[geaux001]

I'm trying to incorporate a a tube preamp, namely a Rogue RP-1, into a HT headed up by a Marantz SR7012 so that I can isolate the AVR when playing music. A Bryston 4B powers the fronts. I can use the HT bypass easy enough but how best to incorporate the subwoofer, an SVS SB2000?

I may still choose a BAT VK3i. I see the Bryston has 1/4" and Balanced inputs, could I run one lead to the Bryston via the 1/4" inputs and another through the balanced and the amplifier would play whatever signal it receives?

Thoughts?

[WGH]

Ideally the sub would be connected to BOTH the Bryston AND the Marantz at the same time. Many subs have two inputs: a high level (speaker) and low level LFE (Low Frequency Effects) inputs. These two inputs are designed to be used at the same time. Unfortunate your sub is not designed for home theater and does not have 2 inputs. Replacing the sub would be the most elegant solution.

Home theater receivers are designed to roll off the bass around 80 Hz to ALL the speakers. The LFE outputs to the sub then does what it is designed to do, it plays all the bass below 80 Hz. This arrangement enables all the speakers to go louder without trying to reproduce bass at 100 dB plus the reduced load means less powerful amps can be used without sacrificing clarity and dynamics.

Stereos don't limit bass unless your L&R speakers are not full range. High Level (speaker) inputs just sound better than the preamp out too. With a high level input the sub then takes on the character and speed of the amp making the sound more integrated.

Stereo:
Preamp --> Bryston amp --> Speaker terminals --> Sub high level connection --> Sub high level input

Home Theater:
Marantz L&R front speakers line out --> preamp home theater mode --> Bryston amp --> front L&R speakers
Marantz LFE Sub output --> sub LFE input

In home theater mode the preamp will receive an attenuated bass signal rolled off at 80 Hz so the sub really only sees the low strong LFE input and is not overdriven.

This configuration allows the Marantz to be off when listening to stereo.

[geaux001]

Thank you for the detailed response. I’m pretty sure I can install I can install it exactly this way…

[WGH]

I’m pretty sure I can install I can install it exactly this way…

Maybe, maybe not. The manual does not cover plugging two different preamps into the sub inputs. If the two sub inputs share the same ground then I don't know what will happen when the preamp and Marantz are both on.

Your amp inputs may be different than the photos I have found.

[NekoAudio]

You cannot connect both the Marantz and the Rogue RP-1 into the subwoofer at the same time.

Connect the Marantz line-level outputs to the HT bypass input on your RP-1. Connect your RP-1 left and right outputs to the SB-2000 line-level inputs. Connect the SB-2000 line-level outputs to the Bryston 4B3. Use the SB-2000 crossover settings.

[WGH]

I’m pretty sure I can install I can install it exactly this way…

Time for some clarification and definitions:

Subwoofer High Level Input: This input is connected directly to the AMP/Speaker Wire, usually by a Neuteric plug. The SVS SB2000 DOES NOT have this connection.

What is a High Level and LFE Connection?
https://relsupport.zendesk.com/hc/en-us/articles/115004486987-What-is-a-High-Level-Connection-


Subwoofer Line Level Input: The SVS SB2000 has two line level inputs. The Marantz has L&R line level outputs and the RP-1 has L&R line level outputs. Pick one or the other, the Marantz and Rogue RP-1 CANNOT be plugged into the SVS SB2000 sub at the same time.

Connect the Marantz line-level outputs to the HT bypass input on your RP-1. Connect your RP-1 left and right outputs to the SB-2000 line-level inputs. Connect the SB-2000 line-level outputs to the Bryston 4B3. Use the SB-2000 crossover settings.

This will work, sorta kinda. I don't know how transparent the SB-2000 Low-Pass Filter is, it would be a shame to insert a crossover between the excellent Rogue and Bryston, but if you must, you must. The Low-Pass Filter in the SVS SB-2000 will send lows to the sub and filtered mids and highs to the Bryston amp. The filter can be adjusted but I didn't read where it can be set as a pass-thru for the main L&R speakers.

The Marantz has Audyssey, Auro-3D and Dolby Atmos calibrations. After calibration ALL THE SPEAKERS are commonly rolled off at 80Hz, this prevents speakers from blowing out woofers when watching Blade Runner 2049 which has strong, high level 15 Hz synth notes. Other films with low bass include Dune; Under Siege 2; U-571; Master and Commander; Godzilla: King of the Monsters (2019) and many more. The sub then reproduces all the bass from 80 Hz on down.



After calibration the Marantz L&R line-level outputs will have all bass below 80 Hz filtered out too, no amount of bass boost will bring it back. The RP-1, Bryston amp, the L&R speakers and the sub will get zero bass.
Unless... you manually adjust the Marantz L&R channels to a full range setting with no roll off, then the sub will get all the bass too. But that means your L&R speakers must also be full range and be able to reproduce 15 Hz at 100 dB without putting the cones in your lap.

The SVS low-pass filter should keep the cone toss from happening and keep your speakers safe although I still don't like the idea of putting a filter between the preamp and amp.

What speakers do you have?

[nlitworld]

Marantz front preout -> Rogue via HT Input -> #1 output to Bryston, #2 output to subwoofer. That would be easiest way to keep music isolated and HT setup clean and tidy. If you need to get an rca-xlr adapter then no problem there. Lots of options available. You wouldn't get the room correction with the subs, but just run your speakers full range and adjust the dials on the back of your sub to best setting. A little more manual labor, but it eliminates a lot of issue. If you still want more subs for HT, then plug one or two more into Marantz only and have the front speakers still set to full range.