The Subwoofer is dead as we know it

[vasubandu]

I am in the planning stage for a new subwoofer, so I decided to make sure it would not be obsolete before  I finished it.  That sounds like a silly concerns, but turns out that it isn't.

 

In 1995, an Itialian compay called Powersoft Audio (http://www.powersoft-audio.com) developed Pulse Width Modulation (PWM) technology that vastly improved the performance of audio amplifiers.  As I understand it, this essentially became Class D amplifiers.  Powersoft somehow leveraged this technology to create an entirely new kind of transducer.  Insatead of a coil, it uses a moving magnet linear motor structure. It actually looks like this

 

 

 

They unleashed it no the world as the M-Force. (http://mforce.powersoft.it/)

 

A number of companies are now making them, but they are being used for things like very large clubs and the Superbowl show.

 

https://www.pksound.ca/products/gravity-30

 

https://mag-cinema.com/mag-cinema-thor

 

https://www.prosoundweb.com/channels/live-sound/atk_audiotek_unleashes_custom_subwoofers_driven_by_powersoft_m-force_transd/#

 

 http://www.auraaudio.fi/xd-series.html

 

 

This is not something that is going to happen.  It is happening, just has not trickled down to our level yet.  It is a 30-inch unit, and I think the housing is large.

 

Every single review I have read says that this is orders of magnitude better than what is in use now.  Everyone seems to agree that this is happening around us.  It appears to be a better technology. 

 

I am just going by what I have read.  Anyone have thoughts?

 

 

 

[CECAA850]

Moving magnet as opposed to a moving coil kind of like a turntable cartridge.   Basically a 30 inch driver in a band pass box as far as I can tell.

[CECAA850]

Here's an early motor driven subwoofer driver.

https://www.soundandvision.com/content/way-down-deep-ii-servodrive-contrabass

 

Seems they've eliminated the issues with the Contrabass by directly coupling the driver to the motor as opposed to mechanical linkages.

[vasubandu]

6 hours ago, CECAA850 said:

Seems they've eliminated the issues with the Contrabass by directly coupling the driver to the motor as opposed to mechanical linkages.

 

They have eliminated some kind of obstacle in what a lot of people are calling a breakthrough.  I do not understand how it works or how it would affect enclosure volume.  A few references I saw seemed to suggest that the required volume may be very high.  It is very frustrating that detailed specs seem to be unavailable.  I am trying to get hold of a La Vegas rep for one of the companies to see if I can get some more information.  

 

I obviously overstated the case when I called it the death of subwoofers as we know them, but it does seem like this technology will work its way down the food chain.  As far as I can tell, the installations to date have not just been night clubs, but huge night clubs and things like the Superbowl halftime show.  Have seen nothing about scaling the device down to a size for a room.

[avguytx]

I don't see these replacing your standard low cost subwoofers anytime soon....and in my lifetime.  Most people just aren't going to care for home use.  The technology is great; the practicality for every day home use is not.  It's a lot easier to pressurize a house with bass response for movie watching versus a club, stadium, etc.

[vasubandu]

12 minutes ago, avguytx said:

I don't see these replacing your standard low cost subwoofers anytime soon....and in my lifetime.  Most people just aren't going to care for home use.  The technology is great; the practicality for every day home use is not.  It's a lot easier to pressurize a house with bass response for movie watching versus a club, stadium, etc.

 

Yo may be right.  I have found precisely zero pricing information.  Not even a mention in an article.  Maybe it is crazy expensive.  Would be a blast to somehow get a used one and see what it does.

[wvu80]

13 minutes ago, vasubandu said:

I have found precisely zero pricing information. 

I saw a reference to an amp with 15,000 watts.  The cost for the amp was around 3000 euros, $3800 usd.  No mention of the cost of the sub driver or enclosure.

[CECAA850]

22 minutes ago, vasubandu said:

I do not understand how it works

Powersoft’s M-Force technology is an innovative and alternative method of acoustic transduction, relying on a moving magnet linear motor structure rather than old moving coil technology to provide extremely high energy in a compact package, and sound quality experience that set a new standard in low-frequency speaker design.

