What is missing from many 2 channel systems.

mantis

What's up everyone? This will be long but might be worth your time to read.

So lets all assume that your 2 channel system is properly placed. Your speakers whatever they are are in the ideal position for creating that imagining we all crave. You spend countless hours getting the tilt , toe and distance correct and when you sit down and listen , they create that wall of sound that we all strive to have.

Some people might have a dedicated room that is properly treated and excellent dimensions for a musical experience.

We all chase how we can improve our systems and start looking at better amps, maybe better speakers, in here most will chase wire and go down a deep rabbit hole trying to figure out what combination of cables makes the system sound it's best. As finding all those pieces to work correctly , I think most always miss the most important piece and never even consider it due to the fact they feel their speakers should be able to do what they are rated to do.

The missing piece in most 2 channel systems that most don't consider is a subwoofer or a pair of them. The reason as mentioned above is the ability of the speakers and no consideration that the room is what dictates the bass.

If you study room acoustics you will quickly learn that just about all of the time where your left and right speakers get placed for ideal placement for your seating, they usually have trouble recreating signals properly from around 200hz and down. This is in no way a fault of whatever speakers you own, it's the room and how those frequencies interact in that space.

So what is one to do? You add a single or pair of subwoofers to the system and remove the lower octaves away from the main channel speakers. First off placement is key for a subwoofer. I suggest looking up Subwoofer crawls . Brief you place a subwoofer in your seating location and then crawl around the room running bass sweeps to see where all the bass frequencies sound the most even. If you can find 2 places where they sound the best , you can place 2 subs one in each location. If you only have 1 seat you don't need 2 subwoofers. 2 subs don't get added to a room for more bass, you get more even bass.

Then which goes against what we all know and love is getting rid of a 2 channel only preamp or receiver for a surround model with tools or high quality. Don't freak out just read on. With a surround processor you now have tools most if not all 2 channel preamps or receiver don't have, room correction or crossover points with sub out's. You now can set your main 6 foot towers to small and start to blend them into a subwoofer and create actual bass that will be smooth and detailed.

Decades ago REL released 2 channel first subwoofers. Their engineers created a sub bass system that at that time realized that most speakers can't even play down to 20hz anyway and do a poor job if they did. Having a subwoofer added to a 2 channel system or a surround system that is also used for music is ideal. They also figured out that tracking the main channel's amp output VIA speaker level was a good way to match the dynamic range of the signal as not all amps track dynamics correctly. This is true and flawed all in one breath. The idea is correct but what is missed here is the conversions. When you take a already converted signal from line level to speaker level then back to line level then back to speaker level you lose some detail and add noise. So from what I have learned over the years is this method isn't the best.

I'm not picking on REL they make some of my all time favorite Subwoofers. What I am doing is pointing out the benefits of having tools in your preamp. The more tools you have to integrate a system into a room the better you can make it without spending hundreds and thousands of dollars chasing details you may already have. I think having a dedicated subwoofer or pair mated with a surround preamp or receiver is way more beneficial to a 2 channel system then buying better cables , speakers or amps. We can assume we already have the ideal source like a CD player , Turntable or music streamer or some kind so I wanted to focus on the room and bass placement and how that effects your overall experience more so then a new power cable, higher end speaker wires or higher current amp your lusting after.

Emlyn

I have tried integrating a subwoofer into an analog two channel system but never to good effect. Anthem has a two channel preamp with bass management and room correction features. That is the only one I know of right now. Others just have jacks for subwoofer outputs and basic bass management. I did have Parasound, B&K, and Marantz surround preamps that I used for two channel before. They were good but not excellent. I think a receiver still is nowhere close to a surround preamp or two channel preamp for stereo sound quality.

Gardenstater

What about separate DSP units for subwoofer integration and room correction with REW and calibrated microphone?

VR3

In my opinion, as a 2 channel purist.

The fun in a 2 channel system for me is to use as little components as possible to achieve the sound I am going for. I also believe high end speakers can perform on their own, even if not full range.

A great example was when I had the Wilson audio cubs, they only went down to 50hz, but they were extremely fun to listen to in their own colored way.

Subwoofers and dsp take all of the fun out of it

SIHAB

Didn't Polk solve these challenges with the L600

guyincognito

I have an Arcam SR250 running as a pre and have it paired with a Parasound JC5 amplifier. The Arcam is kind of an oddity as a 2.1 channel AVR. It sold poorly and has been heavily discounted as vendors cleared out remaining stock which made it a great deal when I snagged one. It has Dirac built in and I have had good results using Dirac with my Revel F208s and SVS sb4000. I use a Umik1 and laptop for room measurements and it all works pretty seamlessly. My ultimate goal is a traditional tube preamp at some point but I am hesitant to loose the Dirac room correction and the convenience of HDMI switching since my system pulls double duty in the main living room of our house.

