Axiom Home Page Forums General Discussion Advice from Axiom Owners Power requirements with ALFR

I have been reworking my media room to make room for my new Active LFR1100 speakers. I have decided to move the DSP + ADA1500 amps to the front of the room beside each of the two speakers. Along with some new built in shelves and some much needed paint alterations, I am almost ready to plug everything back in.

Then it hit me. How do I want to power these new amps? When I originally laid out the room, I had put in a Split Dual 20 amp receptical on the side wall where I had originally put the tower of music parts. For the rest of the room, there are ample plugs, but they are all on a single 15amp breaker shared for all the plugs.

I have moved up from a single ADA1000 to the much larger and likely more power hungry ADA1500, and as well, there are now two of them.

Question: Will I run into power issues trying to run two ADA1500 amps at any decent volume off a single 15amp breaker?

Do I need to look into installing a second Split Dual 20 amp receptical to the front of the room to power these two amps so as not to keep tripping the breaker?

Unless your room is gigantic or you're running them out doors ... you'll be fine. You'll still get all the headroom just can't run it continuously at some ungodly volume ... anyway, it costs nothing to try ... see if you can blow a circuit breaker at some ear blowing level (wear hearing protection).

My guess is that in a reasonably sized room you'll never get close to needing all the current from a 15A circuit. If you do, I'll bet you're either hard of hearing or soon will be JMO.

I know you are likely correct. Part of me wants it to be wrong as then it justifies the upgrade from the ADA1000 to the ADA1500 amps. if you are not pulling enough wattage to blow the breaker then you are clearly not using all the available power that the amp can produce.

I will have to post when I give it a try. If you can't hear my music then obviously I haven't got it cranked up loud enough. You're only 400 or so miles away.

I liken amplifier power with horsepower and capacitor capacity with torque. One's great for top speed, the other for acceleration. You can have both if you throw enough money at it, but few of us truly listen to >100 dB SPL's.

I put in a 100A sub panel into the media room. Not because I felt I needed it but because 1) I wanted the ground runs for all the circuits to be as short as possible and 2) have more circuits than I could possibly need for flexibility. If I decked out the room, the max power demand would be over 10,000watts of amplification. I’m fairly sure that continuously I’d never exceed 5 to 10% of that. 15 to 20Amps would still be plenty.

Actually, I think most will never need the continuous power that the ADA1500 can supply. It’s the dynamic power and high voltage rails which gives it the ummph (a highly technical engineering term I’m including for Mojo benefit ) to keep you clip free.

Besides who can resist the cool factor of balanced inputs and the brag factor of 1500W continuous 4500W (?) dynamic. Think Craigsub once mentioned that it was mind blowing that the amplification on his ALFRs could hit 9000W peaks (one/speaker)

I edited that last post wrong ... meant one ADA1500/speaker

With regards to “justifies the upgrade” this is one upgrade I believe is a no brainer for the actives. I upgraded from the ADA1000 to ADA1250 specifically for the drop in noise floor. I’m evidently VERY sensitive in that area and had lengthy exchanges with both Andrew and Ian. Max output was not my goal but achieving the lowest noise floor and per Andrew, the ADA1250 would provide just that as it is the exact same design as the ADA1500 with a touch less power. You are going to get a very similar improvement but with more available output.

The difference was very marked in my case. Very happy with the upgrade.

the way that Ian explained it to me was that the power requirements for the larger amps are not constant. you have a big coil that powers some really big capacitors. these will store an awful lot of energy that can be given to the speakers when needed, but the amps will never likely ever need this sort of power constantly. it will come in bursts of demand then the coil transformer will re-energize the capacitor.

Running my two ADA1500 + both DSP and the pair of EP500 subs from the same plug likely will never exceed the power limit of a regular 15amp plug except possibly when you turn everything on at the same time. He is running 5 ADA1500 amps off a single plug and never run into a power issue except for the startup. He now uses a staggered 12v signal line coming into the amps so they will each turn on several seconds after each other.

I figured that I can do a similar thing perhaps in a slightly different manor. I have bought some smart plugs and a pair of smart power bars that i can control through my Alexa FireTV box. I've created a scene for the room that will allow me to setup the room so that the lights turn on to the correct level. then it will progressively turn on all the equipment in the order that I choose, so the DSP's on first. Then it will trigger on each of the amps with a few seconds between each so that there is no power inrush that could blow the breaker. it will also allow me to cut away some of the standby power leaching as i can actually cut the power off to the smart plug. The smart switch itself consumes less power than all the plugged in devices do sitting in standby. just got to wait now to get the DSP fixed so that I can give it all a proper test.