[archeion]

Hello,

  I saw on a couple recent threads where people mention setting speakers on top of subs and it sounds like there is a concern about vibration and/or resonances between the two.
Take an N3S, for example, sitting on top of a standard SW-12-04 cab.   

First, I assume that a stereo pair of these subs is preferred to just one, no?

What if you integrated the two boxes fully and they shared one front baffle?  Would that solve the problem?
Or, would you need to offset the N3S front to back and perhaps attach them another way?
Just curious if this  has drawbacks that I don't understand yet.

Thanks,
-Ryan

[lemiongo]

Like this .....   

[jparkhur]

Good question...  what is the difference between this and this...   there is way more power on the bottom of super v's than below the fonkens...and i don't have an answer...I did see a new speaker out that but a sub below, and then had the monitor above it buy was suspended above the sub on special pedestal.... ??

[gregfisk]

Good question...  what is the difference between this and this...   there is way more power on the bottom of super v's than below the fonkens...and i don't have an answer...I did see a new speaker out that but a sub below, and then had the monitor above it buy was suspended above the sub on special pedestal.... ??

This is what I want to do but using Danny's sealed sub and then install a sealed mtm enclosure with Danny's new midwoofers on its own stand above the sub. Now all I need is for Danny to design the crossover for the sealed mtm

[jn316]

Danny answered the V1/Super-V thoughts here at the very end:

http://www.audiocircle.com/index.php?topic=110760.40

...which is probably one of the discussions the OP was referring to in his opening post.

[archeion]

Hi Lemiongo, Is that your setup?  If so, do you notice any negative effects from essentially using subs as stands?

jn316:   Yes, that was one of the threads.  It sounds like one of the subs in that thread is more resonant than what Danny builds.  That's why I was wondering if you used his design if it would be better.  I'm sure the sandbox version would be preferred, but what about the question of attaching them and/or combining baffles?

[Milehighguy]

The problem of woofer vibrations is vastly reduced by using a "push-push" setup, in which you have dual woofers that are on opposite sides of the woofer box, and operate in phase. The drivers then tend to cancel out each other's vibrations. For example, at the RMAF, there was a pair of KEF blade speakers that use this technique, with 4 woofers per cabinet, 2 on each side. All during the show they had a nickel sitting on top of the cabinet, standing on edge. No matter how loud the music played, the nickel never moved or fell over. So with this type of set-up, you could put the monitor speakers on top of the woofer cabinet without worrying about vibrations from the woofer getting to the monitors.

[Coldfusion]

One of the big problems putting speakers on top of subs is the ideal location for the speaker is very rarely the best spot for the subs...

Subs love being along walls, and often in corners.

[Guy 13]

One of the big problems putting speakers on top of subs is the ideal location for the speaker is very rarely the best spot for the subs...

Subs love being along walls, and often in corners.

Hi Coldfusion and all Audio Circle members.

I agree 100% with you
and that's the direction I would like to take in the future.

Unfortunately, I can't really do it with my GR Research V1,
cutting the V1 in two seperate pieces (Sub & coax)
would be a crime punishable with 20 years of prison.

I will find a way to do it...

Guy 13

[JLM]

Many manufacturers (even high end like Wilson) use that exact design (monitor on top of woofer).  No problems.

Yes dual opposing/sealed woofers is ideal but not required.

Yes monitor placement is almost never the "right" placement for woofers, but virtually all the "big boy, full range designs from high end vendors" do it. 

In any room, the most to least ideal is to have:

- 4 subs spread around the room (search swarm/ DEBRA)
- 3 subs spread around the room (if you just can't run that 4th cable or afford the 4th sub)
- 2 subs, the 2nd being a black hole absorber (sub with microphone to sense and counteract standing waves at opposite end of the room):
http://www.spatialcomputer.com/page9/page10/page10.html
- 2 subs at opposite ends (long wise) in the room, rear one wired out of phase
- 2 subs located under monitors, in phase of course
- one sub "properly" located in the room
- full range speakers
- less than full range speakers

[Guy 13]

Many manufacturers (even high end like Wilson) use that exact design (monitor on top of woofer).  No problems.

Yes dual opposing/sealed woofers is ideal but not required.

