How off can my zobel be with good results

[jhw]

I want to recycle a zobel but the component properties are slightly off.

I need 10 uf cap and 10 ohm resistor

But I HAVE a 6.8 uf cap and a 12.5 resistor.

Too far off; worth recylcling or should I buy the new components?

thanks

[Paul K.]

Re: How off can my zobel be with good results

I'd think that the capacitor you have, which is 32% below the value you need, and the resistor you have, which is 25% larger in value than you need, are both more than "slightly" off. The values you have may work out okay depending on what you want and how much their errors degrade the expected performance, but if it were me, I'd buy the proper-valued components.
Paul

I want to recycle a zobel but the component properties are slightly off.

I need 10 uf cap and 10 ohm resistor

But I HAVE a 6.8 uf cap and a 12.5 resistor.

Too far off; worth recylcling or should I buy the new components?

thanks

[Æ]

Re: How off can my zobel be with good results

It will be off. How much? You need to run (measure) an impedance curve to find out.

[Chris Roemer]

Re: How off can my zobel be with good results

I want to recycle a zobel but the component properties are slightly off.

I need 10 uf cap and 10 ohm resistor

But I HAVE a 6.8 uf cap and a 12.5 resistor.

Too far off; worth recylcling or should I buy the new components?

thanks

Tell me your driver. If it's almost any Dayton model (or even quite a few others - as long as I have F/Z data for them) I'll check it for you in a sim.

Chris

[jhw]

Re: How off can my zobel be with good results

Tell me your driver. If it's almost any Dayton model (or even quite a few others - as long as I have F/Z data for them) I'll check it for you in a sim.

Chris

Dynavox LW6004PMR 6-1/2" Woofer 295-605
Thanks

[Chris Roemer]

Re: How off can my zobel be with good results

Dynavox LW6004PMR 6-1/2" Woofer 295-605
Thanks

Here's the deal:

That driver (which I'D call a nominal 6 ohm, rather than 8) hits a minima of 5.5 ohms at 250 Hz. It rises steadily to 20 ohms at 10 kHz.
Any of these Zobels won't affect the minima of 5.5n @ 250 Hz, at all.
Listing resistor ohms, cap uF, resultant ohms @ 900 Hz, 3kHz, & 10kHz:

(what you have won't do much, but it's better than none at all)
12.5n + 6.8uF: 6.8n, 7.9n, 8.9n, - so, still steadily rising, but rate is < half

what you think you need isn't too much better, but it IS a little better
10n + 10uF: 6.5n, 6.9n, 7.7n, - still rising, but closer to only 1/3 as much

10n + 6uF: nearly flat at 8.1n +/-0.4 from 1.4kHz up
8n + 8uF: nearly flat at 7.0n +/-0.4 from 800 Hz up
7n + 14uF: nearly flat at 6.0n +/-0.4 from 110 Hz up
6n + 18uF: nearly flat at 5.4n +/-0.4 from 140 Hz up

If I were using 2 in parallel, I'd have to go with the 10ohm + 6uF, which for two in parallel would be 5 ohms + 12uF, but it would keep my load at approx. 4 ohms to keep an amp happy.

For a single driver, I'd go with a 7 ohm resistor + 14uF cap for a fairly flat 6 ohm load. A "textbook" XO would be best calc'd at a 6 ohm load.

Chris