ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2] 3 4   Go Down

Author Topic: PK Sound Gravity 30 Subwoofer  (Read 6780 times)

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8642
  • Atlanta GA
Re: PK Sound Gravity 30 Subwoofer
« Reply #10 on: November 19, 2017, 05:10:35 pm »

The SDL Contra Bass used the dual 15" with dual 18" passive radiators.
Yeah, that one was the exception.

All of the others were horn loaded.

I believe the contrabass was developed to "talk to elephants" so it had to fit in the back of a jeep.

It later found favor for home listening.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

MikeHarris

  • Full Member
  • ***
  • Offline Offline
  • Posts: 166
Re: PK Sound Gravity 30 Subwoofer
« Reply #11 on: November 19, 2017, 11:41:14 pm »

About the only thing is has in common with the servodrive is that the driver is round and it produces sound.  It pretty much stops there.

Both share a non-conventional method of driving the round thing that produces sound.

Every few years my client Byron Lee (RIP) would have me order belts for his SDL subs. Anything wear out on the PSoft ?
Logged

Chris Grimshaw

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 721
    • Grimshaw Audio
Re: PK Sound Gravity 30 Subwoofer
« Reply #12 on: November 20, 2017, 06:32:07 am »

Anything wear out on the PSoft ?

Shouldn't do. It operates on a similar principle to a normal speaker, except it's the magnet that's being moved. That means you can bolt the voicecoil to a big ol' heatsink and drop 10KW into it.
Not really worth doing for smaller cones (moving coils propel those just fine) up to, say, 21". Past that, moving magnet seems to be the way to do it.

Chris
Logged
Sheffield-based sound engineering.
www.grimshawaudio.com

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8642
  • Atlanta GA
Re: PK Sound Gravity 30 Subwoofer
« Reply #13 on: November 20, 2017, 07:28:54 am »

Both share a non-conventional method of driving the round thing that produces sound.

Every few years my client Byron Lee (RIP) would have me order belts for his SDL subs. Anything wear out on the PSoft ?
So if we are going to go that route, I guess you could add piezo tweeters and "maybe" old (and some new) field coil speakers to the list, if "different" is the thing that makes them "common".
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

MikeHarris

  • Full Member
  • ***
  • Offline Offline
  • Posts: 166
Re: PK Sound Gravity 30 Subwoofer
« Reply #14 on: November 20, 2017, 03:13:16 pm »

Both share a non-conventional method of driving the round thing that produces sound.

Sorry to ruffle your feathers Ivan but I am clearly referring to alternate methods of driving the piston used for subs.
Maybe Tom could comment intelligently
Logged

Keith Broughton

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2887
  • Toronto
Re: PK Sound Gravity 30 Subwoofer
« Reply #15 on: November 20, 2017, 03:29:29 pm »

The SDL Contra Bass used the dual 15" with dual 18" passive radiators.
I heard one of these "back in the day" and was VERY impressed!
As for the Gravity30, I saw published specs of response and output but, once again, no frequency defined relationship  ::)
Logged
I don't care enough to be apathetic

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8642
  • Atlanta GA
Re: PK Sound Gravity 30 Subwoofer
« Reply #16 on: November 20, 2017, 05:09:24 pm »

Sorry to ruffle your feathers Ivan but I am clearly referring to alternate methods of driving the piston used for subs.
Maybe Tom could comment intelligently
OK, they both use a piston.

But how that piston is driven has nothing in common-other than an audio signal.

And just to be clear- you did NOT say anything about subs.  You said a round thing that produces sound.  I gave examples of that.

I'm sorry if I insulted you, but I was just answering the "question" as it was presented.

Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

radulescu_paul_mircea

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 75
Re: PK Sound Gravity 30 Subwoofer
« Reply #17 on: November 21, 2017, 10:28:00 am »

The patent for the M-FORCE https://www.google.com/patents/WO2011125083A1?cl=en
And here is the technology behind it that had allowed it to perform as it does
http://www.powersoft-audio.com/en/docman/993-us-patent-improvements-to-systems-for-acoustic-diffusion/file

Sent from my TA-1053 using Tapatalk

Logged

Kevin McDonough

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 284
Re: PK Sound Gravity 30 Subwoofer
« Reply #18 on: November 24, 2017, 02:25:10 pm »

hey

well, to maybe meet somewhere in the middle I'd say it's a little similar to servodrive in that as you say Ivan, they're both piston like system to move the cone.

Very different i execution though, as (again as Ivan says) servodrive were a belt motor type system, where as this would be a bit closer o a solenoid.

On a traditional speaker it is a moving voice coil inside a fixed magnet. The voice coil had to be pretty thin and lightweight to make sure the cone can move at the required speed, which of course limits how much current can be put into it before it goes pop.

On the other hand, M-force as said flips this around and its the traditional magnet that is the moving part, and the voice coil the fixed part wrapping around it.

This means it can be as big and bulky as needed, with nice big heat sinks, and LOTS more current can be thrown at it.  This then makes cone weight less of an issue as it has the current, and hence motor force, to move much heavier weights. So I'm sure there is a 24", 30" and even 40" cone available that are made from a lightweight plastic rather than paper, so they're super rigid and can push a LOT of air at very high pressure.

K
Logged

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Online Online
  • Posts: 19052
  • Wichita, Kansas USA
Re: PK Sound Gravity 30 Subwoofer
« Reply #19 on: November 24, 2017, 04:43:18 pm »

hey

well, to maybe meet somewhere in the middle I'd say it's a little similar to servodrive in that as you say Ivan, they're both piston like system to move the cone.

Very different i execution though, as (again as Ivan says) servodrive were a belt motor type system, where as this would be a bit closer o a solenoid.

On a traditional speaker it is a moving voice coil inside a fixed magnet. The voice coil had to be pretty thin and lightweight to make sure the cone can move at the required speed, which of course limits how much current can be put into it before it goes pop.

On the other hand, M-force as said flips this around and its the traditional magnet that is the moving part, and the voice coil the fixed part wrapping around it.

This means it can be as big and bulky as needed, with nice big heat sinks, and LOTS more current can be thrown at it.  This then makes cone weight less of an issue as it has the current, and hence motor force, to move much heavier weights. So I'm sure there is a 24", 30" and even 40" cone available that are made from a lightweight plastic rather than paper, so they're super rigid and can push a LOT of air at very high pressure.

K

The fundamental difference is the use of a rotary servo motor and the belt linear motion transformer.

Pistonic transducers, in and of themselves, are not unique.
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut
Pages: 1 [2] 3 4   Go Up
 


Page created in 0.059 seconds with 23 queries.