Inexpensive HT Bypass - SOLVED!!!

[klinemj]

I think I just figured out the answer to my questions...first, I should split the left channel based on another thread about doing this with the DC-1 (although some say you can split either right or left). Second, I think I should split the signal out of the DAC, not out of the xmc-1. If I split it at the DAC, when I am not using the DAC, there will be no signal going to the sub's "source in". To the contrary, if I split it out of the xmc-1 (from the front left, for example), the sub would always have a signal coming into the source in so when playing in multichannel, it would have inputs from the xmc's LFE and from the source in.

Another option is that the sub has stereo RCA source in's, so I could run RCA outs from the DAC to the sub.

Any thoughts on my approach? Anything I am missing?

Mark

[klinemj]

mshump Thank you for the lead! I had no idea subs even had such a feature, so I didn't bother to look into it until you mentioned what yours can do. I am running to Parts Express tomorrow to get an XLR splitter and 10' XLR cable.

Mark

[mshump]

Jun 19, 2016 10:18:38 GMT -5 klinemj said:

mshump Thank you for the lead! I had no idea subs even had such a feature, so I didn't bother to look into it until you mentioned what yours can do. I am running to Parts Express tomorrow to get an XLR splitter and 10' XLR cable.

Mark

Glad I could be of some help. I hope you get the desired response you are looking for. I love using reference stereo with my set-up, the sound quality is fantastic.

Mark

[klinemj]

HOLD THE PHONE! I just got emails from Enrico Castagnetti and Brian Ding, each of Rythmik. They were contradictory - with Enrico saying "sure, go ahead and split it at the DAC otherwise you will have 2 signals coming into the sub when I use Multichannel (1 from DAC split of fronts coming out of XMC-1 and 1 from LFE).

Brian, however said...

I assume DAC does not have volume control. So if you use the outputs from DAC, you lose the volume control function. The best way is to use the “left” channel and “right” channel outputs of the XMC-1. Since there will be no SUB output from XMC-1 in this reference stereo mode, you are good. You will use LPF 50hz/25 to integrate the sub into your 2 channel (by just augmenting the bass where the front speakers start to roll-off naturally)

In HT mode, the LFE channel will feed the SUB out and also left and right channel outputs. So the strategy is to set the front speakers to “small” and set the crossover frequency as high as possible, such as 80hz. That means the left/right channel will have little content below 80hz, and hence minimize the signal duplication.

Well, while my DAC does have volume control, my plan was to run the analog outs from the DAC to the XMC-1 input, splitting off the FL signal coming out of the DAC to feed the sub. What this would mean is that the FR/FL in 2 channel would have volume controlled by the XMC-1 while the sub volume would be controlled by the DAC (and also impacting the FR/FL volume). Not good.

So, I am thinking I will go with Brian's suggestion. Net, I will:
1) Run XLR left/right out of the DAC to the XMC-1's XLR analog in's.
2) Set the F25 to "Dual Mode" (Allowing both "LFE In" and "Source In", with the F25's x-over, phase, etc. only applying to Source In) See F25's back plate details below.
3) Split the XMC-1's FL XLR out and send 1 line to the FL amp/speaker and 1 line to the sub's "Source In".
4) The XMC-1's LFE XLR out will go to the sub's "LFE In"
5) For 2-channel (which will be the "Balance In" input), the XMC-1's input setup will have the FR/FL set to "large" and the F25's Low Pass Filter will be set to 50 Hz/24 dB slope.
6) For any multichannel input, the FR/FL will be set to "Small" with the crossover for the fronts set to 80 Hz. Given the "Dual Mode" setting, the sub will only use the x-overs/etc. from the XMC-1.

Can anyone see anything I am missing for this? Looks like it gets me a sub in reference stereo mode without impacting anything on multichannel listening and with common volume control of LF/LR/Sub for reference stereo. Right?



Mark

[klinemj]

So, here's my final plan...parts are on order. My plan is a result of input from Lounge Members on this thread and via PM, as well as discussions with Brian Ding of Rythmik. Thanks to everyone who helped! See the sketch below for wiring details.

So, as noted, my sub has XLR and RCA inputs, and the XMC has XLR and RCA outputs. And, I can set the sub up so that when it has a single XLR LFE input from the XMC-1, any line inputs will use the sub's x-over, phase, etc. controls. But any LFE input will not use the sub's controls and will use the XMC's.

With the wiring configuration as shown below, here's how it works:
1) To listen to 2.1 with the XMC in reference stereo, I set the RCA input selector to Input #1 and choose the XMC's "Balanced Analog Input" (which is set up for reference stereo and Speaker Preset 1 - which only includes distances and levels). The sub controls will be set to best match my Maggies which start to roll off around 50 hz.
2) To listen to multichannel, I choose the relevant XMC input (TV or BluRay) and set the RCA input selector to Input #2. Given it will have nothing connected to it, it will send no signal at all the the sub. And, the sub will only get the LFE from the XMC. I can set the XMC-1 to whatever settings I want and the sub won't even know.

Note that when I use the XMC-1 to set levels or run Dirac, I will also set the RCA input selector to Input #2 so the sub is only getting a single channel at a time.

Total cost? $24 for a decent input selector and about $30 for a pair of 2 meter RCA's to go from the input selector to the sub.



I will let you know how it sounds after Sunday!

Mark

[mshump]

It looks like it should work !! With my 2 channel set up in the office I ran 2 rca's into the sub and my sub just never sounded right so I went to just the left and it works great. I'm also running a ML Dynamo 500 in that system, it's definitely not the same caliber sub as your rythmik so your results with 2 inputs may be different.

