Adding .1 to the 5 [Archive] - Audio & Video Forums


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12-10-2009, 06:33 PM
Hi Folks,

I'm a Hi-Fi newby looking for some tips... here goes.

Current setup: NAD L75 AV Receiver, Aaron Octagon(Australian made) Floorstanders, 2x Energy Connoiseur XL bookshelf as rears, no centre.

I'm really very pleased with the sound quality of this setup as the Aaron Octagons are very revealling with a great mid-range and with the L75 in stereo mode create an amazing soundstage, from CD, DVD and FM sources. So don't want to change this too much.

What I have available from my first Home Theater setup is a Yamaha RX-V2200 AV Receiver with Mirage FRX-9 floorstanders (these have a built in 100Watt MOSFET 8" subwoofer each). This is a great HT setup, but now I have come to really appreciate the real musical soundstaging, depth, detail and clarity of the L75/Aaron combo.

What the L75/Aaron lacks though is a subwoofer. The Octagons have really good base down to 30Hz and are great with music, but with movies they are missing the deep thump; the really strong feature of the V2200/FRX-9 combo.
The easy option is to go out and buy a subbie, but here in Australia, good subbies are rather expensive, typically twice the dollar value of the same product in the US.

So I was thinking, how can I incorporate the subwoofer portion of the FRx-9's into the L75 setup.

The FRX-9 can be bi-wired/bi-amped and has a bridge that can be removed to separate the sub portion from the woofer and tweeter portions of the speaker. So I was thinking of using just the 8" subbie that's built into these.

I tried connecting an FRX-9 in parallel to the Octagons and the L75 went into PROTECT mode; won't be doing that again. 2x 8Ohm in parallel equals 4Ohm, which the L75 does not like.

I tried running an RCA Y cable from the L75's Sub output jack to the left/right terminals on the FRX-9, but didn't get any response from the FRX-9. I don't think the L75's sub out supplies enough current to run a normal speaker. Any ideas around this? Is there some other way to do this? Idealy I'd like to have at least one FRX-9, if not both running off the L75's subwoofer output jack.

I could try to connect the FRX-9 in series to the Octagon, but that would increase the speaker resistance from 8 to 16 Ohm. So the L75 will need to run harder/hotter to get the same SPL? The L75 is 45 Watts when running in 5.1, 60 Watts is Stereo.

I could connect the Octagon and FRX-9 via a Speaker Switch Box and select the appropriate speaker(s) for music or HT. This allows quick n easy swapping between the two sets of speakers.

Also, the L75 has a digital out. Can I use this to have the L75 as a pre-amp to connect to the V2200 and then have the Octagons on the A-Speakers and the FRX-9s on the B-speakers?
My concern here is that the V2200 is not a very musical receiver, very edgy, overly warm, so I don't want to degrade the current sound quality. Though the V2200 has a Processor Direct setting, so that all the gadgety DSPs don't alter the sound. Will this allow the V2200 to act as a clean amp or will the V2200 still "colour" the output?

Any ideas/suggestions will be graciously received.

Thanks so much! :biggrin5:

Some useful URLs:

Mr Peabody
12-10-2009, 07:45 PM
Don't use the digital out of the NAD, you will just be listening to the Yamaha that way.

Coming out of the subwoofer output is a low level signal and if your Mirage only accepts speaker leads which is a high level signal then you have a problem.

Any way to sit the Mirage right beside the TV and use the center channel, set it to "large".

A switcher may be a good option but may degrade the stereo sound from NAD. Emphasis on "maybe". Another option may be to use banana plugs and just manually switch from speaker to speaker.

Or, have two systems, NAD for stereo and Yamaha/Mirage for surround sound.

12-11-2009, 05:24 PM
If you want to incorporate the Mirages as subs, the simplest solution would be to run the line level subwoofer output from the NAD directly to the Mirages (that is, IF those Mirages can take a line-level input).

If that's not possible, then you'll probably want to use the Yamaha as a subwoofer amp connecting to the Mirages using the speaker outputs.

Run the line level subwoofer output from the NAD into one of the source inputs on the Yamaha (AUX, CD, whatever). Turning all of the DSP effects off and setting all of the speaker sizes to LARGE will bypass the DSP section on a Yamaha receiver (the processor direct switch on the front panel only bypasses the tone controls). Also, make sure that the LFE is set to go through the MAIN output, not the SUB output.

Then you connect the Mirages to the speaker outputs on the Yamaha. At this point, the Yamaha is outputting everything sent by the NAD directly to the speaker. Since you're only running the SUB output, then all that's going to the speakers is the low frequencies. At this point, you'll need to set the levels on both the NAD and the Yamaha so that everything balances out properly. I strongly suggest that you use a test tone and a SPL meter. The subwoofer is typically useful for home theater applications when set to +4 db above the mains.

Good luck.

12-17-2009, 07:26 PM
Just wanted to say "Thanks for your great advice" to Mr Peabody and Woochifer.

I have a spare Sanyo 40W/ch Integrated amp from about 1980 (my dad's actually), so I've run the sub-out line-level signal into this amp and from here to the speaker-level jacks on the FRX-9.

Music sounds a lot better, as that little bit of missing bottom end is now present.
HT sounds a lot better, with doors and windows rattling as they ought to. ;-)

Thanks for your help!

Mr Peabody
12-17-2009, 08:28 PM
You are welcome and glad you got it worked out.