# Adding subwoofer to Sony Reciever without SUB OUT



## PrarieChicken10 (Jan 26, 2021)

I have a sony TA-AV421 powering two KLH 3 way bookshelf speakers. I would like to add a subwoofer. My Receiver does not have a sub out. What can I do? I am looking at getting a KLH GFX550 subwoofer to match my speakers. There is a spot for hi-level input on the sub itself. Could I run empty channels from my receiver to these inputs on the sub? Will that power it? What other options do I have? Do I need a powered sub?


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## bbfoto (Aug 28, 2005)

PrarieChicken10 said:


> I have a sony TA-AV421 powering two KLH 3 way bookshelf speakers. I would like to add a subwoofer. My Receiver does not have a sub out. What can I do? I am looking at getting a KLH GFX550 subwoofer to match my speakers. There is a spot for hi-level input on the sub itself. Could I run empty channels from my receiver to these inputs on the sub? Will that power it? What other options do I have? Do I need a powered sub?


Your Sony receiver has both RCA line level outputs and Speaker outputs.

The KLH sub has both of those types of inputs and outputs as well.

The KLH subwoofer's speaker "in" and "out" connections are "pass through". So you would connect the FRONT full range Left & Right speaker cables from your Receiver to the Subwoofer's speaker input connections. Then use the KLH subwoofers speaker Outputs to connect to the cables to your main Front L & R speakers. The speaker signal will "pass through" the subwoofer and on to your main front speakers.

The subwoofer also has a Crossover Frequency Adjustment Dial which will set the Low Pass Crossover Frequency for the Subwoofer, and at the same time it sets the High Pass Crossover Frequency for your connected Front L&R main speakers. A good starting Crossover Frequency is usually around 80Hz, but it depends on how low your main front speakers can play.

You can also use the Receiver's RCA line-level "Preamp Outputs" to feed the signal to the KLH subwoofer. If you need that output on the receiver to also connect to some other component at the same time, you'll need to buy RCA "Y" adapter cables or "pass-through" adapter cables.

The subwoofer Crossover will work the same way for the RCA inputs and outputs as it does for the speaker connections.

Download the Instruction or Owner's Manual for the KLH subwoofer. They should have detailed instructions on how to hook it up in all type of circumstances, such as yours.


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## PrarieChicken10 (Jan 26, 2021)

bbfoto said:


> Your Sony receiver has both RCA line level outputs and Speaker outputs.
> 
> The KLH sub has both of those types of inputs and outputs as well.
> 
> ...





bbfoto said:


> Your Sony receiver has both RCA line level outputs and Speaker outputs.
> 
> The KLH sub has both of those types of inputs and outputs as well.
> 
> ...


Thank you for your response. I thought that the wire connections on the sub worked like a pass through but was not sure. I will look at a manual for a better understanding. Do I have to utilize the output on the subwoofer for the sub to play or could I just feed wires to the input ? 

For clarification, my receiver does have 3 sets of RCA’s but they are all input and not output. I have attached a picture of my receiver (sorry it is a little grainy). 









My plan now after this new understanding is to run signal from the rear channels of the receiver to my subwoofer and keep the two channels for front speakers to my KLH speakers. Is this a correct assumption for setup ?


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## dumdum (Feb 27, 2007)

PrarieChicken10 said:


> Thank you for your response. I thought that the wire connections on the sub worked like a pass through but was not sure. I will look at a manual for a better understanding. Do I have to utilize the output on the subwoofer for the sub to play or could I just feed wires to the input ?
> 
> For clarification, my receiver does have 3 sets of RCA’s but they are all input and not output. I have attached a picture of my receiver (sorry it is a little grainy).
> View attachment 292086
> ...


Just use the preouts, there is a crossover in the sub


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## maybebigfootisblurr (Nov 4, 2011)

dumdum said:


> Just use the preouts, there is a crossover in the sub


He doesn't have preouts


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## maybebigfootisblurr (Nov 4, 2011)

Are you able to run both A and B channels on your receiver at the same time?


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## dumdum (Feb 27, 2007)

maybebigfootisblurr said:


> He doesn't have preouts


Ah I see, I was presuming bbfoto knew the amp 🙈 just tap off the main speaker out to the high level inputs then


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## PrarieChicken10 (Jan 26, 2021)

maybebigfootisblurr said:


> Are you able to run both A and B channels on your receiver at the same time?


Yes, I can run A, B, or AB.


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## maybebigfootisblurr (Nov 4, 2011)

Yeah, I found the manual for his receiver. His A/B channels are in series when selected A+B, rear are only on with Surround.
Seems like running Ch B to high level input on sub amp would be a simple solution. As stated previously, Ch A to sub amp, passthrough to his front speakers will work too.


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