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Competency check on diy crossover please

J

Joe Hart

pfm Member
Hi,

Long story cut short, I have rebuilt a crossover with new coils and caps, please could someone check i've soldered it in the correct order?
Hopefully, enough photos are shown below including the diagram (wilmslow audio design)

I'm not particularly interested in comments on my soldering quality or if there is a better layout - more just will it sound right/built as per diagram! most photos are of the left side.

Cheers
Joe

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Sorry mate, but it's very difficult to work out if the signal paths are correct from photographs. I'd have to take a few mins to suss it if i was actually holding the thing! With the crossover connected to the speaker, I would suggest a multimeter to check resistance looks ok (owt above 4 ohms) and then run the speakers VERY QUIETLY, off sommeat small and cheap, (so if wiring is wrong, you're not blowing up your Mark Levinson for example) checking each driver in turn
1: is working
2: is not being fed with something it shouldn't be.

Sorry I can't be of more help.
 
walriley said:
Sorry mate, but it's very difficult to work out if the signal paths are correct from photographs. I'd have to take a few mins to suss it if i was actually holding the thing! With the crossover connected to the speaker, I would suggest a multimeter to check resistance looks ok (owt above 4 ohms) and then run the speakers VERY QUIETLY, off sommeat small and cheap, (so if wiring is wrong, you're not blowing up your Mark Levinson for example) checking each driver in turn
1: is working
2: is not being fed with something it shouldn't be.

Sorry I can't be of more help.
Click to expand...

+1 to all that
 
You seem to have commoned all the input 0V and + connections. Why?
If you intend to tri-wire, this is wrong. If you are single wiring the input then you don't need 3 sets of input terminals.
 
S-Man said:
You seem to have commoned all the input 0V and + connections. Why?
If you intend to tri-wire, this is wrong. If you are single wiring the input then you don't need 3 sets of input terminals.
Click to expand...

it's ok we did run it tri-amped hence the box shape and terminals but now will be single amped - but I ain't taking the old connecters off in case we change it again in the future, so don't worry.
 
@awkwardbydesign
Yer I can't put them on the end due to height issues of the box which can't be changed (easily)

I was also advised prior to my design to focus on the ferrite core inductors - hence they are quite far from each other.

I was unsure if non-ferrite core had the same effect.
 
Thanks for comments - appreciate it's hard to tell, did a test with an old amp and all seemed ok.
Nevertheless here are more detailed shots as I know we all like photos.

BASS

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So after listening to a variety of music - CD and youtube, we need some help on attenuating the treble.

Can anyone provide me with a circuit adjustment that will attenuate the treble please? L-Pad? something that will just reduce it by a 'step'
That would be much appreciated

I think after fitting these fancier (but not that fancy) compenents we now have too forward a treble - detailed yes but a touch forward
 
Ferrite core is a way to increase inductance using fewer turns than air core; it is a cost- and weight-savings measure which introduces non-linear behavior.

Coupling between magnetic fields is the issue. The two coils act like a transformer, with flux inducing currents in the opposite coil. This why inductors must be separated and, better yet, in orthogonal planes. Since field strength falls off as r^2, distance is the crucial factor.
 
An L-Pad across the tweeter works as an adjustable voltage divider and allows the right volume to be dialed in. Variable is superior to a fixed resistor because the volume may need adjustment for music type, room dynamics, individual taste, or hearing loss.
 
You have a spike in the treble caused by C4 being too big and/or L4 too small. I am away from home so on a crappy notepad, but I will have a look on Tuesday. L4 and C4 should have at least 1.4 x the resistance driver [in reactance] at the xover freq. The reactance of L4 at the moment is 0.12x6.3xfreq/1000.

1mH would be about right for a 1.5kHz xover.
 
Retrovert said:
An L-Pad across the tweeter works as an adjustable voltage divider and allows the right volume to be dialed in. Variable is superior to a fixed resistor because the volume may need adjustment for music type, room dynamics, individual taste, or hearing loss.
Click to expand...
There appears to be a Zobel across the tweeter, so an L-pad might interfere with that. And it is easier to obtain a high quality fixed resistor than a high quality L-pad.
 
I must say that your soldering needs work, you should make a mechanical connection by hooking wires together or twisting them then solder.

Pete
 
awkwardbydesign said:
There appears to be a Zobel across the tweeter, so an L-pad might interfere with that. And it is easier to obtain a high quality fixed resistor than a high quality L-pad.
Click to expand...

Thanks for that, have you got any specific recommendations of resistor values to start off with?
 
demotivated said:
You have a spike in the treble caused by C4 being too big and/or L4 too small. I am away from home so on a crappy notepad, but I will have a look on Tuesday. L4 and C4 should have at least 1.4 x the resistance driver [in reactance] at the xover freq. The reactance of L4 at the moment is 0.12x6.3xfreq/1000.

1mH would be about right for a 1.5kHz xover.
Click to expand...

Thanks for the reply, did you have a look at anything? open minded to any experiments or solutions to try out.
 
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