What? 2Ch HT?

[Aric M L]

So I'm currently using my 2 CH system for Home Theatre and this gets me some cross eyed looks from speaker folks. I want to know if there's anyone else out there who does this, or anyone who switched from my way and has any sing-the-praise stories that might make me be able to justify investing in 3 more speakers and a surr proc. Or if you think I'm a fool I'd like to know too I suppose.

[Eric Z]

I started with a 2CH HT set-up with an old Sony stereo receiver. I had my TV, stereo receiver, DVD player, and 2 front floorstanding speakers. I was happy because I was used to just watching movies with the TV speakers. Then I ended up getting a subwoofer which helped me with some more bass when watching movies and listening to music (great improvement in sound). I then upgraded to a HT receiver- I noticed a pretty darn big difference in clarity and quality of the sound. Next came the center channel- never thought one speaker would improve a HT like a center channel. It was great to hear the clear dialogue come from the center channel- before the dialogue sounded muffled in the front speakers! After the center came the surround speakers to complete the set-up. It took me a while to complete the system because my Mirage FRX series speakers are discountinued and I wanted the center and surrounds to match and it was a little difficult finding them through Ebay for a decent price.

In the beginning, I thought the 2CH HT set-up was great because I didn't know what I was missing. Now that I know what it can sound like, I don't like to watch movies at my friends house because he has an older receiver and only 2 front speakers.

Now I have a little upgrade-itis! I'm looking to buy some new stuff for the family room and move the old set-up in the living room.

Good luck!
Eric

[dean_martin]

So I'm currently using my 2 CH system for Home Theatre and this gets me some cross eyed looks from speaker folks. I want to know if there's anyone else out there who does this, or anyone who switched from my way and has any sing-the-praise stories that might make me be able to justify investing in 3 more speakers and a surr proc. Or if you think I'm a fool I'd like to know too I suppose.

I have a 2.1 system for movies.

NHT SuperOnes
Velodyne CT-12
NAD C350 integrated
Pioneer Elite DV-C36
older Sony 32" TV

I was on my way to a 5.1 system, but adding the sub added so much dimension and impact to movies that I put my plans on hold and concentrated on a seperate music-only stereo system to spin my vinyl. The NHTs' open top end and ability to create a solid center image for dialog also make me wonder whether it's worth it to re-work this system now. I might go multi-channel when I get a better handle on what's going on with the tv market, new film formats, etc.

[Woochifer]

Pretty simple justification. If you're listening to 5.1 soundtracks, you're not playing them back the way that they are supposed to be heard. If you lack a surround processor and 5.1 speaker setup, then you're listening to it using the analog outputs from the DVD player. Problem with this approach is that the soundtrack gets mixed down to two channels by the DVD player.

This mixdown occurs at preset levels with no way of adjusting the levels or how the channels are assigned. It occurs, whether or not it will sound good. Depending on how the 5.1 mix was done, it can result in very inappropriate levels for some sound elements, and an inconsistent suround effect overall. For example, some 5.1 soundtracks are mixed with the music and effects steered into both the front and surround channels at nearly equal levels. When the downmix occurs, these sounds get blended back into the main channels, having the net effect of boosting those levels by up to 60%. This can drown out the dialog and other sounds intended to only go up front. In addition, the .1 LFE channel that gives you the extra bass effect gets discarded in the two-channel mixdown mode, so if you use a subwoofer in a system without a surround processor, you miss out on that part of the experience as well.

Keep in mind that recording engineers mix the 5.1 soundtracks without accounting for how it will sound in two-channel mixdown mode. CDs are mixed with two-channel playback in mind, so they are mixed and EQ'd to create a phantom center channel that anchors the middle of the soundfield. 5.1 soundtracks don't need this because they are mixed with discrete center channels. Splitting the center channel and redirecting it to the L/R mains in two-channel mixdown will not necessarily create a stable or strong center image, because the recording engineer mixed it solely with a discrete center channel in mind.

