Sub for both music and theater; separate preamps (1 Viewer)

[2handband]

So here's the issue. I have an exceptional hi-end audio system, and am expanding it into a living room home theater. For me rules 1-999 are as follows: thou shalt not compromise music playback in any way in order to implement the home theater.

For surround sound implementation, I have an Onkyo Integra DHC-40.2 preamp. I initially tried swapping that in place of my usual preamp, with predictable results: for music playback, it doesn't sound nearly as good. In particular, the built-in phono stage absolutely stinks.

My solution: run a multi-preamp setup. I'm setting up a switching device to simply switch which preamp is feeding the amplifier that pushes my L/R fronts. Simple enough. Problem: I want to use the same sub for both setups. On the face of it this is not difficult; the subwoofer is feeding off of the main amp via the high-level inputs. But if I understand how decoded surround sound works, it actually separates out everything below 80hz and feeds it to the dedicated subwoofer feed, NOT to the mains.

So my question: is there any way to set up surround so that it runs full-range to the mains? That way I can just leave my sub set up the way I have it. It's been suggested to me that I simply run a separate sub for the theater but honestly... I don't wanna. Any ideas?

 

[JohnRice]

What model is your music preamp?

This really isn’t the ideal way to do it. Running full range to the speakers defeats half the benefit of using a subwoofer. There are some options.

...and, what are your speakers and amp?

 

[2handband]

What model is your music preamp?

This really isn’t the ideal way to do it. Running full range to the speakers defeats half the benefit of using a subwoofer. There are some options.

...and, what are your speakers and amp?

The preamp is a NAD 1130 with a component upgrade package. The speakers are Klipsch Heresy II, with custom biampable crossovers and upgraded tweeters, run biamp with Rotel amps. In actual fact running full-range to the fronts works very well here, because these speakers have a fairly sharp rolloff starting around 60 hz, making for an ideal point to set the low-pass on the sub.

 

[John Dirk]

But if I understand how decoded surround sound works, it actually separates out everything below 80hz and feeds it to the dedicated subwoofer feed, NOT to the mains.

If you're running the sub via high-level [speaker] inputs then you need to enable its low-pass filter to control the crossover. The main speakers can be set to run full-range [Large] on just about any modern Pro/Pro or AVR, so that shouldn't be an issue.

My solution: run a multi-preamp setup.

Or, buy a single Pre/Pro that can adequately handle both tasks such as the Anthem AVM 70 or better yet the AVM 90 if budget allows.

I have an exceptional hi-end audio system

Does that extend to the speakers? Can they handle 25Hz comfortably and at decent SPL's? If so, I would try listening without a sub. That's what I did until recently when I purchased a new set of subs I felt could keep up.

 

[John Dirk]

The preamp is a NAD 1130 with a component upgrade package. The speakers are Klipsch Heresy II, with custom biampable crossovers and upgraded tweeters, run biamp with Rotel amps. In actual fact running full-range to the fronts works very well here, because these speakers have a fairly sharp rolloff starting around 60 hz, making for an ideal point to set the low-pass on the sub.

Ah, this came in just as I was finishing my first post. Now I understand why you want a sub in the system. What make and model of sub do you have?

 

[JohnRice]

In actual fact running full-range to the fronts works very well here, because these speakers have a fairly sharp rolloff starting around 60 hz, making for an ideal point to set the low-pass on the sub.

There are still better options. Running a sub off a speaker level signal is never ideal. Are you open to exploring any of them?

BTW, I've been doing exactly what you're aiming at for almost ten years...
'
What are your source materials?

 

[2handband]

There are still better options. Running a sub off a speaker level signal is never ideal. Are you open to exploring any of them?

Of course. I'll accept any solution that allows me to use the sub both for music and for movies, without having to use the Onkyo for music (seriously, that phono pre sounds BAD). Worth mentioning: if I have to compromise one or the other, I'll compromise the theater experience. We spend a lot more time playing music than watching movies.

 

[2handband]

Ah, this came in just as I was finishing my first post. Now I understand why you want a sub in the system. What make and model of sub do you have?

Klipsch, and I can't remember the model off the top of my head (I'm not home). It's not a great one; one of my weak links, honestly. It's up for replacement in the relatively near term.

 

[JohnRice]

Klipsch, and I can't remember the model off the top of my head (I'm not home). It's not a great one; one of my weak links, honestly. It's up for replacement in the relatively near term.

OK, you want one or two good sealed subs. There are several to choose from, but they will be from internet direct companies that specialize in subs. You'll never really get what you want from a Klipsch sub. Some main brands to select from, SVS, Seaton, Rythmik and PowerSound. Do you have a proposed budget?

@John Dirk can wax poetic about his new dual SVS SB-4000s.

 

[John Dirk]

Klipsch, and I can't remember the model off the top of my head (I'm not home). It's not a great one; one of my weak links, honestly. It's up for replacement in the relatively near term.

We appreciate you saying that so we wouldn't have to.

@John Dirk can wax poetic about his new dual SVS SB-4000s.

These were the best overall fit for me but I readily admit there are other strong contenders out there. In the end it's all about what matters to you the most. Among my needs were excellent tight bass down to 20 Hz, strong pre and post sale support and an iron clad warranty should I have issues. I also wanted subs that could be controlled via an app as opposed to having to get up and fiddle with them. This last requirement was one of the things that steered me away from the Seaton Subversive HP which is an excellent sub I was also fortunate enough to audition.

 

[2handband]

OK, you want one or two good sealed subs. There are several to choose from, but they will be from internet direct companies that specialize in subs. You'll never really get what you want from a Klipsch sub. Some main brands to select from, SVS, Seaton, Rythmik and PowerSound. Do you have a proposed budget?

@John Dirk can wax poetic about his new dual SVS SB-4000s.

I actually have my eye on SVS, coincidentally. Still haven't decided whether to upgrade that or my turntable first. Right now I'm just trying to sort out this connections issue.

 

[JohnRice]

I definitely appreciate what your goal is here. I've had the type of setup you're aiming at for quite a while. What I suggest is to use equipment that is designed to accomplish your goal with the best results.

So, a couple options.

You've mentioned the quality of the phono stage more than once, so one option to try is using the Integra preamp with a better external phono preamp. You can get very good ones in the $200-300 range, though prices go much higher. That will allow you to simplify the setup, and the integration of the sub(s) will be significantly improved. The idea of using the natural rolloff of the speakers as a high pass filter sounds good, but it won't perform nearly as well as using a crossover at the line level, which can be customized for optimal performance.

Another option is that there is a sub-category of high quality stereo preamps which are designed to integrate into a surround system. This is the approach that I use. Essentially, you have a preamp for your music that is designed for optimal music reproduction, with its own sub crossover, which also has a bypass mode that allows you to pass the L&R channels and subwoofer from a surround preamp, and when you are playing back surround, it simply passes the L&R and sub through. In my case, I use the (discontinued) Emotiva XSP-1 for music, which happens to have a stellar phono stage. There are a few other models available with this same function. It's actually an elegant solution.

 

[JohnRice]

Clearly not the advice that was wanted.