Gerres26

I agree with some of your points especially adding a sub or two to get best bass response possible in your room.

I can’t agree with doing away with the dedicated 2 channel preamp in favor of a processor. Once you have had a good or great 2 channel pre, you will find that the sound quality of a lot of those processors just can’t hang. If I had to choose, I’d rather run a dedicated 2 channel rig and get the best sound I can even without a sub than to incorporate a processor to get that lowest octave perfect.

Currently I prefer to let my speakers run full range as they were designed and then run my Rythmik sub through speaker level inputs from my amp and then tweak it using its own built in EQ....others may disagree but this works best for me.

tonyb

The whole purpose of a dedicated processor is to have more tools to tailor the sound to ones liking.

The purest in the 2 channel realm believe less is more in the signal path. I'm more prone to believe that path. Some will suggest, if you have to tinker with the signal that much, then you've chosen the wrong gear/speakers for your room/ears.

My experiences from the old days of R2R or spinning albums, with zilch in the way of tinkering with the signal aside from tone controls which I hated then as much as I do now, and the sounds were glorious to my ears. Maybe because of better recordings, I dunno. Maybe because of the use of tube gear, I dunno. For me, too much tinkering with the signal means something in the system is falling short. Just my .02

Gardenstater

Room treatments are huge. The more sound absorption, in a smallish room, that I add the better it gets as far as imaging and tightness of sound, especially bass. I'm still a far cry from an anechoic chamber and plan on leaving sufficient reverb to not lose the live venue magic. Not even close yet.

guyincognito

The room itself causes issues. How one goes about addressing those issues (or not as I guess that's an option as well) seems to be the issue. Room treatment in a dedicated listening room would be the ideal solution for me and hopefully one day I can explore that route. Currently though, "wife acceptance factor" is a consideration in our living room which makes DSP an attractive solution. I certainly don't have as much experience as others here and I have never owned a great analog pre (that's on the agenda though). But if physical room treatments are not an option how do you deal with room modes? I've seen them in my room when I run the room measurements and I can tell how much better things sound when they are tamed down. I've also heard them in other people's systems who don't have a way to address them (and don't seem to realize they are there). Is this a case of ignorance being bliss?

pearsall001

I couldn't agree more Dan. One can spend oodles of coin on amps, cables etc etc & not match the sonic impact of adding a quality sub/subs for 2 channel listening. It takes some work but once dialed in...you get that, OMG moment!
The room plays an intrigual part & I'm fortunate to have a great sounding room. I can see where guys have tried their best to make it work but the room just didn't cooperate.
I'm thinking about giving the new KEF KC62 sub a whirl.

mantis

Emlyn wrote: »

I have tried integrating a subwoofer into an analog two channel system but never to good effect. Anthem has a two channel preamp with bass management and room correction features. That is the only one I know of right now. Others just have jacks for subwoofer outputs and basic bass management. I did have Parasound, B&K, and Marantz surround preamps that I used for two channel before. They were good but not excellent. I think a receiver still is nowhere close to a surround preamp or two channel preamp for stereo sound quality.

I think you may not have used proper technics to do so. It's not an easy task even for a professional. Sometimes it's hit or miss. When you miss you have to start over and figure it out with the tool available.
I really like the idea of a 2 channel preamp with bass management tools. That's excellent.

mantis

Gardenstater wrote: »

What about separate DSP units for subwoofer integration and room correction with REW and calibrated microphone?

Yes that can work out greatly. Any tools to help integrate into the room is better then none at all.

mantis

VR3 wrote: »

In my opinion, as a 2 channel purist.

The fun in a 2 channel system for me is to use as little components as possible to achieve the sound I am going for. I also believe high end speakers can perform on their own, even if not full range.

A great example was when I had the Wilson audio cubs, they only went down to 50hz, but they were extremely fun to listen to in their own colored way.

Subwoofers and dsp take all of the fun out of it

I use to install Wilson Audio, they make serious stuff. But a speaker that can only go down to 50hz and in room might even be worse then that, you lose the bottom octaves of music. Kick Drums , Bass notes , Piano etc will all fail to replay the lowest sounds and feeling more less. If a speaker can hit down to 32hz your in better shape but it's not really up to the speaker, the room will decide IF that speaker can actually play those frequencies and make it to your listening position from the Left and Right stereo positions.

I guess I can follow the fun factor to a point, I use to think as you do.

mantis

pearsall001 wrote: »

I couldn't agree more Dan. One can spend oodles of coin on amps, cables etc etc & not match the sonic impact of adding a quality sub/subs for 2 channel listening. It takes some work but once dialed in...you get that, OMG moment!
The room plays an intrigual part & I'm fortunate to have a great sounding room. I can see where guys have tried their best to make it work but the room just didn't cooperate.
I'm thinking about giving the new KEF KC62 sub a whirl.

