Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?)

teddis

teddis

Fractal Fanatic
Hi Guys,
I would like to run my Mesa Recto 2X12 in stereo. I know this wont image huge but I like the effect. I have ordered the Road king plate to make the wiring easier.

Say I wanted to swap out the stock V30's for EVL12m's. To get a cleaner reproduction and maybe be able to use cab sims.

Would I again order 16 ohm drivers ? So stereo would be 16 and 16, mono 8ohm. According to the specs below that would only give me 37.5 Watts per side in Stereo, 300W mono ( Huge )
If I ordered 8 ohm EVL12m I would have good 75W per speaker,but for mono 4 ohm would be no good correct ? Rendering this cab Stereo only for this amp.......which may be okay ?
What is my best option here ??

Thank you, I am kind of new to these calculations.



ROCKTRON 300 specs
Unbridged (Stereo)
4 ohm load 150 watts
8 ohm load 75 watts
16 ohm load 37.5 watts (with both channels driven)
Bridged (Mono)
4 ohm load Not Recommended*
8 ohm load 300 watts
16 ohm load 170 watts
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

I would go with 8 ohm speakers for the best results. You would still be able to use the cab with a tube head as most have a 4 ohm tap and with a SS power amp you will get the most out of it power wise.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

Thanks sixstring,
So I am clear......If I load 8 ohm speakers. I cannot use the speakers, Rocktron 300 in Bridged mono mode as that would be 4 ohms, and not rated for this amp ?

If I am to stick with this amp, and 8 ohm speakers....just wire the two speakers direct to an output and not have a mono switch ?
thanks,
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

I am running a pair of EVM12L Black Labels in a Mesa Recto horizontal - honestly, I think you will need more power for headroom, and to get them to open up tonally. If you are sticking with that amp, then definitely go for the 8 ohm ones. The Black Labels are on sale at AMS for cheaper than the Classics, but I would go with the Classics in your case since (200 watt vs. 300 watt). I am pushing 450 watts into my cab - it also worked well with my stereo power amp which pushed 200 watts into it, but I wouldn't go any less than that.

JR
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

teddis said:
Thanks sixstring,
So I am clear......If I load 8 ohm speakers. I cannot use the speakers, Rocktron 300 in Bridged mono mode as that would be 4 ohms, and not rated for this amp ?

If I am to stick with this amp, and 8 ohm speakers....just wire the two speakers direct to an output and not have a mono switch ?
thanks,
Click to expand...

You could go that rought but I would use the Road kings switch plate like you had planned on doing. This way it can still be used as a traditional guitar cab in a mono situation if needed for a tube head.

Then you can also run it in stereo with the rocktron power amp like you wanted. This leaves you with the option to go ether way.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

teddis said:
Say I wanted to swap out the stock V30's for EVL12m's. To get a cleaner reproduction and maybe be able to use cab sims.
Click to expand...

This notion that the EVM-12L is a "neutral" sounding or "flat" sounding speaker is just a myth.
The 12L has a serious spike at 3.5k and a significant bump around 750hz.
A 12L will seriously colour your sound.
What it won't do is distort, unless you play it *really really really* loud.

Unless you're after some sort of a special effect, using the cab sims through *any* guitar speaker, including the 12L, will be fruitless.
You'd be better off using EQ (post-Amp-Block) to try and get the 12L to sound more like some other driver than a Cab Block, IMO.

Contrary to what someone else said in this thread, the 12L will be noticeably louder than any other guitar speaker you've ever run your power amp through. You don't need to worry about under powering them (or about over powering them for that matter). Mesa was using them in their 60 watt Mark Series amps for decades.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

I'd go with 8 ohm EVM12L's. I have a 2x12 cab loaded with 8ohm speakers and a separate jack for each. Using with the rocktron 300 each gets one channel, there is no reason to run bridged. When I use the cab with my Boogie heads I just use two wires and plug each speaker into one of the "4 ohm" sockets on the Boogie because its a 4 ohm load in parallel.

If you want to use a switched plate so you can use one wire, I'd still use two 8 ohm EVM's but change the wiring up so that when running in mono the speakers would be in series, for 16 ohms, while stereo they'd be obviously 8 ohms each.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

joegold said:
teddis said:
Say I wanted to swap out the stock V30's for EVL12m's. To get a cleaner reproduction and maybe be able to use cab sims.
Click to expand...

This notion that the EVM-12L is a "neutral" sounding or "flat" sounding speaker is just a myth.
The 12L has a serious spike at 3.5k and a significant bump around 750hz.
A 12L will seriously colour your sound.
What it won't do is distort, unless you play it *really really really* loud.

Unless you're after some sort of a special effect, using the cab sims through *any* guitar speaker, including the 12L, will be fruitless.
You'd be better off using EQ (post-Amp-Block) to try and get the 12L to sound more like some other driver than a Cab Block, IMO.

Contrary to what someone else said in this thread, the 12L will be noticeably louder than any other guitar speaker you've ever run your power amp through. You don't need to worry about under powering them (or about over powering them for that matter). Mesa was using them in their 60 watt Mark Series amps for decades.
Click to expand...

