SUB amp with Built-in Active Crossover - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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
Reply
 
Thread Tools Search this Thread
Old 9th January 2004, 06:12 PM   #1
diyAudio Member
 
Killjoy99's Avatar
 
Join Date: Dec 2003
Location: Seattle, WA
Default SUB amp with Built-in Active Crossover

I am building Anthony Holtonís Symmetrical Amplifier as a mono Sub amp. I would like to incorporate an active crossover with a low pass Frequency knob and a Volume knob. Are there any simple designs or ways to do this? I was looking over the projects on ESP, specifically:

Project 84
http://sound.westhost.com/project84.htm

Project 28
http://sound.westhost.com/project28.htm

Project 08
http://sound.westhost.com/project08.htm

Would any of these work for me? I would like the crossover to be mounted within the amps case and the knobs on the front. If there are any other designs that would work better I am open to everything.
  Reply With Quote
Old 9th January 2004, 09:25 PM   #2
diyAudio Member
 
Killjoy99's Avatar
 
Join Date: Dec 2003
Location: Seattle, WA
Default Denon Receiver as Crossover

Actually, I might as well ask this first. I will be using a Denon DTS receiver for my surround sound processing and as a preamp for the Power Sub Amp. Does anyone know if the signal coming from the Denon's Subwoofer out in the back is crossovered at all or is it the entire range. I read in the manual and it seems like subwoofer channel will only produce the LFE signal prgrammed on the DVD. Not sure if I'm way off base here, but I figured it was worth a try.

I guess what I am getting at is will I even need a crossover for the Sub Amplifier if the DVD signal first goes through my receiver and than to the power amp.

Thanks
  Reply With Quote
Old 9th January 2004, 09:45 PM   #3
maylar is offline maylar  United States
diyAudio Member
 
Join Date: Jun 2003
Location: Connecticut
I can't comment on your particular receiver, as I have no clue - but the general arrangement for "sub out" channels on decks (at least car decks) is that they have some kind of lowpass filtering built in. You need to investigate the manual further...

As for lowpass circuits, 12 dB/Octave (2nd order) is usually adequate and there are common op-amp circuits for that:

http://www.electroniccircuitanalysis...ve_filters.htm
http://www.linkwitzlab.com/filters.htm

I've been considering these myself, and it looks like to make them adjustable you need to replace 2 resistors with a ganged pot.

dave
__________________
dave
  Reply With Quote
Old 10th January 2004, 10:37 AM   #4
diyAudio Member
 
RobWells's Avatar
 
Join Date: Aug 2002
Location: UK
Most receivers have a 'size' setting for your speakers - large is full range, small routes the low bass to the subwoofer. On my receiver this is at 90Hz, others may differ.

I *think* most receivers do a hi pass at 12Db per octave, and a low pass at 24Db per octave. This to try and intergrate the main speakers natural roll off into a 24Db acoustical slope. - Try blocking your mains ports if you go this route. (turns a vented box into a sealed).

With a receiver you don't need a xo on the sub amp, but a phase knob could come in handy for blending the sub to the mains.

hth

Rob
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Passive crossover into active crossover hahfran Multi-Way 16 10th February 2008 06:16 PM
Active XOs, and Amp built into speaker, or seperate akunec Chip Amps 5 11th May 2005 01:34 AM
I finally designed and built my first crossover! Jim85IROC Multi-Way 17 26th May 2004 07:27 PM
Have anybody built this active pot from Elektor? supernet Solid State 38 3rd November 2003 08:16 PM
XVR1 active crossover, discrete active stage promitheus Pass Labs 18 22nd July 2002 01:29 AM


New To Site? Need Help?

All times are GMT. The time now is 06:22 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2