About Tweeter Capacitor.

[solderdude]

It is only rated 150W when fed through a correct XO filter, the actual voice coil most likely cannot handle 150W (program power?) it is designed to be used with 150W amplifiers..

 

[jst]

It is only rated 150W when fed through a correct XO filter, the actual voice coil most likely cannot handle 150W (program power?) it is designed to be used with 150W amplifiers..

I see, I only use TPA3116d2 amp kit, (zk-tb21) rated 50watt x2 and 100watt for sub. So, I guess shld be ok.

And to my surprise my listening volume only use 2-8 watt based on the dc meter I install on the output of the power supply, and it's already loud enough.

 

[solderdude]

You are only O.K. if high pass filtered at the correct frequency and order.
I cannot find info about the actual power rating of the voice coil.

 

[jst]

You are only O.K. if high pass filtered at the correct frequency and order.
I cannot find info about the actual power rating of the voice coil.

Is adding a capacitor not enough ? what is the correct frequency ? Is it possible to tell just by what I have posted ?

 

[solderdude]

Hard to say as there is not really enough info on this tweeter.

Is it used with a full range speaker, a 2-way or 3 way system ?
Is it used as a super tweeter (on top of an existing speaker) ?

A single capacitor may work well but depends on several factors as mentioned above.

 

[jst]

Hard to say as there is not really enough info on this tweeter.

Is it used with a full range speaker, a 2-way or 3 way system ?
Is it used as a super tweeter (on top of an existing speaker) ?

A single capacitor may work well but depends on several factors as mentioned above.

I am using it with only a 4" full range speaker driver without crossover. And a 6" subwoofer, a 2.1 amplifier kit using dual tpa3116d2. I have posted a measurement video of the fullrange I use in previous page.

Though maybe I'll get a Faital Pro 4Fe32 or 4Fe35 next month. Seems like there are quite many ppl satisfied using that driver on the internet.

 

[solderdude]

Might be best to use a 1st order low-pass on the full range driver too and turn it into a 2-way system.
Now the full range is emitting high frequencies which will likely 'comb filter' with those of the tweeter.
I would recommend to crossover at a frequency where the full range starts to beam or show 'ragged' response.
Could well be in several kHz region in which case 1st order (just a cap for the tweeter and just 1 inductor for the wide-range) will do just fine.

 

[jst]

So. if my fullrange has this kind of measurement. And I decided to crossover at 14.7khz where it starts to go down

And using the calculator posted by mhardy6647 on previous page, I should use a 1.35uF capacitor

So I combine my 1uF+0.22uF+0.1uF = 1.32uF (close enough)

Am I doing it 'somewhat right' or am I embarrasing myself lol ?

But I kinda like how it sounds though.

And What is :
Inductors
L1 = 0.09 mH ??
Is the item in this picture usable ? And what does it do ? Reducing the high above 14.7khz from the fullrange because it's handled by the tweeter ?

 

[mhardy6647]

Interesting calculator, I don't actually use a woofer since the bass is from a 2.1's sub, but I have the tweeter connected parallel to a 4 inch full range, also 8 ohm, with no crossover and open baffle. I'm currently using a 6.8uF capacitor and judging from the measurement of the calculator, the frequency is around 3khz and if I want 20khz, 0.9uF can be used. Good to know.

One may ignore the LF driver rolloff part of the calculator.

PS Nothing wrong with extending the range (at either end!) of an full range extended-range driver. I am - still - a fan of keeping crossovers (at least passive XOs) out of the midrange if at all possible, and as much as possible.


(EDIT: The Silbatone Bae enclosures above are loaded with very vintage Pioneer PIM-8L 'biflex'-style 8" drivers running fullrange and - currently - unaugmented.)

That said...

I know this is apostasy, but at the moment, my three-ish way "Frankenaltecs" are all first order XOs. 600 Hz on the 515B "woofer", 600 Hz on the treble driver (EMILAR EH500-2, currently loaded with an Altec 802D 1" compression driver) and the aforementioned B&C DE35 'supertweeter' (it's all relative to one's hearing, you know?) at 20 kHz

 

[AnalogSteph]

First of all, a calculator is just that. This one only gives vaguely accurate results if both drivers have the same sensitivity, which is almost certainly not the case. You would have to include an extra series resistor for your tweeter both in real life and in the tweeter impedance field.

Second, you generally don't want to cross over as high as 14.7 kHz. Wavelength at that frequency is only about 2.3 cm, and ideally you want a driver spacing (center-center) of no more than half a wavelength or a full wavelength at best. You can simulate the effect with a calculator for the classic double slit experiment (such as this one) which are all over the interwebs - light is also a wave after all, just with much smaller wavelengths, and what counts is the ratio of wavelength to distance.

Third, make sure the inductor you pick is suitable for a crossover. Chokes for power filter applications tend to be quite lossy, you don't want that. It also shouldn't saturate too easily, even though for your application a solid core job would most likely be fine. 90 µH is small enough that you could probably go air core and not be out a fortune or a huge amount of space.

