It is currently Mon Mar 16, 2020 10:15 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 5 posts ] 
Author Message
Post subject: multiple cabs question
Posted: Wed Jul 11, 2012 5:48 pm
Offline
Hobbyist
Hobbyist

Joined: Sat May 14, 2011 7:14 pm
Posts: 5
A friend of mine was getting rid of his Acoustic B410 cab for cheap so I decided to buy it from him. I already have a GK GLX410 and I was interested in running two cabs live, but I wanted to be sure that my head would be able to power both. The GLX410 has 400W power, 4ohm impedance. The B410 has 400W power, 8ohm impedance. I'm currently running an Ampeg Portaflex 350 head (350 at 4ohms, 250 at 8ohms). I'm looking to upgrade the head in the near future, but for the time being I wondered if I could run both cabs. I realize this isn't a "Fender Amp" question, but the basses I'm running through it are Fenders, so hopefully that counts for something :D


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: multiple cabs question
Posted: Thu Jul 12, 2012 1:57 am
Online
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14046
Location: Province de Québec, Canada
A 4 ohms cab with another 8 ohms cab will give less than 4 ohms load . The Ampeg need 4 ohms minimunmas you write.

I won't use both .


Top
Profile
Post subject: Re: multiple cabs question
Posted: Thu Jul 12, 2012 5:29 am
Offline
Hobbyist
Hobbyist

Joined: Sat May 14, 2011 7:14 pm
Posts: 5
I had done some research on other forums and just wasn't positive because there were no definitive answers to something like this, so I figured I'd ask. Thanks for the help.


Top
Profile
Post subject: Re: multiple cabs question
Posted: Sun Jul 22, 2012 12:02 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Thu Aug 07, 2008 3:12 pm
Posts: 6355
Location: Albemarle, NC
Never mismatch cab impedance such as mixing 8 Ohm and 4 Ohm cabs on the same amp as this is very inefficient. Never go below the Ohm load rating on the power amp.

You can use both these cabs as-is only by adding another power amp. You do not have to have another head complete with preamp and EQ, just a power amp for the second cab. Use the "FX LOOP SEND" jack on the back of the Ampeg Portabass head to patch into the slave power amp for the second cab. Then whatever EQ or volume you have set on the Portabass will also be reflected on the output of the cab powered by the auxiliary power amp. Sometimes this is called a "Slave" amp.

Another option is sometimes it is possible to rewire a 4 ohm cab to make it into an 8 or 16 ohm cab. If you are going to consider doing this sort of thing you can use these links to see different wiring schemes to get different loads. http://www.jumbosunshade.com/swd01.htm
http://www.avatarspeakers.com/wiring%20diagrams.htm
Or you can change out the speakers themselves to get the desired 8 Ohm load.

You also might consider selling the 4 Ohm cab and buying another 8 Ohm one ready to go. When using two 8 Ohm cabs you'll be at a 4 Ohm load and it should be safe for the 4 Ohm capable Ampeg amp.

Few Bass heads will safely handle a 2 Ohm load, which would be the result of using a pair of 4 Ohm cabs powered by one head. They do exist, but most do 4 Ohms minimum.


Top
Profile
Post subject: Re: multiple cabs question
Posted: Sun Jul 22, 2012 1:38 pm
Offline
Rock Star
Rock Star

Joined: Fri Apr 08, 2011 5:14 pm
Posts: 3169
Location: Linningrad
How does the Acoustic B410 cab sound on it's own? As good as the GK? Better? Or does it sound like Craigslist? If it's a keeper then have it rewired at 16 ohms, and leave the GK at 4. That way you could use them together without blowin' your 'peg. And for small gigs, just use the 16 ohm Acoustic. It will act as a power soak allowing you to dial in higher volume tone at a lower db. Used correctly, 16 ohms can be your tone friend. :wink:

_________________
2012 Lefty American Standard Jazz
2017 Lefty American Professional Precision
2018 Rumble Studio 40 Combo
2016 Rumble 200 Combo
One day they shall name a GREAT city after me, and they shall call it LINNINGRAD


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: