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Home / Product Category / Whole House Audio / Volume Controls / In-Wall Volume Controls / SVC405 300W Decora Style Volume Control Kit with Impedance Matching and A/B Switching - White

SVC405 300W Decora Style Volume Control Kit with Impedance Matching and A/B Switching - White

Product code: OSD-SVC405

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OSD Price: $45.99
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Features & Specifications


• Decorative, decora style impedance-matching volume control for whole house audio systems and dedicated audio zones
• Rated at 300 Watts (100 RMS) per channel with minimal bass roll-off • Includes 2-source (A/B) switching for two pairs of speakers and one source
• Impedance-matching feature stabilizes the ohm load so parallel connections of multiple volume controls can be installed without damaging the amplifier
• Accepts up to 14-gauge wiring and fits in a standard gang box with a depth of 2.9”
• Includes junction box and screws as well as a white plate to match any room décor
• Precision electronics provide low distortion and a ruler flat frequency response
• Rotary-style knob for a wide range of listening volumes
• Installs easily and works with almost any audio system

OSD Audio SVC405 is a 300-Watt impedance-matching volume control with two-source (A/B) switching that allows you to adjust the volume of a pair of speakers independently of other speakers and control the volume of two pairs of speakers and one audio source. Ideal for both home and commercial installations, this decorative in-wall volume control includes an impedance-matching feature that stabilizes the ohm load so parallel connections of multiple volume controls can be installed without damaging the amplifier. The SVC405 maintains the full hi-fi audio frequency response with no low frequency roll-off and is rated at 300 Watts per channel (100W RMS). The rotary knob adjusts the volume from inaudible to loud, and when you order the SVC405, you get the complete kit that includes the junction box, screws white trim plate.

What is 2-Source (A/B) Switching?

A/B or dual-source switching is a convenient feature that allows flexibility when you’re designing your whole-house audio system. With A/B switching, you can connect two sets of speakers and one source, and those speakers can be in same room or separate rooms. For example, speakers connected to source A could be in the living room and speakers connected to source B could be in the dining room. Then simply use the A/B switch to choose between the zones.

What Is Impedance Protection?

Speakers are specified by impedance, which is a measurement of resistance to alternating current, and a common value for speakers is 8 ohms. When you’re connecting multiple speakers to a receiver or amplifier, you need to stay above the amp’s minimum load requirements because going below the impedance rating can overheat or even damage expensive equipment. The SVC100 allows you to match the impedance with the number of speakers being controlled with the capabilities of your amp. A basic multi-room system will typically have an amplifier/receiver, a speaker selector, four to eight pairs of speakers, and volume controls. Impedance-matching volume controls feature three settings depending on how many speakers you are connecting. For one to two pairs of 8-ohm speakers, the setting is 1/2x; for three or four pairs of 8 ohm speakers, the setting is 4X. Keep in mind that volume controls do not add gain (volume) to your speakers but simply attenuate the volume up or down. During setup, you'll set the source volume to its optimum level, then the volume control turns the sound down to inaudible levels.


Other Product Info

There are two types of volume controller - Impedance matching and Non-impedance matching. If you connect your speaker parallel to the receiver or connect the speakers into an impedance protection speaker selector, use impedance matching volume controller. If you connect just one pair of speaker directly to the receiver or your speakers are connected directly into an impedance matching speaker selector, use regular volume controller.
Quality is critical to the successful sonic performance of any whole house audio system. After all, it’s about how the system sounds and how well it works. From front to back, our pro-install series is built with close attention to performance, reliability and durability. The result is a blend of transparency and functionality, with low distortion and ruler flat frequency response. We bring you seamless control for every room in the house.


21 Questions & 22 Answers
from Atlanta asked:
December 29, 2018
I have installed the SVC405 in a room where I have one set of speakers and two sources. When I switch from the A position to the B position I still here sound from the original source but at a reduced volume. How do I correct this?
2 Answers
HI Andrew: Check your wiring, make sure that the connectors match up with the labeling on the circuit board. Looking at the connectors from the back, the center and left connectors are inputs (should be connected to your amplifiers). The connector labeled output is on the right side. If they appear correct and still an issue then try switching the two input connectors and see if you still have a problem. Lastly, check your wiring for any loose wires that may be touching each other between the inputs of each connector. We can replace if you still have a problem. TL/4346
Submitted by: Tim Leahy on December 31, 2018
Hi Andrew: The labeling is a little confusing on the SVC405. Check your wiring. The right side says output (this should be connected to your Speakers. The center and left connectors are the inputs with one each connected to your amplifiers. Note the connectors are labeled as is the Circuit board. Make sure to match the circuit board. If you still have an issue, then you may need to swap out for a new one. TL/5346
Submitted by: Tim Leahy on December 31, 2018

from Jacksonville, FL asked:
May 5, 2016
I want to use A with impedance matching and volume control. Then I want to use B without impedance matching and no volume control. Will this device work ?
1 Answer
HI Robert: On the SVC-405 both A and B outputs come after the Impedance Matching switch and transformer. So by itself it would probably not work for your application. What you might want is a combination of our AB1.2 (see under in-wall Volume controls) switch and a separate SVC300 Impedance matching Volume Control which combined would be the same cost as the single SVC-405. The In-wall AB1.2 switch has no Transformer or impedance switch built in. Just a simple A or B switch. You would connect the A output to the input of the SVC300 and then out to the speaker you want to Impedance Match (while being able to control the volume). Then use the B output to connect to the speaker you do not need to control Impedance or volume level. Good Luck TL/3863
Submitted by: Customer Service - Q&A on May 5, 2016

from Oklahoma asked:
February 4, 2016
Can you use both A & B at the same time?
1 Answer
Hi Brett: The SVC-405 is a two way switch You can either run it as two (2) in and one (1) output or one (1) input to two (2)outputs. But either way you are limited to A or B. Both will not play at the same time. What is your application? Maybe we can suggest something else. Sorry about that TL/3689
Submitted by: Customer Service - Q&A on February 5, 2016

from St. Louis, MO asked:
February 22, 2012
The description states it can be used with 2 inputs... I want to use it with one input switching between 2 sets of speakers... will this work for that?
1 Answer
Jim, Yes the SVC405 can be used for either two sources, and one pair of speakers, or two pairs of speakers and one source. CL
Submitted by: Customer Service - Q&A on February 22, 2012

from Virginia asked:
June 15, 2017
Is there something similar to this that is A or B and A and B? I have speakers on my outside deck and on my patio by the pool. Fed from a single source, I would like to be able to select either set of speakers or both sets of speakers and control the volume.
1 Answer
Hi Tom: Checkout the SSVC2 Dual Zone Speaker selector with two internal Volume Controls and Dual Source capability with individual A or B switch per zone. This will take care of your initial concern plus allow you to connect a second source. Checkout our XMP 100 amplifier which would provide the power for your second source with multiple options to plug into the amp itself (actually it features automatic Source switching between two sources as well). Ideal for connecting to a Cable or Satellite box, Tablet or laptop. TL/4427
Submitted by: Customer Service - Q&A on June 15, 2017

from alaska asked:
March 29, 2017
would this work as simply an on/off switch between 2 speakers and an amp?
1 Answer
Hi John: We have a model that actually features an on/off switch. It looks identical to the SVC 405 from the front but has one less output. We are bringing them back in stock (model SVC 205) but it will be awhile before we have them again. Technically the SVC 405 will allow you to do the same thing. The switch is open to open versus open to close of the SVC 205. TL/4278
Submitted by: Customer Service - Q&A on March 31, 2017

from Seattle, WA asked:
July 20, 2016
What gauge wire does this control handle, I have 12 gauge speaker wire in the room, but 14 gauge coming from the amp to the room, having difficult finding a control that can accept the larger wire.. Need volume control and A/B switch, does not need to be impedance matching. Or do you recommend just stepping down the wire using some wire nuts before connecting to the control. I have room for a combine control like this, or a separate volume and A/B switch
1 Answer
Hi Cindy: Most of these controls say the are made for 14 gauge but 16 works the best. You can make the 14 gauge work but may remove a couple of the wire strands to make it fit. If you have to step the 12 down try that with the 14 and again remove some of the internal strands when connecting with the outputs of the SVC-405 to the 12 gauge wire in the room. Connect the 14 gauge coming into the room directly to the SVC-405 removing some of the internal conductors. Set the Impedance Matching to 1/2X. TL/3988
Submitted by: Customer Service - Q&A on July 20, 2016

from Montreal Canada asked:
June 2, 2016
HI, will this work on a 70V system ? THnaks Guy
1 Answer
Hi Guy: The SVC-405 is a 8 ohm Stereo Volume Control with an A/B switch. It would not be recommended for 70V. But I would recommend using our MVC-100 70V Mono 100 Watt RMS Volume Control. And add our AB-1.2 switch connecting a single channel on the input side and single channel for output A and a single channel for output B. The two items would be the same price as the single SVC-405 and should work for your application. Good luck TL/3910
Submitted by: Customer Service - Q&A on June 2, 2016

from Seattle, WA asked:
April 23, 2016
This is device control two sets of speakers from a Sonos CONNECT:AMP?
1 Answer
Hi Dennis: This Volume Control features a two way A or B switch. In your case it sounds like you want to connect to pair of speakers to a single Connect Amplifier. So A features one pair and B features the other. So you can either play the pair of speakers connected to A or play the pair of speakers connected to B but not both at the same time. What makes this two way is you could connect 2 SONOS connect Amplifiers to a single Speaker pair and choose between the 2 SONOS. Note this Volume Control with A/B switch also has Impedance matching so it can be used in a system featuring multiple Volume Controls. Please feel free to contact me to discuss your application further. Good luck TL/3833
Submitted by: Customer Service - Q&A on April 23, 2016

from Point Roberts, WA asked:
March 21, 2016
If a receiver is connected to A, and nothing is connect to the B input, could this volume control be used to turn off a source?
1 Answer
Hi JR: The switch is designed to be open or open. It's true application is to choose between either Source A or Source B or connect a single source to speaker A or Speaker B. The Volume control you should be looking at is the VC-105 which has a true On/Off switch. Its switch is either opened (on) or closed (off). It is always best to actually turn off your zone either with a on/off switch of a Speaker Selector or to have a VC-105 so you can control it locally in the actual zone. It is always better to use an on/off switch rather than depending on the Volume Control to turn the sound down to where you can no longer hear the music. Technically the Volume Control is still active and the current has just been diverted into the transformer. So it is still affecting your impedance of the whole system. That is why we recommend the VC-105 and its ability to completely disconnect from the system in the zone it is installed in. TL/3773
Submitted by: Customer Service - Q&A on March 24, 2016

from US asked:
January 17, 2016
Any chance of getting this product in black? If so, you have yourself a customer.
1 Answer
Hi Jay: We have a Black and Brown option for most of our SVC Volume Controls. It covers the outer plate, Decora Insert and Knob. You can replace the outer plate and knob but not the Decora insert that has custom cut out for the A/B switch. Maybe you could do a black knob and outer plate and use the existing white Decora plate and white switch for an art deco look... Sorry about that TL/3666
Submitted by: Customer Service - Q&A on January 22, 2016

from Miami Florida asked:
May 2, 2015
Hello is there any substitute for this Product ? I was thinking to install - a receiver in the input of SPW-8 - in each output zone of SPW-8 connect the A switch of the SVC405" - In the B input of the SVC405 connect a wall plate WP-2 with 3.5 mini stereo RCA cable so I'm able to connect an IPod or a cell phone. However I saw that SVC405 is out of stock. Is there any option of products that am I able to create a system similar as described above ? I am in Miami is there any physical store near by ? Thanks
1 Answer
Hi Daniel, No substitute at the moment but we will be bringing this back. I'm hopeful we may have this in July.
Submitted by: Customer Service - Q&A on May 8, 2015

from New Jersey asked:
March 28, 2014
my receiver is rated at 5ohm output. I want to hook up 2 in ceiling rated at 6 ohm in zone 1. I want to hook up a planter speaker (single but may add another) on porch for zone 2. Is this ok and what would I set the volume control knob to. I understand I can only play one zone at a time.
1 Answer
Hi Mark, What kind of receiver are you using exactly? It sounds like it should be fine if you keep the volume control set to 1/2x, but I would like to learn more about the receiver. Thanks! -BM 2572
Submitted by: Customer Service - Q&A on March 28, 2014

from CA asked:
March 22, 2014
I have one source that is a mono speaker output. To wire up 2 speakers normally need to be in series to keep 8 ohms. Is if I want to use this mono source with the "input A" of this volume control unit, can I install a wire between R+ and L- to accomplish the series wiring? input B will be wired for normal stereo wiring, and have both speakers working for both A and B source.
1 Answer
Hi Jeremy, Yes, wiring it that way will get you series wiring to keep it at 8 ohms. CS 2555
Submitted by: Customer Service - Q&A on March 25, 2014

from Mtn View, CA asked:
January 6, 2014
What gauge wire can the selector accommodate?
1 Answer
Hi Doug, It's best to use 14 gauge or smaller with this volume control. 12 gauge may be a little thick, but if you have no other choice, you can shave down the wire a bit. -BM 2428
Submitted by: Customer Service - Q&A on January 6, 2014

from MN asked:
December 26, 2013
Does this work with 70 volt systems?
1 Answer
Hi Jason, This should only be used with systems using 2-8 ohms. For 70v applications, use our Mono70v volume control. -BM 2405
Submitted by: Customer Service - Q&A on February 3, 2014

from Minneapolis, MN asked:
November 11, 2013
Will this work with line level or only speaker level?
1 Answer
Hi Dan, Thank you. This volume control with A/B switching will only work with speaker level input and output. You can use it either way though. If you have two pairs of speakers and one amp, or if you have two amps and one pair of speakers. Let me know if you have any further questions. Thanks. -BM 2329
Submitted by: Customer Service - Q&A on November 11, 2013

from New York asked:
March 23, 2013
I was disappointed that this came with no instructions. I currently have this connected directly to the B channel of my receiver with another pair of speakers directly connected to the A channel. On the circular "impedance matching" dial I have this set to "2", but the volume of the speakers behind this volume control is DRAMATICALLY lower than the speakers connected without a volume control even when I have the volume turned all the way up. The description on the web site talks about jumpers, but I don't see any place on this system that I can set jumpers. Is there anything I can do to get more volume out of my speakers? As it is now I can't run both the A and B channels at the same time. Thanks
1 Answer
Hi JP Try reversing the connections. In other words, put the volume control on the speaker sets that you would prefer to be at lower volumes. The volume control acts as an attenuator, reducing the power the speaker receives. CL/MA 1726
Submitted by: Customer Service - Q&A on March 25, 2013

from Boston asked:
February 22, 2012
I am looking for a 2-source selector switch and volume control combination for outdoor speakers, how would this SVC405 device survive in New England if it where protected within a sealed outdoor weather proof receptical with a raintight clear plastic while-in-use cover? or would temperature differences cause material condensation issues? Also, a previous question asks if this controller can completely turn off the signal to the speakers, and the response was not completely - but does the lowest click on the volume control at least result in no noticeable sound eminating from the speakers?
1 Answer
OJH - You could do it with the weatherproof box. I don’t see condensation being an issue. Typically, when you get to the lowest click, it is in audible. This does depend how loud your source is set to, however. CL
Submitted by: Customer Service - Q&A on February 22, 2012

from Minneapolis, MN asked:
December 24, 2011
I am looking to have the a/b select on the control like this product, however, I also want to be able to turn the speakers off from the control...can this be accomplished with this product by turning the volume control down to the first position? Thanks.
1 Answer
Hi Cory, The volume control does not disconnect totally when turned all the way to the left for either A/B. A better choice for your application would be our SSVC2 that features a dedicated volume control for each speaker as well as an on/off switch per zone. It also features dual source inputs switchable per zone. Our factory direct price of $89.95 is very competitive as well. TL/MA
Submitted by: Customer Service - Q&A on December 27, 2011

from Phoenix asked:
December 5, 2011
Can the speakers be selected to play A and B at the same time or is it just either A or B playing at once?
1 Answer
Hi Z Either A or B, but not both. TL
Submitted by: Customer Service - Q&A on December 5, 2011

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