Dayton Audio 0.10mH 20 AWG Air Core Inductor Crossover Coil

Dayton Audio 0.10mH 20 AWG Air Core Inductor Crossover CoilDayton Audio 20 gauge air core inductors are a great choice and the best value for building high quality crossovers. Features fully annealed refined copper wire, perfect layer windings and air core construction to ensure no hysteresis...

www.parts-express.com

 

[mhardy6647]

Might be best to use a 1st order low-pass on the full range driver too and turn it into a 2-way system.
Now the full range is emitting high frequencies which will likely 'comb filter' with those of the tweeter.
I would recommend to crossover at a frequency where the full range starts to beam or show 'ragged' response.
Could well be in several kHz region in which case 1st order (just a cap for the tweeter and just 1 inductor for the wide-range) will do just fine.

I didn't want to edit my earlier post again, but I do want to acknowledge @solderdude's advice, which is sage.
I will note, however, that the gambit of a very high but shallow (6 dB per octave) passive XO can (ahem... might ) shift the worst of the comb filtering up high enough that it won't be objectionable. It's also possible that, empirically, on-axis will be audibly acceptable to the listener (i.e., @jst) irrespective of weird comb filtering or directivity effects in the treble. Yeah, I know, we're not supposed to talk about such things here -- kind of like Bruno (not that Bruno -- Disney's Bruno!)

 

[mhardy6647]

First of all, a calculator is just that. This one only gives vaguely accurate results if both drivers have the same sensitivity, which is almost certainly not the case. You would have to include an extra series resistor for your tweeter both in real life and in the tweeter impedance field.

Or a variable L-pad

N.B. @AnalogSteph's is all sound (no pun intended) advice, though!

 

[solderdude]

So. if my fullrange has this kind of measurement. And I decided to crossover at 14.7khz where it starts to go down
View attachment 402461

And using the calculator posted by mhardy6647 on previous page, I should use a 1.35uF capacitor
View attachment 402463

So I combine my 1uF+0.22uF+0.1uF = 1.32uF (close enough)
View attachment 402464

Am I doing it 'somewhat right' or am I embarrasing myself lol ?

But I kinda like how it sounds though.

And What is :
Inductors
L1 = 0.09 mH ??
Is the item in this picture usable ? And what does it do ? Reducing the high above 14.7khz from the fullrange because it's handled by the tweeter ?
View attachment 402465

Perhaps look for inductors on loudspeaker websites.

The inductor shown is not recommended. That is a choke.
I would recommend to XO at around 6kHz or so as the treble quality starts to matter there.
That will be fine in first order filtering.

Also you would probably want to know the sensitivity (or efficiency) of both speakers.

 

[mhardy6647]

@jst if you're in the US, here are two reasonable, and reasonably easy, sources of good inductors for XOs, if you wish to experiment with attenuating the HF output of your "fullrange" driver.

Crossover Inductors

Shop Crossover Inductors in air core, copper foil, and solid core styles at Parts Express. Shop brands like Dayton Audio, ERSE Audio, Jantzen Audio, and more.

www.parts-express.com

Inductors: Speaker Components & DIY Audio Parts | Madisound

Speaker drivers, kits, and audio components for DIY speaker building. Browse woofers, tweeters, crossovers, and complete speaker kits from leading manufacturers.

www.madisoundspeakerstore.com

If you're outside the US (and my sense is that you may well be), I am sure there are similar resources of which you may avail yourself.

 

[egellings]

1a) capacitors "exist" (i.e., are purposefully manufactured) into the range of low picofarad values (1 uF = 1E6 pF).
1b) This is a capacitor that can exist even if not purposefully manufactured (i.e., for-profit manufactured).
View attachment 402254

GIMMICK CAPACITORS by SM0VPO

2) It's all relative! I.e., a very high (i.e., ridiculously high) first order XO isn't as absurd as it might seem. For example, the "supertweeters" on my Altec-esque loudspeakers have first order XO using a 1 uF Sprague "Atom" capacitor. That is a nominal XO frequency of 20 kHz for an 8 ohm load! The drivers are very sensitive, and the slope of the XO is only 6 dB per octave, so there's plenty of output (- 6dB, nominally) at 10 kHz ... and even below.

EDIT: Here's a handy first order XO calculator:

2-Way Crossover Calculator / Designer

Design a 2-way high / low pass crossover with a range of choices for type and order.

www.diyaudioandvideo.com

View attachment 402258

Gimmick caps are good for a couple of picofarads at most, which in some applications, is enough.

 

[jst]

@jst if you're in the US, here are two reasonable, and reasonably easy, sources of good inductors for XOs, if you wish to experiment with attenuating the HF output of your "fullrange" driver.

Crossover Inductors

Shop Crossover Inductors in air core, copper foil, and solid core styles at Parts Express. Shop brands like Dayton Audio, ERSE Audio, Jantzen Audio, and more.

www.parts-express.com

Inductors: Speaker Components & DIY Audio Parts | Madisound

Speaker drivers, kits, and audio components for DIY speaker building. Browse woofers, tweeters, crossovers, and complete speaker kits from leading manufacturers.

www.madisoundspeakerstore.com

If you're outside the US (and my sense is that you may well be), I am sure there are similar resources of which you may avail yourself.

