Anchor chain - anchors your subwoofer system firmly to the Benthic depths of Frequency!

Finally, there is a purpose built, high-quality speaker-level subwoofer input cable that sounds perfect for the task of hooking up the high-level inputs of any subwoofer amplifier.** 

What do you mean, "finally?" 

The current industry standard is to try to cram low gauge speaker wires into the high-level inputs of any subwoofer amplifier that might catch the eye...because you'd want to use the same low gauge high-quality oxygen-free copper speaker wire that is used to hook up the main full range speakers, right? Wrong! Low gauge wires for this connection are incorrect practice because of the minuscule amount current that is actually going into the high-level input binding posts on the subwoofer amplifier. Therefore, the cable that feeds those high-level input binding posts should be rated for the actual input loads that the subwoofer amplifier's circuitry is expecting to see.

Wait.  So then what the heck is really going on inside my subwoofer amplifier?

The internal circuitry of any subwoofer amplifier's high level input stage is arranged such that after those high level (speaker level) input binding posts, the subwoofer amplifier input circuitry steps down the voltage of its left and right speaker level inputs to that of line level (RCA) connections.  This line level, full range stereo input signal exists for a brief period in stereo inside the pre amplifier stage of this subwoofer amplifier.  

The next stage in the subwoofer amplifier then internally sums that signal into a single mono, full range, line level signal that is then tailored by the low pass crossover circuitry inside the subwoofer amplifier (this signal, is what is then being controlled by the adjustment knobs for frequency, gain, phase, and etc. on the back of the sub amp!) 

This low passed mono line level signal now represents any bass content that may be coming from either the left, the right, or both channels, from the left/right high level outputs of your stereo power amplifier.  

This stereo-summed-to-mono bass signal then goes to the final mono speaker level amplification stage in the subwoofer amplifier's circuit. This is the point at which the subwoofer amplifier can then finally drive the binding posts with main sheet speaker cables that go all the way to the passive subwoofer cabinet(s) in the room.

Given this complete explanation about the internal circuitry of the subwoofer, the most appropriate cable for the high level inputs of a subwoofer amplifier is, then, clearly going to be the same kind of cable that is ideal for driving the low level inputs of any other kind of power amplifier - which is low capacitance Oxygen Free Copper (OFC) RCA cable like that in the Bowline RCA cable.  

The custom terminations that turn this RCA cable into an Anchor chain cable are just as simple as the reinforced solid copper pins I terminate the cable with. These copper pins are specially designed to facilitate bi-wiring with any conventional multi-way binding post terminals found on the back of the speaker or the back of a typical hifi amplifier.* which, in the case of a subwoofer amplifier's inputs, are the signal inputs/outputs of this line level signal connection that actually exists between the subwoofer amplifier's inputs and the outputs of your stereo amp.  

Hookup of this cable into your system is accomplished via insertion of the copper pin connectors of the Anchor chain wire into the through hole (screw down) connection points on the multi-way binding posts which are on the backs of Blumenstein speakers (these binding posts are also similar to the kinds of binding posts that are typically found on the back of your stereo amplifier).  The thicker speaker wire signal going to the full-range loudspeakers is uninterrupted by bi-wiring the anchor chain connection, as the second, outer insertion hole is employed for the connection of the speaker level banana plugs into the binding posts.  (The banana plug terminations found on the Main Sheet Cable perfectly fit the binding posts in the backs of speakers), 

*Biwiring Anchor chain and Mainsheet cables to the binding posts can also be done from the binding posts that are on the rear of the full range speakers as shown in this picture - it will sound exactly the same as the other way of biwiring the cables - from the stereo amplifier. 

**If you are already using high-level inputs into a subwoofer from another manufacturer in your stereo system, I think that you will hear a drastic improvement by upgrading to Anchor chain cables in your system. My cable is purpose built and thoroughly researched for this kind of connection in a way that no other cable that I am aware of is. You can only get a design like the Anchor Chain here at Blumenstein Audio. 

Why is Blumenstein Audio committed to driving the high-level inputs of a subwoofer amplifier properly? I feel that the high-level inputs of subwoofer amplifiers are generally the best set of inputs to drive (as opposed to the low-level inputs, which are a close runner up) because each different stereo power amplifier out there has a unique way of presenting the bass content of a recording. Anchoring the subwoofer amplifier's inputs firmly down to the unique (often desirable) way that your stereo amplifier may have of presenting bass material in recordings is beneficial for sound quality. This is especially true the higher and higher end your stereo amplifier becomes. 

However!  RCA cables also make great subwoofer amp input cables.  The point is - wherever you stand on the great subwoofer amplifier input driving debate, you are fully taken care of with the offerings from Waterline cables.