A good example of this is the Heat: SE DVD that I just bought last night. I watched the first 10 minutes of the movie not knowing that the surround processor was switched off. The soundtrack immediately sounded odd to me. The dialog sounded too low, and the sound balances in general did not sound right. When I checked the center speaker level, that was when I saw that the surround processor was not switched on.

If you have fewer than five speakers, then it's still fine to just get a surround processor/receiver and use the virtual surround functions built into those. The main advantage with those is that they further process the soundtrack and create a pseudo surround effect rather than just blending everything together a preset levels. Plus, you can direct the LFE channel back through the main speakers or a subwoofer, so that you don't lose out on the deep bass.

But, the goal should be at least a discrete 5.1 speaker setup. The extra sense of dimensioning that you get with a timbre matched and properly setup 5.1 set is beyond what two channels alone can ever provide. Listening to a 5.1 music disc or a well done movie soundtrack like "Master and Commander" is really where you hear what multichannel is capable of. The side imaging is solid and stable, you get depth perception, and depending on how it's mixed, the soundtrack can also convey a sense of space. But, the key is to have all the pieces in place, AND to properly position them and set them up once you have everything assembled.

[Aric M L]

So are you saying without a surround processor I'm losing out entirely on the LFE channel? I'm running on a HK Avr 40 home theatre reciever if that makes any difference. If that is the case I'd only be about half surprised as sometimes I feel that my speakers are putting out some great bass, and other times I feel like maybe theres a little more to be had.

[markw]

In theory, all the channels in the HT experience (including the 5.1) are folded into the 2 channel analog output. How well the blend comes out of the two speakers is another story.

Anyhow, here' my take on your original question. Well, listening to video through your stereo is light years ahead of using that tiny lil' speaker (or two) inside the TV itself. I did that myself back in the 60's and 70's before there even was stereo TV, much less videotapes, DVD's et al. Lemme tell ya, Don Kirshner's rock concerts sounded pretty durn good even in mono coming through a Marantz 2270 into a pair of JBL Lancer 55's!

But, for movies I think you are denying yourself a tremendous experience by forgoing 5 channels plus the subwoofer, particularly in this day and age where good HT sound is exteremely reasonable. You can equal and, in many cases, surpass the sound you get in first run theaters and there are many other benefits. No expensive snacks, you can pause it to go to the bathroom and kitchen and, most importantly, you can watch movies in your underwear! Try THAT in yer local Lowes!

Seroiusly, that LFE channel going to a dedicated sub and add a world of enjoyment to the experience. Granted, your speakers are good but there's nothing like having a dedicated subwoofer that just handles the lows, nothing else. Low freqs drain the power of your amps and by having thenmchannelrs to it's own amp, your mains are free to handle everything else.

And, some action movies make durn good use of the surround chanels. To sum it up simply... yeah, it's well worth it for movies...

[Woochifer]

So are you saying without a surround processor I'm losing out entirely on the LFE channel? I'm running on a HK Avr 40 home theatre reciever if that makes any difference. If that is the case I'd only be about half surprised as sometimes I feel that my speakers are putting out some great bass, and other times I feel like maybe theres a little more to be had.

Looked up your model. It's a Pro-Logic receiver, and since it relies on the analog connection from the DVD player, you're hearing no LFE content. My understanding is that the two-channel analog mixdown that's done with a DVD player does not include the LFE channel. There's still a lot of bass that typically goes through the other channels and is included in the two-channel mixdown. But, you just don't get that extra deep extension that the LFE provides. To hear the LFE through a two-channel setup, you need a surround processor that can redirect the LFE channel through the main speakers. A Pro Logic receiver won't do that.

[Aric M L]

So if I'm not ready to make the move to 5.1 but I do want to add a subwoofer. What kind of decoding would I need to support to actually have an LFE, if that's even possible. I do enjoy a bit of rumble in my movies, and I'm thinking of getting a B&W ASW 300. I know it's just an 8 inch but I love how tight it sounds IMO and I have a small living space.

[markw]

The LFE info is already "folded" into the two channel mix. It's already there.

Dunno that sub in particular, but here's some general guidelines.

1) If it has speaker level inputs, you cab hook it up the your speaker outputs.

