How do I find out what amperage DIY speakers take?

[kizm0]

I want to know how to find out what Amperage my ZMV5's need.

Here's a link to the speaker build page:
http://www.zaphaudio.com/ZMV5.html

The crossover I used is this one:
http://www.zaphaudio.com/ZMV5-options-reducedBSC.gif

I know that to choose a good amp for my speakers, they should be close or spot on to the requirements of the speakers.

The amperage of the Amplifier should be equal to the monitors requirements.

The OHM rating also needs to be equal for best results.

I need somebody to completely explain this, or link me to some place that already did that.

I've googled for some time..it's probably out there..oh well thanks people.

[Dr.EM]

The amplifier doesn't need to supply a specific amount of current. It just needs to be capable of supplying the current required, which naturally will change dependant on the level. An amplifier with a well built power supply, high damping factor and suitable power output will supply the current needed. These speakers don't present a particularly difficult load in any case, so finding/building a suitable amp should be quite trivial

The impedance (in ohms) of the speakers that the amp can power must be considered, and is related to the current requirement. Fortunately, this speaker design is 8 ohm nominal and just about any modern amplifier will be able to power them with ease (most can do 4 ohm too, which requires more current).

If you've posted in this sub-forum as you intend to build a chip-amp to power these, then one of the many LM3886 designs should be quite suitable. I'll let someone more experienced with them elaborate on this though

[AndrewT]

Hi,
the speaker and it's crossover demands current.
It's the amplifier's job to meet this demand with as little voltage variation as possible.

Look in the spec at dBV for different load resistances.
If it drops 0.4dBV going from 8r0 to 4r0, then it supplies current well.
If it drops 1dBV, then it's mediocre to OK.
If it drops <=1.5dBV, then run ... fast. It cannot supply decent current to match the demand.

If you are looking for a 4ohm speaker compatible amplifier, then compare the 4r0 and 2r0 dBV values.

Unfortunately, few of the usual specifications tell us anything about the amplifier's ability to drive reactive loads.

BTW,
Cordell's rule of 180% power into half load resistance ~= -0.4dBV
eg. 52W (20.4Vac) into 8r0 falling to 95W (19.3Vac) into 4r0.

[h_a]

This speaker appears as an easy guy to drive, don't worry about amp requirements.

Have fun, Hannes