Ampeg SVT 3 Pro - What a Difference!

[mik900]

I use a Ampeg SVT 3 Pro with the Ampeg HLF 4 X 10 cab. Whilst this seems ok, I used the head with a 4 X10 cab and 1 x 15, both connected at 4 ohms and the power from the amp was awesome! Although this was adding approx another 300W from the 1X15 I was left thinking why such a huge difference in power output from the amp than my 4X10HLF on it's own? Normally I use it with master approx 4 O'Clock and Gain at 2 O'clock, with the extra cab the master was only at 9 O'clock and still being told to turn down!) Is this just how it is??

Mike

[casapete]

Are you sure your 410HLF is 4 ohms, and your other 1x15 cab is 4 also? If thats the case then the amp will be working into 2 ohms, which unfortunately it is n't designed to do. Running it this way would result in a massive jump in output BUT!! the Ampeg may work for a while but ultimately will overheat and cause some damage to both itself and maybe your cabs too. The amp will only run into speakers totalling 4 or 8 ohms.
(Using two 4 ohm cabs means its a 2 ohm total load on your amp). Even some amps that state they will run down to 2 ohms often are n't happy at being used this way (Peavey etc), so please take care!
I had an SVT3 Pro and found it a touch lacking in output even with 450 watts into its minimum 4 ohm load - perhaps you'd be best off (if you like the Ampeg sound) finding a more efficient (louder!) 4 ohm cab - the Ampeg 6x10 may be worth a look or one of the many other cabs available.
Hope this helps, cheers.

[mik900]

[quote name='casapete' post='893658' date='Jul 13 2010, 01:03 PM']Are you sure your 410HLF is 4 ohms, and your other 1x15 cab is 4 also? If thats the case then the amp will be working into 2 ohms, which unfortunately it is n't designed to do.[/quote]
Thanks for that. I think I might have confused you a bit. The rig I tried (4X10 and 1X15) were not mine they were both 8 ohms. So I was running at 4 ohms. I was just staggered how little master I had to use! (I normally feel through my HLF that I am almost out of head room.) So is this just through moving more air?? And as you say maybe need to consider a more powerful 4 x 10?? (quite like SWR goliath)

[rmshaw37]

i have the 410 hlf and also the single 15 by ampeg, i have tried the 410 115 combination but found the 410 drowns out the 115

my way around this is this wwkend i've made 2 8 ohm 2x10 sealed cabs out of the hlf plus about £50 for wood, connectors, feet etc, found i can still hear the 115 tone, but the 2x10 on top really rounds the sound out.

now i have a gorgeous rig for out and about and a little practice rig in the front room!

but i didnt get on with the hlf sound either