2) If the sub has speaker level outputs, you can hook up your mains to the sub and it will srtrip off all bass from the mains. You may or may not want this depending on how it sounds.

3) If you like option one but wish to forgo option 2, I would suggest you hook it up in parallel with your speakers since it presents such a high impedance tlod to the amp that it will be safe. This will channel ALL the LFE to both the sub and your mains but it may not sound as good as you would think. There's always option 1 or 2.

4) If you have preamp outs on the receiver and R/L inputs on the sub, you can split the preamp output for both channels and send it back to the main amp AND the two line level inputs on the sub. This will allow you the most options to adjust the sub's low pass, gain et al. This is what I did with my system. My sub is adjusted so it only kicks in below 50 hz.

5 ) a caution. If the sub only has one line level input, don't use a "Y" connector to combine the two channels. Trust me on this.

[Woochifer]

The LFE info is already "folded" into the two channel mix. It's already there.

The LFE channel is not part of the stereo downmix, it gets discarded. The only way to obtain the LFE content in two-channel mode is through a receiver/processor with whose bass management and DSP functions allow you to redirect the LFE into the main channels. With the two-channel analog output from a DVD player, the LFE's not part of the picture.

The other channels might have plenty of low frequency content folded into the stereo mixdown that can get directed to the subwoofer by the receiver's crossover, but whatever is mixed into the LFE channel gets discarded during the two-channel fold down. Dolby's 5.1 mixing guidelines explain why it's done this way. (p.5)

http://www.transtec.nl/downloads/Pro/dolby/5.1_mixing.pdf


So if I'm not ready to make the move to 5.1 but I do want to add a subwoofer. What kind of decoding would I need to support to actually have an LFE, if that's even possible. I do enjoy a bit of rumble in my movies, and I'm thinking of getting a B&W ASW 300. I know it's just an 8 inch but I love how tight it sounds IMO and I have a small living space.

Simple, you need a receiver/processor with a digital connection. Using the default two-channel analog output, the LFE track is discarded during the mixdown process. However, with a digital connection, the DSP functions on a typical AV receiver allow you to redirect the LFE into the main speaker outputs if you don't have a subwoofer hooked up. Or it can direct the LFE into the subwoofer output.

All receivers have a virtual surround mode of some kind to use with two, three, or four speaker setups. This uses the receiver/processor's DSP capability, and allows for multiple options on how to handle the LFE track even with two speakers.

However, even in your current setup, adding a subwoofer should give you added rumble. You simply wire the speakers into the subwoofer and use its crossover to direct the lows to the subwoofer and filter out the low end going into the main speakers. Even though the LFE track is missing in the two-channel analog output, the main channels will still have plenty of bass content, just not that really deep punch that the LFE provides.

[markw]

The LFE channel is not part of the stereo downmix, it gets discarded. The only way to obtain the LFE content in two-channel mode is through a receiver/processor with whose bass management and DSP functions allow you to redirect the LFE into the main channels. With the two-channel analog output from a DVD player, the LFE's not part of the picture.

I didn't know that. Thanks for edjumacating me. See? Even an old dog can learn new tricks.

[Sir Terrence the Terrible]

I didn't know that. Thanks for edjumacating me. See? Even an old dog can learn new tricks.

Your not a old dog, you an experienced one!

In addition to Wooch's great post, with downmixing your are stuck with the lowest bit rate of 192kbps per channel. Now if you think that Dolby digital sounds compressed, you should hear the difference between a downmixed DD track, and a well done 2.0 linear PCM track, that is a ear opener.

Also with downmixing from the player level, the overall balance of the mix is tipped towards the upper frequencies by way of lack of deep bass. Unless there is a dedicated optimized 2.0 stereo mix, or that the mix was altered by putting some of the deep bass from the LFE channel into the main channels. This latter is the least desireable in that it alters the Dolby Digital 5.1 mix. I would be very careful of DVD's that do not carry a dedicated 2.0 mix, as the Dolby digital 5.1 mix is will have to be compromised in order to make it compatible with mixdown. If you want to make the soundtracks backward compatible to prologic users, that is the only way outside a dedicated stereo 2.0 mix