RCA Plug to Subwoofer terminals (1 Viewer)

[Barry Ford]

My ONKYO 601 has a single RCA plug for the subwoofer connection but my sub has two normal binding post connections. How do I connect? Do I have to build a cable?

Thanks,

 

[ScottCHI]

what subwoofer is it? is it passive?

 

[Wayne A. Pflughaupt]

The Onkyo’s output is a signal-level feed for an active (i.e., self-amplified) subwoofer. It sounds like your sub doesn’t have an amp built in. If that’s the case, you’ll have to get one. You can’t just “build a cable” because a signal level feed isn’t going to drive the sub

Regards,
Wayne A. Pflughaupt

 

[John Garcia]

If your sub is indeed passive (no amplification of it's own, which it sounds like), you can pick up any basic used receiver, integrated or amp and run your pre-out from the 601 to said external amplification.

 

[Bob McElfresh]

Hi Barry.

That type of sub is called a "passive" or "un-amplified" sub. You need to fool your receiver into powering it.

You run Speaker wire from your L/R speaker outputs on the reciever to the sub. Then more speaker wire from the outputs on the sub to your L/R speakers.

This allows the sub to strip off the power and frequencies it wants, and pass the rest onto your L/R speakers.

Another thing: after you connect your sub, you need to go into the setup menu on the reciever and tell it that your L/R speakers are now "LARGE". (Large means it has a woofer). This will cause your receiver to send all the low frequency sounds for all the other speakers (which you should have setup as "SMALL") to the subwoofer.

Hope this helps.

 

[Nathan Stohler]

Hi Bob,

How does that work? In this configuration, are you saying that the L/R speakers will only receive the frequencies above the crossover frequency set on the subwoofer?

In the manual for my (powered) subwoofer, it says you can run speaker wire from the receiver to both the sub and L/R speakers. In this case, I think you'd have to set the crossovers just right for the sub and L/R speakers. Otherwise, you would either overlap and get double bass at some frequencies, or you would miss a range of frequencies and get no sound there.

But in the way you've described, it sounds like that isn't an issue?

Thanks.
--Nathan

 

[John Garcia]

With a powered sub, if you use speaker level inputs, it is performing the x-over function and passing the filtered signal on to the speakers. This allows user selection of the correct x-over point for your particular speakers in most cases. In this setup, you cannot overlap frequencies, because the sub's speaker level outputs are almost always filtered by the internal x-over, unless the speaker level outputs are at a fixed point (much less common).

 

[ScottCHI]

most powered subs have a fixed high-pass filter for the speaker-level outputs at around 80-100Hz. very few have a variable high-pass filter. usually, only the low-pass filter frequency can be variably controlled.

 

[John Garcia]

Two of the three subs I've owned had variable high pass. Not sure about my current one (VTF-2). Never used it on any of them though. Most of the ones that I've seen that were fixed were in the range of 100-120Hz, which is not ideal when using larger bookshelf speakers. What about SVS?

 

[Barry Ford]

Thanks Bob and all,

That explains why my old receiver (that died) had extra speaker connections for the sub.

I just bought a new of speaker wire, sounds like I'll need it.

Of course, the easiest thing might be to buy a new powered sub

 

[ScottCHI]

most subs' high-pass filters are fixed, including the vtf2. "crossover" is a misnomer as it's really just a fixed high-pass filter/variable low-pass filter on most subs. like i said, very, very few subs have a variable high-pass capability.

the decent subs don't fix it too low, though, but yes, many of the "pseudo-subs" that are meant to be paired with smaller satellites will have the high-pass filter fixed at a higher point than is ideal.

of course, none of this may even be relevant to barry's passive sub. we still don't really know what it is or what it may or may not be capable of.

what is it, barry?

 

[ScottCHI]

this allows you to still run your speakers full-range, but connect your sub via a speaker-level connection when a pre-amp level sub connection isn't an option. and yes, it requires dialing-in the sub's crossover (really a low-pass filter!) to match the speakers' natural roll-off.