Connecting two 8ohm cabs in series to a DSL20HR amp



I own a DSL20HR amp and I'd like to connect two 1x12 speaker cabinets to the amp simultaneously. Both cabinets are Marshall 1912 cabinets (1x12", 8ohm speaker). There are three speaker cabinet output jack sockets in DSL20HR:

one 1 x 16 OHM socket to connect a single 16ohm speaker cabinet, and

two 1x16 OHM sockets to connect two 16ohm speaker cabinets simultaneously or to connect a single 8 Ohm speaker cabinet to either one of these sockets.

How do I connect two 8ohm cabinets to this amp? I'd like to connect these cabs in series to have 16ohms in result, but the cabs don't have sockets for connecting them in series. There is only one input in 1912 cab. And if I find a device to connect this two amps in series, do I then connect the first cab's input cable to the DSL20HRs single 1x16 OHM input (the first input option)? Is this safe? The manual doesn't say anything about connecting cabinets in series.

Thank you! The new amp is great btw!

asked 17 Feb 2018 at 10:27 AM

Matias Voutilainen (1)
You'll have to wire a cable up so they are in parallel or series.
Former will get you 8 ohm between the two and the latter will obviously be 16 total.

I could be wrong but I think thats you're best bet. It obviously means drilling a small hole in one of them for passthrough.

Its annoying I know but if you don't know how to solder its a good skill and if you're super worried just use crips.

I'd also invest in a multimeter and test it first.

I just went through the same thing with my DSL 1w as I only have the backstar 4x8 cab thats 8 ohm. I had to wire it to 32 ohm series.

Again its late and I could be overlooking something obvious.

Hope thats some help....
- Sean Toohey 17 Feb 2018 at 12:49 PM
Hold on.. are the two labeled "1x8 ohm/2x16 ohm" both just 8 ohm outputs?

I have a feeling they are in that case you'd be fine.
- Sean Toohey 17 Feb 2018 at 12:52 PM
Answers: 1


Thank you for the comment! 

I found a device called "series box" to connect two speakers in series. I'm thinkin of buying it to connect my two 1912s in series into DSL20HR. Those two outputs in DSL20HR are labeled "1x8 ohm/2x16 ohm", which I believe, means that the chosen cabinet(s) which is connected through these two sockets, needs to be 8ohms in total (two 16ohms via parllel = 8ohms, or just one 8ohm cabinet into either one of the outputs). Marshall's manual doesn't say anything about connecting cabinets in series. So does this mean that Marshall doesn't recommend connectin in series? 

From the DSL20HR manual:

"WARNING - Although the amplifier has three speaker outputs, never attempt to connect more speaker cabinets than rated. The safe combinations are: 1 x 8 Ohm speaker cabinet, 2 x16 Ohm speaker cabinets or 1 x 16 Ohm speaker cabinet. Any other speaker cabinet configuration may stress the power amplifier section and in extreme cases may lead to valve and/or output transformer failure. "


answered 17 Feb 2018 at 01:08 PM

Matias Voutilainen (1)
Ah cool cool.
Again I probably over thought it.
its probably very easy to make so worth looking into.
- Sean Toohey 17 Feb 2018 at 02:30 PM
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