Hi,
Generally no, unless you want to completely redesign the speaker.
FWIW the designer of said speakers was not afraid to to make
his designs "showroom impressive" rather than long term nice.
Its just as likely the issues are related to the topend roll
off of the bassmid as they are to any tweeter issues.
rgds, sreten.
Sometimes such speakers simply work better upside down.
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Heybrook HB2R schematic
Hi there,
Opened other Heybrook tonight.. Same burnt resistor. It measures 17ohms, and on the other xover 15ohms. I guess this measurement is of no meaning since the component is burnt..
Here is a drawing of the schema I observed. I know nothing about xovers in general. I'm more at ease in a tube amp..
I don't understand what's for this resistor between the + terminal of the woofer and the - in parallel with a capacitor?? if it's a drop resistor, gee, it's got lots of watts to swallow..
I've indicated the few values I could identify.
Thanks!
Can't wait to buy replacement components. Anybody has a schematic??
Hi there,
Opened other Heybrook tonight.. Same burnt resistor. It measures 17ohms, and on the other xover 15ohms. I guess this measurement is of no meaning since the component is burnt..
Here is a drawing of the schema I observed. I know nothing about xovers in general. I'm more at ease in a tube amp..
I don't understand what's for this resistor between the + terminal of the woofer and the - in parallel with a capacitor?? if it's a drop resistor, gee, it's got lots of watts to swallow..
I've indicated the few values I could identify.
Thanks!
Can't wait to buy replacement components. Anybody has a schematic??
Attachments
So it is a resistor, it seemed like a small electrolytic to me but those charred foils come from the yellow cap it dig in after all.
Maybe its a crude way to even out the woofer's impedance having a resistor across it. It should have been 2-3 times the woofer's nominal if so. But guessing is not enough info.
Maybe its a crude way to even out the woofer's impedance having a resistor across it. It should have been 2-3 times the woofer's nominal if so. But guessing is not enough info.
I suspect a wiring error on that crossover. A small resistor would quickly burn out connected across the bass.
Something like below makes more sense. 15R and 1uF across a 1mH bass coil forms a tank that notches a bass cone at 5kHz. It would work well with a polymer (plastic) bass, I'd reckon.
Something like below makes more sense. 15R and 1uF across a 1mH bass coil forms a tank that notches a bass cone at 5kHz. It would work well with a polymer (plastic) bass, I'd reckon.
Attachments
Mis-wiring?
Thanks System 7
Wiring error seems to make sense, though I saw no sign of mods on these xovers. What do you suggest then? rewiring? and do you think the 15ohm value makes sense? I mean, do you think the values (15-17ohm) I measured are still representative of the "original" value?
It would be interesting to find somebody who has HB2R to have a look at their xovers.
As you can see on the pics I took, the signal gets by the terminals at the center of the board, where black and blue is the link for - of both drivers. Red goes to woofer, brown to tweeter.
I'll go in my workshop tonight have a look to make sure I did no mistake while drawing this schema.
Thanks System 7
Wiring error seems to make sense, though I saw no sign of mods on these xovers. What do you suggest then? rewiring? and do you think the 15ohm value makes sense? I mean, do you think the values (15-17ohm) I measured are still representative of the "original" value?
It would be interesting to find somebody who has HB2R to have a look at their xovers.
As you can see on the pics I took, the signal gets by the terminals at the center of the board, where black and blue is the link for - of both drivers. Red goes to woofer, brown to tweeter.
I'll go in my workshop tonight have a look to make sure I did no mistake while drawing this schema.
"2" resistors..
Hi System 7
Me again.
Comparing your re-drawing of the circuit (wich makes sense) to the pic I've taken (see my november 19th post with the picture I've taken) I do realise that in "reality" the xover has 2 resistors, not one. One is in the tweeter circuit, and the other one (the burnt one) in the woofer circuit.
If I understand you well, then, I should only "remove" the burnt resistor and leave the existing circuit as is? (just replacing the burnt capacitor)
Hi System 7
Me again.
Comparing your re-drawing of the circuit (wich makes sense) to the pic I've taken (see my november 19th post with the picture I've taken) I do realise that in "reality" the xover has 2 resistors, not one. One is in the tweeter circuit, and the other one (the burnt one) in the woofer circuit.
If I understand you well, then, I should only "remove" the burnt resistor and leave the existing circuit as is? (just replacing the burnt capacitor)
Exactly, Sylver, it is the "TANK" on the bass circuit that has problems. 15R +1uF is a pretty typical value for good phase alignment.
Rewire it according to my diagram. These commercial speakers made a great deal of simple crossovers. The reality is that a complex one wouldn't fit on the back of the input socket fixing....
I don't actually know what the tweeter shunt is, but leave that bit well alone. You might upgrade all this later when you grow strong in the force that is diy. You will need to visit maplin store or radioshack or such to get more components.
I would buy a hot 40W soldering iron and some lead-free solder, a fresh 1uF polypropylene capacitor and a 7W 15R wirewound resistor. Maybe some plain wire too. Soldering is pretty easy if you practise first. Get in and out quick before you fry stuff. If I'm more than 5 seconds, I back off and blow on it to cool it down.
Rewire it according to my diagram. These commercial speakers made a great deal of simple crossovers. The reality is that a complex one wouldn't fit on the back of the input socket fixing....
I don't actually know what the tweeter shunt is, but leave that bit well alone. You might upgrade all this later when you grow strong in the force that is diy. You will need to visit maplin store or radioshack or such to get more components.
