Another subwoofer connection question

[cousinarlo]

First I'll apologize for asking a question that seems to have been asked a hundred times here. I did read several threads but didn't fully understand if they applied to my situation; in one thread that looked promising, it devolved into an argument and just added to my uncertainty.

I have a subwoofer that has a single RCA input jack. The receiver/amp I want to use is an NAD C352 that has no dedicated subwoofer output jack but has two pairs of pre-out jacks which some reading has told me might be the connection point to use. The problem is that almost every explanation I've read has left me with another question. Here's what the NAD website said:

"The best way to hook up a subwoofer to an amplifier with no dedicated subwoofer out is to use a "Y" splitter cable.

Steps:

• Take out the pre-out / main in jumpers on the rear of your amplifier.
• Replace the jumpers with "Y" connectors. (The male side coming out of the "pre-out")
• Connect one of the female sides back into the "main-in", while connecting the other side of the "Y" to the subwoofer. (RCA cable extentions will be needed as well in most cases.)"

Here is the back of the receiver:

I read their answer and searched for Y connectors. I found some with two males and a female, two females and a male, and that search quickly bogged down. Plus reading some info elsewhere that said maybe it couldn't be done at all.

Can anyone tell me if it can be done and provide a literal description of the type of cable to buy? I have two other home theatre receivers purchased at garage sales that I could use, but I'm trying to keep the NAD in the picture as it was my dad's system before he sold his house; sort of a sentimental thing. Thanks for the help!

 

[nbk13nw]

A dual Male to single female"Y" connector for preout 1 on the amp. A single RCA to RCA connect from the single end of the "Y" connector at the amp to the single RCA on the sub input.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.amazon.com/Mediabridge-ULTRA-RCA-Y-Adapter-Inches/dp/B005DL2OVE&ved=0ahUKEwjN0YnCmIXaAhUJrlQKHUnlDQMQFgjABDAA&usg=AOvVaw3Z8D25HRU4t5vAiYZ_0xnH

 

[WaynePflughaupt]

Any reason you can’t just use the Pre Out 1 jacks for your sub?

If not, you need a splitter with two males to a single female, like this. The two male ends plug into the receiver’s Pre Out 2 and Main In jacks, while your subwoofer cable plugs into the splitter’s female jack.


https://www.cablestogo.com/product/03181/6in-value-series-one-rca-female-to-two-rca-male-y-cable

Regards,
Wayne A. Pflughaupt

 

[shadyJ]

First I'll apologize for asking a question that seems to have been asked a hundred times here. I did read several threads but didn't fully understand if they applied to my situation; in one thread that looked promising, it devolved into an argument and just added to my uncertainty.

I have a subwoofer that has a single RCA input jack. The receiver/amp I want to use is an NAD C352 that has no dedicated subwoofer output jack but has two pairs of pre-out jacks which some reading has told me might be the connection point to use. The problem is that almost every explanation I've read has left me with another question. Here's what the NAD website said:

"The best way to hook up a subwoofer to an amplifier with no dedicated subwoofer out is to use a "Y" splitter cable.

Steps:

• Take out the pre-out / main in jumpers on the rear of your amplifier.
• Replace the jumpers with "Y" connectors. (The male side coming out of the "pre-out")
• Connect one of the female sides back into the "main-in", while connecting the other side of the "Y" to the subwoofer. (RCA cable extentions will be needed as well in most cases.)"

Here is the back of the receiver: View attachment 23799

I read their answer and searched for Y connectors. I found some with two males and a female, two females and a male, and that search quickly bogged down. Plus reading some info elsewhere that said maybe it couldn't be done at all.

Can anyone tell me if it can be done and provide a literal description of the type of cable to buy? I have two other home theatre receivers purchased at garage sales that I could use, but I'm trying to keep the NAD in the picture as it was my dad's system before he sold his house; sort of a sentimental thing. Thanks for the help!

the procedure in the steps you have outlined is probably the best way to approach this, at least without spending a lot of money for a mixer. Just use a cable like this. Use it to bridge just one of the pre-outs and main-in circuits, and use the loose end of the split cable to go into a subwoofer, and for that you will probably have to buy a RCA extension cable (RCA female to male).

 

[shadyJ]

Any reason you can’t just use the Pre Out 1 jacks for your sub?

