Is making an XO on a PCB a bad thing?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
M

mr_push_pull

Member
Joined 2004
I had the idea of making the XO on a PCB and I read that some recommend against that. I also left big areas of copper (I etched only a few millimeters around the traces because I had little etchant left and I was too lazy to go buy some) and I'm wondering if the capacitance made from the big copper areas will hurt the sound. Should I bother to redo the XO's?
 
C

Colin

Member
Joined 2003
ejjordan.co.uk
There's a feeling that PCBs are an unnecessary complication and may even make things worse - by hard wiring you can wire the components directly together (reducing the solder connections and intervening pcb tracks), it's easier to fix them to the board ina more robust fashion and you can space the components farther apart to reduce interactions. I remember Russ Andrews telling me of some experiments he did when working as a consultant - they took the x-over components off the pcb, spaced them farther apart and reconnected them - then fell about laughing at the size of improvement it made.

Colin
 
H

Hornlover

Member
Joined 2004
A pc board will work just fine. Just make sure your trace width can handle the expected current. Close spacing if inductors is fine if they are in the same branch. Even if they are in different branches, unless you expect large currents, they dont need to be placed very far apart. If you have a scope, look at the output of the mid or high section while feeding a low frequency signal to the bass section. How much energy do you see?
 
M

mr_push_pull

Member
Joined 2004
Hornlover said:
A pc board will work just fine. Just make sure your trace width can handle the expected current. Close spacing if inductors is fine if they are in the same branch. Even if they are in different branches, unless you expect large currents, they dont need to be placed very far apart. If you have a scope, look at the output of the mid or high section while feeding a low frequency signal to the bass section. How much energy do you see?
Click to expand...
The traces are about 4-5 mm wide and I covered them with solder alloy. I think I'll hardly get into the region where current is a concern.
 
M

MarkMcK

Member
Joined 2003
madspeaker.com
Besides capacitance, you can worry about eddy currents. Dahlquist tried beautifully made pc boards on the DQ10 in the late 80s and had to recall them because of too many complaints of "distorted" sound. And yes, it could be measured as well as heard. Big wide traces, with lots of conductor surface area, make nice eddy current pickups.

Like everything, it is not a case of pc boards or not pc boards, but how a particular project is designed and constructed.

With all of the free fft based spectrum analyzers available it is easy to measure component interaction when prototyping board layout.


Best of luck to you,

Mark
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom