Jump to content
Sonic Electronix

Power Compression? 2002 Forester


Recommended Posts

Is there was to test for power compression? Not really looking to keep beating this dead horse if its heavily compressed. https://www.facebook.com/Baltimorescoobie/ is the build

2002 Forester

Alpine INE-W927HD, Hertz Mille Legend 3 way 2 DC Level 6's,Bit One Audio , Audison Voce Due and Quattro, 4 Twisted Sounds 3.5K, 8 G31 Batteries, DC Power XP 270 Alternator. All Sky High OFC wire.

 

Link to comment
Share on other sites

You can test for total compression (power and port compression together) pretty easily.  Determining how much compression is port and how much is power is a little more challenging. 

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

To test you need to be able to measure SPL and/or impedance at different power levels and frequencies. 

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

ok got term lab and clamp and a scope

2002 Forester

Alpine INE-W927HD, Hertz Mille Legend 3 way 2 DC Level 6's,Bit One Audio , Audison Voce Due and Quattro, 4 Twisted Sounds 3.5K, 8 G31 Batteries, DC Power XP 270 Alternator. All Sky High OFC wire.

 

Link to comment
Share on other sites

Ok, so you are going to get the most power compression at the frequencies where you impedance is the lowest.  Thats going to be right at your tuning frequency and then you are impedance is going to get pretty low again up above around 70 Hz (depending on your sub).  Right at your tuning frequency is where you will get the most port compression as well.  Measuring at your tuning frequency is going to tell you how much total compression you are getting and that's what I assume you care about the most.  

Starting a low volume with a sine wave tone at your tuning frequency, you want to measure your output and record the number.  Using a DMM measure the output voltage out of your amp as well.  From there you want to keep increasing power and taking measurements.  Increasing power in 3dB increments usually works well.  A 3dB increase in output requires a 1.413x increase in output voltage.  So play with your volume to increase the output voltage from your amp by 1.413x.  You will notice that a 3db increase in output voltage isn't going to get you a 3db increase is SPL.  The difference is how much compression you are getting.  

Be careful when you are doing this, sine wave tones take a lot of power and will heat up your coil pretty fast at higher volume levels.  Obviously you want to be care not to send your subs a clipped signal either.  

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   0 Members, 0 Anonymous, 968 Guests (See full list)

    • There are no registered users currently online
×
×
  • Create New...