help, hot resistors

[Ryanschmidt224]

Hello,
This is my first speaker project...and pretty much my first electronic project... so bear with me for a bit... but anyways i'm building this...

1.618 - DIY 3-Way Hi-Vi Tower Loudspeaker Project

I believe i have everything wired correctly but the resistors get burning hot, can't even touch them for a second, in a matter of a minute if i crank my stereo up.

The receiver i'm using is 75w/channel

I have 3 questions

Do I need to mount a heat sink to them?
Are they supposed to get that hot?
If i am not running the intended speakers that the crossover was built for could it cause the excess heat? (I am running an old cheap system to proof out the crossover before the real speakers)

Thank you

[Cal Weldon]

It's not that expensive to up the resistors to 20 watt from 10 watt.

[Ryanschmidt224]

what difference will upping it to a 20w be? Will it have an effect on the power?

[Cal Weldon]

It means they will handle double the power and will run cooler for the same input.

[Ryanschmidt224]

thank you,
Should i be running a heat sink? right now i just have them suspended in air, im trying to avoid burning my house down

[Cal Weldon]

I've not seen resistors mounted to a heatsink in a speaker. People usually up the wattage of them so there's no problem.

[dewardh]

Originally Posted by Ryanschmidt224

Are they supposed to get that hot?

No. Did you use the resistors specified in the parts list?

[godfrey]

It is a bastard of a crossover. With all those L-pads, the resistors are probably consuming more power than the drivers. I'm not surprised they get hot when you crank the volume. Heatsinking is probably a good idea, if there's a sensible way to attach the resistors to the sink.

[Ryanschmidt224]

ya, i copied the parts list and bought those exact same pieces he had listed. What causes the resisters to get soo hot? I know that when you restrict current it creates heat and all that, i just wouldn't expect soo much. I'm assuming since im using all the same parts listed i did something wrong. I am cautious about just upping the wattage because I don't want to sidestep the real problem by fixing something else.

[LineArray]

I do not know what was the reason to pad the woofer
down ...

It seems odd to me. Maybe there were problems, which
should have been solved in a different way.

Possibly the rolloff of the woofer's low pass did not match
the desired result and the constructor could not do better
than using an L-pad.

The resulting Q of the woofer rises, calling for a
different alignment of the enclosure: Maybe the current
enclosures alignment relies somehow on that modified
driver parameters.

This is IMO not a design which should have been
communicated as a building plan to be followed by
others anywhere outside the constructor's workshop, sorry.

It can be - at best - accepted to be an intermediate
state in some development.