Mark

[klinemj]

My gear to set up my HT Bypass is here, and I am about to hook it up. Two 6' rca's, a new optical line (not needed for HT Bypass...just needed in general), and a switch. A few quick connections and a level check on preset1, and I will be playing reference stereo with a sub via my XMC-1!



Mark

[novisnick]

Jun 25, 2016 16:57:13 GMT -5 klinemj said:

My gear to set up my HT Bypass is here, and I am about to hook it up. Two 6' rca's, a new optical line (not needed for HT Bypass...just needed in general), and a switch. A few quick connections and a level check on preset1, and I will be playing reference stereo with a sub via my XMC-1!



Mark

Please Show as you go Mark! Thanks

[klinemj]

Got it all hooked up, and sure enough...I am getting sub out of reference stereo as planned. The only odd thing I cannot figure out is that when I go to set levels, if I use the standard predefined approach to set levels and have the switch set so the fr/fl RCA outputs are disconnected from the sub, I can set levels using the xlr outs to my speakers and sub.

If I use the switch to engage the rca's from the xmc to the sub (and turn off my amps to the fr/fl...so only the sub should play), I get no sound at all from the sub when I try the test tones on the fr or fl. But, if I get out of test tone mode and just let the balanced in's play, the sub is clearly playing. And if I adjust the sub volume on its amp panel, it is clearly impacting the sub volume.

I will have to think about this one a bit! But for now, not even dialing the sub in at all other than setting proves off the xlr, setting the sub's controls for 50 Hz crossover and a 24 db slope...it is something good an sounding better than when I toggle the sub off.

Mark

[klinemj]

Jun 25, 2016 17:34:02 GMT -5 novisnick said:

Jun 25, 2016 16:57:13 GMT -5 klinemj said:

My gear to set up my HT Bypass is here, and I am about to hook it up. Two 6' rca's, a new optical line (not needed for HT Bypass...just needed in general), and a switch. A few quick connections and a level check on preset1, and I will be playing reference stereo with a sub via my XMC-1!



Mark

Please Show as you go Mark! Thanks

I got so carried away, I forgot to add the pic! Added now! Pic of switch and Geek in place to follow.

Mark

[klinemj]

Here it is...dirt simple. Set switch to "1", and the fr/fl rca's send signal to the sub in reference stereo. Set it to anything else and it does not. So, for reference stereo, switch setting 1 has sub, others don't. For multichannel, set switch to anything but 1 and the LFE goes to the sub via xlr and the others speakers get only what they would normally in multichannel.



Mark

[sahmen]

Mark :

To complicate this further, how would this system work if you were working with two subs instead of one?

[klinemj]

Jun 25, 2016 18:05:05 GMT -5 sahmen said:

Mark :

To complicate this further, how would this system work if you were working with two subs instead of one?

It would work exactly the same, providing both subs have the capability the Rythmik's! F25 does. Each sub would be wired to take an LFE out from the XMC via XLR, and the switch would be set up the same way, but a single RCA would go to each sub instead of left and right going to a single sub.

Mark

[klinemj]

Initial verdict... sounds great even without optimizing the sub setup! Just listened to some Grateful Dead Ripple, Sugar Magnolia, Friend of the Devil, Box of Rain), Steve Martin/Edie Brickell (Sarah Jane, Atheists Don't Have No Songs, When You Get to Asheville, Pretty Little One), U2 (various off Songs of Innocence), Dire Straits Six Blade Knife, and Chili Peppers Power of Equality.

Sweet upper and mids with a nice little bass boost vs. the Maggie's alone!

A good investment of time to figure it out and a $25 switch and $35 worth of RCA cables.

Mark

[sahmen]

Nice.  Incidentally, I do not have XLR connectors on my subs.  Each one has two RCA L/R inputs, out of which the L channel serves the dedicated LFE input from the pre pro (XMC-1).  I am thinking that the remaining R input on each sub can serve the External DAC with crossover set on the Sub...  Tom at PSA also says it can be done, so I'm not too worried.  Here's what my subs (Power Sound Audio xs15se) look like from the back.

[mshump]

Glad it works Mark !! Reference stereo with the 1.7's and a sub is awesome !!


Mark

[klinemj]

Sure is! Now, I just need to modify my Logitech remote to get to the xmc's input 8 directly instead of having to use the xmc's remote.

EDIT: Now done...system all controlled by universal remote. That said, there is no remote for the Geek, so if I want to change filters or inputs on it, I actually have to get up and walk over to it. Luckily, I don't do that very often.

Mark

[hemster]

Jun 25, 2016 18:31:33 GMT -5 klinemj said:

Initial verdict...wounds great even without optimizing the sub setup! Just listened to some Grateful Dead Ripple, Sugar Magnolia, Friend of the Devil, Box of Rain), Steve Martin/Edie Brickell (Sarah Jane, Atheists Don't Have No Songs, When You Get to Asheville, Pretty Little One), U2 (various off Songs of Innocence), Dire Straits Six Blade Knife, and Chili Peppers Power of Equality.

Sweet upper and mids with a nice little bass boost vs. the Maggie's alone!

A good investment of time to figure it out and a $25 switch and $35 worth of RCA cables.

Mark

So you love it because it hurts so much?     



BTW, nice music selection! 

[klinemj]

LOL! Fixed that! Thanks!

Mark

[GreenKiwi]

klinemj - if you got the 3.7s, you wouldn't really need a sub

I'm glad you got it all sorted.