Sounds good to me, good luck with it Trasher, im sure you have your calculations right, nothing wrong with a double check, as Harry Greene (QVC D.I.Y Expert) says, ‘Measure Twice, Cut Once’ 😯 and also that all time classic line, ‘Safety first, D.I.Y second’ 😆 .

Ahh, sunday mornings and QVC, nothing can beat it. 😆

SS amps are pretty robust, but im not sure your techie guy has given you the right info there, if it were me, id mail Bedrock to double check that advice, better to be safe than sorry as 👿 Evil Kenevel 👿 eventauly said.

I’m not sure about SS amps in general, and I know nothing about the Bedrock. Just thought I’d mention that a 4ohm cab with a 8ohm cab in parallel = 2.6ohm total impedance.

If you have the cabs connected to the amp’s different output jacks and it works, then that’s great. To be absolutely honest, I don’t know enough to disagree with your tech. I only hoped to point out possible disasters before plugging in. Glad you’re sorted,
1BL

Trasher, first of all, try a good search engine. Copernic is a favourite of mine – a free download. You will find Bedrock amp hits such as a Bedrock forum on Bravenet.com

Secondly, I echo Lee’s caution. Do you mean that your amp’s output jacks are wired in parallel? They certainly will be. If they were wired in series, then you’d have no volume out unless they were all connected. I suggest that you daisy-chain your cabs, then connect cab #1 to the most appropriate output jack on your amp.

It may be boring, but please read my dull thread on “impedance theory” posted on this forum. Also, check the link to David Zsabados’ website contained within. Some of this reading can save you from an expensive mistake.

Trasher, just make sure you are 100% before you start, it could be an expensive mod. Double check your info.

Trasher, just in case your ‘notify me’ is switched on, I did a new topic called “some impedance theory”, as others have put similar Qs. There has since been another thread on the subj from Riz you may want to read.

I hope something posted here is useful.

[quote=”1bassleft”] On a long cable, this will affect the impedance the amp “sees” and there may be a mismatch.[/quote]

Good call on that one bass, i forgot about about the extra impedence the long copper cable makes.

Trasher, no need to apologize for the English. Faultless, certainly better than my German.

Lee is, as often, right. Chain two 16ohm cabs together and connect this to the 8ohm output. Or, chain two 8ohm cabs and connect to the 4ohm output.

Lee makes the excellent point that speaker cable is not the same as instrument to amp cable. I’ve never mentioned this before. Apart from the point Lee makes, an instrument cable is shielded. On a long cable, this will affect the impedance the amp “sees” and there may be a mismatch. Quality amp to speaker cable will be unshielded and have heavier duty ‘hot’ wire to carry the amplified signal. Keep it as short as you can live with. If the head is on top of the stack, 6m is a waste and has bad effects. 1m is preferable.

You need to get 2 stacks of the same total impedance, if you already have a 4×12 cab and its rated at 16ohms then you need another of that impedance link the together in paralell (cab1 output jack – to cab 2 input jack ) then take a cable from the input jack of cab 1 to the 8 ohm output jack of your amp.

if however you have a 4×12 rated at 8ohms, then you need another 4×12 of the same rating, link them in the same order as above but connect the input jack of cab 1 to the 4ohm output jack of your amp.

Apeice of advice, a lot of people use patch leads and guitar leads to link their cabs to the output jacks of their cabs, when in fact you need good quality speaker cable, like you use for your speakers at home, a good multistranded
OFC copper cable would be good to use, the inner core of a lot of guitar cable is a thin strand of copper and isnt up to the job, sound quality and reliabilty is greatly improved, would you risk a speaker cable breakdown in the middle of a set? and if you are running a nice expensive valve amp think of the damage that could cause.