More Power or use subwoofer to boost bass for music

But since statistics is science, let’s consider the “odds “ of getting 4  or as some would say 5 objects placed in a convenient location vs. one....

having a bit of fun Ralph, you are a true warrior for the science and the music

Vandersteen = 11 bands of EQ with more cut than boost with EQ centers set on typical room nodes not typical 1/3 octave bands... some science cult thinking at work there... since 1977 and still going strong and I might add a supporter of swarm IF done correctly so as not to muck of the stereo image...

The idea of a “swarm” of subs is based on evening out the nodes. It’s an admirable goal but rarely practical.

This statement is false. A distributed bass array such as the Swarm is far more effective at getting the bass right in a room than room correction or bass traps; its a more elegant approach.


This isn't to say that using bass traps and room correction won't help, but if you have a standing wave in the room (which can be a reason why a single sub or pair of subs don't seem to make much bass despite having plenty of power and the bandwidth needed) all the room correction will do is make the amps make more power at the frequency of the standing wave cancellation. No amount of power will solve a standing wave, since the energy is being cancelled.


Bass traps don't intelligently work at the frequency needed to prevent the standing wave (which is the result of the bass waveform bouncing off of the wall behind the listener and cancelling itself at the listening position)- they work at all bass frequencies.


Now if you combine all three then you can get spectacular results.

Jesus, the 4 sub cult is strong here.

Just physics. Cults, to my knowledge aren't bassed (see what I did there?) on physics.


IMO its fairly easy to set up a set of Swarms in a smaller room and keep it neat, since the Swarms are designed to work placed against the walls and also work best if the placement is asymmetrical.


Of course you can get good bass with only one sub, but it has to be placed in exactly the right location, which (more often than not) may not be the most convenient.

Jesus, the 4 sub cult is strong here.

I worked at Magnolia for a bit, and their standard setup had the 804s positioned very close to the back wall so maybe not surprising you remember hearing more punch when you were there (I used to pull them 4’ out into the room where they sounded much better albeit with less bass emphasis). Regardless, 804s have never had prodigious bass output and could certainly benefit from at least one good sub. As @noble100 mentioned, the improvements extend beyond bass to expanding the soundstage and overall image palpability. I’ll never forget the first time I heard a good system with properly dialed in subs. Of course there was the expected bass depth and impact, but when he disengaged the subs the entire soundstage collapsed and the sound overall went limp. You can certainly achieve better sound with room treatments and EQ, but there’s really no substitute for what good and well-integrated subs can do. I like the suggestion of a pair of SVS SB1000s that run $950 and offer a generous in-home trial period, but I seriously doubt you’d be returning them.

One last thought — if your speakers are new and don’t have at least 100 hours of quality playtime on them you may not yet be hearing all that the 804s have to offer.  In any event, best of luck.

Sometimes amps are the problem, if you can get a loaner, go for it. If that doesn't help you dramatically, look to the room.

Reason for A31 is because I only run a 3 channel (L,R,C) home theater.   I don't have room for surround speakers.   I have the Marantiz 8802A preprocessor for both movies and music (via Pure Direct mode).    I'm also looking for a stereo pre-amp right now.  I'm considering Parasound JC-2 or Mcintosh C49.  I actually had another post in this forum about that.

Any particular reason you went with the A31 vs the A21/A21+ or even JC5? While a swarm might be one of the options for big low end, often they are impractical space/position wise and still require proper setup to get right. So reality is, any sub setup will require proper placement and dialing in. You might be better off to try the above first, room treatment, speaker placement etc. These are all things that need to be done anyway if a sub/subs are part of the picture. Also, cabling can make a big difference as well, power particularly as well as the rest. 

i don't remember what the dealer use.  It was actually in Magnolia shop of Best Buy when I heard them for the first time.  I think they might just be using a Rotel integrated.

dual subs; as large and powerful as you can fit and afford. I like the big HSU Research units

What amp did the dealer use ??????

xcool OP Just found proper test on the A31 as I thought not much current ability into low impedances. The 4ohm wattage should be a lot higher, and they didn’t do the 2ohm as it would have been trouble (bang maybe). Not the amp for these speakers.

 Cheers George

BHK Labs Measurements: Parasound Halo A31 Three-Channel Amplifier

1% THD 232.8W @ 8 ohms, 352.0W @ 4 ohms

10%THD 285.0W @ 8 ohms, 422.9W @ 4 ohms

Thanks George.   Thanks for the information on Parasound A31.   That is good to know.   Maybe I do need more power to drive those B&W.   I'll checkout the review.

Also, many thanks to others for information on room treatment and multiple subwoofers.    One thing I should have mentioned in my original post, is that I live in an apartment, not small, but average size.  I don't have a lot of options to accommodate multiple subwoofers.   I actually do have a subwoofer now.  It's a very old Def Tech subwoofer from the 90's.   It doesn't have a whole lot of connection options.   I only use it for movies.  I was looking to replace that anyway.   

I do like the option of adding some acoustic panels, and will look into that further.

Thanks!

xcool OP

The combined impedance and -phase angle graph shows these 804’s are a hard load in the bass from 60hz to 150hz where all the power is needed
https://www.stereophile.com/images/913B804fig1.jpg
Yet the frequency response shows that they have a slight rise in that area, and should give big bass if driven well. https://www.stereophile.com/images/913B804fig4.jpg

The second page of the Stereophile review often complains about the lack of bass from the 804 D’s. And looking at what they drive them with, it was the same amp as you a 3 channel HT Parasound A31 that has trouble doulbing wattage from 8 to 4ohms, let alone down to 2ohms
https://www.stereophile.com/content/bowers-amp-wilkins-804-diamond-loudspeaker-page-2

I think your amp just like the reviewers, is not up to driving the bass with good current delivery, try something that can, and you then won’t need any subwoofers and the problems they bring to seamlessly blend in to the mains.