I would buy a hot 40W soldering iron and some lead-free solder, a fresh 1uF polypropylene capacitor and a 7W 15R wirewound resistor. Maybe some plain wire too. Soldering is pretty easy if you practise first. Get in and out quick before you fry stuff. If I'm more than 5 seconds, I back off and blow on it to cool it down.
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don't you ever..
Hi System 7
This is real time chat! don't you ever sleep? if it's 20h30 in Canada, there must be around 2h30 am in UK? ;-)
I just don't understand a thing to xovers.. but I've built quite a few nice tube amps! ;-) so, yes, I should be ok replacing these components. I'll have to buy these caps and resistors though, so, I should give you news about the new sound of these HBs soon. I guess it should improve things.. except for the highs that I found a bit shrill..
Thanks again for your support.
Hi System 7
This is real time chat! don't you ever sleep? if it's 20h30 in Canada, there must be around 2h30 am in UK? ;-)
I just don't understand a thing to xovers.. but I've built quite a few nice tube amps! ;-) so, yes, I should be ok replacing these components. I'll have to buy these caps and resistors though, so, I should give you news about the new sound of these HBs soon. I guess it should improve things.. except for the highs that I found a bit shrill..
Thanks again for your support.
Chat? Yes, I can do that.
My secret vice is my love of American Football as we call it in the UK. You'd call it NFL.
The Steelers @ Baltimore kept me up to 5AM last night. Love that brutal fixture. Only one concussion...RB LeVeon Bell on the penultimate pass. I was on the Steelers as it goes.
Most everything I know about 8" bass plus 1" tweeter is in this thread:
http://www.diyaudio.com/forums/multi-way/245917-diy-kef-celestion.html
These days I hate dome tweeters, which just don't sound musical to my ears. So in the long run, I hope you try a cone tweeter.
TW 70 - 8 Ohm
HT-22/8
I expect you can find something similar in your neck of the woods.
My secret vice is my love of American Football as we call it in the UK. You'd call it NFL.
The Steelers @ Baltimore kept me up to 5AM last night. Love that brutal fixture. Only one concussion...RB LeVeon Bell on the penultimate pass. I was on the Steelers as it goes.
Most everything I know about 8" bass plus 1" tweeter is in this thread:
http://www.diyaudio.com/forums/multi-way/245917-diy-kef-celestion.html
These days I hate dome tweeters, which just don't sound musical to my ears. So in the long run, I hope you try a cone tweeter.
TW 70 - 8 Ohm
HT-22/8
I expect you can find something similar in your neck of the woods.
Looks to me like maybe its another cap.
I've never seen a resistor burn up leaving a burnt plastic film.
Is that filmy stuff the melted remains of the coppery color printed outer label similar to the capacitor?
And the lead looks to be welded in the center more like a cap than the coil.
And the burnt part and capacitor are both on those yellow pads.
Also, why would they use 2 resistors in series?
Maybe sim it to see how it behaves.
I've never seen a resistor burn up leaving a burnt plastic film.
Is that filmy stuff the melted remains of the coppery color printed outer label similar to the capacitor?
And the lead looks to be welded in the center more like a cap than the coil.
And the burnt part and capacitor are both on those yellow pads.
Also, why would they use 2 resistors in series?
Maybe sim it to see how it behaves.
Attachments
Dave, it's quite hard to guess the designer's intention here. 3.3uF is a very typical first order treble value.
It would be easy enough to wire the resistor between the bass output and Input positive. That forms a TRAP. But you don't usually use a trap in this context. And it doesn't do much here either. But you could try it. It might help phase alignment.
The Tank is a common enough circuit to line up phase a bit and roll off the bass. Again it's subtle in effect. This is what I'd try first. But, quite honestly you probably wouldn't notice much if you just used the bare coil on the bass.
I can't think of any other circuits that use these 3 bass components.
It would be easy enough to wire the resistor between the bass output and Input positive. That forms a TRAP. But you don't usually use a trap in this context. And it doesn't do much here either. But you could try it. It might help phase alignment.
The Tank is a common enough circuit to line up phase a bit and roll off the bass. Again it's subtle in effect. This is what I'd try first. But, quite honestly you probably wouldn't notice much if you just used the bare coil on the bass.
I can't think of any other circuits that use these 3 bass components.
Attachments
Burnt xover components..
The burnt component (obviously black..) is sitting on a yellow capacitor.. that got partially burnt as well, but the burning resistor.. If you look at the diagram I had drawn, you see how it was linked. Resistor ended being linked between - and + woofer's terminals.
The burnt component (obviously black..) is sitting on a yellow capacitor.. that got partially burnt as well, but the burning resistor.. If you look at the diagram I had drawn, you see how it was linked. Resistor ended being linked between - and + woofer's terminals.
Chat? Yes, I can do that.
Sorry that I'm not into sports. Shame on me! ;-)
But it could be nice to chat in real time.
Most everything I know about 8" bass plus 1" tweeter is in this thread:
http://www.diyaudio.com/forums/multi-way/245917-diy-kef-celestion.html
These days I hate dome tweeters, which just don't sound musical to my ears. So in the long run, I hope you try a cone tweeter..
I can only agree with you. Lately, I was using the little Goodmans Maxims, and as peaky as they are (and they really are.. could this be due to capacitor drifting in value with time?) I like their "imediacy" their pace and coherence. When driven by a 2A3, they sound really cool.
Today I shifted back to my Klipsch KG4, and I'm impressed again about how horns, suitably driven.. can sound real, coherent. Though, nothing compares to my Tannoys..
Soon, next project should be about bringing back to life Sonabs OD-11 (cone tweeters) I can't wait to give them a listen, live with them for a while. My collection of speakers is too long to list here.. lol. It could be the start of a new thread.
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