A different slant on subwoofer connection

John K.

String, welcome to Club Polk. As was mentioned above, the article from PS Audio was flawed in several respects and shouldn't be taken seriously. The portion that you quote, relating to using a Y connector(which had nothing to do with his previous discussion), and strangely creating a 2 meter distance consideration, in any case has no application to your equipment. You have no sub output on the R113 which might make use of a Y connector.

Yes, connecting the speaker level outputs in the way you describe would create a parallel load, but as you've already read, the sub speaker level inputs present an impedance so high(typically in the tens of thousands of ohms)that the net effect on the combined impedance, which has been calculated mathematically in other threads, is practically zero.

No, unfortunately neither the R113 nor the Sub 800 have any provision which would allow for the highly desirable removal of the low bass from the mains(despite the Parts Express video which claims otherwise). Some of the previous replies shared a misconception that subs have an internal crossover which can provide for bass management on main speakers connected through the sub. As was pointed out, the control on the sub is only a low-pass filter which rolls the sub off above the frequency set, but forces the mains to attempt to run full-range. The control on the Sub 800 is incorrectly labeled as a "crossover"(and incidentally, the other control is incorrectly labeled "Gain", although it's simply a level control which varies the amount of incoming voltage which is subjected to the fixed gain of audio amplifiers). So, there's no provision with your present equipment to lessen the bass burden on your mains, which occasionally creates audible distortion. Modern HT receivers with full bass management provisions are of course available at moderate cost.

Erik Tracy

Just 'cuz HT's have bass management is no guarantee that the resultant sound is 'better'.

Everything is system dependent and experimentation for what works best with your rig, your room, your preferences is the best - don't be a lemming.

This talk of 'burden' on the mains and amp - phooey in my book if you have right components.

Give me better quality stereo components over an AVR any day of the week.

kevhed72

OK....I have read this thread three times now and have to throw this Q out there. If I want to add a DSW MicroPro to my current system, and the sub itself will be located physically OUTSIDE of the (integrated) amp to speaker line (or wire), then I should connect the sub to the end speaker with another run of speaker wire (to the sub's high-level input???)

And to add - REL's Speakon cable is basically a connection which runs from speaker terminal on your amp directly to the sub's high-level input?

rooftop59

kevhed72 wrote: »

OK....I have read this thread three times now and have to throw this Q out there. If I want to add a DSW MicroPro to my current system, and the sub itself will be located physically OUTSIDE of the (integrated) amp to speaker line (or wire), then I should connect the sub to the end speaker with another run of speaker wire (to the sub's high-level input???)

And to add - REL's Speakon cable is basically a connection which runs from speaker terminal on your amp directly to the sub's high-level input?

I am assuming that this is on the music setup? Then you probably have two options. 1. Do as you say. Run the speaker wire out of the Cambridge integrated into the sub's high level inputs, and then another run of speaker wire out of the subs high level outputs (if it has them) into the speakers. Option 2. If the integrated has two sets of speaker outputs (a and b), then just run the second one to the high level inputs. If the sub does not have high level outputs, and the integrated does not have and second set og outputs, then you may be in trouble. But option 3. if the integrated has per-outs then you can run out of those into the low-level inputs on the sub. Surely one of those will work.

Good luck!

wiredguy

When you run speaker wire from the high level amp outputs to the sub, in my case a sony sa 2500, and then run speaker wire from the sub to the right and left speaker, polk 75ts...do you/are you useing the subs built in amp or do you leave it turned off?

[Deleted User]

Hello wiredguy,
Welcome to Polk's forum. You would leave the sub's amp turned on, that way it can power the woofer. Your receiver is providing a signal to the sub, the receiver continues to power your speakers and the sub's internal amp powers the sub's woofer.
Enjoy, Ken

wiredguy

Thanks for the quick answer! That emboldens me to ask one more Years ago I connected a DAK passive sub woofer the same way, no amp in the sub to confuse the issue. At that point I worried about the impedence load on the receiver dropping to 4 ohms or less so I used a Russound wb 1 which is an impedence matching transformer. It is used between the receiver and sub to prevent the impedence from dropping below 8 ohms. Whar are your thoughts on that for the sony powered sub?

[Deleted User]

There's no need to be concerned, the powered sub has its own amplifier which usually has a very high input impedance, as a result it doesn't load down the receiver at all.

wiredguy

Thank you sir !

[Deleted User]

You're welcome!

Inspector 24

Reading this makes me want to get a 2nd VTF-15h and try this setup.

Good reading!

audiomagnate

Kenneth Swauger wrote: »

There is one big difference, however, and that?s the effect the main loudspeaker?s power amplifier had on the signal we reduced in level. Remembering that all power amplifiers affect the sound of the music that passes through them (phase shift at the lower extremes, tube amps with their output transformers, solid state amps, vs. class D amps etc.), we'd be much better off using the already-amplified output of the power amp to feed our sub because that output will be much closer matched, sonically, to what's being fed to our main loudspeakers.

If we use, instead, the low level input directly from the preamplifier's output we have not only lost the advantage of matching the amplifier's sound but we risk the possible degradation of adding another length of interconnect to the preamp?s output which, in many cases, can do a lot of sonic damage (depending on the interconnect's length and the preamp's design).

This is one of the stupidest things I've ever read on the internet.

rooftop59

audiomagnate wrote: »

This is one of the stupidest things I've ever read on the internet.

You must not get around much.

tonyb

Obviously the guy knows little about audio.....much less spends any time researching anything.

WLDock

The difference can be heard running the RT3000P subs off the high level input....the guy I bought mine from found that out during the demo when i was picking them up.

Inspector 24

WLDock wrote: »

The difference can be heard running the RT3000P subs off the high level input....the guy I bought mine from found that out during the demo when i was picking them up.

More info? What did you experience?

audiomagnate

1.The small amount of phase shift introduced by the main amp can be easily replicated using DSP.

2. Paul implies this technique should be used even when the main amp is a tube amp. Output transformers are anathema to deep bass. Taking this damaged signal and passing it on to your sub(s) is definitely NOT a good idea.

3. Paul believes that a passive interconnect is more degrading to sound than an amplifier. I don't.

Paul has another unusual sub hookup procedure that I happen to agree with under certain circumstances. He likes to run the mains full range, i.e. without a low pass filter. If your main speakers go deep and power handling isn't an issue this is a great idea. It's the same as using multiple subs to smooth out room nodes.