a 96dB average?

No, I just don't run ARTA calibrated. I run REW calibrated, but the SPL calibration is the only thing about REW I like better than ARTA. These tests were probably around 82db or so.

[johnnyrichards]

Re: $3 1" dome tweeter.

Internal resonance due to inadequate rear chamber damping more likely.

That is my assessment as well. I may take it apart and see whats inside. Might just be the QC guys missed a clump of foam, or something.

[Sidi]

Re: $3 1" dome tweeter.

What QC Guy? You think there was one for a $3 item? heuheuheuhe

[dlr]

Re: $3 1" dome tweeter.

Internal resonance due to inadequate rear chamber damping more likely.

Almost certainly I think. That would be from a reflective surface 0.5" from the backside of the dome. It's very deep and very symmetrical, another indication. Looks like a pole piece vent that's capped and with no damping at all. Easily improved with a cotton plug, best kind being what comes in (name brand) medicine bottles of aspirin, etc. The density and consistency of that is excellent. The next time you buy an aspirin bottle with cotton in it, keep the cotton.

dlr

[Wolf]

Re: $3 1" dome tweeter.

Easily improved with a cotton plug, best kind being what comes in (name brand) medicine bottles of aspirin, etc. The density and consistency of that is excellent. The next time you buy an aspirin bottle with cotton in it, keep the cotton.

dlr

Does that aspirated-cotton only help the damping for 4 hours and then you have to put in more? ;)
...Or does it also kill the pain your ears have when they listen to these?:rolleyes:

Wait- I got it.... It prevents blockages and allows the music to flow freely!

Later,
Wolf

[greywarden]

Re: $3 1" dome tweeter.

Does that aspirated-cotton only help the damping for 4 hours and then you have to put in more? ;)
...Or does it also kill the pain your ears have when they listen to these?:rolleyes:

Wait- I got it.... It prevents blockages and allows the music to flow freely!

Later,
Wolf

He'll be here all week, folks. :D

[biscuitbarrell]

Re: $3 1" dome tweeter.

I've been playing around with a couple of these, and the sound really isn't bad, especially for the price. The lower than advertised sensitivity meant fewer XO components, I can forgive a few squiggles if my EQ can counter likewise;) I'm toying with this on two fronts- one paired with the mcm 6.5incher Johnny has mentioned before, in a smaller than optimal box, to be paired with a sub ( total expenditure for woofer AND tweeter = $7.68, at sale prices a few months back. Fun for cheap, and already sound better than my b652 cheapos! The other is paired with a Jamo 8", a-la "Rompicollo" (thank you Mr. Richards!), but that box is still a work in progress. As I said, super cheap but capable of sounding darn good ( Cork-sniffers may exit quietly now) for my dollars! I don't find them at all harsh or fatiguing, they do share a trait with their budget mcm brethren, however; it has been my experience that they need a good few days to break in. I work close to home, so to break my speakers in, I just let them play while I'm gone and check on them at lunch, change the volume level, and leave them til I come home that evening. After about a weekof this, I came home for lunch one day, turned up the volume and did a Moe Howard double-take. It sounded like someone had completely replaced my speakers with more smooth and warm and spacious sounding models! I'm really hooked now.

[johnnyrichards]

Re: $3 1" dome tweeter.

Biscuit - I have a design close to ready using those MCM drivers. We should compare notes

[Zach C.]

Re: $3 1" dome tweeter.

Johnny,

Does it look like these can be opened up for mods?

Pics sure don't look like it. If I ever ordered from mcm, I'd just give it a try, but I couldn't tell you the last time I needed anything from them.

[johnnyrichards]

Re: $3 1" dome tweeter.

Johnny,

Does it look like these can be opened up for mods?

Pics sure don't look like it. If I ever ordered from mcm, I'd just give it a try, but I couldn't tell you the last time I needed anything from them.

Why yes, it does appear to be openable.