Subwoofer on 2 channel stereo system anybody?

[kfz03110]

Even with my 15" woofer JBLs , I still think the bass is not deep or heavy enough. I am very interested in adding aone or two powered subwoofers to my system. Like to hear from you that have added subwoofer/s to your 2 channel system. Is it one or two subwoofers.? how do you connect the powered sub to your 2 channel amplifier? How do you like the final results?





JBL 4367 + Mcintosh MAC 7200( 200Wx2)

[svollmer]

I have four stacked vertically near a corner and running in mono and have been very happy with the results. Many feel that stereo sub are the better way to go though.

If your preamp has two sets of outputs, you can send one stereo set directly to your amp for the main speakers and leave them running full range, since it appears they're floor standing, full-range speakers. Then you can send the second stereo set to an outboard crossover which would then send the low frequencies to your subs (either in stereo or mixed to mono). That's assuming they're not powered subs.

If they are powered, they'll most likely have a full-featured crossover built-in and you can blend the subs with your main speakers. The lower the crossover frequency, the less likely you'll be able to hear where they are located.

If you don't have two sets of outputs on your preamp, you can use Y-connectors.

The more subs you have, the flatter they'll be and each one will have to do less work. If I could fit another four in my room, I would so they'd each be doing hardly any work at all.

[Robh3606]

I use subs in 3 systems. I don't see any issues just advantages. I use stereo in one system and mono in the other 2. In all 3 systems I am using analog crossovers. I see some claim to have lots of issues where they are not happy with the blend with their mains. I don't get it as I don't seem to have an issue with any of the 3 set-ups. Maybe it just me not being too fussy but they sure sound good. Sub placement is key and I always keep the subs as close to the plain of the main speakers as possible.

Rob:)

[svollmer]

I use subs in 3 systems. I don't see any issues just advantages. I use stereo in one system and mono in the other 2. In all 3 systems I am using analog crossovers. I see some claim to have lots of issues where they are not happy with the blend with their mains. I don't get it as I don't seem to have an issue with any of the 3 set-ups. Maybe it just me not being too fussy but they sure sound good. Sub placement is key and I always keep the subs as close to the plain of the main speakers as possible.

Rob:)

I have the same experience. I'm using an old Audio Control Richter Scale III analog crossover and have never fiddled with it at all. Maybe it helps that I'm crossing over at 40 Hz just to "fill in" the lowest notes. The use of bass traps in all four corners helps too, but I've heard great bass without them too.

[rdgrimes]

Even with my 15" woofer JBLs , I still think the bass is not deep or heavy enough. I am very interested in adding aone or two powered subwoofers to my system. Like to hear from you that have added subwoofer/s to your 2 channel system. Is it one or two subwoofers.? how do you connect the powered sub to your 2 channel amplifier? How do you like the final results?





JBL 4367 + Mcintosh MAC 7200( 200Wx2)

Using a sub will "free up" considerable overhead in your amp. But you could also try a bigger amp or monoblocks. I'd go for the sub, which should have speaker-level inputs for both channels. Or stereo line-level inputs are fine too. Or you can get a stereo pre-amp/processor that offers bass management. I'd put those 4367 on a 40 or 60Hz crossover.

OTOH, most stereo music has VERY little content below 40Hz. Honestly, I might try a higher power amp just for fun.

[Ed Kreamer]

Well, we don't know what 15 you are using. Some of them are not meant for very low bass. It's possible that room interaction is causing the lack of very low end. In any case, a separate sub will most likely help, and you can very the

placement, to obtain the best low end. Two would be better. that is what I run, with 4410's. Floyd Toole addresses this in his book. I suggest you obtain a copy.

Have fun and Merry Christmas

Ed

[RMC]

Hi ED,

Since Floyd Toole and Harman generously made this available to all for free, here it is right from the man himself...

Richard


82996


EDIT: There's a number of others from Toole which I also have but the above one is the most understandable and concise.

[RMC]

The eternal debate of one VS two or more subwoofers was also addressed in a thread called "Stereo B460" here where different views are shown.

I reported on Greiner's view on this and later started to report on other Harman Engineers' analysis of the subject called "Low-Frequency Optimization Using Multiple Subwoofers" which is another "Bible" on this, with Floyd Toole's, but I never really got to finish their story, too many things in the oven... I might when I get more time since their explanations are quite interesting, revealing and more nuanced than what some folks have mentioned in that thread.

Things aren't all black or white as some may think on single vs double subwoofers or more. Welti and Devantier, both Harman Electrical Engineers, Welti also being an Acoustician, are somewhat pretty tough about the value of some of the litterature/studies/experiments made previously on single vs more subs...

Richard

[Mr. Widget]

First, in answer to the original poster's question. Sure, when properly implemented adding subs to a two channel system can be of tremendous help. The key is knowing how to implement them. It is also very easy to make a mess of things.

