I was running a Hartke 3500 through a 4 ohm 215 cab that I had rewired to 16 ohms since the hartke is an 8 ohm amp. I found a RBI for a steal so decided to switch to a crown xls drivecore 1000. I also rewired the cab back to 4 ohms. Here's what I dont understand. The Hartke was running 350watts @8 ohms through a 16ohm cab and that setup sounded much much louder than then crown running 1100 watts bridged mono @ 4 ohms. ***??? The numbers dont make sense to me. I could never take the Hartke past 7 without feeling like the walls were going to come down. I can max out the RBI and the crown and it just seems loud. What say the experts?
You are comparing gain structure here more than absolute power. The Crowns output level is entirely dependent on how much voltage the RBI can put into its inputs. IIRC the Crown amps need a fair bit of voltage to go to full output. Also make sure you have wired the drivers properly. If one is wired with reverse polarity, your output will be markedly compromised.
As per Hartke's user manual for the 3500... 3500 @ 4 ohms = 350 W 3500 @ 8 ohms = 240 W 3500 @ 16 ohms = 145 W Not sure why you'd want to run a 16 ohm cab.
The hartke head does put out incredible volume for the watts, I use one over plenty of other heads I've tried out because of the amount of volume it gives on a low setting, incredible heads and ultra reliable.
I agree with Paul. Chances are the RBI isn't putting out enough voltage to drive the Crown to its full output. I think the XLS series needs at least 1.25 volts at the inputs to drive the outputs fully. You might be able to squeak a little more out of the RBI by turning up the DRIVE control a bit. Also make sure you haven't enabled the -20dB output pad.
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