If not, you need a splitter with two males to a single female, like this. The two male ends plug into the receiver’s Pre Out 2 and Main In jacks, while your subwoofer cable plugs into the splitter’s female jack.


https://www.cablestogo.com/product/03181/6in-value-series-one-rca-female-to-two-rca-male-y-cable

Regards,
Wayne A. Pflughaupt

You don't want to ever combine two outputs, that will short out the outputs since they will both be sending current into each other. You can split an output into as many inputs as you want (well there are some limits), but never allow the connections to have two outputs connect to each other.

 

[cousinarlo]

Thank you all for the replies. As a worry wart I always try to eliminate the doubt my mind creates, sometimes with mixed results! Here is the back of the sub woofer, plus two diagrams I made so that someone might "check my homework".

First diagram has a two-male/one-female Y-cable that connects the Pre Out 1 left and right jacks from the amp/receiver toward the subwoofer. Then I just connect the male-male cable I already have to the female end of the new Y-cable.

Second diagram has a two-male/one-male Y cable out from the same Pre Out 1 jacks on the amp/receiver, then I need a second cable that is single female RCA to single male RCA.

If I'm not mistaken the links in the three replies (thank you all) lead to 3 different cables; one male/two female, two-male/one-female, and then two-male/one-male.

I didn't make a diagram for the one-male/two-female because I don't know how that would be connected.

Regardless of which cable is correct, do I leave in place the jumpers that currently connect the pre-out 2 jacks to the Main jacks? (see orig photo of receiver above). Or do they come off?

Diagram 2

**Jumpers currently on receiver not shown in diagrams

 

[WaynePflughaupt]

You don't want to ever combine two outputs, that will short out the outputs since they will both be sending current into each other. You can split an output into as many inputs as you want (well there are some limits), but never allow the connections to have two outputs connect to each other.

Huh? Nothing I mentioned there said, or even implied, anything about combining two outputs.

Regards,
Wayne A. Pflughaupt

 

[shadyJ]

Huh? Nothing I mentioned there said, or even implied, anything about combining two outputs.

Regards,
Wayne A. Pflughaupt

I must have misread you.

 

[lovinthehd]

Thank you all for the replies. As a worry wart I always try to eliminate the doubt my mind creates, sometimes with mixed results! Here is the back of the sub woofer, plus two diagrams I made so that someone might "check my homework".

First diagram has a two-male/one-female Y-cable that connects the Pre Out 1 left and right jacks from the amp/receiver toward the subwoofer. Then I just connect the male-male cable I already have to the female end of the new Y-cable.

Second diagram has a two-male/one-male Y cable out from the same Pre Out 1 jacks on the amp/receiver, then I need a second cable that is single female RCA to single male RCA.

If I'm not mistaken the links in the three replies (thank you all) lead to 3 different cables; one male/two female, two-male/one-female, and then two-male/one-male.

I didn't make a diagram for the one-male/two-female because I don't know how that would be connected.

Regardless of which cable is correct, do I leave in place the jumpers that currently connect the pre-out 2 jacks to the Main jacks? (see orig photo of receiver above). Or do they come off?

View attachment 23806


View attachment 23801

Diagram 2

View attachment 23805


**Jumpers currently on receiver not shown in diagrams

The cable for the sub is a female to male?

 

[shadyJ]

Thank you all for the replies. As a worry wart I always try to eliminate the doubt my mind creates, sometimes with mixed results! Here is the back of the sub woofer, plus two diagrams I made so that someone might "check my homework".

First diagram has a two-male/one-female Y-cable that connects the Pre Out 1 left and right jacks from the amp/receiver toward the subwoofer. Then I just connect the male-male cable I already have to the female end of the new Y-cable.

Second diagram has a two-male/one-male Y cable out from the same Pre Out 1 jacks on the amp/receiver, then I need a second cable that is single female RCA to single male RCA.

If I'm not mistaken the links in the three replies (thank you all) lead to 3 different cables; one male/two female, two-male/one-female, and then two-male/one-male.

I didn't make a diagram for the one-male/two-female because I don't know how that would be connected.

Regardless of which cable is correct, do I leave in place the jumpers that currently connect the pre-out 2 jacks to the Main jacks? (see orig photo of receiver above). Or do they come off?

