Speakerplans.com Homepage
Forum Home Forum Home > General > Amp Forum
  New Posts New Posts RSS Feed - Powersoft X4 real power
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Powersoft X4 real power

 Post Reply Post Reply Page  <1 192021
Author
Message
Timebomb View Drop Down
Old Croc
Old Croc
Avatar

Joined: 11 October 2004
Location: Lancaster
Status: Offline
Points: 2625
Post Options Post Options   Thanks (0) Thanks(0)   Quote Timebomb Quote  Post ReplyReply Direct Link To This Post Posted: 12 September 2019 at 7:55pm
Id say the opposite,  high voltage rails and good limiters peak + RMS are the are the most useful tools to safely rinse every last dB out of a cabinet.  If it does limit / reduce output a bit on the occasional sustained low crest factor section then not really the end of the world, less chance of cooking a coil.  
James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
Back to Top
csg View Drop Down
Old Croc
Old Croc


Joined: 17 September 2007
Location: bedford
Status: Online
Points: 5404
Post Options Post Options   Thanks (0) Thanks(0)   Quote csg Quote  Post ReplyReply Direct Link To This Post Posted: 12 September 2019 at 8:12pm
off course, but i kind of think you miss my point. what you are talking about is doing it properly and relatively safely.
fsl.online
Back to Top
Elliot Thompson View Drop Down
Old Croc
Old Croc
Avatar

Joined: 02 April 2004
Location: United States
Status: Offline
Points: 4371
Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 12 September 2019 at 8:52pm
Originally posted by csg csg wrote:

off course, but i kind of think you miss my point. what you are talking about is doing it properly and relatively safely.


Exactly!

 

The common mistake that many assume is the loudspeaker is immune to damage due to offering a limiter. If the user forces a stronger signal into the limiter, the limiter will just reduce the peaks further until it offers a similar output level as the RMS.

 

It is similar to those assuming a HPF will prevent loudspeaker damage. All a HPF does is reduce lowest frequencies from passing through which, may be useful if the loudspeaker you are using is incapable of producing the rolled off frequencies without, a high dose of excursion based on the amount of power you are feeding it.

 

However, using the above method creates havoc to the voice coil for it relies on cone movement in order to extract the heat from the voice coil. When JBL first released the EON around 20 years ago, it used the cone excursion to not only reduce the voice coil from heating up but, to cool off the amplifier as well.

 

Best Regards,

Elliot Thompson
Back to Top
Earplug View Drop Down
Old Croc
Old Croc


Joined: 03 January 2012
Location: Europe
Status: Offline
Points: 5602
Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 9:46am
Originally posted by Elliot Thompson Elliot Thompson wrote:

Originally posted by Earplug Earplug wrote:



Yes, which is why it´s always far better to add more (efficient) cabs/drivers than 'swop out' an existing driver for something 'with more power' - a request I get constantly from those who don´t have a clue - and have bought (cheapo)  cabs with stupidly inflated power ratings. The first question those ask is always "what power" rather than "what spl".    Unhappy




What you are saying is falling upon deaf ears. The majority wants to extract every bit of SPL from the least amount of loudspeakers and, are not content until the amplifier clips during the process.

 

Best Regards,

 


Yes, true - like the dj´s that aren´t happy unless everything is in the red. I guess that it keeps the reconers and repair engineers in business.  Ermm


Earplugs Are For Wimps!
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 2252
Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 9:58am
Originally posted by Timebomb Timebomb wrote:

No, 100W rms with 12dB crest factor is 12.5W real power.

Continual sine wave is 3dB crest factor, 6dB CF is 1/2 the real power (50% Duty cycle),  9dB CF is 1/4 the real power (25% duty cycle) 

Very heavy bass in some music can be as low as 6dB crest factor, most music is higher, 9-12dB typical.  


I had always assumed that into a resistive load the RMS power was equivalent to the real power. so are people defining RMS power as the power that would theoretically be delivered by a sine wave signal with same peak voltage as the actual signal (which is not a sine wave)?

PP
Back to Top
Timebomb View Drop Down
Old Croc
Old Croc
Avatar

Joined: 11 October 2004
Location: Lancaster
Status: Offline
Points: 2625
Post Options Post Options   Thanks (0) Thanks(0)   Quote Timebomb Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 10:12am
Originally posted by snowflake snowflake wrote:

Originally posted by Timebomb Timebomb wrote:

No, 100W rms with 12dB crest factor is 12.5W real power.

Continual sine wave is 3dB crest factor, 6dB CF is 1/2 the real power (50% Duty cycle),  9dB CF is 1/4 the real power (25% duty cycle) 

Very heavy bass in some music can be as low as 6dB crest factor, most music is higher, 9-12dB typical.  