Yes monitor placement is almost never the "right" placement for woofers, but virtually all the "big boy, full range designs from high end vendors" do it. 

In any room, the most to least ideal is to have:

- 4 subs spread around the room (search swarm/ DEBRA)
- 3 subs spread around the room (if you just can't run that 4th cable or afford the 4th sub)
- 2 subs, the 2nd being a black hole absorber (sub with microphone to sense and counteract standing waves at opposite end of the room):
http://www.spatialcomputer.com/page9/page10/page10.html
- 2 subs at opposite ends (long wise) in the room, rear one wired out of phase
- 2 subs located under monitors, in phase of course
- one sub "properly" located in the room
- full range speakers
- less than full range speakers

Hi JML and all Audio Circle members.

You state:

{{ 2 subs at opposite ends (long wise) in the room,
rear one wired out of phase. }}

Therefore, on my A370PEQ Rythmik plate amplifier,
I have a phase switch,
it will do the same if I set one to " 0 " and the other to " 180 " ?

Guy 13

[archeion]

Do the Wilsons  just sit on top of the woofer, or do they attach somehow?

[Danny Richie]

If the mini-monitor had spiked feet and they set on the outer edged of the sub cabinet (not in the center of a large flat panel) then that would work out pretty well.

Something like this would not be good. All of those cabinet resonances will just be transmitted right into the mini-monitor.



Check out some recent feedback from the poster that started this discussion:

http://www.audiocircle.com/index.php?topic=110760.msg1149879#msg1149879

[archeion]

Thanks Danny.

Do you agree with JLM's  ranking?

Does using OB subs change this?

[Danny Richie]

Therefore, on my A370PEQ Rythmik plate amplifier,
I have a phase switch,
it will do the same if I set one to " 0 " and the other to " 180 " ?

Guy, you don't have a switch on that amp to select either or. You have a complete phase control knob that will let you select anything in between. Just set the one int he front of the room in phase with your main speakers and set the one in the rear to the opposite setting to the front amp.

Thanks Danny.

Do you agree with JLM's  ranking?

Does using OB subs change this?

What he outlined works great, but open baffle servo subs can trump all else. I really like open baffle servo subs in the front of the room and a pair of sealed servo subs in the back of the room that are out of phase from the front woofers. That will really give you a nice balanced sound without room related effects.

[stevenkelby]

I really like open baffle servo subs in the front of the room and a pair of sealed servo subs in the back of the room that are out of phase from the front woofers. That will really give you a nice balanced sound without room related effects.

Danny, with open baffle subs in front, what advantage is there to sealed subs in the back of the room vs more open baffle subs in the back of the room?

Smaller size? Higher output? More punch, from pressurizing the room?

I may want to add more subs in the back of the room with my Super V up front one day

Thanks,

Steve.

[Danny Richie]

Danny, with open baffle subs in front, what advantage is there to sealed subs in the back of the room vs more open baffle subs in the back of the room?

Smaller size? Higher output? More punch, from pressurizing the room?

I may want to add more subs in the back of the room with my Super V up front one day

Thanks,

Steve.

While the open baffle subs cancel at 90 degrees off axis and don't really load the front of the room (no room boom in the corners) they still put some pressure in the room that loads up in the back corners of the room. So running the subs out of phase from the fronts and setting them in the rear corners takes away that room loading and adds a little horse power to hit those really low notes with authority in larger rooms.

[stevenkelby]

So running the subs out of phase from the fronts and setting them in the rear corners takes away that room loading and adds a little horse power to hit those really low notes with authority in larger rooms.

Thanks Danny.

So the sealed subs do that more effectively than OB?

[Danny Richie]

Thanks Danny.

So the sealed subs do that more effectively than OB?

An OB sub would need to be place more out into the room (away from the wall). The purpose of the subs in the rear corner is to take away the loading effects or the accumulation of bass in those rear corners. So a seal sub lets you stick it right in the corner.

[JerryLove]

Something like this would not be good. All of those cabinet resonances will just be transmitted right into the mini-monitor.

I wouldn't think that they were coupled well enough for the waves to transfer. OTOH: that lack of coupling is why they may actually rattle (assuming they don't start walking).

I would also be concerned about diffraction where your baffle suddenly widens at the sub.