 

In conventional subwoofer drivers the cone is attached to a coil of wire and the coil sits in a magnet.  Current is introduced via an amplifier and the cone moves in and out.  Apparently they've attached the cone to the magnet in their application.  I'd need to see a bit more to explain further but I'm assuming the coil is stationary and current moves the magnet.  Why it's more efficient that way is a mystery to me. 

 

 

 

[RoboKlipsch]

Vanu ive made a few general comments here ill share a comparison

 

i live in chicago where for my entire lifetime the cubs tried to outfox the rest of the league.  they would try and be smarter than the rest of the league.  they had almost all day games.  they would trade away stars thinking they could do better with their farm team and scouts.  they would bring back past stars after their prime and try to milk the emotional appeal.

 

everything except sound club management.  they outfoxed themselves, for over 100years, until they finally hired a brillant gm and let him do what was known to work elsewhere.  a few years later they won their first world series.

 

ive mentioned before i love your fire and fever for speakers.  u want not just the best but a wow factor that will be the envy and forefront of subwoofers.  the issue with that is you just cant jump ahead, skip the important elemental physics of speaker engineering and jump to a new technology and have a chance of making it work. i didnt comment on the sonotube idea here or on avs precisely because the idea of 2 24s in a long tube missed many important basic considerations.....a 24 can use 10cft sealed, let alone 20 or 30cft ported.  2 drivers are so heavy its unmanageable....and the box cant be made big enough to work well.

 

i love theoretical discussions.  But the best starting point is one of 2 things.  either just read and learn without planning to build, or better yet specify to yourself exactly what it is you want to achieve in  a subwoofer.  Every possibility has pretty much been done,  which is why i came to the possibility that you dont really know what you want so much as you want to design something new, unique, and mind blowing.

 

the cubs couldnt do that.  they first had to do it the conventional way, and their results were perfect.  that was only because the goal was set clearly....win a championship.....not win better than anybody ever had....just win.

 

food for thought.  i really enjoy your thoughts, but feel youre struggling to filter what u really want.  i hope u take this in the positive nudge it is intended to be

[Ceptorman]

Very well put Robo....

[vasubandu]

22 hours ago, RoboKlipsch said:

i love theoretical discussions.  But the best starting point is one of 2 things.  either just read and learn without planning to build, or better yet specify to yourself exactly what it is you want to achieve in  a subwoofer.  Every possibility has pretty much been done,  which is why i came to the possibility that you dont really know what you want so much as you want to design something new, unique, and mind blowing.

 

I really enjoyed your post.  I am a baseball guy so the analogy worked.  Of course the Oakland A's turned everything upside down with their moneyball theory, but after a few years, it seemed not to work anymore. So maybe it was a fluke.

 

The thing is, I am not really trying to create something new, unique and mind blowing.  All of those really concern the reaction that other people have.  I don't care how people react to whatever I make or what they think about it except to the extent that I choose to care.  This is not about proving something to anyone but myself.  I do care what the people here think because I consider them friends or community for all of the help that they have given me, and because I respect their knowledge and experience.  And I am trying to take all of that into account while still trying my project and testing my ideas for myself.  I get how frustrating it must be so see someone on a collision course with a brick wall who won't listen to you telling them how to avoid it, but in my own world and for my own purposes, I don't mind running into that wall.  I expect to learn a lot through the process, and almost all of it is reusable.

 

I think that I have come across an some kind of know-it-all who thinks he is going to rewrite subwoofer history.  I sometimes express myself that way even when I don't mean to.  I really am just having fun and trying to  compress a lot of learning and experience into a single project.  With any luck, this project will give me some insights that will allow me to decide what I want to achieve in a subwoofer in a way that is based on reality instead of numbers.

[CECAA850]

First you say in the other thread:

 

And if this works, I wanted it to be something completely different

 

Then:

 

 

14 minutes ago, vasubandu said:

The thing is, I am not really trying to create something new, unique and mind blowing.