Yea I'm outside the US, I think it already sounds fine now with the calculator you posted earlier, using 1.32uF even without adding the 0.09mH inductor, or like other said it's small enough to be negligible.

---------------

I would recommend to XO at around 6kHz or so as the treble quality starts to matter there.
That will be fine in first order filtering.

Also you would probably want to know the sensitivity (or efficiency) of both speakers.

Using the 2way calculator, if I XO at around 6khz, should I then cut the fullrange's 6khz and above ? Because the fullrange can play to like 17kHz but starting to go downslope at 14.7khz.

Does the 2 way calculator result below give the inductor value to cut the fullrange at 6khz when i put 6000hz in there ? with 0.21mH inductor.
my 4 inch fullrange sensitivity=90dB
my tweeter sensitivity = 91dB

Am I understanding it right ? pls confirm

I can try it if I understand it correctly, found it cheap at local store at around $2 each for 0.21mH

 

[jst]

Or a variable L-pad

N.B. @AnalogSteph's is all sound (no pun intended) advice, though!

Is this it ?

It has 3 pins + - and something

It can adjust tweeter volume without resistor ?

I think it's quite similar to what you posted above

I am - still - a fan of keeping crossovers (at least passive XOs) out of the midrange if at all possible, and as much as possible.

Do you mean you prefer to not attach any crossover to your midrange ? Meaning it should sound as is without adding any xo.
Coz I like my fullrange as is, without adding xo, I bought a 1way fullrange XO the other day, and it kinda suppresses it and not as loud anymore.

 

[solderdude]

Correct... 3.3uF for the capacitor (no need to parallel another 10nF)

The inductor can be either 0.2mH (200uH) or 0.21mH or even 0.22mH.
The one you selected is fine.

Yes, the full range driver can work to 14kHz BUT it certainly will not be as good performing as the tweeter can above 6kHz.
6kHz is also well above the 'problematic' range for midrange sound quality.

The L-pad (for the tweeter only) is only needed if the efficiency (sensitivity) of the tweeter is higher than that of the full range. You can 'dial' the tweeter level back this way.

It has 3 pins... one is connected to the - of the tweeter, the middle one to the + of the tweeter and the other pin goes to the 3.3uF capacitor that would otherwise be connected to the + of the tweeter.
As said ONLY needed if the tweeter is louder than the full-range.

 

[mhardy6647]

Yes, your arrow, @jst, points to an L-pad. The component you posted a photo of might be an L-pad, but it is at least as likely (probably more likely) to be a potentiometer (variable resistor) or a rheostat (essentially a very robustly built potentiometer with a higher power rating). An L-pad is actually two potentiometers (rheostats), one connected in series with the load, the other in parallel. They're "rigged" to attenuate the signal going to the load while maintaining a constant impedance. In the perfect world (i.e., when the load's impedance curve is flat), the L-pad is a "perfect" attenuator, with no impact on the impedance "felt" by the rest of the crossover.

This is a schematic showing the inner working of a variable L-pad:

note that the photo shows a stereo variable L-pad (two separate channels' worth of L-pads sharing one adjustment control shaft), but the schematic shows a single variable L-pad!
source: https://soundcertified.com/l-pad-calculator/

In the perfect world, we use a variable L-pad to adjust the output of the driver to a desired level (e.g., based on frequency response measurements, or - gasp! - by ear ), measure R-sub-series and R-sub-parallel and substitute two good quality fixed resistors to provide the desired attenuation. It is important to ensure that the L-pad, whether fixed or variable, can handle the anticipated amount of power that might conceivably be delivered to the load (driver). Realistically, for midrange or tweeter applications in a domestic (home) setting, that's not too burdensome.

Here's an L-pad calculator that can show you how the R-sub-series and R-sub-parallel vary to achieve a given level of attenuation into a load of a given (theoretically fixed) impedance.

L pad calculator - attenuation dB damping impedance decibel loudspeaker speaker voltage divider - sengpielaudio Sengpiel Berlin

L pad calculator impedance attenuation damping dB decibel loudspeaker speaker voltage divider - Eberhard Sengpiel sengpielaudio

sengpielaudio.com

In terms of midrange and XOs -- I prefer, if possible and as much as possible, to have the midrange reproduced by a single driver, unaffected by any crossover filter networks. Extended range drivers (e.g., the aforementioned Pioneer PIM-8L, or something like an Electrovoice "Wolverine" LS-8 twincone driver) can permit this. Electrovoice once sold a surprisingly nice little three-way loudspeaker system called the Esquire that was designed along such lines -- although they used less of the LS-8's frequency range than they could have.



This is an EV LS-8 "fullrange" 8" twincone driver. These were inexpensive in their day, yet very well made, with a cast basket, 2" edgewound copper VC and high sensitivity and high efficiency in converting electrical input power into acoustic output power. Those were the days!

 

[jst]

Thank you all, I now have a bit of understanding about XO and apply a custom one to the drivers I use, I've tried 3 and not satisfied with how they sound.

--
One more thing, if my tweeter is 8 ohm and fullrange also 8 ohm, when coonected like the diagram, is it then 4 ohm or still 8 ?