Where Does The Extra Wattage Go?

[SurferJoe46]

Take a 600 Watt combo (210 speakers, horn and amp in one container) and turn off the horn.

Where does the power that was dedicated to go to the horn, now go?

Why I wonder about this is - since there's just a ON/OFF switch for the horn - and no obvious network (and possibly the horn doesn't NEED a network since it won't work below "X" frequency anyway) - then why can't just a volume control pot be used to control the output of the horn?

I may misunderstand it - since but a piezzo horn doesn't use Wattage, but voltage and if just a switch being opened will turn off the horn and not cause any damage for lack of a load to the finals on the amp - then a potentiometer should suffice - NO?

[JimmyM]

where does the wattage go? why wattage heaven, of course!



it doesn't go anywhere. you're just not using it.

[SurferJoe46]

Originally Posted by JimmyM

where does the wattage go? why wattage heaven, of course!



it doesn't go anywhere. you're just not using it.

OK, James - now answer the rest of my question.

[seamonkey]

It goes to heat, turn down the treble if you turn off the horn, then less power will go to treble and get wasted in heat.
You need and l-pad to do it right - but
No need for a l-pad if you turn down the treble.

[SurferJoe46]

Originally Posted by seamonkey

It goes to heat, turn down the treble if you turn off the horn, then less power will go to treble and get wasted in heat.
You need and l-pad to do it right - but
No need for a l-pad if you turn down the treble.

I need more info then - if possible.

What I see in the iso-schematic of my amp is that there is NO network in the lines to/from the horn.

Physically I looked when I had the cab open, but there are two dedicated pairs coming out a sealed hole from the amp, above the main enclosure.

One pair (blk/red) goes to the 2-10s and the other pair (blk/blu) go directly to the horn.

There is a switch only interrupting the horn leg (just one wire) and there is no pad or resistor bank to keep the amplifier happy thinking the horn is still on the other end of the wires at all.

I thought an L-pad was needed in a balanced and 'needs to see a constant load' type system.

And wouldn't an L-pad need to be capable of the whole 600 Watts too? I don't think there's one with that capacity without some fan-cooled rheostats.

I just want some control over the output of the horn besides an either/or situation.

[otis_thick]

If the horn has a pad,,,it goes into the resistor and is turned into heat...that's why some cab makiers recommend that you do NOT turn the horn down all the way if you are using high wattage....over time playing at high wattage can cause the pad turn burn the hell up!

[JimmyM]

i thought they had fixed that problem with tweeter attenuators a long time ago. they still can burn up if they're off?

[johnk_10]

if the 4 wires from the cab's jack goes to the speakers and horn (wired in parallel) with no other circuit other than the switch, when you flip the switch that disconnects one wire, all of the power is now just going to the speakers.

[fractiouslowend]

can't you just admire the magic that is bass amplification? :P

[otis_thick]

Originally Posted by JimmyM

i thought they had fixed that problem with tweeter attenuators a long time ago. they still can burn up if they're off?

Sho Nuff ...I've done it twice....it was bad 2...smoke and fire! There is a note that comes with the Avatars with horns...this goes for the L-Pad not a plain on/off switch. Its also mentioned at Eden

[KJung]

Originally Posted by johnk_10

if the 4 wires from the cab's jack goes to the speakers and horn (wired in parallel) with no other circuit other than the switch, when you flip the switch that disconnects one wire, all of the power is now just going to the speakers.

+1 For example, Don from LDS provides both an attenuator and an 'on/off' bypass switch for his tweeters (by request)... so you can either have a two way (or three way cab), or literally take the tweeter and crossover completely out of the circuit. If you just turn the attenuator down, it is just, as said above, 'absorbing' the power that originally passed through to the tweeter.

Of course, another issue is if the tweeter circuit is based on a simple lo pass filter or a true crossover. If the tweeter is lo passed, then if you turn the attenuator down, the driver is still running at full range (this is kind of how the Epifani cabs work... at least the UL's). If it is crossed over, then usually the top end of the driver's range is cut-off, and the result will not be very pleasant (unless you have a true bypass switch).

[billfitzmaurice]

Originally Posted by SurferJoe46

And wouldn't an L-pad need to be capable of the whole 600 Watts too? I don't think there's one with that capacity without some fan-cooled rheostats.

Power content drops by 1/2 with each octave increase in frequency, so above 4kHz there might be 15 watts in a 600 watt full bandwidth signal. The problem with toasting LPads, and tweeters for that matter, comes from inadequate crossover slopes. A 12dB filter lets through too much low frequency power to the LPad and tweeter. 18dB is considered the minimum acceptable for pro-level gear, with 24dB preferred. But 12dB filters are less expensive, ergo...