Author Topic: I Need Help (Read 7645 times)

Guitarzan · « **on:** September 29, 2005, 01:03:13 AM »

I am in the market for a new speaker for my solid state Crate GFX50. Does anyone know what would happen If i put an 8 ohm speaker on in replacement of the 4 ohm stock speaker. Also what do ohms affect with the sound and tone anyway? Any help will be appriciated.
Guitarzan

HJM · « **Reply #1 on:** September 29, 2005, 07:16:57 AM »

If your Crate is a transistor, your amp may sound quieter than before - rule of thumb is double the speaker impedance your power output is divided by 2. But of you choose a sensitive speaker like the Vintage 30 an 8 ohm speaker may come out louder than the 4 ohm as it can deliver more dBs per watt!

Also your amp would be happier with a higher load, so should last longer.

If your amp is valve, disregard all of the above and find a 4 ohm speaker!

PhilKing · « **Reply #2 on:** September 29, 2005, 12:41:08 PM »

Another option is to get an 2x12 extension cab. You can wire two 8 ohm speakers in parallel to get 4 ohm. If the cab has an original resistance of 16 ohm, then it will have two 8 ohm in series, if the original resistance is already 8 ohm, then forget it! It will be two 16 ohm in parallel and you will be stuck!

HJM · « **Reply #3 on:** September 29, 2005, 03:35:48 PM »

Yeah but we need 4 don't we??? :P

Bob Johnson · « **Reply #4 on:** September 29, 2005, 04:29:27 PM »

An 8ohm speaker will actually reduce the load on the output stage of the amp, Ohms law shows that load is inverse to resistance and the same principal stands for impedance even though the relationship and the math is more complex. This will reduce the output of your amp for a given input.
Depending on how the output stage is configured, this can affect the biasing causing some components to eventually fail.

It's a gamble really.

HJM · « **Reply #5 on:** September 29, 2005, 04:33:54 PM »

yeah..that's what I meant, just you make more sense Bob!

indysmith · « **Reply #6 on:** October 01, 2005, 11:46:03 AM »

Why are you getting a new speaker? :? I'd be saving for a small valve amp!

Guitarzan · « **Reply #7 on:** October 01, 2005, 03:25:31 PM »

I do have a small valve amp. But both that and the solid state are sh**. There is no treble at all. I want to replace both but I don't know anything about the valve because it is so generic there is no labels on it at all. I am thinking about an Eminence Legend for the solid state and an eminence Rajin Cajun for the valve.

big steve · « **Reply #8 on:** October 01, 2005, 04:12:03 PM »

if the valve amp is sounding cr@p, perhaps it's time for some new power tubes.

Guitarzan · « **Reply #9 on:** October 02, 2005, 12:53:26 AM »

No, the tubes are fine I think... It's been played sparingly for the past 2-3 yrs. It's just REALLY bad. The crate is poor to moderate sound quality.