 

And

18 minutes ago, vasubandu said:

I sometimes express myself that way even when I don't mean to. 

 

 

It makes it hard for us to keep up when you're all over the map.

 

 

 

 

OK, when are you going to start making saw dust and get out of cyberworld with your project?  Are the drivers on the way?

[muel]

Why don't you build a couple of these in the low profile version: http://www.billfitzmaurice.com/THT.html  

Tried and true...  You were talking about 72" tubes at one point... there you go.  Gives you something to enjoy while you study your plans to build your weaponized bass drivers.

Not worth 2 cents probably but I'm throwing it out there anyway.

 

 

[vasubandu]

3 minutes ago, CECAA850 said:

It makes it hard for us to keep up when you're all over the map.

 

 It is even harder to be all over the map.  When I say something different, I mean different for me. Something that pushes my boundaries, not the boundaries of knowledge.  But I certainly get it.

 

I was going to pick up the  plywood pieces today but pushed off to tomorrow. I know it is backwards in some senses, but the plywood is not exact, and I have not worked with it before. It will have to be strong enough and stable enough to  hold up a 115 pound driver, and it seemed to make sense to have something physical to measure before spending $1,279 apiece on the drivers.  I want to take the shell and do all the calculations to be sure it will work first.  It seems like the drivers are a known, so I do not have to have them in hand to make sure that they will work.  

 

I have a lot of learning to do, both in general terms and in mastering the software.  I want to be absolutely positive that things will fit, and that will take a little while. I have learned the hard way that rushing things never works.

[SWL]

Why don't you build a couple of these in the low profile version: http://www.billfitzmaurice.com/THT.html  

Tried and true...  You were talking about 72" tubes at one point... there you go.  Gives you something to enjoy while you study your plans to build your weaponized bass drivers.

Not worth 2 cents probably but I'm throwing it out there anyway.

 

 

Tried and true is right. I have two of these co-located in a corner and now that I have a Mini-dsp controlling them, they are by far the best subs I've owned and I've had a few.

 

Unbelievable power.....tight, punchy and smooth. No rumble here.

 

Sent from my SM-G950U using Tapatalk

 

 

 

[vasubandu]

13 minutes ago, muel said:

Why don't you build a couple of these in the low profile version: http://www.billfitzmaurice.com/THT.html  

Tried and true...  You were talking about 72" tubes at one point... there you go.  Gives you something to enjoy while you study your plans to build your weaponized bass drivers.

Not worth 2 cents probably but I'm throwing it out there anyway.

 

 

 

I just ordered his plans and sent him an email asking for a little advice.  Thanks.  This looks like it might be a much better approach.  If he responds, I will post what he has to say.

[vasubandu]

8 minutes ago, SWL said:

Tried and true is right. I have two of these co-located in a corner and now that I have a Mini-dsp controlling them, they are by far the best subs I've owned and I've had a few.

 

Unbelievable power.....tight, punchy and smooth. No rumble here.

 

Sent from my SM-G950U using Tapatalk

 

 

 

Thanks @SWL that certainly looks like a more developed  idea for the tower concept than  I could ever create.  I ordered his plans and will have to see them. In a perfect world, they could be adapted to a round column.  I sent him an email, so I hope he will answer.

[muel]

Just now, vasubandu said:

 

I just ordered his plans and sent him an email asking for a little advice.  Thanks.  This looks like it might be a much better approach.  If he responds, I will post what he has to say.

Hey build a couple extra for me too... I've been trying to get to this for a few years now but still have a stack of plywood in the middle of another project.  

[SWL]

Learn from my mistake/procrastination. Don't wait two years to get some kind of DSP to control these subs. Like I said, I use the Mini-dsp 2x4 HD and it works FRICKEN AMAZING. Thanks to JasonSTR.

Sent from my SM-G950U using Tapatalk

[vasubandu]

@SWL if you mean this https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4, I have already ordered it.  A guy names BassThatHz in AVS told me I needed one.  I have come to trust his advice, so when he said to get one, I just did.