Ampeg SVT 3 Pro- What a difference!

MIKE900 · #1 07-13-2010, 03:38 AM

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 when 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

Low Sound Love · #2 07-13-2010, 03:46 AM

the HLF is a 4ohm cab, so the svt3 pro will be putting out its maximum of 475Watt with that speaker alone as well.
Adding an extra cab (you used 2 8ohm cabs making for a total load of 4ohm) will result in more air being pushed, that's probably why it seems to be louder.
If you used 2 4 ohm cabs the total load would be 2 ohm, and that would damage your amp.

KJung · #3 07-13-2010, 05:20 AM

As stated above, I think the HLF only comes in 4ohm version. If that is the case, your amp is putting its full, rated, safe power into that cab, and you can't safely add another cab.

If you did add another cab (the 8ohm 115), then you are running your amp at 2.67 ohms, and it will eventually shut down due to heat, etc., and possibly even be damaged in the long run. So, again, assuming you have a 4ohm HLF, don't do this again!

Any time you add a second cab, you will get a different, louder, more full tone, due to the increase in output from the amp (your 3Pro will be putting out more than its safe rated power), the extra cone area, and the coupling of the cabs.

Edit: Also, the power rating of your 115 does not indicate how much additional power the head is putting out. This is determined by the impedance of the cab(s). The power rating of a speaker is a loose guideline for safe MAXIMUM power, and has nothing to do with absolute volume or SPL (loudness per watt).

Groover · #4 07-13-2010, 06:25 AM

The SVT3-Pro never ceases to amaze me. I connected to an NV215 and I was just blown away how nice it sounded.

MIKE900 · #5 07-13-2010, 07:01 AM

Quote:

Originally Posted by KJung

If you did add another cab (the 8ohm 115), then you are running your amp at 2.67 ohms, and it will eventually shut down due to heat, etc., and possibly even be damaged in the long run. So, again, assuming you have a 4ohm HLF, don't do this again!

(loudness per watt).

Thanks all. I think I may have confused you a bit. I used my SVT head using a 4X10 and 1X 15 (not mine!) they were both 8 ohms so as Low sound says it was running at 4 ohms. My point was that I was just staggered at the difference in response from the amp and how little master I had to use. Normally I feel like I'm pretty much driving the amp near max with my HLF. Is this just down to moving more air??

Cheers Mike

meycom · #6 07-13-2010, 07:03 AM

My SVT 3 Pro loves my 4ohm SWR Goliath Sr. Never can put it beyond 2-3. Massive power and sound.

KJung · #7 07-13-2010, 07:04 AM

Quote:

Originally Posted by MIKE900

Thanks all. I think I may have confused you a bit. I used my SVT head using a 4X10 and 1X 15 (not mine!) they were both 8 ohms so as Low sound says it was running at 4 ohms. My point was that I was just staggered at the difference in response from the amp and how little master I had to use. Normally I feel like I'm pretty much driving the amp near max with my HLF. Is this just down to moving more air??

Cheers Mike

Ah, thought the 410 was the HLF you mentioned... OK, cool.

However, now we have an apples to oranges. Your HLF cab is a relatively low SPL cab (voiced deep and low). So, it is hard to know if adding the 15 was the main driver or that the other 410/15 combination was just higher SPL in general. You might have experiences something similar if that other 410 was 4ohm, if it was higher SPL than your HLF.

That being said, a second cab usually gets you about +3db, which is a lot!

NKBassman · #8 07-13-2010, 07:13 AM

My 3-Pro sounds kind of blaaaa at home through my 8 ohm 4x10 and at low volumes, but there just so happens to be an extra 8ohm 4x10 at the jam space, so every now and then I'll stack the two cabs and crank it at 4 ohms and it really, REALLY opens up nicely. IMO, that cab demands a 4 ohm load.

panama · #9 07-13-2010, 07:25 AM

Having the stack puts more of the sound up at ear level. That's the difference.

NKBassman · #10 07-13-2010, 10:13 AM

That may have something to do with it. Regradless, it sounds better.

pedulla1 · #11 07-14-2010, 05:42 PM

Quote:

Originally Posted by KJung

As stated above, I think the HLF only comes in 4ohm version. If that is the case, your amp is putting its full, rated, safe power into that cab, and you can't safely add another cab.

If you did add another cab (the 8ohm 115), then you are running your amp at 2.67 ohms, and it will eventually shut down due to heat, etc., and possibly even be damaged in the long run. So, again, assuming you have a 4ohm HLF, don't do this again!

