Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

DC offset affect on biamped speakers
DC offset affect on biamped speakers
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 2nd July 2006, 01:12 PM   #1
daly2k is offline daly2k  United States
diyAudio Member
Join Date: Aug 2005
Default DC offset affect on biamped speakers

I need some feedback on the following issue. I just finished a line array speaker project that was designed to be eventually bi-amped. I plan to use my Aleph 1.2's for the tweeters and my Pass/tharagard A-75 for the mid bass. I have 12-5" ribbon tweeters and 12-5" eton mid bass drivers and I am currently using a crossover pt of 2600hz at 24db. I want to get a digital DEQX system to help with room problems and then use a digital crossover set pt at 96db anywhere from 21-- to --3000hz depending on the sound.

The question is that for the tweeter array I currently have capacitors in the crossover that block DC from the amps on turn on or the usual dc offset. My aleph's offset is less than 50mv and my pass A75 is less than 20mv after warm up. My speaker drivers are series-parallel connected to give me 6.2 ohms. When biamping the amps will be hooked up directly to the speaker drivers with no crossover protection as it is now infront of the amps. Using the equation of V=IA, I get .050v/6ohms=.008ma. With 12 tweeters sharing the load does anyone think I should put a cap in front of the tweeters for protection from DC offset. I am not worried about the midbass drivers as they can take the abuse but with Fountex ribbon tweeters at $100 a pop, I am a bit nervous. I will install fuses in my Alephs for short circuit protection and my A-75 already output fuses. thanks for any advice. dave
  Reply With Quote
Old 3rd July 2006, 11:35 AM   #2
harryeng is offline harryeng  Netherlands
diyAudio Member
Join Date: Dec 2004
Location: Roosendaal
Hi dave,

I do not longer own a DEQX anymore, (building a MOX) but when you look in the Yahoo group for owners, you will find a lot of best practices.

One of the best practices is to use a capacitor as protection for your tweeters. A lot can go wrong! The capacitor not only protects against DC, but will also help the DEQX. The lowpass will also reduce the calculation time, leaving more room in delay functionality. (You will understand this when you get your DEQX)

Greetings, Harry
  Reply With Quote
Old 3rd July 2006, 01:48 PM   #3
daly2k is offline daly2k  United States
diyAudio Member
Join Date: Aug 2005
Default dc offset

Harry, thanks for your help, I will look up DEQX in Yahoo and read some of the information. I am thinking to use a 2500uf computer grade cap with a PP bypass for protection. dave
  Reply With Quote
Old 3rd July 2006, 07:59 PM   #4
Nelson Pass is offline Nelson Pass  United States
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
DC offset affect on biamped speakers
My experience is that you can put significant DC on drivers
without too many problems, so I set the offset as low as
possible and sleep soundly at night.

BTW, I bought a much of 4 inch drivers on a clearance from
Parts Express and ran them with with a .6 amp DC bias, and
they actually measured lower distortion
  Reply With Quote


DC offset affect on biamped speakersHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone used the 41Hz Amp 6Basic in Biamped active speakers? MikeHunt79 Class D 1 13th March 2009 08:50 PM
Biamped System with LM4780s kent Chip Amps 1 27th June 2006 12:43 PM
Tube amp for biamped speaker navin Tubes / Valves 39 25th November 2005 12:36 PM
Grounding in a biamped buffered system Raka Chip Amps 20 19th November 2003 01:49 PM
Wattage required for biamped ESL phishead8 Planars & Exotics 6 3rd July 2002 01:42 PM

New To Site? Need Help?

All times are GMT. The time now is 04:07 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio