electronic audio low pass / inversion stage for bridging - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

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 20th January 2005, 10:47 AM   #1
diyAudio Member
 
Join Date: Aug 2004
Location: Stavanger
Default electronic audio low pass / inversion stage for bridging

Hi all,

I should begin by admitting that I know almost nothing about electronics so please forgive what might seem like lots of stupid questions. If you have the poatience please put me right using words of as few syllables as possible!

I'm wanting to build an active subwoofer. The idea is sketched out in the subwoofer forum. Part of this needs to be a stage that will split the signal, inverting half of it and not inverting the other, then feeding the to my low pass network which will balance the natural rolloff of the unit and give a flat response down to around 20Hz. I found a schematicf that looks fairly good ( http://home/new.rr.com/trumpetb/audio/009js.html). All I need to do is forget the high pass bit, and build two of the rest with the first op (TL082CP in the schematic) inverting one signal and not inverting the other. then connecting them in parallel.

Is this right so far?

Some questions:

1. What about input impedance? Do I need to take this into consideration in vew of the parallel connection?

2. Gain: The schematic isn't explained, but I would like the overall gain of each "half" to be 1. I know that the 3 pF cap and the 100K resistor across op1 control this but don't know the equation. How does leaving out the high pass circuit effect the overall gain?

3. Topology: Presumably there's a good reason for the order of the ops. By reversing the order I could get away with only one filter network, splitting the signal afterwards (1 TL074CN, and 2 TL082 CPs). I assume this would not be a good solution.

4. choice of components: I want the sound quality to be as good as poss. How do the suggested ops compare with others? In the 405's I ended up using NE 5534 (more available than a BB OPA604AP, both were recommended). What about stability issues with various ops at low gain?

I will also end up building high poass networks for the front pair as my speakers are good down to 43 Hz, and I don't know how they roll-off below that. Far better to controll the X-over at around 70 Hz.


If anyone has a schematic for a better circuit please let me know. Otherwiose I would be happy for any help here.


Many thanks!
  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
Brand new to the audio electronic world monrac Introductions 1 7th November 2007 01:54 PM
Audio Electronic Supply AE-25DJH no xo Tubes / Valves 4 28th June 2006 02:36 AM
Electronic low-pass x-over madman Solid State 0 25th February 2004 04:55 PM
need audio electronic service sma Parts 0 17th December 2003 08:41 AM


New To Site? Need Help?

All times are GMT. The time now is 05:25 PM.


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