Any time you add a second cab, you will get a different, louder, more full tone, due to the increase in output from the amp (your 3Pro will be putting out more than its safe rated power), the extra cone area, and the coupling of the cabs.

Edit: Also, the power rating of your 115 does not indicate how much additional power the head is putting out. This is determined by the impedance of the cab(s). The power rating of a speaker is a loose guideline for safe MAXIMUM power, and has nothing to do with absolute volume or SPL (loudness per watt).

Ken so you are saying even though this is a stereo amp the resistance per side affects the overall power output? I assumed a 4ohm load on one side gets 275 watts and an 8ohm load on the other side gets 300 watts.

bassmanbiff · #12 07-14-2010, 05:54 PM

I'm curious why you suspect this is a stereo amp. While I'm not that familiar with an SVT3-pro, it looks like a normal amp with multiple outputs.

JimmyM · #13 07-14-2010, 06:14 PM

it's not a stereo amp.

Buster Brown · #14 07-14-2010, 07:27 PM

Quote:

Originally Posted by KJung

As stated above, I think the HLF only comes in 4ohm version. If that is the case, your amp is putting its full, rated, safe power into that cab, and you can't safely add another cab.

If you did add another cab (the 8ohm 115), then you are running your amp at 2.67 ohms, and it will eventually shut down due to heat, etc., and possibly even be damaged in the long run. So, again, assuming you have a 4ohm HLF, don't do this again!

Any time you add a second cab, you will get a different, louder, more full tone, due to the increase in output from the amp (your 3Pro will be putting out more than its safe rated power), the extra cone area, and the coupling of the cabs.

Edit: Also, the power rating of your 115 does not indicate how much additional power the head is putting out. This is determined by the impedance of the cab(s). The power rating of a speaker is a loose guideline for safe MAXIMUM power, and has nothing to do with absolute volume or SPL (loudness per watt).

Yep, you are correct. I always thought of that as the one major drawback to the 3Pro. I mean, I really liked the head, but the 4 ohm limit was a little too much of a limitation for me..

JimmyM · #15 07-14-2010, 09:11 PM

4 ohms is about par for the course with ss heads. some of the more powerful ones do 2, but i'm so used to the 4 ohm limit with ss heads that 2 isn't even a selling point for me. of course it never was, considering at my loudest i was using 100w into a 4 ohm 810

Buster Brown · #16 07-14-2010, 09:15 PM

Quote:

Originally Posted by JimmyM

4 ohms is about par for the course with ss heads. some of the more powerful ones do 2, but i'm so used to the 4 ohm limit with ss heads that 2 isn't even a selling point for me. of course it never was, considering at my loudest i was using 100w into a 4 ohm 810

Dang Jimmy...what a difference when you consider that the old Acoustic 370 could do (if memory serves) something like 1.34 ohms and never break a sweat...

pedulla1 · #17 07-14-2010, 09:30 PM

I owned 2 of those amps and just assumed since they had 2 outputs that made it stereo LOL. Thanks for setting me straight guys.

JimmyM · #18 07-14-2010, 09:33 PM

Quote:

Originally Posted by pedulla1

I owned 2 of those amps and just assumed since they had 2 outputs that made it stereo LOL. Thanks for setting me straight guys.

no problem. for future reference, a stereo amp has to have two separate amps inside and usually has two separate speaker outs for each amp. the 3 pro has one amp and two speaker outs.

JimmyM · #19 07-14-2010, 09:33 PM

Quote:

Originally Posted by Buster Brown

Dang Jimmy...what a difference when you consider that the old Acoustic 370 could do (if memory serves) something like 1.34 ohms and never break a sweat...

ya, all due respect to our pal vetchking, but i was never a big fan of acoustics

my chorus director had a 370/301 and i had a 136 combo, but as soon as i heard my first ampeg rig, it was all over

Buster Brown · #20 07-14-2010, 09:49 PM

Quote:

Originally Posted by JimmyM

ya, all due respect to our pal vetchking, but i was never a big fan of acoustics

my chorus director had a 370/301 and i had a 136 combo, but as soon as i heard my first ampeg rig, it was all over

HEHE...

I heard through the grapevine.....ahh...never mind..

But seriously folks.....

I'm in your camp! Love me some Ampeg..but I have always had a soft spot in my heart for the good ol days with Acoustic!