ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: 4 ohm amp into 8 ohm speaker cab?  (Read 5728 times)

Efrain Guzman

  • Newbie
  • *
  • Offline Offline
  • Posts: 34
4 ohm amp into 8 ohm speaker cab?
« on: March 09, 2010, 12:09:02 am »

So we finally made some purchasing decisions on the amp head and cab, but it seems we didn't examine everything...

We purchased a Line 6 HD400 400W Amplifier Head...
The back of this amp head states... SPEAKER OUTS: Only use a 4 Ohm speaker cabinet when running in mono. Only use 8 Ohm speaker cabinets when feeding a pair.

We bought an Acoustic b410 400W 4x10 8 Ohm Impedance Bass Cabinet.

So since it states to either connect an 8 Ohm pair or a 4 Ohm single I decided to connect a JBL JRX115 250W continuous 2-way speaker cab.

My first question is can this damage the JBL speaker?

My second question is can I just run the 8 Ohm Acoustic b410 Bass Cab with the 4 Ohm Speaker Output of the Line 6 HD400 Amp Head?

Logged

Arnold B. Krueger

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 850
    • http://www.pcavtech.com
Re: 4 ohm amp into 8 ohm speaker cab?
« Reply #1 on: March 09, 2010, 08:20:41 am »

Efrain Guzman wrote on Tue, 09 March 2010 05:09

So we finally made some purchasing decisions on the amp head and cab, but it seems we didn't examine everything...

We purchased a Line 6 HD400 400W Amplifier Head...
The back of this amp head states... SPEAKER OUTS: Only use a 4 Ohm speaker cabinet when running in mono. Only use 8 Ohm speaker cabinets when feeding a pair.

We bought an Acoustic b410 400W 4x10 8 Ohm Impedance Bass Cabinet.

So since it states to either connect an 8 Ohm pair or a 4 Ohm single I decided to connect a JBL JRX115 250W continuous 2-way speaker cab.

My first question is can this damage the JBL speaker?



Sure you can *always* damage speakers with a reasaonably powerful amp, unless you use reasonable care.  You can always crash a car if you drive stupid. This is life in the real world!

There are people who advise using amps with twice the continuous power ratings of the speakers. If you don't do anything stupid and listen carefully at all times for bad sound from your equipment (indicating it is being overstressed) there shouldn't be a problem.

Quote:


My second question is can I just run the 8 Ohm Acoustic b410 Bass Cab with the 4 Ohm Speaker Output of the Line 6 HD400 Amp Head?



Yes. The warning in the manual can be read more than one way, but the usual rule with solid state amps is that they will run well into loads that have higher impedance than their minimum rating.
Logged

Brad Weber

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1484
Re: 4 ohm amp into 8 ohm speaker cab?
« Reply #2 on: March 09, 2010, 09:14:56 am »

Thought this might be a common question and a quick search showed that to be true, http://line6.com/community/message/106680#106680.
Logged
Brad Weber
muse Audio Video
www.museav.com

Efrain Guzman

  • Newbie
  • *
  • Offline Offline
  • Posts: 34
Re: 4 ohm amp into 8 ohm speaker cab?
« Reply #3 on: March 09, 2010, 10:51:44 am »

Perfect!  Thanks for the info everyone!
Logged

Matthias Heitzer

  • Full Member
  • ***
  • Offline Offline
  • Posts: 123
Re: 4 ohm amp into 8 ohm speaker cab?
« Reply #4 on: March 09, 2010, 03:59:28 pm »

Solid state amps (practically everything thats not a tube amp) only require a minimum impedance to work with (usually 2 or 4 ohms). If the speakers impedance is higher, the output voltage will result in a smaller current and therefore less power. Thats all.
If several cabinets are connected, you have to be carefull. If they have the same impedance, each time you double the cabinets, the impedance is halved.
Logged
I'm from Germany,so please excuse my bad english.

ProSoundWeb Community

Re: 4 ohm amp into 8 ohm speaker cab?
« Reply #4 on: March 09, 2010, 03:59:28 pm »


Pages: [1]   Go Up
 



Page created in 0.02 seconds with 18 queries.