View attachment 23806


View attachment 23801

Diagram 2

View attachment 23805


**Jumpers currently on receiver not shown in diagrams

That is not what you want to do. That is what I thought Wayne was explaining, but I was wrong. Definitely do not connect your sub that way. Just use one of the pre-outs. You don't have to use them both, bass is usually mixed in monoaural, so you will get 99.9% of the bass by just using one pre-out. If you want to use both pre-outs, you need to buy a mixer, and it's not worth it with a sub like that.

Just do this:

 

[TLS Guy]

Your problem is that your sub only has one input, and not a right and left input.

That leaves you with a problem as you can not combine either the pre out 1 or 2, or your whole system will be mono. You have no true sub preout.

Now a lot of subs have a right and left in. This combines the left and right inputs though a thing called a buffer amp. This couples the right and left output in a way that does not make your whole system mono.

So currently you can send the signal from either the right or left channel to your sub, but not both.

So you only have two solutions.

1). Purchase a sub that has right and left inputs.

2). Purchase a buffer amp so that you can send a combined right and left mono signal to your sub.

Unfortunately for you no one actually makes the device you really need. I suspect you would not be able to construct one.

ATI make a very nice one, but it costs $325. Also it is a balanced device, and so you would have cabling expense to use it.

Your cheapest solution is a small active mixer. Do not use a passive one. An active mixer needs to be plugged into a power source.

Something like this would do the trick.

So you would send your right and left pre outs to individual channels on the mixer. Then you would be able to combine the outputs of the mixer and send it to your sub.

 

[cousinarlo]

The cable for the sub is a female to male?

The jack on the subwoofer is female, and is currently connected to an A/V home theatre receiver which has a sub out jack. I just use a single male/male cable on it.

 

[lovinthehd]

The jack on the subwoofer is female, and is currently connected to an A/V home theatre receiver which has a sub out jack. I just use a single male/male cable on it.

Thanks, just asking since you had one diagram that way....would be very odd!

 

[TLS Guy]

The jack on the subwoofer is female, and is currently connected to an A/V home theatre receiver which has a sub out jack. I just use a single male/male cable on it.

If you are using an AV receiver, then what is all that about that old NAD unit, the pictures and the diagrams?

 

[cousinarlo]

Thank you to everyone who's taken the time to stop and have a look at my situation here. Clearly it's more technical than I have experience with, and it also sounds like a case where the wrong approach could have consequences like equipment damage.

Last night I connected the existing single male/male RCA cable to the Pre Out 1 left jack on the NAD. The sub produced sound, but very low level compared to when I had it hooked up to the other receiver with a dedicated sub out jack. It was the same with the right jack of Pre Out 1. To those of you with the sound knowledge I lack this may have been predicted. It's such a low level (even with the sub's own volume knob turned up full) that it's not really worth it especially if I have to rearrange furniture to move the sub closer to the NAD.

It was suggested that I could use a mixer to combine the left and right channels from the Pre Out 1 jacks and then connect the mixer to the sub. Every mixer I've looked at has dual output jacks, but the sub still has only one. How would the output from the mixer with two jacks then be connected to the single input jack on the sub, and would that approach result in more normal volume levels from the sub?

The other question is more general and is about the instructions in the NAD manual and the jumpers on the amp/receiver. The two jumpers currently connect the Pre Out 2 left with the Main In left and the Pre Out 2 right with the Main In right. I have read what the manual says about the Pre Outs and it sounds confusing. It says the Pre Out 2 is normally connected to the Main In sockets (#11 on the diagram); that's the way it is now. But for Pre Out 1, it says in normal use it is connected to the Main In sockets #9. Well according to the diagram the #9 sockets are the Tape 1 In and Tape 2 Out. And under Main In, it says they are normally connected to the Pre Out sockets #10. However, in the diagram, #10 sockets are Pre Out 1 and Tape 1 out. Very confusing for me. Can anyone explain what they are trying to say?

It also says the Pre Out 2 jacks are affected by the receiver's volume controls; maybe they are the jacks to connect to the sub?

In my opinion the instructions that came with this equipment (amp, tuner, cd player) are very unclear and assume a level of knowledge beyond a layman's.

 

[cousinarlo]

If you are using an AV receiver, then what is all that about that old NAD unit, the pictures and the diagrams?

