Subs for 2ch duty

[tutomac]

Hello all.

I am interested in using my two JL Audio subs (e-112) for 2ch listening.

Currently, the subs are being used for HT duties.
I use the LFE output from MX121 to Sub #1 line in (WW Oasis cable), and sub#2 is piggybacked to #1 through #1's line out (WW Oasis cable).

Question is: is it possible to use both subs for both HT and 2ch duties, and if so, what is the best way to achieve this? (connection and cables?). I do not have a 2-ch preamp, only the MX-121.

Thanks all in advance and cheers!!

[Erik Tracy]

If you only have the MX121 HT processor, what 2-channel sources are connected to it now?

[tutomac]

MCD 500 (cd's SACD's) unbalanced to CD ANALOG AUDIO IN and D-100 (DAC for Sonos and Mac Mini) balanced to AUX1 BALANCED INPUT.

Cheers!

[Erik Tracy]

So with 2-channel sources connected to your MX121 and the subs connected to LFE output from the MX121 are the subs not outputting anything?

[tutomac]

Correct.
Both subs work for HT (5.2) but not in 2ch (pure direct) mode on the MX121.

Uh-uh, is it something to do with "Pure Direct"? I thought that just eliminates the digital processing...

[jameslrock]

I think Pure Direct is the reason. I have a spare Denon 4308Ci that I used years ago and from what I recall using Pure Direct eliminated sub output.

[tutomac]

Well I hope you're right... I will test it this afternoon and confirm it here.
Thank you for your valuable time and patience with a novice😉

[Erik Tracy]

If McIntosh's implementation of Pure Direct is like other Pre/Pros and AVRs, then it is a 2-channel signal path and stays analog from input to output on Front Left/Right outputs only.

Therefore, no bass signal is sent out the LFE output.

I ran into the same issue with my home setup.

There should be a different setting that may be called something like Stereo/Straight.

That should give you sub outputs with 2-channel sources. However, I am pretty sure this involves an A/D conversion inside your pre/pro to synthesize the bass signal and then another D/A conversion to send signals out the Front L/R and LFE outputs.

Another option would be to use the Front L/R preouts, split them to send to your amp and then to the subs, but this would mean foregoing bass management to your fronts, if that is an issue for you, because you'd have to sent Fronts=Large.

[tutomac]

Originally Posted by Erik Tracy

If McIntosh's implementation of Pure Direct is like other Pre/Pros and AVRs, then it is a 2-channel signal path and stays analog from input to output on Front Left/Right outputs only.

Therefore, no bass signal is sent out the LFE output.

I ran into the same issue with my home setup.

There should be a different setting that may be called something like Stereo/Straight.

That should give you sub outputs with 2-channel sources. However, I am pretty sure this involves an A/D conversion inside your pre/pro to synthesize the bass signal and then another D/A conversion to send signals out the Front L/R and LFE outputs.

Another option would be to use the Front L/R preouts, split them to send to your amp and then to the subs, but this would mean foregoing bass management to your fronts, if that is an issue for you, because you'd have to sent Fronts=Large.

Hello Erik. Indeed, the the 121X has three settings for 2ch (STEREO)music: DIRECT, PURE DIRECT, and AUTO. It is not possible to use one's sub(s) under these settings... just L/R mains.

About the last option you offer (splitting the Front L/R pre outs)... I use the balanced outs to the amps, and my subs do not have balanced inputs, just unbalanced. Is it possible to use the unbalanced pre outs to the subs simultaneously (while the balanced pre outs are sent to the amps)?

Thanks!

[Erik Tracy]

Originally Posted by tutomac

Hello Erik. Indeed, the the 121X has three settings for 2ch (STEREO)music: DIRECT, PURE DIRECT, and AUTO. It is not possible to use one's sub(s) under these settings... just L/R mains.

About the last option you offer (splitting the Front L/R pre outs)... I use the balanced outs to the amps, and my subs do not have balanced inputs, just unbalanced. Is it possible to use the unbalanced pre outs to the subs simultaneously (while the balanced pre outs are sent to the amps)?

Thanks!

Nothing definite - check the McIntosh manual to see if both output types are active and can be used at the same time.

I do know that for some AVRs it is NOT recommended to use the RCA pre-outs and speaker terminal outputs at the same time.


More options to consider:
1) Abandon the balanced outputs to your amp and instead use the RCA outputs with splitters to your amp and subs and set the MX121 to Fronts=Large

2) Abandon the balanced outputs to your amp and run RCA outputs with splitters to your amp as well as the LFE output you have now. Have two saved memory configs on the MX121 where you use Bass Management Fronts=Small and the LFE output to the subs as you do now. But also have a second setting where Fronts=Large. You then have to manual swap connections to the sub when you want to have bass management for movies (LFE output) or 2-channel (Front pre-outs).

3) Build a hybrid HT/2-channel rig by purchasing a preamp with HT bypass.

{edit} Are you sure that the Stereo settings does not offer a sub output? My Yamaha AVR allows the sub to operate in Stereo mode with 2-channel inputs.