Mark V 25 Cab Matching

Discussion for the new Mark V

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odboy
Bottle Rocket
Posts: 6
Joined: Tue Jan 23, 2018 2:35 am

Mark V 25 Cab Matching

Post by odboy » Tue Jan 23, 2018 2:40 am

Hi guys,

I am a new Mesa Boogie amp owner.
The Mark V 25 is an outstanding amp - really love it.
I have a question regarding the user manual.

I read the manual and couldn't understand why it is stated that: "If you have one 4 Ohm cabinet, connect it to the 4 Ohm
SPEAKER Output. This will be a proper impedance match, but you may experience a slightly softer attack characteristic than you
would using a single 8 Ohm Cabinet." - while a couple of sentences before that the manual states that if you have two 8 Ohm cabinets you can daisy chain them (in parallel) and plug them into the 4 Ohm tap.
I mean - daisy chaining two 8 Ohm cabs in parallel is exactly like plugging one 4 Ohm cab to the 4 Ohm tap - so why does the manual states
that in the latter situation there will be a slightly softer attack?

I have a cab loaded with two 8 Ohm V30 which I personally wired in parallel (4 Ohms total) -
would plugging my cab to the 4 Ohm tap result in a softer attack?
Why?

Your interpretation to the user manual will be appreciated.

Thanks for your help here.

odboy
Bottle Rocket
Posts: 6
Joined: Tue Jan 23, 2018 2:35 am

Re: Mark V 25 Cab Matching

Post by odboy » Wed Jan 24, 2018 11:42 am

Anyone?

thomasfxlt
Bottle Rocket
Posts: 12
Joined: Sat Jan 20, 2018 7:35 am

Re: Mark V 25 Cab Matching

Post by thomasfxlt » Wed Jan 24, 2018 1:10 pm

odboy wrote:Hi guys,

I am a new Mesa Boogie amp owner.
The Mark V 25 is an outstanding amp - really love it.
I have a question regarding the user manual.

I read the manual and couldn't understand why it is stated that: "If you have one 4 Ohm cabinet, connect it to the 4 Ohm
SPEAKER Output. This will be a proper impedance match, but you may experience a slightly softer attack characteristic than you
would using a single 8 Ohm Cabinet." - while a couple of sentences before that the manual states that if you have two 8 Ohm cabinets you can daisy chain them (in parallel) and plug them into the 4 Ohm tap.
I mean - daisy chaining two 8 Ohm cabs in parallel is exactly like plugging one 4 Ohm cab to the 4 Ohm tap - so why does the manual states
that in the latter situation there will be a slightly softer attack?

I have a cab loaded with two 8 Ohm V30 which I personally wired in parallel (4 Ohms total) -
would plugging my cab to the 4 Ohm tap result in a softer attack?
Why?

Your interpretation to the user manual will be appreciated.

Thanks for your help here.
I recently bought the MV:35 combo. I plugged in a second 1x12 Rectifier cabinet so I moved the internal combo connection from 8ohm to 4 and used the 2nd 4ohm output to the Recti 1x12. Sounds fine IMO. Loud and as punchy as you want to get it.

odboy
Bottle Rocket
Posts: 6
Joined: Tue Jan 23, 2018 2:35 am

Re: Mark V 25 Cab Matching

Post by odboy » Thu Jan 25, 2018 12:40 pm

Thanks for the response.
I still don’t understand the logic behind the manual.

IronSean
Mark III
Posts: 237
Joined: Mon Sep 29, 2014 12:17 pm
Location: Canada

Re: Mark V 25 Cab Matching

Post by IronSean » Thu Jan 25, 2018 3:52 pm

I think the manual might be stating the difference between a single 8 ohm cab, and a single 4 ohm cab:

A single 8 Ohm cab on the 8 Ohm out will have one sound. If you switch to a 4 Ohm version on the 4 Ohm out, you might experience a different feel because although it's am impedance match it's still using the transformers and things in a different way.

A better example might be a 412 that has two different inputs: One that's 4 Ohm (4 16s in parallel), and one that's 16 Ohms (4 16s mixing series and parallel). And an amp that has a 4, 8, and 16 Ohm output. You can plug the 4 into the 4 input, or the 16 into the 16 input and although both are a perfect match they'll still sound different because it'll be using the Output Transformer differently, and hitting a different impedance with a different signal.

So I think they were just saying "if you use the 4 Ohm output it might sound different than the 8 you're used to".
Mark V
Studio Preamp
formerly: Quad Preamp, Rocket 44 112

odboy
Bottle Rocket
Posts: 6
Joined: Tue Jan 23, 2018 2:35 am

Re: Mark V 25 Cab Matching

Post by odboy » Mon Jan 29, 2018 2:40 am

IronSean wrote:I think the manual might be stating the difference between a single 8 ohm cab, and a single 4 ohm cab:

A single 8 Ohm cab on the 8 Ohm out will have one sound. If you switch to a 4 Ohm version on the 4 Ohm out, you might experience a different feel because although it's am impedance match it's still using the transformers and things in a different way.

A better example might be a 412 that has two different inputs: One that's 4 Ohm (4 16s in parallel), and one that's 16 Ohms (4 16s mixing series and parallel). And an amp that has a 4, 8, and 16 Ohm output. You can plug the 4 into the 4 input, or the 16 into the 16 input and although both are a perfect match they'll still sound different because it'll be using the Output Transformer differently, and hitting a different impedance with a different signal.

So I think they were just saying "if you use the 4 Ohm output it might sound different than the 8 you're used to".
OK - thanks!

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