Using Home Theater Bypass To Share 2 Channel Speakers With 5.1 Surround System

One of the questions I get fairly frequently is how to merge a two channel sound system with a surround system in a home theater. This type of approach will use the main speakers for stereo and possibly the subwoofer to improve the bass response of the two channel system while also having the ability to do 5.1 or more channels for home theater use. There are several ways to approach this type of system. All of these approaches must address several problems if the stereo and home theater sound are going to perform at their best.

When integrating stereo and home theater the volume setting on the two channel system should not change the main speaker volume level on the surround system. If this is not done the relative channel levels of the main speakers to the other channels in the home theater system will not be maintained along with the relative level of the subwoofer in the home theater configuration to bass extension in the stereo configuration and the relative level of the subwoofer in bass extension in stereo to LFE level in the theater. Another common problem is maintaining proper bass management in theater and stereo. It is important to blend the subwoofer with the other speakers such that the low frequency response is flat. Obtaining the desired ease of use when switching from stereo to home theater use is one reason to keep the volume control on the stereo preamplifier independent of the home theater system.

The easiest solution is to purchase high quality surround sound electronics and avoid a separate two channel preamplifier so that you can get the best sound possible in two channel mode without the complexity of having two preamps. Most modern high quality surround processors also have the benefit of including equalization that can compensate for speaker deficiencies. The surround processor will also include crossovers for bass management to properly integrate the subwoofer with the main speakers. I would consider an Emotiva UMC-1, Marantz AV-7005 processor or Classe SSP-800 for anyone interested in high quality stereo reproduction in their home theater. How these systems detect and process a two channel signal will be important to how the processor will work for stereo reproduction. Being able to force stereo processing with or without the subwoofer is a useful feature to allow maximum flexibility in sound reproduction. The Classe is one of the best available at this.

The next easiest solution is to use an analog preamp that includes bass management along with a home theater bypass for the subwoofer and main channels. This type of system will work best when the main speakers and subwoofer do not need equalization to obtain an accurate frequency response. Products that offer this feature include the Emotiva USP-1 and Parasound Model 2100. An example of how these connections will appear on the back of the preamp are shown below.

Emotiva USP-1 Bass Management

The next easiest solution is to use a stereo preamplifier with the surround preamp that has a home theater bypass, but does not include the subwoofer. This type of system will work best when the main speakers are full range and the subwoofer is not needed for low frequency extension. If the subwoofer needs to be used it will be difficult to integrate it properly in this type of system. The subwoofer needs to be high pass and low pass filtered with the main speakers or the frequencies where the two overlap will be exaggerated creating excessive bass response. This can be done correctly by using the low pass and high pass filters found on many subwoofers on the low level signal inputs. To use these the output from the stereo preamp must be routed through the subwoofer and then to the amplifier for the main speakers. The home theater preamplifier should be set to no subwoofer and large main speakers in this type of configuration. When the system has multiple subwoofers and external crossover is going to be required. Preamplifiers that offer this capability are VAC’s MKI, MKIIa, MKIII preamps, Conrad-Johnson PV14LS and Cambridge Audio Azure 840E. An example of how the connections look on the back of this type of unit are below.

VAC MKIII Cinema Bypass

The final options are to either switch the main channel outputs from the stereo and home theater preamps physically or through a switch. Goldpoint sells some nice passive switches the SW2X-I for XLR connectors and SW4 for RCA connectors.

Goldpoint XLR Switcher

What ever option is chosen careful setup of equipment and selection of the equipment will determine the quality of the results.

W. Jeff Meier

ISF and THX Certified Home Theater Consultant

7 Comments
Desmond Lau

After reading the article 3 times I still can’t get most of it. Can u provide some diagram with wiring connection? It will help very much if u do.
What is my best option if I hv a 2 chnl set up playing computer files through a dac n a tube integrated amp. For movies I hv an Onkyo AVR going to a 5.1 speaker system. The front 2 speakers are shared.
I wld like to integrate the 2 system into 1, n configure it with a HT Bypass.

AudioRube Bryston

This is info I’ve been searching the net for for a few weeks. I bought the Parasound 2100 for it’s capability per the purpose of integrating with a surround processor. A surrounf pre-pro I don’t have yet. Like Desmond I’m still at a loss per the actual connections between the Parasound 2100 and a surround processor. If I understand correctly surround processor outs must go to the HT bypass on the two channel preamp? One question I have is if the surround processor must have a pair(s) of analog preouts for this purpose? I’m looking at an Outlaw Audio Model 975 which doesn’t appear to have any such outputs. While other more expensive AVRs and pre-pros do. Is this what the Zone 1 and or Zone 2 outputs are used for. The Emotiva UMC-200 is another pre-pro I’m considering…which does have Zone outputs the Outlaw 975 does not. Or maybe you connect the front right and left 7.1 outs to the two channel preamp…along with the surround processor subwoofer outs to the bypass port labeled for the subwoofer? So yeah…more extensive diagrams would be helpful.

