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Russound SDB-2.1 2-pair speaker and source selector with volume control

Item # 543SDB21

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8 questions - 14 answers

Item # 543SDB21

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About the Russound SDB-2.1

You want to crank the tunes up on the patio where the party's going strong, but not in the kitchen where the cook likes the music softer. Now you can make everybody happy. The Russound SDB-2.1 gives you flexible speaker-switching options for multi-room applications. It allows you to connect two pairs of speakers and play them all simultaneously without damaging your equipment. Impedance-matching protection circuitry ensures that your amplifier or receiver operates at a safe load. This selector even lets you connect two source amplifiers and switch between them. So the patio crowd can keep stoking the salsa music, while the kitchen patrol chills to something old-school.

Product highlights:

  • play 2 pairs of speakers simultaneously
  • 11-step volume control, 42dB maximum attenuation
  • allows switching between two source amplifiers
  • impedance-matching protection circuitry ensures that your amplifier or receiver operates at a safe load
  • handles up to 100 watts per channel
  • accepts up to 12-gauge speaker wire
  • includes room/speaker labels
  • 8-1/2"W x 3"H x 7-7/16"D
  • warranty: 10 years
  • MFR # 3615-604010

What's in the box:

  • Dual source two speaker selector
  • Installation Manual
  • Sheet of 52 room labels and 8 blanks

Customer reviews for Russound SDB-2.1

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4.5 out of 5 stars
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More details on the Russound SDB-2.1

Research Team
The Russound SDB-2.1 replaces these items:

Product Research


Overview: The Russound SDB-2.1 is a dual source speaker selector that allows you to control two pairs of speakers. The front panel has separate volume controls for each speaker pair so you can adjust the volume in each room from one convenient location. At each volume control, you can turn each pair of speakers on or off, and select amplifier A or B using the two 2-position push-buttons on the front panel.

Ultra-Match Technology: The SDB-2.1 uses high quality impedance matching autoformers that distribute maximum power throughout the system while maintaining a safe operating load at the amplifier. You can use the speaker selector with 4- or 8-ohm speakers. Internal jumpers allow you to select the degree of impedance matching for your speakers and amplifier.

Note: The unit is set at the factory at 2x, which is proper for most applications. If certain applications require changing the impedance setting, you will need to remove the cover and reposition the jumper on the autoformers.

Volume Controls: The SDB-2.1 has two rotary volume controls with 11 steps of volume, plus an off position. The volume control provides a total of 42 dB attenuation.

Connections: The speaker selector features four 4-pole screw terminal blocks, two for the inputs from the amplifiers, and two for the outputs to the two speaker pairs. The terminals allow you to connect up to 12-gauge speaker wire. The terminals can be unplugged from the volume control for easier wiring.

Room Labels: The SDB-2.1 comes with a sheet of non-adhesive room labels which slide into a groove in the front panel. A total of 52 labels and 8 blanks are included.

Performance: The unit will accept up to 100 watts RMS per channel (300 watts peak).

