Why do the resistors of my 3 way crossovers get very hot on high volumes?

[NINaudio]

SO is there still a chance if I were to remove the resistors and not solder a wire back, will the bass, mid and tweeter all work or will any of them not work until I solder a wire or other resistor back?

If you remove them from your crossover board, you must replace them with something, even if its only wire, or you will have an open circuit – no current can flow. Are you certain that's what the crossover designer said, that you can remove them and not affect the function of the board? If so, why were they put there in the first place?

I don't think you're listening/reading here...

They are part of the path for energy to flow to your speakers. If you remove them you are breaking that path and at least one speaker will no longer produce any sound. If you replace it with a jumper (straight piece of wire) it is extremely likely that one speaker will produce much louder sound than the rest. We can't tell you much more than this without crossover schematics and more driver details.

I would very highly advise you to NOT remove the resistor.

 

[Kvn_Walker]

When KingNoob discovers DIY...

 

[ryanosaur]

Ok, so perhaps it’s a Zobel then, used to help control the driver impedance/load your amplifier sees. It would be shorting one of the driver networks.
In this case, that path could be cut. Whether it should be is a different matter.

But then again... if we were gonna get in to “should” here...

 

[nickless]

The seller seemed to misunderstand some of my emails as he first thought I was asking to remove the plastic pieces under the crossovers that act as stands but later informed me that I should not remove the resistors.

I know I don't have a professional speaker set up but thanks for all your advice. I'd rather just use what I have since I don't know other specs about them other than they're wattage and are 8 ohms, and will not be buying new speakers to replace them as of now. I had to remove the resistors because they were getting too over heated on very loud volumes or else they would of burned eventually or even damage the crossovers.

By removing the resistors, the bass and mid range worked but there was no sound for the tweeter. I then noticed by placing a wire over the 2 terminals where one of the resistors were, the tweeter sound came back but just a little louder than before. If I decide on just using a wire in place of one of the resistors per crossover since I can lower the treble and highs on my EQ's (I only need 1 wire per crossover to get the tweeter sound), does anyone know if wire glue will be good enough? I actually need to buy a new soldering iron if I do it the other way, unless I buy wire glue. Or is there a pen type of soldering device that allows me to precisely drip melted solder onto a spot?

HERES 1 review on amazon.com for this wire glue-
"It does appear to make a good conductive connection without using anything else, like a soldering gun. I tried it on a broken car antenna wire, which was in a place where it would have been impossible to use a soldering gun. It made a good electrical connection!".

 

[lovinthehd]

.

I asked the seller around 5 hours ago if I were to remove the resistors would I need to replace it with a wire running across if I don't replace with a better resistor and he didn't respond yet. I asked him yesterday would removing the resistors cause an affect or difference to the crossovers and he replied yesterday and said exactly this, "Nope, the white stand-offs just allow the crossover to sit up a bit, other than that no function." and then he also replied, "The resistors in the crossover help it maintain a constant 8 ohms to your amplifier".

SO is there still a chance if I were to remove the resistors and not solder a wire back, will the bass, mid and tweeter all work or will any of them not work until I solder a wire or other resistor back? I'm kind of an amateur and would rather not solder at all for fear I may damage the crossover, can I use a tool to remove the resistors or is melting the silver solder the only option?

FINAL question, if I decide to buy a new 3 way crossover now or in the furture, can I buy a 3 way crossover with NO resistors? Do they make 3 way crossovers with no resistors or do all of them have them?

He's talking about the stand-offs (little feet/risers for the board itself) can be taken off....doesn't sound like he's suggesting removing the resistors.

What really needs to be done is some actual speaker design work....

ps saw after I posted this has been realized....at least the stand-offs part

 

[ryanosaur]

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If our friendly OP @nickless were so inclined, these are all great books on designing and building speakers. The first two by Weems and Murphy respectively are good, very basic books that can get you going.
The third, by Alden is a little more advanced and gives great info for doing the Math yourself.
Lastly, Dickason's LDC is more advanced still and the most in depth of the four. It definitely requires more familiarity with the topic than a passing fancy.

No pressure, just leaving the info here so you may choose to pursue it if interested.

As I have suggested in earlier threads by people posting about building speakers... this should be where you begin. I did and am fumbling my way through my own growing pains learning a Speaker Modeling program on my way to my first designs. Though being an electrician, physicist and cabinet maker might make this a little easier, I fully enjoy the efforts I've put in to learning about Speaker Design and have gotten more enjoyment of my own rig for what I've learned.
Getting to engage with some of the cats here who have designed or built speakers is much more rewarding when you can understand their/our recommendations.

 

[Verdinut]

If a 10 watt rated resistor in series with a tweeter gets hot, the SPL must be quite high. That would definitely be dangerous to the extent of damaging the hearing acuity over a short period of time.

 

[MR.MAGOO]

Sorry for this stupid question: Could a resistor be considered a mini "step down transformer" in a circuit?

 

[Verdinut]

Sorry for this stupid question: Could a resistor be considered a mini "step down transformer" in a circuit?

Although a resistor's function is to reduce the current going to any electric or electronic object in a circuit, it's not a step down transformer but you would have a similar result of a reduced voltage in an AC circuit. The transformer only works on AC current whereas the resistor will also work on DC.

 

[Bruce53]

I've read over the articles on crossovers and have decent general idea how they work for 2 drivers. How would a crossover look for a speaker that has tweeter, midrange and woofer? Is there another article that explains this?

 

[slipperybidness]

Sorry for this stupid question: Could a resistor be considered a mini "step down transformer" in a circuit?