W. Jeff Meier

You are correct the preamplifier/receiver low level outputs for the left and right front channels go through the 2100 along with the subwoofer. Page 8 of the manual for the 2100 shows the wiring diagram.

To use this type of product you need a power amplifier for the left and right mains and receiver or preamplifier with low level outputs. Either the UMC-200 or the Outlaw 975 will work with the 2100. I would choose the UMC-200 over the Outlaw 975.

This is not what the zone outputs are for.

Dave

I stumbled into the Emotiva XSP-1 and I think that may be the answer i’m looking for. I have a Krell Showcase processor and amp powering Sonus faber Venere speakers. It sounds great for 5.1 HT but like all modern HT systems it sucks for music so i’m using a Dolby Surround receiver I bought in 1995 from Circuit City for $500 as my music system. I’m tired of switching wires to swap systems.
I would connect my TiVo and BluRay player to the XSP-1 using stereo analog connections (what’s going now to my old receiver). I would make balanced connections from the XSP-1 outs to the Krell amp and use those 2 amps to power the Venere 3.0 towers. I could then connect the sub to the XSP-1 and play around with bass management settings – it may help – i’d have an actual signal that has bass in it so it would be interesting to hear what bass management does to the sound – the Krell has the same crap that HT receivers have – you’re “managing” a signal that is anywhere from -6dB to -12dB in the bass range – what’s the point? why bother? The XSP-1 has a process loop that the Parasound lacks as well as balanced connections on the HT bypass and a more robust bass management. I’d get an old-school 10-band EQ and add that to the process loop. I’d have a genuine 2-ch audio system full signal but powered with the Krell amp. That should sound better than the old receiver if not i’ll toss all of it and give up on anything built since 95. The only thing remaining is to make balanced connections from the Krell processor to the XSP-1 for FL, FR and SW into the HT Bypass inputs. Then i’d make a balanced connection from the Krell processor to the Krell amp for the Center and surround channels and power those speakers using the 3 remaining amp channels.
I’m trying to not write a super long post but – my sub has good output below 50Hz but not above it so I get a sound hole in the 50Hz to 100Hz range using the Krell or any other HT processor. So another solution would be to buy a better sub that has adequate output up to 80Hz and just use the Krell for music. I’m not sure I could be happy with that sound even if I could find such a sub – and how much would that cost? Any suggestions on a sub with a musical sound and even output up to 100Hz? I’m thinking small light driver?
I’m disagreeing with you when you say higher cost equipment is an answer. It’s not. It’s just more $$$. Yes it sounds better than HT receivers but that’s not saying very much.
Sorry for the long post.

W. Jeff Meier

I would look at the subwoofer manufacturers I list at the bottom of my blog. I believe the best value musical subwoofer that reaches over 100Hz would be a 12″ Rythmik in the new market. Martin Logan and Paradigm also make excellent musical subwoofers in their more expensive offerings. You might be able to find one of these in the used market.

I am not sure where you read in my article that more expensive is always better. I am a fan of finding the best value for my clients. That means matching the equipment to their environment, budget and goals. A poor environment negates many of the benefits of the best equipment which is expensive and is foolish to install in sub optimal environments because the subtle improvements that they offer will be lost in the room. Many low cost pieces deliver much better performance than those that are more expensive.

I am a big believer in a systems approach to audio or video. This includes equipment, environment and setup. Obtaining poor performance on any of these categories will leave much on the table. Doing them all well will enable some very modest systems to outperform much more expensive ones that do a poor job with one of these categories. I see this all the time in my work.

For example, I worked on a classic McIntosh 2 channel rig recently. I changed nothing, but the equipment setup using my excellent tools and experience. The improvements were astonishing. That old gear from the late 70’s did a great job and out performed many newer systems I hear. The client was amazed. He had something similar done by McIntosh in the past when they would visit a client’s home to setup their gear. My results were superior because I adjusted more parameters than they did and have superior test equipment to what they had available in the past.

defyroy

Having trouble installing home theatre or struggling with Denon and Marantz issues, give us a call at the Marantz repair center in Gurgaon at +919313235774 .or simply visit our website.

Leave a Reply

Your email address will not be published.