Did some testing yesterday at unit, with 2x15 reflex cab (4 ohms) + 1x15 top cab, each cab per channel of 600wpc @ 4 ohm class AB amp.
(Usually used for compression drivers... )
First time testing extension block with built in Ammeter I bought for cheapness.
Fully opened up amp, (small amount of dub eq ), and when fed 0 db, on bass notes, the current draw "often" peaked at 5A (1200W).. !?
Don't forget peeps, only 1x channel on sub, and the 2x15 was only loaded with Kappa Pro 15As, not PD 1550s.
Kinda concerning, when one considers current needed to power 4x 1850s, and only ring mains is available.
nickyburnell wrote: Is the scale of, "whats needed" linear though?
IMHO, numerous factors need considering.
Sub content of music, amount of eq uitlised, hi pass cut off freq, amp efficiency, speaker cable gauge/length, mains cable gauge/length are some of the factors. Have spectrum analyser on laptop, so could see which freqs caused current draw.
If music type with not much below 50hz is played, with almost no eq, driving 4x 18s of household socket, even with saggy mains issue will be walk in the park.
Completely different, if you're playing the stuff I did yesterday, with hi pass set at 32hz/24db, with some bassline peaks 35-45hz, + paramc eq added.
EDIT:Guru just reminded me, Amps with minimal smoothing storage, will also attempt higher current draw.. Explains much..