If you grab one of those I may have to come over and check it out. Your SPL's will have no place in your system anymore. Are you gonna try one out first then decide on a 2nd if worthy? The spec's seem worthy.

pearsall001

mantis wrote: »

pearsall001 wrote: »

I couldn't agree more Dan. One can spend oodles of coin on amps, cables etc etc & not match the sonic impact of adding a quality sub/subs for 2 channel listening. It takes some work but once dialed in...you get that, OMG moment!
The room plays an intrigual part & I'm fortunate to have a great sounding room. I can see where guys have tried their best to make it work but the room just didn't cooperate.
I'm thinking about giving the new KEF KC62 sub a whirl.

If you grab one of those I may have to come over and check it out. Your SPL's will have no place in your system anymore. Are you gonna try one out first then decide on a 2nd if worthy? The spec's seem worthy.

It's definitely on my radar. I strictly use the twin Velo SPL 1200's for HT.

I run a KEF Kube 8b for 2 channel with my R3 mains. I'll tell you what, KEF makes incredible subs. They're just not in the limelight some of the other companies.

Also the KF92 is on my radar (twin 9" drivers)
The new KC62 has twin 6.5" drivers but they really broke the mold with their design on this one. They're both pricey though 🤔 We'll see 😉

VR3

So, as a counter argument, kick drums don't generally go below 50hz.. So to say a speaker that digs to 50hz and slightly lower in room is missing alot of information just wouldn't be a true statement.

There is definitely information missing, but definitely not to the point I'm missing kick drums and I wouldn't say 50hz covers a large range of musical instruments and genres. 😜

F1nut

mantis wrote: »

Then which goes against what we all know and love is getting rid of a 2 channel only preamp or receiver for a surround model with tools or high quality. Don't freak out just read on. With a surround processor you now have tools most if not all 2 channel preamps or receiver don't have, room correction or crossover points with sub out's. You now can set your main 6 foot towers to small and start to blend them into a subwoofer and create actual bass that will be smooth and detailed.

Decades ago REL released 2 channel first subwoofers. Their engineers created a sub bass system that at that time realized that most speakers can't even play down to 20hz anyway and do a poor job if they did. Having a subwoofer added to a 2 channel system or a surround system that is also used for music is ideal. They also figured out that tracking the main channel's amp output VIA speaker level was a good way to match the dynamic range of the signal as not all amps track dynamics correctly. This is true and flawed all in one breath. The idea is correct but what is missed here is the conversions. When you take a already converted signal from line level to speaker level then back to line level then back to speaker level you lose some detail and add noise. So from what I have learned over the years is this method isn't the best.

I'm not picking on REL they make some of my all time favorite Subwoofers. What I am doing is pointing out the benefits of having tools in your preamp. The more tools you have to integrate a system into a room the better you can make it without spending hundreds and thousands of dollars chasing details you may already have. I think having a dedicated subwoofer or pair mated with a surround preamp or receiver is way more beneficial to a 2 channel system then buying better cables , speakers or amps. We can assume we already have the ideal source like a CD player , Turntable or music streamer or some kind so I wanted to focus on the room and bass placement and how that effects your overall experience more so then a new power cable, higher end speaker wires or higher current amp your lusting after.

mantis

VR3 wrote: »

So, as a counter argument, kick drums don't generally go below 50hz.. So to say a speaker that digs to 50hz and slightly lower in room is missing alot of information just wouldn't be a true statement.

There is definitely information missing, but definitely not to the point I'm missing kick drums and I wouldn't say 50hz covers a large range of musical instruments and genres. 😜

Some Kick drums do go lower then 50hz depending how they are tuned. Again even if a speaker can hit down to 50 hz or lower , is it placed correctly in the room to reproduce those frequencies? Most of the time they are not. Many speakers can play down to 50 hz or lower but due to the placement in a room , you can't experience those frequencies. The lower you go in frequencies the longer it takes for 1 wave to complete it's cycle. It's been bounced around the room a few times before you experience it if at all.

VR3

I can say I'm very fortunate to have a decent listening space (15*22*8) and have a relatively flat response in room with minimal adjustments

pearsall001

VR3 wrote: »

I can say I'm very fortunate to have a decent listening space (15*22*8) and have a relatively flat response in room with minimal adjustments

I hear you about the room. My room is similar in size 13x30x7.

Excellent sounding without having to tinker with much.

But just to add to the conversation about adding a sub or dual subs.

Whether you have monitors or floorstanders adding a sub will give the music more body, more weight, smoother response along with increased soundstage in width, height, front to back. It will sound more like you are there live.