A resistor in a circuit may act as a voltage divider (in series) or a current divider (in parallel).

 

[highfigh]

I asked the seller around 5 hours ago if I were to remove the resistors would I need to replace it with a wire running across if I don't replace with a better resistor and he didn't respond yet. I asked him yesterday would removing the resistors cause an affect or difference to the crossovers and he replied yesterday and said exactly this, "Nope, the white stand-offs just allow the crossover to sit up a bit, other than that no function." and then he also replied, "The resistors in the crossover help it maintain a constant 8 ohms to your amplifier".

SO is there still a chance if I were to remove the resistors and not solder a wire back, will the bass, mid and tweeter all work or will any of them not work until I solder a wire or other resistor back? I'm kind of an amateur and would rather not solder at all for fear I may damage the crossover, can I use a tool to remove the resistors or is melting the silver solder the only option?

FINAL question, if I decide to buy a new 3 way crossover now or in the furture, can I buy a 3 way crossover with NO resistors? Do they make 3 way crossovers with no resistors or do all of them have them?

You can't just remove a resistor and replace it with a piece of wire; the resistor is used for a reason- decrease the signal to the driver in order to decrease its output.

You need to look into the principles of crossover design, amplifier power, audio and if you really want to understand what's happening, think in terms of Physics.

The reason the resistor becomes hot is due to a well-known phenomenon that follows one of the basic laws of Physics- Energy can neither be created, nor destroyed but it can be changed from one type of energy to another. The thing is, changing from one form to another always wastes some of the initial energy as heat.

The next bit has to do with the fact that when a conductor's temperature increases, it will resist electron flow. If you were to measure the resistance of your resistors at room temperature and after they become hot, you WILL see a difference.

What receiver (brand and model) are you using, what brand of speaker components and how are they wired- series, or parallel (referencing your midrange comment)? You listed two of each- is this in each cabinet, or total for two speaker systems?

How are you determining the receiver's power- some dealers (like Best Buy) state total power from all channels on the card stuck to the shelf, some state it very optimistically.

 

[highfigh]

A resistor in a circuit may act as a voltage divider (in series) or a current divider (in parallel).

Or, a voltage divider can be set up as one resistor in series with another parallel, to maintain the impedance in an audio circuit.

 

[highfigh]

I've read over the articles on crossovers and have decent general idea how they work for 2 drivers. How would a crossover look for a speaker that has tweeter, midrange and woofer? Is there another article that explains this?

The circuit depends on what is needed- The woofer will usually have some component(s) to determine the high frequency limit, the midrange will have component(s) to determine the high and low frequency limits and the tweeter will have something to prevent frequencies that could cause damage- all drivers have physical limits and operating outside of this guarantees bad performance, or damage.

Here's a link that has some info that might help-

Passive Crossover Networks

www.the12volt.com

 

[Bruce53]

Thank you; that helps.

 

[ryanosaur]

I've read over the articles on crossovers and have decent general idea how they work for 2 drivers. How would a crossover look for a speaker that has tweeter, midrange and woofer? Is there another article that explains this?

This is a very basic 3-way 1st order (6dB per octave slope) crossover design.

The Capacitor on the tweeter acts as a High Pass Filter, just as the Inductor on the Woofer acts as a Low Pass Filter. The Inductor and Capacitor in series on the Mid is a Band Pass Filter setting both Low and High Passes that limit the range of signal reproduction to a specific frequency band (hence the name).

By adding an extra component after each of the above filters, you can create a 2nd order (12 db slope) design:

Again, these are very simple schematics without any added Zobels, L-pads or Trap filters.

 

[Bruce53]

Thank you also. What I really wondered was how the midrange would be able to block both low and high. So putting it in series accomplishes this.

 

[slipperybidness]

Thank you also. What I really wondered was how the midrange would be able to block both low and high. So putting it in series accomplishes this.

The key definition here is "band pass filter".

 

[ryanosaur]

Thank you also. What I really wondered was how the midrange would be able to block both low and high. So putting it in series accomplishes this.

yes.

 

[nickless]

What receiver (brand and model) are you using, what brand of speaker components and how are they wired- series, or parallel (referencing your midrange comment)? You listed two of each- is this in each cabinet, or total for two speaker systems?

I rather not mention any brand or model names. I have a high end 2005 receiver, its almost 50 pounds in weight, $2000 brand new, amazing low freqs it produces. I was lucky to find it lightly used 2 years ago on internet for almost $400 including delivery.

The stats on my receiver is 120 watts x 7 (840 watts-not 500 watts as I stated before), 8 ohms, also using a seperate EQ, have 2 speaker boxes, per speaker box includes all 8 ohms- 1- 15" bass subwoofer 600 watt, 1- 8" midrange 300 watts each, 1- 3.75" tweeter 300 watts, not sure of other info.

The crossovers I bought 2 months ago (over heating resistors started 4 or so days ago), are generic and handles 1000 watts each at 8 ohms. The resistors had to go due to them getting too hot to the point of smelling like over heated plastic or ceramic only when playing at very loud volumes for an hour. They would of eventually burned or damaged the circuit board. Will either solder a wire or 20 watt resistors, may order a solder gun today or tomorrow. At least with a solder gun you don't have to use a 2nd hand to hold the solder, you just use 1 hand and press the lever and place melted solder at a precise spot.

The crossovers I had before I bought the new crossovers lasted 15 years and they never had resistors. The midrange (not the tweeter) sounded too loud on those older crossovers (as well as the new ones) and I all I need to do is lower the highs on my EQ's to give me the exact sound I want.