Bare Knuckle Pickups Forum

At The Back => Time Out => Topic started by: Transcend on July 10, 2010, 05:36:28 PM

Title: Guiatar speaks
Post by: Transcend on July 10, 2010, 05:36:28 PM
Right im looking to upgrade the speaker in my tsl

and there is a switch for 8 or 16ohm

is this just for use with a 2x12  or does it mean i can use 8 OR 16 as the internal speaker??

I'm asking because the input from the internal one says "internal speaker 16ohm"

and i was wondering if that was just because the g12h80 is a 16ohm speaker or if it has to be a 16ohm to replace it.

If that made any sense.

Thanks
Title: Re: Guitar speakers
Post by: Frank on July 11, 2010, 03:43:35 AM
You can put an 8 or 16 ohm speaker in there but remember to set that switch accordingly or you may risk damaging the output tubes (or more expensively, the output transformer!)
Title: Re: Guiatar speaks
Post by: Transcend on July 11, 2010, 07:47:10 AM
I thought as much and which jack would i use for it? the one that the internal speaker is already connected to or the extra one that i presume is for an extension cab?

Sorry if these questions are a bit stupid sounding i just dont want to risk damaging anything.
Title: Re: Guiatar speaks
Post by: Twinfan on July 11, 2010, 10:45:49 AM
The same one it uses now  :)
Title: Re: Guiatar speaks
Post by: d1dsj on July 11, 2010, 07:30:21 PM
I would replace it with a 16ohm speaker. That way if ever you want to use another extension cab, but one that is also 16ohms (doesn't matter if it's a 1 x 12, 2 x 12 or 4 x 12 as long as it's also 16ohms) you just set the amp to 8ohms ASSUMING YOU WILL BE USING THE INTERNAL SPEAKER AT THE SAME TIME. Hope this helps?  :)
Title: Re: Guiatar speaks
Post by: Transcend on July 11, 2010, 08:21:11 PM
I am going for another 16ohm

what i was planning on doing was using just the internal atm

then using a 2x12 for live

i didnt know you could use both at the same time that is pretty cool.

Thankyou for the information that was really helpful
Title: Re: Guiatar speaks
Post by: Frank on July 12, 2010, 10:10:39 AM
ah right, didn't realise you were going to use TWO speakers ... if you have a 16 ohm and you add a 16 ohm speaker in parallel then the impedance is 8 ohms

don't use an 8ohm cab in parallel with an internal 16ohm or you'll end up with 5.333 ohms and you can't set that impedance on the amp
Title: Re: Guiatar speaks
Post by: Frank on July 12, 2010, 10:13:16 AM
if I get time this evening I'll do you a diagram of the wiring options and impedance settings
Title: Re: Guiatar speaks
Post by: Transcend on July 12, 2010, 03:19:03 PM
well at the moment i am just going to be using the internal speaker so theres no need.

the extension cab was going to be something that came later when this new project gets going.

Thankyou anyway
Title: Re: Guiatar speaks
Post by: Frank on July 12, 2010, 04:31:43 PM
I did this for you anyway!

http://kineticnorth.com/impedance.htm
Title: Re: Guiatar speaks
Post by: Transcend on July 12, 2010, 04:43:02 PM
Wow that is great thanks.

Ill keep that bookmarked.
Title: Re: Guiatar speaks
Post by: andymac on July 17, 2010, 09:27:16 PM
I did this for you anyway!

http://kineticnorth.com/impedance.htm

Totally impressed.

Andy
Title: Re: Guiatar speaks
Post by: HairyChris on July 18, 2010, 11:37:47 AM
ah right, didn't realise you were going to use TWO speakers ... if you have a 16 ohm and you add a 16 ohm speaker in parallel then the impedance is 8 ohms

don't use an 8ohm cab in parallel with an internal 16ohm or you'll end up with 5.333 ohms and you can't set that impedance on the amp

According to Mesa, if you do have mismatched speakers you should pick the setting below the total resistence (so for 5.333 use 4).

I can vouch for how output transformers melt themselves if you do it wrong.
Title: Re: Guiatar speaks
Post by: ailean on July 18, 2010, 01:51:03 PM
I've only owned one combo amp, but with that one when I plugged in the external cab the internal speaker was switched off internally, don't know if that's the case with the JVM though.