Cheers George

Hello cool,

     Millercarbon is correct, a 4-sub distributed bass array (DBA) will provide excellent bass performance throughout your entire room and integrate seamlessly with your main B&W speakers.
     If you’re only concerned with attaining excellent bass performance at a single designated listening seat, however, using 2 good quality subs will will work about just as well as a 4-sub DBA.  You may even be able to attain very good bass performance at a single listening seat with a single higher quality, and more expensive, sub that comes with a mic and has room correction software.   You would first optimally position the single sub in your room using the crawl method (you can google it) and then utilize the room correction function to fine tune the results.
     2 subs, even if they’re smaller and less expensive, will generally perform about twice as a single sub, even if it’s larger and more expensive. The benefits of using 2 subs are increased bass power and dynamics when the music calls for it, neither sub is operating near its limits and the bass will be better integrated with your main speakers.     Whatever sub or subs you decide to use, it’s very important that each sub has separate controls for Volume, crossover frequency and continuously variable phase.  These controls are critically important for adjusting them optimally to your room and system.  It’s also beneficial for the subs to have the choice of inputs, rca line level and high level speaker wire.       You’ll also notice an improved soundstage and improved midrange and treble performance of your main speakers utilizing 2 subs.
     I suggest trying a pair of SVS SB-1000 subs or similar Hsu subs for about $1,000/pair.

Good luck,
    Tim

To enhance bass you need to try to position the speakers closer to walls to amplify the lower bass, or add subwoofers. The answer is not adding multiple subs or adding bass absorption. The rational approach is to start with proper imaging using a method such as The Master Set. Imaging is key to proper sound from a stereo source. Once the imaging is perfect you can then add subwoofers for the lowest frequencies if you want more bass. It may help to use a computer and microphone to real time analyze the frequencies in your room. Then you will know how far down your speakers go. If you want 20 Hz or below you will need subwoofers. They are tricky but to get 20 Hz and below you have to move air. Lots of air. You will need 15” woofers. The idea of a “swarm” of subs is based on evening out the nodes. It’s an admirable goal but rarely practical. One well placed sub is good but not easy or perfect. Two well placed subs are better but beyond that you are spending a lot to get a little. Like horsepower. Look up Harman Kardon white paper on sub placement. Seminal work. Proper placement of stereo speakers doesn’t necessarily mean the proper placement for bass or subs. I recommend Hsu Research or SVS for affordable well made subs. That way You can afford two or three. Hsu sells pairs of identical subs. Best of luck and keep us posted. 

Someone should tell millercarbon to stop adding a link to every post he submits. One look at that room would send most running from the multiple sub approach.

Also IF flat frequency response in room was the only measure of bass quality why are there a plethora of bass guitars, standup bass, etc out there....?

this from a bass player of LiL reknown....

OP you are new and don’t yet understand that the answer is 4 or more subs in a forest of box’s and wires placed quasi randomly about your room.

bass is a wide topic and for most music listeners spans from 30 HZ to the power range of 200-250 HZ. You might try to recall or ask the dealer where those speakers were placed in the demo from side and back wall. IF you do have to compromise with near surface ( back and or side wall ) coupling, then GIK or another brand of broad band absorber panel or three to address reflections will help w imaging. Finally also you might need to tweak your listening position a bit. Room modes effect. Bass , especially below 120 HZ... even a few feet can matter.

there are other ways to add great subwoofers if Indeed the problem lies below 100 HZ. One has built in EQ.

and yes, swarm aka multiple subs...works if the crossover frequency is low enough and you like the clutter.

Sorry xcool, you are new and have no way of knowing the answer to every question is GIK. Even though you specifically want more bass, and everything GIK makes can only absorb bass and never enhance it, still the answer is GIK. Or EQ. Surprised he didn't say EQ. Maybe saving for later?

koestner is right. First step is always speaker placement. Closer to the walls, either front or side, will have a big effect on bass response. Also your listening position. But the walls also reflect higher frequencies as well and so if the speakers are closer than about 3 feet to a side wall the reflections begin to interfere with good imaging. So its a balance and a trade off.

You may be a minimalist, and so am I. More power won't work. One sub won't work. GIK will improve everything and your bass will have greater definition but by absorbing not enhancing. When it comes to bass the fact of the matter is the minimalist approach is four subs. Check it out. https://systems.audiogon.com/systems/8367 Read the reviews, do a search, read about DBA. 

Thanks.  I'll take a look at GIK acoustics.  I've always been intrigued by the idea of room treatment, and know very little about it.   Also, I think my options might be limited.   My listening area is near a stretch of windows with no curtains, just shades.   I always think there's very little to do about it unless I put up thick curtains, but I'm not willing to do that.   I just need to strike a balance, I supposed.

BTW, what are bass traps?  Are they for enhancing the bass, or calming down the excess bass?

Thanks.

Try to put the speakers closer to a wall or corner. You should see an improvement in bass.

I remember the bass was pretty punchy when I heard it in the dealer showroom, but I don’t seem to get that in my setup.

While I love subwoofers, room acoustics are a better place to look first.

The key part of your description here is that you say they sounded great in the showroom, which was probably better treated.

Why don’t you give GIK acoustics a call, and in particular ask about their soffit traps?

Do your room first, then you’ll be in a much better place to evaluate.

Best,

E

i would think that getting a 'sub woofer' would be the answer!