I had always assumed that into a resistive load the RMS power was equivalent to the real power. so are people defining RMS power as the power that would theoretically be delivered by a sine wave signal with same peak voltage as the actual signal (which is not a sine wave)?

PP

Yes basically that is what they are doing, peak voltage x 0.707.  But the test signals are often sine waves with duty cycle.  EG when a manufacturer specs 1000Wrms@8ohms 6dB crest factor, it might be a 1KHz sine wave but with 50% duty cycle, 1ms on / 1ms off, then they take the RMS voltage of the sine wave when its on (89.4V) and calculate the 1000Wrms@8ohms power with that.    

RMS means Route Mean Squared, it does not mean continual power, or real heating power.


James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
Back to Top
U.Viktor View Drop Down
Young Croc
Young Croc


Joined: 04 May 2010
Status: Offline
Points: 657
Post Options Post Options   Thanks (0) Thanks(0)   Quote U.Viktor Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 11:59am
I was unable to measure even ~400W continuous per channel on the X4, if I remember correctly.

If Powersoft says X4 is a 4* 1600W amp.. it could be OK!

But keep in mind it sold as 4* 5000W amp, total 20000Watts which are very, very far from the reality.
This is the only thing what is disturbing me.
Back to Top
Earplug View Drop Down
Old Croc
Old Croc


Joined: 03 January 2012
Location: Europe
Status: Offline
Points: 5602
Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 12:21pm
"RMS means Route Mean Squared, it does not mean continual power, or real heating power."

No, Root Mean Square means exactly that!  Smile

Here:





Edited by Earplug - 13 September 2019 at 12:24pm
Earplugs Are For Wimps!
Back to Top
Timebomb View Drop Down
Old Croc
Old Croc
Avatar

Joined: 11 October 2004
Location: Lancaster
Status: Offline
Points: 2625
Post Options Post Options   Thanks (0) Thanks(0)   Quote Timebomb Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 2:22pm
Its not the same as long term heating power / real power, or it is not with a signal other than a continual sinewave.  Its the RMS voltage of the sine wave while it is playing, but not long term.  
James Secker          facebook.com/soundgearuk
James@soundgear.co.uk               www.soundgear.co.uk
Back to Top
snowflake View Drop Down
Old Croc
Old Croc


Joined: 29 December 2004
Location: Bristol
Status: Offline
Points: 2252
Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 2:49pm
edit

Edited by snowflake - 13 September 2019 at 2:52pm
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Online
Points: 10025
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 3:18pm
Originally posted by U.Viktor U.Viktor wrote:

I was unable to measure even ~400W continuous per channel on the X4, if I remember correctly.

If Powersoft says X4 is a 4* 1600W amp.. it could be OK!

But keep in mind it sold as 4* 5000W amp, total 20000Watts which are very, very far from the reality.
This is the only thing what is disturbing me.



I'll trust PP's tests over yours, thanks.

Also, they very clearly do not state that power is continuous sine wave, because as discussed, the real world does not require almost anybody to actually power that. When they do, they commission a K22 from Powersoft... if you don't know what that is, you don't need to know.

6dB crestfactor noise bursts of 200ms (AES) or 500ms (Meyer) are a much more usable measurement figure, for the real world of compressed, heavy dance music. 12dB crestfactor for these periods is indicative of almost everything else.

Where the issues really lie, for me, are with amps like the LA12X that use only 8ms and 20ms bursts for their ratings.

Sadly the XTA APA4E8 hasn't been reviewed by PP, but I have gone through their own spec sheet in detail. It has a lot of storage capacity internally, and the output side is super strong, but the limit is still going to be the power supply - perfectly reasonable, given the focus on touring, and the real world.

Let's have a look at some world-class touring 4 channel amps, shall we? Sinus goes first, various burst signals second.

XTA APA4E8
All channels driven (230V)
RMS sine wave long term continuous power with all channels run
simultaneously (over an hour assuming 20 degree ambient)
3000 W (4*750W) one hour



Lab Gruppen PLM12K44



L'Acoustics LA12X aka CAMCO Q-POWER14



d&b D20 - no measurements of D80



Linea Research 44M20



Powersoft X4



And here's some info on XTA's test types, which are close to PP's, and why:


Isn't data lovely?


Edited by toastyghost - 13 September 2019 at 3:21pm
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Online
Points: 10025
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 13 September 2019 at 3:35pm
Found d&b D80, way back in March 2014:

Back to Top
 Post Reply Post Reply Page  <1 192021
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.109 seconds.