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Customer Q&A

8 questions already asked

I would like to add two sets of speakers to this unit, eight speakers in total. ALL are 8 OHM ?? speakers, from the same AVR, Front lefts and rights, connected in parallel, I was thinking I could connect the front lefts and rights to input A from the AVR, and the rear lefts and rights to the input B to this unit. both sets connected in parallel could I do this and if so, could I listen to ALL speakers connected to this unit if I engage the A and B buttons both at the same time?
mark  May 28, 2022
1 answer
IF you wire two sets of 8-ohm speakers in parallel to both the A AND B terminals of this speaker selector, that will yield a 4-ohm load to each terminal. This unit can safely be connected this way. It can handle 100 watts RMS per channel, So splitting that power, you will get 50 watts RMS ( maximum) to each speaker. You will need to refer to the owners manual, and adjust the internal jumpers to set the impedance matching needed for such an application.
thomas  Jun 02, 2022 (Staff)
I have the sony str dh790, and wanted to use 4 atmos speakers instead of only 2. All 4 speakers are sscse. They are 6 ohms. Will this work for what I am hoping to accomplish?
chris  Feb 17, 2021
1 answer
Hi ! :) I think You should be OK using It as You describe ! I run a stereo that offers only 1 pair of stereo Outputs at a nominal 8-ohms each ... Before I added the Russound unit , I could only run 1 pair of Speakers :( With the addition of the Russound Unit, however, I can add a 2nd pair of Speakers and I can run Them at the same time !
faron  Feb 20, 2021
does the volume control retain the stereo signals or does it mono-tize the signal? also can 1 amp stereo input supply two individual stereo outputs with each having volume control?
mark  Aug 31, 2020
2 answers
It does mono tize signals,. I use this in an odd ball way I piggy back it Denon 7.1 to power my patios speakers .
craig  Sep 04, 2020
Does not monotize signal. It Offers separate volume controls for both channels, however the receivers volume control ultimately determines your total volume output
gary  Sep 04, 2020
What is the power input requirement for the sdb-2.1? 120vAC, 12v DC?
david  Jul 17, 2019
4 answers
Im not positive in case something is wrong with mine, however I didn't receive or have a power cord or port to plug in the power plug. The wiring from the amp to this speaker control should be the power source. Please confirm with Crutchfield.
jeffrey  Jul 17, 2019
I have it connected to a "Sonos Connect-amp". This puts out 55w per channel. the SDB-2.1 is then connected to a pair of in-wall Yamaha speakers and a pair of Bose out door speakers. I find that the SDB gives me all the flexibility I want to adjust various volumes. I am totally happy with it. It is made well, the only negative is that the wire connectors are jammed too close together. Not sure the reason for that.
brian  Jul 17, 2019
There is no power input required.
chad  Jul 17, 2019
The only power it requires is in the incoming signals. There is neither power cord nor battery.
whitney  Jul 17, 2019
Are there fuses in the amplifier input stage?
kenny mak  May 22, 2019
1 answer
Not that are evident externally for replacement. Also not that I've tripped, using this to attenuate the full load from a power amp, on channels bypassing the pre-amp's volume and tone controls.
whitney  May 22, 2019
The instructions are not at all clear to me since everything has terms I don't really understand. I have a Yamaha R-N301 (Minimum RMS Output Power 100 W + 100 W 8 ohms) connected to a pair of bose 251 environmental speakers (100W IEC continuous power handling; rated 6 ohms) on channel A and a pair of Klipsch CA-525T speakers (NOMINAL IMPEDANCE 8 ohms) on channel B. I want to use a Russound SDB-2.1 so I can control the volume independently since yamaha doesn't have separate channel volume controls. Am I looking at the right specs first of all and if so how should jumpers be set?
keith garry  Jul 01, 2017
2 answers
I have an Onkyo two channel 85 watt unit in my bedroom for music primarily but also use it for movies. Have a Outlaw Audio sub hooked to the unit and as my main speakers I have a set of older Paradigm 11 towers. The SDB-2.1 is hooked to the receiver via the B speaker output to the input of the SDB-2.1 So I have a Speaker Craft dual pole speaker in the ceiling of my master bathroom, and a set of Paradigm smaller studio monitors on the night stands by the bed, hooked to the SDB-2.1. So I have three sets of speakers hooked to the receiver. So if I want to listen to music I turn on the main unit and have it set for speaker select A/B on and using the SDB/2.1 I can set the volume on the monitors for the best volume balance from front to back speakers listening, The small monitors are about 4 feet from your head, as the 11s are 13 feet from head. And If I want tunes in the bathroom just push a button. Great unit, very good quality, and think I'll buy another unit and set up my guest bedroom the same way. When I built my house a also put a Speaker Craft dual pole speaker in the ceiling of the hall bathroom and the speaker hook-up is the guest bedroom. So I use the SBD-2.1 for the three speaker sound distribution and volume control for my back channel. So when I use the main volume control of the reciever the sound levels stay in synk through the entire volume range of my main unit. Just set the SDB-1 and forget it. Hopes this helps. I'm an analog guy and this thinks rocks. If this doesn't help I can draw a wiring diagram. Let me know.
brian s  Jul 03, 2017
Ideally you want speakers with matching ohm impedance. The way you have this paired may cause some amplifier performance issues. You will not be able to control the volume independently but you can press the button and turn one pair off or run both pair at the same time but you go back to ohm impedance mismatch. You probably want to call yamaha to make sure you do not damage your amplifier trying to operate it that way.
ben  Jul 02, 2017
I want to have two amps as inputs to one pair of speakers. Will this switch be safe to use with a tube amp and 1 solid state amp? Because I've heard that tube amps should not be left unloaded as when switching to the solid state amp.
william  Jun 19, 2015
2 answers
I fried a tube bass amp many years ago by having the speakers not plugged in. More modern amps may have "no speaker" protection but I wouldn't risk it otherwise. Having said all that, see if the switch loads the second input circuit if nothing is connected - the electronics required ain't rocket science. I have one of those switches which I use with a single solid state amp and 2 speaker zones - fantastic little box.
john  Mar 05, 2022
Don't have the technical knowledge to answer that. But, can say that I have 2 solid state receivers connected and it works great.
michael  Jun 20, 2015

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Russound SDB-4.1

Russound SDB-4.1

High-power 4-pair speaker selector with volume control
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Controls four pairs of speakers

The Russound SDB-4.1 offers these features:
  • 11-step impedance matching volume control for four pairs of speakers
  • handles 200 watts per channel
  • switch between two powered sources, like an amplifier and receiver
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