Reusing my speakers?

[motokok]

The most important thing to decide on coils is that they are closest match to Troels' DCR values on the schematic.

 

[system7]

70 or 35 Euros for a 3.9mH coil looks way too much money to spend to me. 🙂

I am sure these generic own-brand ones will do:

Ferrite 4 mH proabably 0.5R:
4 00mH Ferrite Inductor

Air-Coil 3.9 mH 1 ohm:
TLHP coil, L10-3.9 mH - 10/10e +-3%

Thing is, the voicoil is at least 6 ohms, and I would guess a 10% tolerance is inaudible. Can't see a 1 ohm coil overheating either, especially if well ventilated away from acoustic wadding. Surprising how little power a speaker actually consumes. Think a few Watts.

Boutique capacitors can be quite huge too. Never had a problem with 250V types or 5-10 W ceramic resistors. All seems to work.

These are 630V no-name capacitors, which get huge above 10uF, but I use smaller 250V ones too:

 

[lecriquet]

I didn't imagine that the choice of the coil was such a thing 😀
Of course I would appreciate not to spend crazy money in marginal gains.

System7 --> so you would go for TLHP one, even if Rdc is 1.165 ohm, 6 times higher than the ferrite coil I proposed first?


Resistors are cheap stuff, I will go for ceramic or MOX


My question is still open for capacitors. Should I take something like Mundorf Supreme for the biggest one and MKP for the others?

 

[system7]

Mundorf make so many capacitors, I wouldn't know where to start! 😕

All snake oil IMO. 400V jobbies like Solen can't be bad. Fairly small too.

Thing is, crossover design can allow for any resistances too, especially with coils. But I really wouldn't worry about it.

I always leave component leads quite long, so reuseable in later projects too.

This MT design might interest you:

Seas ER18RNX with 27TDFC

I bet that would work with your similar CA18RNX. Nice circuit. Reasons to think it is a good sounding filter.

 

[motokok]

That THLP 3.9 coil DCR = 1.165 but Troels' spec is 0.28ohm. You'll be changing the filter responses if you deviate from the design specs....

http://www.jantzen-audio.com/wp-con...18RNX-2½-Way-All-kit-versions-with-prices.pdf

Jantzen coil part numbers used are in the pdf - why not just get the specified coils?

For caps, Jantzen Crosscaps or Standards are their cheapest ones. The equivalent from other brands like Mundorf / Solen / etc will be the same price so.

 

[system7]

I think there is far too much agonising going on here. I can never hear a 10% component change! Lot of these things, like box tuning are a matter of taste anyway.

CA18RNX

Looking at Troels's design, I see no reason you cant build a separate box fort the lower woofer. Might save some woodwork.

All you'll do with a high resistance coil is lose a bit of damping. The Q might change 10% at most. Will you hear it with all the nonsense of room gain bending the sound? I doubt it.

 

[lecriquet]

That THLP 3.9 coil DCR = 1.165 but Troels' spec is 0.28ohm. You'll be changing the filter responses if you deviate from the design specs....

It was my first guess, but system7 seems to think otherwise.

Jantzen coil part numbers used are in the pdf - why not just get the specified coils?

Precisely because the biggest one has an iron core and it seems that iron core don't have good press

For caps, Jantzen Crosscaps or Standards are their cheapest ones. The equivalent from other brands like Mundorf / Solen / etc will be the same price so.

Ok thanks

 

[lecriquet]

I think there is far too much agonising going on here. I can never hear a 10% component change! Lot of these things, like box tuning are a matter of taste anyway.

CA18RNX

Looking at Troels's design, I see no reason you cant build a separate box fort the lower woofer. Might save some woodwork.

All you'll do with a high resistance coil is lose a bit of damping. The Q might change 10% at most. Will you hear it with all the nonsense of room gain bending the sound? I doubt it.

What you say about the components is quite surprising. But if you are right, I'll go that way.

My living room is far from being perfect for HiFi.


I think I'll stick with Troels's design.


Any other inputs are welcomed, though

 

[system7]

I may do this later today, but you can always bung a few similar drivers into Boxsim and fiddle with component values and resistances and see how it affects things:

Software | Visaton

Use Troels' filter.

W170S woofers and G20SC tweeter can't be much different. Give you an idea. Then you become "a light unto yourself", if you follow. 🙂