Speaker specs/ Blues Jr.

[svenoleary]

I'm running my Blues Jr. through a 2x12 cab. Two 16 ohm speakers in parallel yield an 8 ohm load. My question is...will the power delivered to the speakers also be halved, (like the ohmage). The Jr. runs at 15 watts, so do I want speakers that handle 15-20 watts? I'm working from the assumption that speakers should be rated at twice the amps output.
Many Thanks

[Julia343]

Not necessarily. It depends upon if you want speaker breakup or not. If you're rated too high you won't get the cone smoothing. So here's the deal. If you want something that's compatible with the Blues Jr. (8 ohm) speaker output with sufficient headroom and yet have it sound different than the BJ, I'd go with a closed back cab with 2 Celestion Heritage G12M Greenbacks (rated at 20W each). speakers should be 16 ohms wired in parallel. You should be fine. But you might want to check with a speaker cab maker like Avatar.

[SRVTWO]

Yep when pushed into a 2-12 cab you are spliting the power between the two speakers. This is what made it possible back in the day for a 4-12 Marshall Cab loaded with 4 25 watt speakers to handle a 100 watt head. Julia above is right that if you want any cone breakup you need to get close to the power rating or speaker breakup wont really happen. My opinion though is to get a speaker with a high efficiency rating as the 15 watts from the Blues Junior are precious.
Mike

[svenoleary]

Thanks all.
Mike, just how efficient a speaker would you suggest??

[SRVTWO]

Well the more efficient the speaker the better. I use a Eminence Govenor in mine which is rated 102db....Remember this, for every 3db of efficiency you are theoretically doubling your wattage. The difference in a 50 watt amp and a 100 watt amp, everthing else being equal is three db. So every db you can get is precious. If you think about it you can make your Blues Jr. louder than a 100 watt amp with the right speaker combination.
Mike

[zzmoore]

Originally Posted by SRVTWO

If you think about it you can make your Blues Jr. louder than a 100 watt amp with the right speaker combination.
Mike

I have a 1971 Marshall 100 Watt Super Lead. I will meet you at sundown. You had better tell your "loved ones" Good Bye.

[SRVTWO]

No, no, no, no wishes for death here , remember I did use the term theoretically. But a perfect example would be a 50 watt Marshall through 100 db speakers and a 100 watt through 95 db speakers and the 50 watter is gonna sound louder. Its just the way the human ear perceives things.
Mike

[Scumback Speakers]

Originally Posted by SRVTWO

Yep when pushed into a 2-12 cab you are spliting the power between the two speakers. This is what made it possible back in the day for a 4-12 Marshall Cab loaded with 4 25 watt speakers to handle a 100 watt head. Julia above is right that if you want any cone breakup you need to get close to the power rating or speaker breakup wont really happen. My opinion though is to get a speaker with a high efficiency rating as the 15 watts from the Blues Junior are precious.
Mike

Back in the day, Marshall put two 4x12 100 watt cabs with their 100 watt amps, not one. Those speakers won't be around real long if you expect them to handle a healthy 100 watt Marshall. I can't tell you how many thought that and then contacted me for 65 watt versions of the speakers they just blew.

The 100 watt Marshall into a 100 watt cab (unless you play on less then 4 all the time) will damage your speakers over time. But hey, if you've got plenty of cash, then no problem. :AOK

[Captain Midnite]

I owned a '74 Super Lead, totally ripping BUT volume-wise unusable past 2.

[SRVTWO]

Originally Posted by Southbay Ampworks

Back in the day, Marshall put two 4x12 100 watt cabs with their 100 watt amps, not one. Those speakers won't be around real long if you expect them to handle a healthy 100 watt Marshall. I can't tell you how many thought that and then contacted me for 65 watt versions of the speakers they just blew.

The 100 watt Marshall into a 100 watt cab (unless you play on less then 4 all the time) will damage your speakers over time. But hey, if you've got plenty of cash, then no problem. :AOK

Totally agree, :AOKNot a great idea to run the 100 watt tube head into a 100 watt cab. A healthy 100 watt tube amp can totally put out transient bursts feeling closer to 200 watts. Its always safer to er on the side of caution when dealing with $. I know after running an AC30 into two alnico blues rated at 15 watts a piece is a scary feeling but it sounds sooooo goood right before it blows up. No seriously, I never blew it up but it is a sound that is dependent on all the components running right at the edge of chaos.
By the way love you guys' stuff keep makin those kick ass speakers.
Mike

[Guitar Josh]

Originally Posted by Southbay Ampworks

Back in the day, Marshall put two 4x12 100 watt cabs with their 100 watt amps, not one. Those speakers won't be around real long if you expect them to handle a healthy 100 watt Marshall. I can't tell you how many thought that and then contacted me for 65 watt versions of the speakers they just blew.

The 100 watt Marshall into a 100 watt cab (unless you play on less then 4 all the time) will damage your speakers over time. But hey, if you've got plenty of cash, then no problem. :AOK

Is this why the Dual Rec cab is 240 watts for a 100w head?