Bass Heads and Cabs explained? As well as some advice :)

[Luke575443]

Hi guys, I have a Hartke HA3500 head with outputs as follows; 4ohm as 350w and 8ohm 250w. I'm now looking at getting a cab; my budget dictates not the largest of cabs. I've got one in mind, but I'll have to see how it sounds. Its a 4ohm cab with 250w output. My question is whether this is suitable, Im not gonna have to be wary of what volume I'm putting through it etc etc.

Also if you could give me a brief explanation of ohms and watts going together so i dont have to ask this sort of question again, that'd be awesome.

Thanks guys

 

[joedownunder]

Supposedly that's a hundred more Watts than the cab can handle. If your head is rated at 4ohms that's the minimum load it can handle and that's all of your Watts. Since its a 4 ohm cab its going to use all of your power from your amp. 2 8 ohm cabs = 4 ohms. 2 4ohm cabs = 2 ohms and so on

 

[ahc]

Yes... you will need to be "wary" of the volume and amount of bass eq you're putting through the cab. Use your ears. If the cab complains (farting) turn down the volume and/or the bass eq.

 

[Luke575443]

Cheers for input guys, I'm probably gonna look at getting a cab with more similar wattage then.

 

[nashman]

The information you seek is available in the AMP FAQ section here: http://www.talkbass.com/threads/amp...overunderpowercabs-diy-techtalk-links.166225/

If you buy a single 4 ohm cab, you will not be able to add any more cabs. You might consider buying an 8 ohm cab, allowing you to add a second 8 ohm cab now, or later. This would also reduce the risk of your amp having too much power relative to what you cab(s) can handle.

 

[Luke575443]

The information you seek is available in the AMP FAQ section here: http://www.talkbass.com/threads/amp...overunderpowercabs-diy-techtalk-links.166225/

If you buy a single 4 ohm cab, you will not be able to add any more cabs. You might consider buying an 8 ohm cab, allowing you to add a second 8 ohm cab now, or later. This would also reduce the risk of your amp having too much power relative to what you cab(s) can handle.

Thankyou for the link

 

[nashman]

You are most welcome - and welcome to the forum!

 

[Downunderwonder]

You need to spend a few hours reading the AMPS forum sticky.

Basically, sensitivity plus power handling adds up to loudness. This makes 8ohm cabs the go for most solid state amps.

 

[Jim Nazium]

(Hoping not to start a flame war)
The output ratings on speaker cabinets don't really tell you much. They're usually the "thermal" limit, meaning the continuous power that will burn up the voice coils. In practice, most speakers will reach their excursion limit (the farthest the speaker cone can physically move) long before the thermal limit. Also, because cabinet sensitivities vary greatly, a cab that's rated for 350 watts might not be any louder when pushed to its limit than a cab rated at 250 watts. Personally I pay almost no attention to advertised cabinet power ratings. If it plays loud enough without farting out, then it's loud enough.

Impedance, however, is important. Hooking up a cabinet or combination of cabinets with a lower impedance than the amp is rated for can damage the amp.

There's a a lot more info in the FAQ. Have fun.