On to the discussion of multiple subs.

We are currently working on a dedicated theater that is at the professional screening room level. We are using Meyer Sound Acheron speakers and subs and are working with an acoustician. The room is being built within a basement shell and will have complete sound isolation and acoustic treatment. We originally were planning on (4) 18" subs behind the screen wall, but during acoustic modeling no amount of bass traps or other room tricks worked in filling in a major hole in the prime seating location. We modeled subs in all four corners and moving the seats a bit. Ultimately locating four subs mid point on all four walls walls with minor tweaks solved the problem.

Moral of the story... if you don't have a powerful computer program, know the construction details of the room, and an expert acoustician, plan on some trial and error.


Widget

[Ed Kreamer]

Thank you Richard

I should point out that I use mine in Mono, not stereo. I did try mine in stereo but found that mono worked best, with a crossover set at 40 or 60 Hz. I tried various positions, the sub woofers I mean, and found the best

compromise. Certain WAF considerations did come into play. Oh I didn't catch at first that the system in question uses 4367's. Every plot I've seen on those indicate that they are quite flat. So maybe they are too dry? or maybe

the room has a null.

Ed

[Titanium Dome]

I'm using a Synthesis® S2S 15" passive sub with each of my K2s. I'm using the bass management on a Parasound P7 (purchased through Mr. Widget) to implement a 50Hz crossover. The K2s are actively bi-amped using BSS FDS 366 Omnidrive units with Greg Timbers curves applied (courtesy of grumpy). ATI 2003 amps power each channel: one bi-amped K2 and one sub.

We have a really big room to fill, and the K2+S2S stereo combo never leaves us feeling disappointed.

Here's a candid shot of the magnificent (but messy) right channel.

82997

[RMC]

Hi Widget,

RE: "The key is knowing how to implement them. It is also very easy to make a mess of things." Agreed.

Toole gives good general guidelines but he sure doesn't know the exact characteristics of one's own room and sound system...

For such reason its quite easy to agree with your mention of a computer program, room details knowledge and the use of an acoustician, otherwise its bound to be a trial and error thing for any particular room, if one can't afford the expert and/or the programs.

But I'm more curious about "We are using Meyer Sound Acheron speakers and subs", from a "JBL man"?? Harman didn't have anything suitable or budget constraints for example?

Also, RE: "We originally were planning on (4) 18" subs..." How did you determine originally it would be four of those subs (why not six for example?), without having modeled the room with the program I suppose (right or wrong). Because of four walls or corners in a room? Purely on VLFexpected sound level? Or another ballpark formula? Regards,

Richard

[Ian Mackenzie]

Even with my 15" woofer JBLs , I still think the bass is not deep or heavy enough. I am very interested in adding aone or two powered subwoofers to my system. Like to hear from you that have added subwoofer/s to your 2 channel system. Is it one or two subwoofers.? how do you connect the powered sub to your 2 channel amplifier? How do you like the final results?

JBL 4367 + Mcintosh MAC 7200( 200Wx2)

A few questions gives a bit of context to your questions?

Are your mains the 4367?

Assuming you are referring to the 4367’s there are several ways of looking at the issues you raise.

The 4367 woofers have sufficient displacement for modest bass boost at 30 hertz. The designer has been over this previously. Depending on your expectations that might go someway towards helping the issue particularly if you use that system for music.

Also investigate you placement and listening position. If there is an acoustic problem adding more bass power may not be an effective route to solving the issue.

If you need louder and deeper bass a powered sub is a neat solution. Many now have adjustments for frequency and phase to help integration. Consider Y rca splitter plugs or a pre output to drive the line level sub inputs. You may find you don’t need to introduce a high pass crossover to the mains if you really need more bass extension.

About one or two subs see if a friend can lend you a sub(s) to evaluate your listening environment before you buy. Some dealers will let you do that. It might take some practical experimentation to get the best overall result.

On the topic of one or two it depends on a lot of factors including the latitude you can afford in terms of placement. Earl Geddes a highly regarded acoustics consultant has suggested several or multiple subs can be an improvement over a single sub in terms of dealing with problems with bass frequencies.

Lastly l would recommend you audition the sub with your system if you can before you go ahead. Some subs are better at certain characteristics particularly when it comes to blend with the mains.

[toddalin]

Thinking a bit outside of the box, and assuming that your 2-channel receiver has a tape monitoring loop, there is another way to do this.

Get a dBx subharmonic synthesizer. This goes in the tape loop and has a dedicated sub output so you don't need an amp/crossover designed for subs. Plus you can both boost the bass and add another octave of bass 1 octave lower, if desired

[Mr. Widget]

Hi Widget,

But I'm more curious about "We are using Meyer Sound Acheron speakers and subs", from a "JBL man"?? Harman didn't have anything suitable or budget constraints for example?

