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bigdawg
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Post by bigdawg » Thu Aug 21, 2008 10:33 am

Is there anyway I can link up 2 cabs, one rated 8ohms & one rated 16ohms?? I was thinking 8ohm socket to 16ohm speaker and D/chained to 8ohm speaker. Something in my mind is tellig me it wont work but cant find anything on t'net to tell me so...

And if I do will the volume difference be too great between the two to play them??
Jesus said - Come forth and I will grant you eternal life...

But I only came fifth and got the kettle...

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Dont knock on death's door....

Ring the bell and leggit.... that really p**ses him off

Le Chat Noir
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Post by Le Chat Noir » Thu Aug 21, 2008 10:40 am

You can't do it, the options as far as I know are as follows:

2 x 16 ohm cabs into the 8 ohm jacks (because 2 16 ohm cabs gives an 8 ohm load, right?)

1 x 16 ohm cab into the 16 ohm jack

1 x 8 ohm cab into one of the 8 ohm jacks
Teddy
The Blackwater Rebellion: 2-piece alt rock duo http://theblackwaterrebellion.bandcamp.com/
I play an AD30TC

Andy H.
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Post by Andy H. » Thu Aug 21, 2008 11:20 am

Whatever you do <u>DON'T</u> connect one cab to a 16 ohm output and another to the 8 ohm output. It isn't a good idea to ever use both impedance taps at the same time. (Unless you are talking about some Mesa amps which it seems let you do this.)

If you were to run both a 16 and an 8 ohm cab from the two 8 ohm outputs (or daisy chain both cabs from one as you suggested - same result) you'd get a total load of 5.333 ohms. That is a moderate low mismatch (-33%) and almost certainly won't do the amp any harm. It <i>will</i> cause the power valves to have to work harder than normal - always the case with a low mismatch. You'll also get fractionally less power output from the amp and a slight tonal shift too - always the case with any mismatch, low or high.

Generally speaking you can normally get away with an impedance mismatch in the 1/2 to 2x range without serious risk, and FOR THE AMP ITSELF it is less dangerous to mismatch low. While there are never any 100% guarantees that slight low mismatch shouldn't be a real problem IMO.


Andy.
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Andy H.
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Post by Andy H. » Thu Aug 21, 2008 11:28 am

On the volume difference between the cabs, running in parallel the 8 ohm cab will take twice the power of the 16 ohm cab, so it will be a 2/3 vs. 1/3 power split.

How much of a difference that makes volume wise depends on the cabs and the speakers in them. Speaker efficiencies (and numbers) will play a large part. All other things being equal the 8 ohm cab will be just marginally louder than the 16 ohm one, but what exactly are the two cabs you are planning to run?


Andy.
Only dimly aware of existence, a dimly existing awareness...

You get a wonderful view from the point of no return.

bigdawg
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Post by bigdawg » Thu Aug 21, 2008 12:27 pm

thats what I thought, thanks guys.

THe two cabs are an Orange 112 (Vintage Celestion 16ohm) & a Mesa 112 (original Black Shadow (pre celestion) 8ohm) - Ive been offered the mesa cab real cheap.

Also was a bit curious about the speaker sound differences clashing (vintage rock & modern rock speakers)

May just get another orange 112 as they seem to have come down in price a bit in the UK...
Jesus said - Come forth and I will grant you eternal life...

But I only came fifth and got the kettle...

----------------------------------------

Dont knock on death's door....

Ring the bell and leggit.... that really p**ses him off

Le Chat Noir
Duke of Orange
Posts: 5723
Joined: Fri Aug 17, 2007 9:29 am
Location: United Kingdom

Post by Le Chat Noir » Thu Aug 21, 2008 3:41 pm

I wouldn't worry about speaker types 'clashing' - if anything, two different speakers which accentuate differenmt frequencies blend really nicely to give a fuller, more complex tone.
Teddy
The Blackwater Rebellion: 2-piece alt rock duo http://theblackwaterrebellion.bandcamp.com/
I play an AD30TC

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