Hi! It's because I want the NAD to be the main system. The reason I have the sub connected to the A/V receiver is because the A/V has a sub out jack, and I could then tune the NAD and the A/V to the same radio station and hear the sub at the same time (there are no other speakers connected to the A/V). However, I have my iPod connected to the NAD and wanted to connect the sub to the NAD system as well. Using the NAD is partly sentimental as it was my dad's system originally.

 

[TLS Guy]

Thank you to everyone who's taken the time to stop and have a look at my situation here. Clearly it's more technical than I have experience with, and it also sounds like a case where the wrong approach could have consequences like equipment damage.

Last night I connected the existing single male/male RCA cable to the Pre Out 1 left jack on the NAD. The sub produced sound, but very low level compared to when I had it hooked up to the other receiver with a dedicated sub out jack. It was the same with the right jack of Pre Out 1. To those of you with the sound knowledge I lack this may have been predicted. It's such a low level (even with the sub's own volume knob turned up full) that it's not really worth it especially if I have to rearrange furniture to move the sub closer to the NAD.

It was suggested that I could use a mixer to combine the left and right channels from the Pre Out 1 jacks and then connect the mixer to the sub. Every mixer I've looked at has dual output jacks, but the sub still has only one. How would the output from the mixer with two jacks then be connected to the single input jack on the sub, and would that approach result in more normal volume levels from the sub?

The other question is more general and is about the instructions in the NAD manual and the jumpers on the amp/receiver. The two jumpers currently connect the Pre Out 2 left with the Main In left and the Pre Out 2 right with the Main In right. I have read what the manual says about the Pre Outs and it sounds confusing. It says the Pre Out 2 is normally connected to the Main In sockets (#11 on the diagram); that's the way it is now. But for Pre Out 1, it says in normal use it is connected to the Main In sockets #9. Well according to the diagram the #9 sockets are the Tape 1 In and Tape 2 Out. And under Main In, it says they are normally connected to the Pre Out sockets #10. However, in the diagram, #10 sockets are Pre Out 1 and Tape 1 out. Very confusing for me. Can anyone explain what they are trying to say?

It also says the Pre Out 2 jacks are affected by the receiver's volume controls; maybe they are the jacks to connect to the sub?

In my opinion the instructions that came with this equipment (amp, tuner, cd player) are very unclear and assume a level of knowledge beyond a layman's.

View attachment 23811 View attachment 23812 View attachment 23813

I see the problem is that the instruction book is wrong. It is full of error.

The point is that it is the preout 2 sockets that are under volume control, which is why the jumpers go from preout 2 sockets to main in.

So you will have to use the preout 2.

I think due to the age of the unit there will not be enough output to drive the sub. So you will need a mixer with gain.

So you need two Y connectors. Remove the jumpers, but don't loose them. Now plug the single end of the Y cables into pre out 2 left and right.

Connect one end of each Y to main in left and right. The other ends of the dual Y go to the mixer.

Now combine the mixer outs with a Y and put the single end of the Y into your sub.

If you have a mixer with gain you should get a strong enough signal to drive the sub.

Whether all this is worth it is up to you. Vintage equipment of that age was not designed to run subs, hence this complex work around.

Quite honestly the best way to do this would be with the ATI buffer amp, but it is $325. It has lots of gain.

If you want to spend that much I will show you what you need. You are going to need four xlr to RCA cables which will be an added expense. That will be in addition to three Y-splitters.

It might well be cheaper and simpler to get a sub with left and right ins. That would be a sub with a built in buffer amp and lots of gain.

You biggest problem in all this is the absence of a buffer amp currently.

 

[shadyJ]

Here is a mixer that is cheap and should do the trick. It has 1/4" outputs, so your cable needs to be 1/4" to RCA tipped. Just connect the pre-outs of the NAD to the inputs on the mixer, than go from the output of the mixer into the sub. It's cheap because its a mono mix, so it's perfect for your situation.

 

[TLS Guy]

Here is a mixer that is cheap and should do the trick. It has 1/4" outputs, so your cable needs to be 1/4" to RCA tipped. Just connect the pre-outs of the NAD to the inputs on the mixer, than go from the output of the mixer into the sub. It's cheap because its a mono mix, so it's perfect for your situation.

Perfect, well done Shady!

 

[cousinarlo]

Thank you very much shadyJ, TLS Guy, and everyone else for all your insights. I finally see how to do it and understand the limitations of what I'm trying to do. I'm very glad to hear that it wasn't just me with the manual's cryptic and erroneous instructions!