Also, RE: "We originally were planning on (4) 18" subs..." How did you determine originally it would be four of those subs (why not six for example?), without having modeled the room with the program I suppose (right or wrong). Because of four walls or corners in a room? Purely on VLFexpected sound level? Or another ballpark formula? Regards,

Richard I don’t want to derail the thread, but I was trying to show that even using top drawer gear with a massive budget, you still need to accommodate the laws of physics.


Widget

[kfz03110]

Here are my 4367 positions: they are about 12” away from the back wall. not that their bass is not good; just not chest pumping or ground shaking Compare to subs. Also like to make my music more energetic and real. If I go to a soft rock concert ; I should feel the shake when the drums got hit. That’s all

[Ian Mackenzie]

Are the speakers in phase...LOL

One possible explanation is you might not be playing it loud enough or your expectations might be beyond the scope of a domestic hi fi system.

Typically that kind of bass belongs in a club not a house.

[Radley]

+1 on what Ian said.

I'd double check the polarity of the speakers and I'd pull the woofers too. Even factory wiring can be off sometimes. I'd also double check there's no high pass filter somewhere.

Put the speakers on the floor and closer to the wall and see if the bass increases. If it doesn't you definitely have a polarity problem. Play a mono recording and verify the image is in the center.

[RMC]

Hi KFZ,

I agree with posts # 17 and 18.

Typically, what you have is a nice hi-fi type of setup and I wouldn't mind having it... I do note your speakers are not only about a foot from the wall as you say but also elevated off the floor on a base.

I haven't seen the Owner Manual specific recommendations regarding the placement of these speakers, sometimes directions will say on the floor (e.g. 2 Pi placement) others not, for example. If you did follow the manufacturer's directions then I assume you got what you paid for.

"chest pumping or ground shaking" bass and feeling the shake of the drum at a rock concert typically belongs more to sound reinforcement type of systems, these are not as nicely mannered as your monitors, but do have way more output level (more energetic as you say).

So if Radley's tricks aren't enough for you, then you may have to manage your expectations, look for another type of system or complement this one with high power subwoofer(s) or bass cabinets, with another amp and crossover... Regards,

Richard

[rdgrimes]

Here are my 4367 positions: they are about 12” away from the back wall. not that their bass is not good; just not chest pumping or ground shaking Compare to subs. Also like to make my music more energetic and real. If I go to a soft rock concert ; I should feel the shake when the drums got hit. That’s all

I still think that what you are describing can at least be partially ascribed to a lack of power.

[toddalin]

If you want to feel the hit on the snare, you need to get an 8" - 12" cone on an accordion surround in there. The 2251Js really convey this slam that the horns just don't get.

[1audiohack]

Hi KFZ:

It’s the poinsettias on top. ;)

I have 4365’s in my living room that is asymmetrically shaped similar to yours. I have a pair of Array 1500 powered subs that I just have to tickle to get the low frequency energy that I like for most of my music.

In a nutshell I find integrating subs into a well behaved set of full range mains like yours easy, if you only need a bit of augmentation. It is much harder to add a lot of LF without sloping gently upward out of typical subwoofer territory so as not to have a noticeable step in the bass response and then timing and position becomes everything.

I consider 4365’s and 4367’s as medium small speaker systems and they have their limits.

As Todd said there are several bass augmenters available and some sound great and some don’t. If you don’t listen real loud your speakers likely have the headroom for a bit of boost.

Do you have a way to quantify your listening levels? Like an IPhone app?

I hope you enjoy them.

Barry.

[RCAdog]

Its my belief that if you have quality subs and amps that can get you as low and punchy as you want to go, it depends on your crossover point as to whether you can really hear the difference between mono or stereo subs. If the room is not too wide, and if your mains go deep enough, I doubt you will hear much difference between mono and stereo if you are crossing over under 85hz or thereabouts. jm2c

[kfz03110]

Actually 90% of the time, I listen between 20%-40% of my amplifier's volume level (under 2 Watts). I need to raise the volume level above 40% to feel some vibration of the bass. Good bass but not comparable to my friends low end surround sound system with 2 small subs. I also agree that my 200W SS amp is on light side. How much bass will it increase if I upgrade to 450W SS? My guess is won't be as much as a powered sub(300+W)

[Mr. Widget]

How much bass will it increase if I upgrade to 450W SS? My guess is won't be as much as a powered sub(300+W)You're right... all things being equal you'll get about 3dB more output. More but not significantly.

If all you want is gut grinding bass, that is fairly easily and relatively inexpensively attained by adding HT subs as you mentioned. If you want objectively better performance that is a significantly more complicated question.


Widget