Comparing tube power with an open back cab to SS power with a closed back cab is apples to oranges. In an open back cab, you will benefit from the heavier cone/stiffer suspension of the EV since there is no back pressure to limit the cone excursion. It will be much more responsive with lower power in this configuration. 60 watts of tube power vs. 37.5/75 watts of SS also isn't the best comparison. In a sealed cab, they take a fair amount of power to get them to open up and sound their best - a low volume, bedroom speaker they aren't - they are pretty flat and lifeless. 75 watts per speaker is probably the minimum, though you won't have any headroom leftover, hence why I would look at using more power. These speakers have 5X the Xmax of a typical guitar speaker - it's part of what makes their low end so great, but you need some power to take advantage of it and get them pumping. Otherwise, just get a more conventional speaker and save yourself the $$ and weight. Their efficiency is the same as a V30 - they are loud, but not louder than everything else.

I totally agree that they aren't a flat speaker, and I wouldn't use cab sims with them either. What I have found is that they do dirt and clean amazingly well; there is a lot of verstility in that regard, which makes them a great match for all the different amps in the Axe, and a great alternative to going the FRFR route.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

Thanks for all the input guys. I think I may try a pair and see what happens.......
Will let you know.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

Hi,
Well, I couldnt wait for the faceplate, so I just clipped off the leads to the parralel out jack and I am now 8 ohm Stereo. I am reallly happy with it. It sounds MUCH better. Could this be due to the 16 ohm X 2 load ??? It does not stereo image per say....but it sure as hell has a nice diffuse sound to it.Very happy.

I noticed a ground loop through all this.... a real low level hum. I have a Furman, with the Rocktron 300 and AXE FX connected through normal supplied power cables, unbalanced phone. Here is how I killed the ground loop.
Removed all components from the rack...take a dremmel tool to remove all the paint from the inside of the rack mount components, ( Furman,AXE,300 ) ......so that thte components are metal to metal on the rack screw holders...NOT paint to metal. The 300 had to have the bracket removed to get the paint off of the inside. Voila......silence :) This is a requirement at my work by C.S.A. when foreign equipment comes in. Makes total sense.

I hope this may help someone else :)
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

teddis said:
Hi,
Well, I couldnt wait for the faceplate, so I just clipped off the leads to the parralel out jack and I am now 8 ohm Stereo. I am reallly happy with it. It sounds MUCH better. Could this be due to the 16 ohm X 2 load ??? It does not stereo image per say....but it sure as hell has a nice diffuse sound to it.Very happy.

I noticed a ground loop through all this.... a real low level hum. I have a Furman, with the Rocktron 300 and AXE FX connected through normal supplied power cables, unbalanced phone. Here is how I killed the ground loop.
Removed all components from the rack...take a dremmel tool to remove all the paint from the inside of the rack mount components, ( Furman,AXE,300 ) ......so that thte components are metal to metal on the rack screw holders...NOT paint to metal. The 300 had to have the bracket removed to get the paint off of the inside. Voila......silence :) This is a requirement at my work by C.S.A. when foreign equipment comes in. Makes total sense.

I hope this may help someone else :)
Click to expand...

Hmm, normally you want to isolate the components from the rack rails to eliminate ground loops.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

Hi,
What would happen ( hehe ) if I dropped 2, 8 ohm, 12inch Radian Coax speakers in place of the V30's into my Mesa slant. Just a straight hook up, stereo from the Rocktron and ran FRFR. I know no cubic air, or resonant calculations would be done, Cause I dont know how :roll: Would this Fail ? Would there be a problem because there is no control of the Horn per say ? I see it says 90 degress off cone..........is that good ?

I am still looking for a FRFR set up in traditioanl Guitar cab form.

thanks !


http://www.radianaudio.com/index.php?pa ... &Itemid=40
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

I have two mesa 2x12 rectos (I stack 'em). One was custom made by mesa many years ago, with 2 8 ohm vintage 30's and the stereo/mono jackplate (8 per side stereo or 4 ohms mono). I used to have two, and I sold one of them awhile back I tried to replace it recently, and mesa wouldn't do it stereo/mono even as a special order. Odd, since all of their preamps are stereo! Mesa custom shop my ass!! But I found a used one and the guy had already put 8 ohm V30's in it for some reason (he had them wired in series as a 16 ohm cab, so I re-wired it in parallel to be 4 ohms). If I use just one cab I use the bottom one. When I use both in mono, they're both 4 ohms.

I always run stereo, even though it doesn't "image" well. I like the way effects shimmer.
I suspect you'll get much better tone if you go with lower impedence speakers, 16 ohms per side is probably sucking a lot of your headroom.

+1 on EV's not being flat. Incredibly clean power handling capability and the project like nobody's business but they are not any more "uncolored" than any other speaker, they have quite a double mid hump happening. And 2x12 recto cabs have an unusual frequency curve too, big bottom and a little scooped in the mids. If you want to go FR, just go FR.
 
Re: Rocktron 300 and 2X12 Mesa Slant speaker swap ( stereo ?

Bump :)

Hi,
What would happen ( hehe ) if I dropped 2, 8 ohm, 12inch Radian Coax speakers in place of the V30's into my Mesa slant. Just a straight hook up, stereo from the Rocktron and ran FRFR. I know no cubic air, or resonant calculations would be done, Cause I dont know how Would this Fail ? Would there be a problem because there is no control of the Horn per say ? I see it says 90 degress off cone..........is that good ?

I am still looking for a FRFR set up in traditioanl Guitar cab form.

thanks !


http://www.radianaudio.com/index.php?pa ... &Itemid=40
 
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