noob question

Synergy/MTS Forum

Help Support Synergy/MTS Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

mercuriel

New member
Joined
Jul 30, 2011
Messages
4
Reaction score
0
Hi good people. First time head & cab owner here, not too sure what I'm doing so need help getting around this. Had read alot of articles to understand enough warning that I have to match the impedance on the head and cabs, but here is what confusing me:

My 50w Randall head has a 4 ohm and 8 ohm output impedance. While the cab has a power handling of 100w instead, with input impedance at 4 ohm and 16 ohm mono each. So I ran a speaker cable from the head at 4 ohm output, to the speaker cab at 4 ohm input. Am I right so far?

The cab is lalso abeled as stereo 50w/Chn, Mono 100w RMS. On top of that, the cab input is also labeled 8 ohm right and 8 ohm left. There is a switch just below that to select either Stereo or Mono. So do I select Stereo or Mono for normal head and cab hook up?

I assume the stereo switch is meant to be used with an additional cab? So if I select stereo, does it mean I have to plug the amp output to 8 ohm? Will it kill the amp/cab if the cab is plugged to just the left input?

One other thing, since the head is 50w, will I be in trouble if mono is selected at the cab? I mean the cab should be rated 100w in mono, if I understand it correctly.

The more I think, the more confusing it gets. -_-"
 
Plug into the cab, labelled 8 ohm mono, and into the head, labelled 8 ohm. Make sure the switch is switched to mono, as well.
 
d-shep said:
Plug into the cab, labelled 8 ohm mono, and into the head, labelled 8 ohm. Make sure the switch is switched to mono, as well.
Please see the pic.

If mono is selected, does it mean either 4 ohm or 16 ohm input is available for use. Which should mean 100w handling.

And if stereo is selected, then plugging to left input 8 ohm instead?


Click to expand


I don't quite understand the stereo/mono switch indicates which input to use..
 
Oh I see. That is a really cool option of inputs. The way it looks, if you use both inputs they are 8ohms each. I you use a single input you have the options of 4 or 16 ohms. Single 4ohms on left and single 16 ohms on right. If just using a single input select mono. Using both select stereo.
 
Thank you BigB for clearing that up, makes alot more sense now. :)

So assuming stereo is chosen, can I just plug into one input and leave the other input unplugged? Would it hurt the amp or cab? I think stereo mode means, if your connecting an additional separate 8 ohm cab (right?).

What about power? I mean, since the cab mono (single input 4/16 ohm) should be 100w and the head is only 50w, does it hurt either amp or cab?

Sorry all for the silly questions, better to ask before I do something really stupid and fry the amp. Been a combo amp user for years, this is my first ever head/cab. I didn't realize that there's really alot more than simply plug and play until now. My speaker cable hasn't arrived yet, so plenty of time for making myself look bad.. lol

Thank you all for your advise, appreciate you sharing your knowledge.
 
mercuriel said:
Thank you BigB for clearing that up, makes alot more sense now. :)

So assuming stereo is chosen, can I just plug into one input and leave the other input unplugged? Would it hurt the amp or cab? I think stereo mode means, if your connecting an additional separate 8 ohm cab (right?).

What about power? I mean, since the cab mono (single input 4/16 ohm) should be 100w and the head is only 50w, does it hurt either amp or cab?

Sorry all for the silly questions, better to ask before I do something really stupid and fry the amp. Been a combo amp user for years, this is my first ever head/cab. I didn't realize that there's really alot more than simply plug and play until now. My speaker cable hasn't arrived yet, so plenty of time for making myself look bad.. lol

Thank you all for your advise, appreciate you sharing your knowledge.
I believe if you kept it on stereo and only plugged into one side it would be okay. It just means you are running one side of the cab at 8ohms. Also at 50 watts.
As far as ohms go as long as you cab matches or is higher than your amp ohms you are fine. If your cab is lower than the amp you risk damage to your amp.
 
easiest approach is what you first suggested: 4 ohms on the amp, 4 ohm socket on the cab, switched to mono.

if you use the 8 ohm setting, you will only be using one side of the cab (depending on which socket you plugged into) and only have 50 watts to play with. As Brewtus said, the cab has to be switched to stereo for this, otherwise it will be 4 or 16 ohms depending on which jack you've plugged into.

The stereo switch allows you to plug a stereo source (does your Randall have left and right outputs?) into the cab and run your righthand signal through the right speakers and the lefthand signal through the left speakers. Can be really groovy for swirly stereo effects, but no one in your audience will notice because they're generally too far from the source to notice the stereo separation.

As for your other question, running a 50 watt head through a cab rated for 100 watts is absolutely fine. It means the cab has sufficient wattage to handle the power of your head. If you were running a 100 watt through a 50 watt cab there would be a potential to damage the speakers as you turn the amp up.
 
That certainly helps alot, thank you guys for sharing your knowledge.

Unfortunately the RT503H does not have dual out, just simply 4 ohm and 16 ohm single. But it's ok, at least I can now sleep better knowing that I can plug into 4 ohm in/out without the amp destroying itself.

Have heard complains on the RT503H having problems. Hope mine will be alright. Otherwise it will be a huge huge pain trying to get an RMA.
 
Top