Help chosing high SPL drivers for 3way classic loudspeaker

Interesting! A search only returned an incredible number of businesses selling Tetra diapers. :(

Yes, that's it. They are made in variuos thicknesses here, varying from gauze like material to denser cotton (my youngest is 3yo so memories are fresh). Most of them are very loosely weaved. Denser than gauze but looser than what was shown in post 137.
 
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Hi Danny, that's some nice information there. But don't you think that the flux paths are equally orthogonal in both Fig. 5 and Fig. 6 on Mr. Gravesen's website that is, "out of table / towards screen (90*) in Fig. 5" and "out of table / parallel to screen (also 90*)" in Fig. 6 ? Hope you understand what I'm saying. Thanks for the link.

DrZoidberg said:
I rearranged XO...What about saturation currents .... do we need certain amps ?

I think the new placement is alright. You may reduce the distances or else the capacitors will end up having long interconnections, needing more copper (cost/inductance/size). Hope you have a PCB plan for the network.

You're right about the saturation current limit, one needs the biggest value that he/she can get for the size/money. However, note that we always look for air-core inductors first (end-game).
 
In case of 5 and 6, imagine the flux as a line through the core donut hole.
In case of 5, the left coil has a vertical flux line, the right has a horizontal flux line that goes through the left core, the flux lines are crossing.

For 6, the right has a horizontal flux line that doesn't go through the left core, the flux lines are not crossing and also not parallel.
 

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Try cotton, gauze like, material called "tetra pelene". Available in every pharmacy, DM, Lilly stores. Buy 1 piece for testing. It's cheap and ubiquitous.
Thanks, i totally forgot about those oldschool diapers, material and weave is the same i think as standard cheesecloth.


Looks way too 'rich', but if it passes the talk/blow test..........

Regarding this talk/blow test, should it allow or block it ? For thicker damping i get it should block it, but dont know about "cheesecloth"


I think the new placement is alright. You may reduce the distances or else the capacitors will end up having long interconnections, needing more copper (cost/inductance/size). Hope you have a PCB plan for the network.

You're right about the saturation current limit, one needs the biggest value that he/she can get for the size/money. However, note that we always look for air-core inductors first (end-game).


Well, leads on coils are very short anyway, i was thinking to use some copper wire i had leftover from where i had to reduce two air coils, they were slightly bigger values.

PCB will be this white plywood board, going to paint it black, drill holes for leads and zipties. and then raise it with little wood feet or something. I plan on keeping XO board outside, near amp.



I know everyone preference is air coils, why is this ?
 
danny_66 said:
.. the flux lines are not crossing ...

So it's not enough if the flux paths are perpendicular, they should not be crossing each other, got it, thank you very much!


DrZoidberg said:
i was thinking to use some copper wire i had leftover...PCB will be this white plywood board ..... preference is air coils, why..

I suggest you make a proper "printed" board as the capacitor leads need to be fairly low inductance. On a PCB, this becomes possible as the trace width can be widened (less inductance) as far there's space. Note that the copper wire/plywood method fails in this respect.

Air-core are preferred in the audio industry as they don't exhibit any non-linear behaviour (vs. steel/ferrite) such as saturation, hysteresis, remnance etc.
 
I suggest you make a proper "printed" board as the capacitor leads need to be fairly low inductance. On a PCB, this becomes possible as the trace width can be widened (less inductance) as far there's space. Note that the copper wire/plywood method fails in this respect.


Well i dont think its possible to make a PCB, and at this point it will be additional hassle i have to take care of.

Maybe i can optimize placement so it only uses components leads. But i still want to make sure two ferrite coils are in opposite corners from each other, min 20cm. Air coils i can stack as in guide showed.


As for glasswool wrapping, could this cheesecloth silk be used ? I will see what is cheaper.

Also, i just realized i will place woofer once box is sealed, so i will have to apply it on outside rim, maybe glue it a bit or something and then install driver in cabinet.
 
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Since crossover networks are usually simple, I could design the PCB for you (no charges) if you have the means to get it printed. A PCB is always more reliable. Placement could be retained as you wish, not a problem. Only the circuit diagram, positioning and component sizes would be required.

In my opinion, any thin cloth would be sufficient for wrapping up the felt / glass wool. If the fibres are held together they would prefer to stay together that's all.
 
Since crossover networks are usually simple, I could design the PCB for you (no charges) if you have the means to get it printed. A PCB is always more reliable. Placement could be retained as you wish, not a problem. Only the circuit diagram, positioning and component sizes would be required.

In my opinion, any thin cloth would be sufficient for wrapping up the felt / glass wool. If the fibres are held together they would prefer to stay together that's all.


Thats the thing, i dont know anyone who can print it. I guess design wouldnt be that hard. I do agree PCB will look nicer. For now its going on board, i could always repackage it.
 
Regarding this talk/blow test, should it allow or block it ? For thicker damping i get it should block it, but dont know about "cheesecloth"

Anything loosely draped around anything acoustic needs to protect, yet allow sufficient airflow to minimize resistance, such as cheesecloth or similar. Apply an increasing number of layers will of course progressively increase its acoustical resistance, but you're only interested in protecting the driver, XO from any insulation dust/particles, so just a single layer. Best then to put the XO in a ventilated box.
 
This comes across like there's only one side of the coin... There are drawbacks and advantages to each type.


Do you have some guide/paper that explains different types of coils ?



Anything loosely draped around anything acoustic needs to protect, yet allow sufficient airflow to minimize resistance, such as cheesecloth or similar. Apply an increasing number of layers will of course progressively increase its acoustical resistance, but you're only interested in protecting the driver, XO from any insulation dust/particles, so just a single layer. Best then to put the XO in a ventilated box.


Soo... cheesecloth is there to prevent stuff flying into the speaker etc... not to adjust something acoustically. Maybe better to put it on smaller array speakers than the bass if this is the case.
 
Don't worry about amplifier power, as 101 dB is good enough (I already said this earlier). However, it is always better (and reliable) if a larger amplifier (say 10W) operates at a fraction of its power capability (say 1W) than a smaller one working hard at full power.

This is not really true. Noise is a larger contributer than distortion in modern amps, so it is best to have your amplifiers not too large.