Watts, Power Amps, Etc...

[McLeanAB]

Hey all!

I have a 90 watt per side solid state power amp, the ISP Technologies Stealth... it can bridge to 180 watts, but don't care so much.

I have a 16ohm 25 watt Greenback and a 16ohm Alnico Cream 90 watt and would love to have them paired in a good ol' fashioned 2x12.

Want to do parallel wiring to bring it to 8ohms total.

HOWEVER, will the wattage be spread out evenly between the speakers (in which case it'll be 45 watts slamming into the Greenback) or will the Alnico Cream 'absorb' most of the wattage?

Thanks!

 

[Smash]

Hey all!

I have a 90 watt per side solid state power amp, the ISP Technologies Stealth... it can bridge to 180 watts, but don't care so much.

I have a 16ohm 25 watt Greenback and a 16ohm Alnico Cream 90 watt and would love to have them paired in a good ol' fashioned 2x12.

Want to do parallel wiring to bring it to 8ohms total.

HOWEVER, will the wattage be spread out evenly between the speakers (in which case it'll be 45 watts slamming into the Greenback) or will the Alnico Cream 'absorb' most of the wattage?

Thanks!

I think it would be even, unfortunately. However, is that 90 watts at 4 ohm? Or 90 watts period. Some of the solidstate is set at a 4 ohm load so it would be 45 at 8 ohm

 

[DanTravis62]

To be safe, I would just run them at 16 ohms stereo on each side and do the volume independently.

That will give you maximum volume AND control

 

[311splawndude]

In a 2x12 with varying watts, like in your example McLean, the total load of cabinet will be 2 times the lowest wattage speaker. So 2 x 25 = 50. Your cab will be seen from the amp as a 50w load. Your Greenback will be fine. I ran a 2x12 Avatar for a long time using a G12H30 + CL80, so 60 watts.

I like Dan's idea though too with being able to spread the sound out more, but do consider the Ohms as Smash is saying and also 'what' the amp has as far as load capability. Some will have 2 sperate speaker outs and you then run in parallel or otherwise you have to daisy chain, which automatically makes it a serial connection - which is the most common scenario actually.

PS: Not familiar with your power amp, or power amp set ups in general though so grains of salt needed

 

[McLeanAB]

Thanks, all!

 

[7704A]

In a 2x12 with varying watts, like in your example McLean, the total load of cabinet will be 2 times the lowest wattage speaker. So 2 x 25 = 50. Your cab will be seen from the amp as a 50w load. Your Greenback will be fine. I ran a 2x12 Avatar for a long time using a G12H30 + CL80, so 60 watts.

I think you got that flipped. Each speaker will receive half the wattage that the amp outputs. So the greenback will get 45W at full tilt. The load the amp sees is determined by the impedance, not the wattage rating, of the speaker(s). You may be thinking of the rule that the safe amp wattage (assuming no clipping) for a mixed-speaker cab is 2 times what the lowest-rated speaker can handle. In this case, 50W.

 

[311splawndude]

I think you got that flipped. Each speaker will receive half the wattage that the amp outputs. So the greenback will get 45W at full tilt. The load the amp sees is determined by the impedance, not the wattage rating, of the speaker(s). You may be thinking of the rule that the safe amp wattage (assuming no clipping) for a mixed-speaker cab is 2 times what the lowest-rated speaker can handle. In this case, 50W.

I was strictly talking about how the speakers are treated if they vary in wattage. 2 x the lowest rated speaker (in a 2x12).

https://celestion.com/blog/power-ha...w/#:~:text=As a rule of thumb,-watt = 60-watt.

As a rule of thumb, the cabinet power handling should be calculated as a multiple of the lowest rated speaker. For example in a 2×12 containing a 60-watt speaker and a 30-watt speaker, overall cabinet power handling is 2×30-watt = 60-watt.

That said, I believe you are right as @McLeanAB is asking what the amp is delivering, not what the speakers are working at. If that is true then his question is will 45w to a 25w Greenback be bad? I'm guessing YES?

Thanks for the clarification

 

[7704A]

I'm guessing YES?

I'd say so, though it may not blow right away. A friend got away with pushing 35W of clipped tube amp through a 30W Celestion for a couple months if I recall correctly. That's a smaller overload though, so perhaps the Greenback will go kaput much sooner as it's seeing almost twice it's wattage rating.

 

[rsm]

I have the ISP Tech Stealth 180 W Power Amp.

Specs:

Type: Solid state
Number of Channels: 2
Total Power: 80W @ 4 ohms per side (up to 90W 10% dist), 180W @ 8 ohms Mono Bridge mode
Inputs: 2 x 1/4"
Outputs: 2 x 1/4" (stereo mode), 1 x 1/4" (mono bridge mode)

So at 8 ohms per side you'll be getting 40W per side. Note, bridge mode is at 8 ohms, so you will be getting full 180W!!!!

This is the one I have:

https://www.sweetwater.com/store/de...-180-watt-pedalboard-power-amp-with-rack-ears

 

[McLeanAB]

So... if I understand correctly, parallel wiring with a 16ohm Greenie at 25 watts and an Alnico Cream 16ohm at 90watts will destroy my Greenie if I pump 90 watts of power amp at them.

But, if I also understand correctly, if I pair (in parallel) a 16ohm 65watt Creamback and the 90 watt Alnico Cream at 16ohm my 90 watt power amp will NOT destroy the Creamback?