I have a subwoofer with its own external amplifier that connects to an older receiver through a tape loop
(record out/playback) from the 1980's-90's era. The receiver died so I am considering a Denon-AVR-S510bt-5.2-Ch-x-70-watts but can't seem to figure out how to connect the sub to the receiver. Is there some way to rig a connection to the AVR? Is there any current receiver that would accommodate this kind of connection. Do I need a new sub? Any advice would be appreciated.

You should be able to use the component out or analog out jacks on that Denon.

The Denon has two sub-woofer outputs on the back. why would you not use one of them as it's just like the tape-loop out except instead of sending all the sound and then having the sub try and filter out the high frequency sounds off, the Denon does all that for you

Thanks for your suggestions. I should have mentioned that it takes 4 RCA plugs to hook up this sub. L/R Input and L/R Output (High Pass).

But that is the whole point of the Sub output on your new Denon receiver. it does not need 4 RCA plugs.

Your old system you were feeding all the sound (left & right) out the tape out port to the sub amp where you did your high pass filtering to pull out just the low sound that the sub would play, and fed back through the tape input your high frequency sound that you would play through your normal speakers.

But the Denon doesn't need any of that. it has all the logic built inside itself that old receivers did not have. it can internally do all the high pass/low pass filtering along with digital source material that has encoded LFR (low frequency range) data. So inside the setup of your Denon, you specify at what crossover point you want the sound sent to your sub. You don't even need to run a left and right as the Denon inernally looks at all the channels for you.

You really should (RTFM) on your Denon as it should have covered all of that in the section about the sub.

You old DIY sub setup amp might be more happy with a left and right input, so you can use a Y-connector or as the Denon has two sub outputs use them both.

You don't need anything running back to the Denon from your sub as there is no high pass filtering going on. simply ignore that cable as it is now redundant.

Pierre Sprey from Mapleshade Audio recommends as follows:

For achieving seamless integration of the subwoofer sound in both two channel and surround systems, always use the speaker cable input on the sub, never the RCA line level input. That means adding a pair of speaker cables, one end connected to the same amp (or receiver) output posts that are driving the left and right mains and the other end connected to the left and right speaker-level inputs on the sub. The quality of the cables to the sub affects the sound of the main speaker cables, so don’t use bad-sounding zipcord or high end “garden hoses.” Make sure you leave the two main speakers connected directly to the main amp outputs, not to the subwoofer’s output binding posts. If you’re using a processor, set it to “Large Speaker” for the mains (or for all speakers) and turn off the LFE channel.

• Always fire the subwoofer driver left or right, not directly at you or down into the floor. If the subwoofer is off center, then test left-facing versus right-facing to see which sounds better. If your subwoofer is designed to fire down, set it on its side with the driver facing left or right. Be sure to rigidly mount it to the floor or platform as per the second bullet below. You’ll love the increase in bass articulation and clarity.

• By ear, set the crossover at the lowest possible frequency that doesn’t leave a bass “hole in the middle”. To do this, use as a test track one minute of a well-recorded bass solo that covers almost the entire range of the bass. Start with the crossover much too low so that there’s an obvious bass weakness somewhere in the middle or lower octaves of the solo. Nudge the crossover up 5 herz at a time until the bass weakness just barely disappears. Setting the crossover slightly too low sounds far better than setting it too high.

MatMan: From what you are saying there is a way to hook up my sub through a newer Denon receiver. I am confused about the hook-up however. The sub's amplifier requires 4 RCA plugs that go the older receiver's tape loop. Wires are also connected from the sub amp to the sub itself. If I am to connect the sub amp to a new Denon receiver, if I understand you, it will require a different kind of connector. Are you saying to use a "Y" connector from the sub amp input and connect it to the Denon sub output? What kind of jack is used to connect it to the Denon? My guess is that the "Y" connector will have two RCA's jacks connected to the sub amp in the input area and the single jack goes into the sub output, right? I'm not tech savvy so I hope you understand my questions.

Captain, perhaps you can post the make, model or anything to identify your sub?

You should be able to use just a single rca cable from the Denon to the left or right channel of the sub amp. It shouldn't need anything else.

Lee, there may be some problem with terminology here. You say that it's an "external" sub amp with "High Pass" outputs to the sub. If you mean that, rather than an internal amp within the sub enclosure, with high pass outputs(which remove bass and pass higher frequencies), it couldn't be connected effectively to the sub, since the bass frequencies would be missing.

If you can, clarify what the form of the present sub amplification actually is.

Hi John: Yes, this is a 1979 vintage sub-woofer that uses an external amp. Connections are made from the amp to the sub through regular speaker wire. The connection design to the receiver requires a tape in/out loop in the receiver using four RCA plugs...2 for L/R Input and 2 for L/R High Pass Output. The sub is from "Speakerlab" and came with two satellites. It is now working with my M80v3's and an old 1990's Technics 50 watt receiver that I believe is too taxed by the 4 ohm speakers. So I thought to buy a new receiver hoping I can find a way to connect the sub to it.

Okay; what wasn't clear to me before was that there was speaker wire connected to the sub to power it, rather than the low level high pass wiring, which of course can't do it.

It appears that as Matt and Rick(Wid)suggested, a single coaxial cable with RCA plugs, connected to a receiver sub out and in to one of the sub amp inputs(by convention, usually the left)would work. And yes, considering the quality of your M80s, it would seem that relatively little is added by that sub.

Incidentally, if you'd consider spending a bit more, the factory refurb X2000 here is a good deal.

Thanks John. I believe the sub does add somewhat to a fuller bass sound and goes down to 25Hz similar to the M80's. At some point the future I am looking at an EP500. I have looked at all the Accessories4Less Denon and Marantz receivers and will make a decision very soon. The X2000 has the connections I need. I've heard much about Atmos in terms of sound processing. This technology may enhance my music listening. Any comment on this?

I understand that a TV is needed for the settings on a Denon receiver (or any recent modern receiver). Do Denon receivers have factory settings? I do not have a TV with a HDMI input.

Most modern AVRs have software that you can use if you hook your device up to a network. take a look at that option