After my experience with both monitors & floorstanders & with the addition of a sub & hearing the additional enjoyment of the presentation I won't consider a system complete without one.

VR3

My problem with adding a subwoofer via rca jacks is that I have never heard a system where it didn't take away from the dynamics and spatial imaging of the mains.

Now running a subwoofer via speaker line level may fix that problem but the list of subs that still offer it are slim

tratliff

I added a pair of REL Carbons to my system about a year ago. They are connected via high-level inputs that REL recommends. I have enjoyed the firm grip and control that my system now has and feel like it has opened up the soundstage. Now it is to much sometimes and I make adjustments to compensate for recordings. A good example of this is the latest MOFI Dire Straits albums. The bass on the recordings is very strong and my subs need to be turned down.

I also have a TOTL Yamaha receiver integrated into the mix. It passes the signal thru my two channel via theater bypass. And the RELs also have an LFE input and control that can be used in combination with the high-level.

From my experience I feel like the two channel integration works best. My goal in purchasing the subs was strictly two channel. So the gain they provide my theater setup is just added benefit.

I would recommend to all searching for two channel nirvana to try adding subs. When I was searching I found many dealers that would allow me to audition them in-home. This gave me a chance to test the different connection methods and then make a decision on how to move forward.

pearsall001

VR3 wrote: »

My problem with adding a subwoofer via rca jacks is that I have never heard a system where it didn't take away from the dynamics and spatial imaging of the mains.

Now running a subwoofer via speaker line level may fix that problem but the list of subs that still offer it are slim

Are you running an AVR for both HT & 2 channel or do you have a separate preamp for 2 channel.

I have a separate tube pre along with a AVR for HT. Using the AVR in HT bypass & the rca outs from the pre directly to the sub works great.

Now I do have dual Velo subs strictly for HT & a separate sub just for 2 channel. Best of both worlds.

VR3

Yeah but to run a 2 channel pre to an Avr with ht bypass, that would be awful for music? That would basically be negating your 2 channel preamp?

For ht I run a full in ceiling definitive setup with 4 x 18 in subs in an infinite baffle and 4,000 watts of power

Joey_V

Interesting conversation.

I do agree, the room tends to wreak havoc.

I have also attempted to install subs into the 2 channel system. I have thought about going RELs, but I have not been completely convinced to go REL. Currently, I am experimenting with JL Fathom 113v2 duals... after running room correct, it sounds... almost unnoticeable which is exactly how you want it. I have to still work on the LP crossover point, I would probably need the JL CR1 to complete the integration.

pearsall001

VR3 wrote: »

Yeah but to run a 2 channel pre to an Avr with ht bypass, that would be awful for music? That would basically be negating your 2 channel preamp?

For ht I run a full in ceiling definitive setup with 4 x 18 in subs in an infinite baffle and 4,000 watts of power

My bad...I forgot to mention I have a 2 channel amp in the mix. That's where the HT bypass comes into play. For HT the preamp is off & for 2 channel listening the AVR is off.

pearsall001

Joey_V wrote: »

Interesting conversation.

I do agree, the room tends to wreak havoc.

I have also attempted to install subs into the 2 channel system. I have thought about going RELs, but I have not been completely convinced to go REL. Currently, I am experimenting with JL Fathom 113v2 duals... after running room correct, it sounds... almost unnoticeable which is exactly how you want it. I have to still work on the LP crossover point, I would probably need the JL CR1 to complete the integration.

Those subs are top notch & will be your end game when it comes to subs. With proper integration you won't know the sub is there.
A fun experiment is to shut the subs off & instantly you'll know what's missing. Turn them back on & the magic is back. You won't want to be without them!
Patience grasshopper when it comes to getting them dialed in correctly.

SCompRacer

Lets look at a more detailed chart. I suggest to folks that they consult a chart to see what they are listening to and do a room frequency sweep. You are either fine or missing something.

I listen to music at times that goes well below 40Hz and employed subs to augment those frequencies. I sure enjoy hearing and feeling more than a faint hint of those frequencies.

msg

What is a room sweep, and how does one do it?

SCompRacer

To do a room sweep, you need a computer, microphone and software.

You can use free software like REW https://www.roomeqwizard.com/

I purchased software with a calibrated mic, Dayton Audio OmniMic V2. Omnimic and I think REW uses a burst tone. If you play steady frequencies they can load up in a room and give you false readings. In other words, play a 40Hz tone too long, it could spike then null.

https://www.parts-express.com/Dayton-Audio-OmniMic-V2-Acoustic-Measurement-System-390-792

You end up with a graph that shows sound levels in dB across the frequencies. You have to lower the spikes and raise the nulls. It's boring work, move speakers slightly, test, see what changed, improved, worsened. Add treatments, test, move etc. Very difficult to achieve perfection, like +- 3dB across the frequency range.