Subwoofer connection using receiver's speaker terminals

Yaayuh! · 30 Sep 2012 at 12:39

Hi guys, quick one as I've thought of doing this and a friend has an awkward request.

He has an older receiver that just has speaker terminal outputs and no pre-out but wants to attach a sub. The sub has speaker level inputs but to complicate things it doesn't have high-level outputs (i know this as it's the same sub that i'm using with my PC setup (Wharfedale PC10+)).

So with that it mind would it be ok (or more importantly, safe) to connect the sub in parallel with the speakers using the receiver's terminals?
Looking at the manual for the sub this is one of the suggested ways to connect.. But from my knowledge and experience connecting parallel isn't a good idea given the stress/resistance issues.

Tape/CD/MD recording loops are available but they will be a fixed volume.

Thoughts?

Doug · 3 Oct 2012 at 01:08

Of course

that's how they're meant to be connected.

Read the manual if you're unsure

Yaayuh! · 3 Oct 2012 at 08:27

Rossi~ said:
Looking at the manual for the sub this is one of the suggested ways to connect.. But from my knowledge and experience connecting parallel isn't a good idea given the stress/resistance issues.

Doug said:
Of course that's how they're meant to be connected.

Read the manual if you're unsure

I did. Though i do not trust it.

After reading more about it, i have found that the resistance on these speaker level inputs are very high, which means it should be ok. Designed to cut as much power from the input so it can amplify it itself without overload.

Doug · 3 Oct 2012 at 16:20

Ah! You were looking for a technical answer rather than just a thumbs up

You're exactly right: the very high resistance on the high level inputs mean that they pull an almost insignificant current.

Yaayuh! · 11 May 2013 at 19:51

*raises thread from the dead*

Right-o got another question to add to this.

When connecting in parallel with the speakers, the speakers are still getting full range, there is no crossover involved.
I have a FiiO E17 in the E09K dock and can use the E09K to pre-amp if required, which means i can run the connection to my sub using the RCA input, run the crossover at 65 or 75 and then run out of the sub to the amplifier.

My question is this: Will it degrade the quality of the sound running PC --> DAC -->Pre-Amp --> Sub --> Amplifier --> Speakers

?

lucid · 13 May 2013 at 01:49

Logically the fewer the connections the better, but can't say whether you'd be able to tell the difference in practise at this level.

The only thing that really strikes me is the possibility of a level imbalance with the wiring as you suggested. The main speakers powered by the receiver, so their volume is controlled by the receiver too. But the sub is being driven directly by the E09k (which in turn drives the input on the amp). Two volume controls in one system. Not the ideal way of working for this type of simple sub/sat arrangement.

It would be better to have the E09k driving just the input on the amp. Then have the sub connected in series with the front satellite speakers. The crossover point relies on the natural roll off of the satellites. So you set crossover and volume to fill the gap and provide sufficient overlap.

Yaayuh! · 13 May 2013 at 08:25

lucid said:
Logically the fewer the connections the better, but can't say whether you'd be able to tell the difference in practise at this level.

The only thing that really strikes me is the possibility of a level imbalance with the wiring as you suggested. The main speakers powered by the receiver, so their volume is controlled by the receiver too. But the sub is being driven directly by the E09k (which in turn drives the input on the amp). Two volume controls in one system. Not the ideal way of working for this type of simple sub/sat arrangement.

It would be better to have the E09k driving just the input on the amp. Then have the sub connected in series with the front satellite speakers. The crossover point relies on the natural roll off of the satellites. So you set crossover and volume to fill the gap and provide sufficient overlap.

This is exactly what i was thinking.
If i had it running off of the E09K then i would just of used that for the volume, but it's just messy really.

I'm going to get some small speak cabling this week and connect it all up from scratch with the sub off of the speaker terminals and see how it is.