Q: Buster 2x10" Combo & Diesel 1x15"

[Der_Jan]

Hi folks,

hope you can help me in some way...

I'm the proud owner of one Buster 2x10" 6x6L6 Tube driven combo-amp... looking for a extension I recently bought a used Diesel 1x15" cabinet, housing the great EVM 15L.

Ok, now here it starts to get complicated: The two 10s are 16ohms each, wired in parallel (=8ohms). If I add the 1x15" and put them on the 4ohms-connector of the output-xformer I get an uneven spl distribution. The 15" is quite a bit louder than the two 10s. As a matter of fact this is exactly what i was afraid of - look at the power distribution: The 15" gets 50% of the output power, the two 10" also, but beeing in parallel each one only has to deal with 25%.

I wonder if anyone has the same problem with his 2x10/1x15-stack?


Maybe the spl of the 10"-speakers is just a few dB too low... I had a look at them and they don't seem to be original EVM 10. They have a quite small magnet, looking like the discontinued EV FORCE 10 series... maybe they even manufactured them with special parameters to give a good bass response out of the relatively small combo.

I had an idea how to solve the problem: I could run the internal speakers on the 8ohms output and connect the 1x15" cab to the 4ohms side. This would give halve output voltage to the 15" speaker, in terms of power (P=U²/R) it would be 25% of total output power of the paralleled 10" (sharing the output power to 50% each speaker). This would cause a overload on the power tube side but I don't think tube life would be very shortened. The impedance curves of the two speaker systems surely differ from each other and don't lead to a massive overload.

Any suggestions?

 

[FC Spoiler]

No problems with my 2x10 and 1x15 combi...

 

[Guymandude]

A 15 is a completely different animal from your 2x10. Giving them the same signal will not sound great unless you crossover and add a power amp. I would not recommend using it as an extension like on the other side of the stage 'cause it sounds completely different. If you like the sound of your 2x10 combo a 2x10 or 8 ohm 4x10 extension cabinet is what you need, make sure they're the identical drivers to your Buster's.
You're getting in over your head with the power ratios and percentages and stuff. It's apples and oranges. Unless you've got identical stuff, its easier to do it by ear.
I use my Buster Head with a walkabout cabinet or two rectos fitted with Bag End ELF 12s.
Try unplugging the 10s and using just the diesel you might want to add another 15 and disconnect the 10s for larger venues.
Good Luck, a Buster is a wonderful thing. Sweet as sugar!

 

[Boogafunk]

an efficient 15 will almost always make more noise than a couple of 10's. this is just a fact of life. what you have to do is use your eq to give the 10s more juice in the higher midrange frequencies where they are more efficient than the 15. don't mismatch the impedance loads on your amp, i am not an amp tech but i don't think you will get the desired result.

before you try anything else, eq the rig to sound the best to your ears, then try it without the 10's. i think you will be surprised at how much sound you are missing. probably a lot of sound you thought you were getting out of the 15.

btw a crossover is the best solution from an audio standpoint, but it is probably impractical for your set-up. many of the "best" bass sounds fly in the face of audio engineering. if it sounds good it is good.

 

[uyvu_taman]

I have the same problem with you.

Please help me how to hookup the extra mesa powerhouse cab 1X15" to my combo mesa boogie buster 2X10". Help.....help....please

 

[Der_Jan]

Update:

I wrote to Mesa customer service... telling the story of my 1st post. The answer was:

Thu, 08. May 2008 16:37:28

Hello there,

I truly don't know if there will be much you can do with your current speaker setup. We don't have specs on the older speakers/cabs, but I would assume that the sensitivity level on the 2x10 is much lower than that of the 1x15. The only way to possibly cure this would be to swap out the 10's with speakers that have a higher sensitivity level. Again, I'm not even sure if that would fix it, but it may get you closer to where you want to be.

We definitely do not recommend plugging one 8 ohm cab into the 8 ohm jack and one 8 ohm cab into one 4 ohm jack of the amp. This will put too much strain on the amp and possibly cause damage. Hope that helps.

Best Regards,

Marcus Daniel
Customer Service/Product Specialist
Mesa/Boogie

Things have changed a bit since I have messed with the "spl-problem". I now also own a "Bass 400" that I bought together with another 1x15 cab. The amp and cabinet is end-80s-stuff. Surprisingly, when I tried out the big rig with my two 1x15" cabs, I discovered that the old 15" that came with the amp isn't as loud as the other cabinet I had the problems with.

The combination of Buster Combo/older 15"-cab sounds very well balanced to my ears

I think that the louder 15"-cab is just too new. The guy that sold it to me played guitar and barely used it. The construction is also different: The older cabinet is much lighter (wood?), has removable casters but not the Trak-Loc-system, single 1/4" input without type label.

Ok, problem solved - I just pick up the old cab if I need some extra power with my Buster.

 

[Der_Jan]

an efficient 15 will almost always make more noise than a couple of 10's. this is just a fact of life. what you have to do is use your eq to give the 10s more juice in the higher midrange frequencies where they are more efficient than the 15. don't mismatch the impedance loads on your amp, i am not an amp tech but i don't think you will get the desired result.

before you try anything else, eq the rig to sound the best to your ears, then try it without the 10's. i think you will be surprised at how much sound you are missing. probably a lot of sound you thought you were getting out of the 15.

You're right, the EV 15L is one hell of a efficient speaker! I tried EQ-ing the setup with the graphic bands but there was always this feeling that the bigger speaker just played too loud... of course, the 10s added a sparkling high end to the overall sound, but if you left the "sweet spot" of the angeled 10s they just disappeared.

It's fine with the other 15" cabinet.

 

[bigbajo60]

I personally wish that Mesa would reintroduce the Buster as a more manageable 1x12 combo... with a matching 1x12 extension cab! An all-tube version of the Walkabout, if you will!

I always thought the 1x15 Buster combo I owned for awhile was an awesome sounding, but unwieldy beast! But I'd be ALL OVER a 1x12 Buster!!!