Ashdown: Where are the missing 200 watts

[Phil Adams]

An idle question of very little consequence really.
If Sir were to purchase an Ashdown RM C112T 500 Evo combo it claims to be rated at 500 watts.
If Sir were to purchase an Ashdown RM 112T Evo cab it claims to be rated at 300 watts, seemingly has the same white line speaker.
Who has the missing 200 watts, or shouldn't I ask....

[bartelby]

Is that 500w at 4 Ohm?
So around 300w at 8Ohm...


And the speakers are both 300w 8 Ohm speakers. So you'd need an extension cab to get 500w out of the combo?

Edited February 24, 2017 by bartelby

[Dood]

It's an interesting one. The speaker is an 8 Ohm unit. The amplifier will output 507W RMS in to 4 ohms. Therefore, you will need two of those cabinets to get 507W from the amp. The rating they are giving is if the RM C112T was also connected to an extension cabinet.

[lowhand_mike]

pretty much all amp manufacturers do this, they state the highest power the amp can deliver but its generally at 4ohms and most people only buy one cab which will be rated at (generally) 8ohm which as stated gives you about half to two thirds of the power. Combos are just like having one cab so they run at 8ohms.

[BrunoBass]

I'm an intelligent, educated man. However I find this whole impedance / ohms thing utterly baffling. I'm new to the whole head / cab thing, surely there's a way I can get my head round it? I can't be that complicated?

[xgsjx]

[quote name='PaulGibsonBass' timestamp='1487983400' post='3244897']
I'm an intelligent, educated man. However I find this whole impedance / ohms thing utterly baffling. I'm new to the whole head / cab thing, surely there's a way I can get my head round it? I can't be that complicated?
[/quote]
Ohms go down, not up.
If you put 2 8 ohm speakers on an amp, it makes a 4 ohm load. Two 4 ohm speakers make a 2 ohm load.
If you put an 8 & a 4 ohm speaker on an amp, you then are adding a 4 ohm and putting @ another load on of 8 ohm, which brings the load to 2.66.
Most bass amps will go down to a 4 ohm load , but some go to 2 ohm.
The more load you put on the amp, the more power, the more power, the more watts at full volume, the more stress you're putting on the amp's electrical circuit.
Using more watts doesn't necessarily mean things are going to be louder, that part is down to the cab(s).

[Sparky Mark]

[quote name='PaulGibsonBass' timestamp='1487983400' post='3244897']
I'm an intelligent, educated man. However I find this whole impedance / ohms thing utterly baffling. I'm new to the whole head / cab thing, surely there's a way I can get my head round it? I can't be that complicated?
[/quote]

Try Google ing Ohm's Law. Wikipedia should explain it clearly for you.

[Phil Adams]

Ahhh, so what they really mean is that in its current form it should deliver 250-300 watts, but it's capable of 500 if brought down to 4 ohms with the addition of a second 8 ohm cabinet.
I'm gonna sue, something along the lines of French and Saunders case against Ralph McTell.
Exhibit "A" m'lud.

[Bill Fitzmaurice]

[quote name='Phil Adams' timestamp='1488025758' post='3245120']
Ahhh, so what they really mean is that in its current form it should deliver 250-300 watts, but it's capable of 500 if brought down to 4 ohms
[/quote]That's what they mean, but it's of no consequence anyway. Output is limited by voltage swing, which is the same irrespective of the load, while sound levels are measured in decibels, and there's no direct correlation between power and decibels.

[Chienmortbb]

Of course the maximum voltage swing is a limiting factor in the power output by an amplifier but is not the only one. Many amplifiers have power supplies that cannot supply the extra current needed by 4R speakers. As an example, the Hartke 3500 Is rated at 250 watts into 8R and 350 watts in to 4R.

The power supply cannot supply enough current. Power is the product of Volts x Amps so Voltage is important but cannot be considered in isolation.

As for the actual SPL, if using the same driver in the same enclosure, not driven too hard there will be a correlation between a change in the power output by the amp and and change in the acoustic output from the speaker system. It may not be linear but over a limited range it will be affixed relationship.

Of course if you drive the speaker too hard, power compression becomes a factor and the relationship is broken.

[Count Bassy]

[quote name='Bill Fitzmaurice' timestamp='1488030444' post='3245175']
That's what they mean, but it's of no consequence anyway. Output is limited by voltage swing, which is the same irrespective of the load, while sound levels are measured in decibels, and there's no direct correlation between power and decibels.
[/quote]

Output swing,[i] and the current/thermal limits of the output devices[/i]!