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Crossover Roadshow


Deang

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Guest David H
Please don't get upset.

I don't think anyone is upset fritz, we are either proving or disproving a theory.

The JBL bias is already proven. I like the theoretical benefits of your bridge network, however I would prefer proof that is works.

Dave

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"The battery in the bridge circuit is creating a voltage between two internal foils, but not within the same cap."

That's wild. For sure, when I jump to the two caps on the other side that are connected directly to the negative side of the battery, I get a reading. I guess I have to issue a retraction and apology.

It half works. : )

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Last picture before bed.

Sorry Fritz, you know I don't mean nothing by it. You're not the only one that gets beat up around here. Hey, I spent the last three hours trying everything possible to make it work - it's an interesting idea.

post-1106-0-84600000-1396320997_thumb.jp

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Yeah I know, I can be a real jerk. Sorry Fritz. I'm getting needlessly defensive because for some idiotic reason I feel like I need to defend my use of one method over the other. Dave's right, it should just be investigative fun.

Edited by DeanG
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Dave and me played with this thing for about an hour while on the phone. I learned I was wrong about something - I was able to get readings on all of the inside leads, but I had to flip the probes around (reverse them) to do it - which still has me shaking my head a little. I have to admit, I'm a little embarrassed about this - I still don't get it.

I'm gathering that the negative connection of the battery back to the AC common connection is required for this to work. At least, that's the way it looks using the picture I drew based off of your example.

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Dave and me played with this thing for about an hour while on the phone. I learned I was wrong about something - I was able to get readings on all of the inside leads, but I had to flip the probes around (reverse them) to do it - which still has me shaking my head a little. I have to admit, I'm a little embarrassed about this - I still don't get it.

I'm gathering that the negative connection of the battery back to the AC common connection is required for this to work. At least, that's the way it looks using the picture I drew based off of your example.

In light of this, are Michaels and my crossovers wired correctly?

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Drawing things out physically instead of logically helps quite at bit, I should have done that at the beginning.

Getting a reading on the voltmeter doesn't mean the cap is charged. Why do I always do these damn 5th grade science experiments when I should be asleep.

Edited by DeanG
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Dave and me played with this thing for about an hour while on the phone. I learned I was wrong about something - I was able to get readings on all of the inside leads, but I had to flip the probes around (reverse them) to do it - which still has me shaking my head a little. I have to admit, I'm a little embarrassed about this - I still don't get it.

I'm gathering that the negative connection of the battery back to the AC common connection is required for this to work. At least, that's the way it looks using the picture I drew based off of your example.

In light of this, are Michaels and my crossovers wired correctly?

yes they are Carl. the current discussion is about a separate method involving more components than what we have (if I'm following correctly).

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yes they are Carl. the current discussion is about a separate method involving more components than what we have (if I'm following correctly).

That's good to know. I'd hate to have to convince my self that they sound crappy now......................

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hi all,

as i'm trying to following this topic and trying to understand the concept and ideas of those more knowledgeable, weather the battery needs to remain in the circuit,

with the battery out does the constant influence of the dc voltage negates the benefit of any internal bias. to maintain the ref point the battery would need to be replaced as it degrade,

:unsure:

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Please don't get upset. I am just a humble 9th grade drop out, everything I learned about electricity I learned by sticking a fork in an electrical outlet during the 3rd grade.

This might be the best thing I've read in this thread. Made me laugh out loud (as well as some of my office mates!).

No need to get stressed over it all. I guess we get to learn from everyone else getting stressed.

Bruce

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Guest David H

Mark, I think I understand what you are getting at, but the purpose of this bridge is to isolate the battery from speaker ground.

lookup the benefits of the http://en.wikipedia.org/wiki/Wheatstone_bridge

All capacitors have parasitic resistance

Look at the dielectric resistance of the capacitors as the resistance in the Wheatstone Bridge.

Dave

Edited by GotHover
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Guest David H

This is the way I see the capacitors charging, and you are correct, the resistor on the bridge bias circuit might as well be removed.

Dave
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yes they are Carl. the current discussion is about a separate method involving more components than what we have (if I'm following correctly).

That's good to know. I'd hate to have to convince my self that they sound crappy now......................

Hey I laughed........ this thread needed a little humor

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Guest David H

Ok, it's clear that I am not making a good case for the bridge method.

I think I will get back to what I am good at - fixing cars and making saw dust.

Dave

Edited by GotHover
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In the JBL two cap version, the A foil and the B foil are both referenced to ground, and thus B is 9V above A. A bias is established.

proved that with measurments. I think you will find that the sole function of the first cap...the one that is between the battery and the amp .....is to provide a capacitance value which can be averaged into the second cap.....the one between the battery and the speaker.....the cap pairs are needed in series to average back to the original value...so original value of cap say 2uf......put two 4uf caps in series and now you have a 2uf cap....the bias is in the middle....but prove that the first cap is being baised.......if your going to say that half a bridge implementation is not being biased then you have to apply the same logic and say the first cap is not being baised in a traditional implementation and only the second one is. also...I think you folks are confusing battery bias concepts with charged capacitor concepts....are they the same? think back to the tin foil hanging on a wire in a glass experiment and the foil curls back....was the cause of the curl a charge or a bias?

Edited by " "
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