Never Ordering a Schroeder Cab Again

[ThisBass]

Knock off the nitpicking, OK? It would work fine, with single digit losses for a good part (most transformers are rated 95 to 98.5% efficient), unlike the massive losses of the prior suggestion of using resistors. Transformers work in tube amps, 70v line systems, and power distribution, etc. With a good part, it would work here as weel - just not cheap or light weight.

Transformer efficience depends on transformer nominal power and workload.

Very small transformers show an efficiency of 50% at most while very big transformers may equal an efficency of 99%.

For a 100VA transformer which was charged with 50% duty cycle the resulting transformer efficiency may equal about 80%.
Its common sense that Audio program material does rareley demand 100% of available power. Except on the bench when the transformer was checked with a steady sine wave signal but, a steady sinusoidal signal tells nothing about things that actually do happen powerwise in real practice!
Just to save weight (and costs) its good practice to design a transformer for audio application with a duty cycle number that equals 50% at most.
So a 100VA transformer was good enough to match pretty good to a 200 Watt (RMS) amplifier. If I was optimistic enough I'd estimate the transformer efficiency for about 85%

 

[eyeballkid]

this thread is STILL going???!!!
even the vultures are done with this horse.

 

[BadExample]

But not the Turkey Buzzards!

 

[wmhill]

This thread is going in circles - and that’s being polite...

Vultures always circle first

 

[TomB]

Vultures always circle first

True, but I was thinking more about a drain...

 

[Eddie LeBlanc]

Don Henley says it best my friends: (Nuff said)

 

[tadawson]

But why use a heavy and expensive transformer when you can use a sleeker, lighter, and much more effective series box?

Because a series box is incapable of presenting a 4 ohm load with two four ohm cabs, and a transformer could? The comment I was replying to was regarding power loss in series, and then an even more absurd suggestion of using resistors . . .

 

[12bass]

Because a series box is incapable of presenting a 4 ohm load with two four ohm cabs, and a transformer could? The comment I was replying to was regarding power loss in series, and then an even more absurd suggestion of using resistors . . .

Sorry... should have used the sarcasm smiley. What is the power loss in series (4 + 4 = 8 ohm total load) versus parallel (8 + 8 = 4 ohm total load) with a 4 ohm rated amp?

 

[Munjibunga]

Transformer efficience depends on transformer nominal power and workload.

Very small transformers show an efficiency of 50% at most while very big transformers may equal an efficency of 99%.

For a 100VA transformer which was charged with 50% duty cycle the resulting transformer efficiency may equal about 80%.
Its common sense that Audio program material does rareley demand 100% of available power. Except on the bench when the transformer was checked with a steady sine wave signal but, a steady sinusoidal signal tells nothing about things that actually do happen powerwise in real practice!
Just to save weight (and costs) its good practice to design a transformer for audio application with a duty cycle number that equals 50% at most.
So a 100VA transformer was good enough to match pretty good to a 200 Watt (RMS) amplifier. If I was optimistic enough I'd estimate the transformer efficiency for about 85%

That's what I was going to say.

 

[ThisBass]

Sorry... should have used the sarcasm smiley. What is the power loss in series (4 + 4 = 8 ohm total load) versus parallel (8 + 8 = 4 ohm total load) with a 4 ohm rated amp?

Losses are caused by current. For any other things being equal except current and load.

P1 = I1^2 * 4 Ohm
P2 = I2^2 * 8 Ohm

P1 = P2

I1^2 * 4 Ohm = I2^2 * 8 Ohm

8 Ohm / 4 Ohm = I1^2 / I2^2

I1^2 = 2 * I2^2

I1 = SQRT (2 * I2^2)

I1 = 1.41 * I2

For any other things being equal a 4 Ohm amplifier runs about 41% more of current into 4 Ohm load versus 8 Ohm load.
This means that the thermal losses caused by the amplifer itself (due to increased current the amplifier has to push into 4 Ohm load) the thermal (power) losss inside the amplifier will be increased by factor 2.

 

[12bass]

Losses are caused by current. For any other things beeing equal except current and load.

P1 = I1^2 * 4 Ohm
P2 = I2^2 * 8 Ohm

P1 = P2

I1^2 * 4 Ohm = I2^2 * 8 Ohm

8 Ohm / 4 Ohm = I1^2 / I2^2

I1^2 = 2 * I2^2

I1 = SQRT (2 * I2^2)

I1 = 1.41 * I2

For any other things beeing equal a 4 Ohm amplifier runs about 41% more of current into 4 Ohm load versus 8 Ohm load.
This means that the thermal losses caused by the amplifer itself (due to increased current the amplifier has to push into 4 Ohm load) the thermal (power) losss inside the amplifier will be increased by factor 2.

The dUg Ultra Bass 1000 is rated at 1000W/4 ohms and 600W/8 ohms. Wouldn't that result in a 2.22 dB SPL loss in the 8 ohm series configuration versus the 4 ohm parallel configuration (assuming that the cabinets are of equivalent sensitivity)? Or is there something else in factor in?

 

[eyeballkid]

 

[ThisBass]

The dUg Ultra Bass 1000 is rated at 1000W/4 ohms and 600W/8 ohms. Wouldn't that result in a 2.22 dB SPL loss in the 8 ohm series configuration versus the 4 ohm parallel configuration (assuming that the cabinets are of equivalent sensitivity)? Or is there something else in factor in?

The question you asked was "what is the power loss .... with a 4 Ohm rated amp"

Sorry... should have used the sarcasm smiley. What is the power loss in series (4 + 4 = 8 ohm total load) versus parallel (8 + 8 = 4 ohm total load) with a 4 ohm rated amp?

I tried to give an answer.
The question asked was free of any power rating, so same way for the answer

 

[drpepper]

4 or 8??? Forget about loss of power…what about loss of consciousness? Would it be more efficient and effective to take 4 or 8 steps from standing still to bash my head into a brick wall to bring this to an end?

d = vit + (1/2)at2
d = vit + (1/2)(F/m)t2
d = (0 m/s)(4 s) + (1/2)(8 N / 100 kg)(4 s)2
d = (0 m/s)(4 s) + (1/2)(0.8 m/s2)(16 s2)
d = (0 m) + (6.4 m)
d = 6.4 m
a = F/m
a = 8 N / 100 kg
a = 0.8 m/s2

or

d = vit + (1/2)at2
d = vit + (1/2)(F/m)t2
d = (0 m/s)(8 s) + (1/2)(8 N / 100 kg)(8 s)2
d = (0 m/s)(8 s) + (1/2)(0.8 m/s2)(64 s2)
d = (0 m) + (25.6 m)
d = 25.6 m
a = F/m
a = 8 N / 100 kg
a = 0.8 m/s2

Turns out for all other things being equal, it really doesn't matter...

 

[drpepper]

But not the Turkey Buzzards!

Wait! Late entry with the makings of a great TB throw-down! Buzzard and vulture are synonyms vs buzzards and vultures are totally different...and go

 

[Deleted member 165050]

Wow still going at 25 pages... anyone summarised it all yet?

Requirements misunderstanding + Cable incompatibility + Overreaction from buyer + Underreaction from seller = Golden opportunity for extended TB melodrama

 

[BadExample]

 

[mcnach]

Wow still going at 25 pages... anyone summarised it all yet?

Requirements misunderstanding + Cable incompatibility + Overreaction from buyer + Underreaction from seller = Golden opportunity for extended TB melodrama

Can't wait for the HBO series

 

[Deleted member 165050]

Can't wait for the HBO series

I want to be played by Emilia Clarke.

 

[Eddie LeBlanc]

Just reminded me: This is my summary....... LMBO