I need an active sub filter!

[hernanstafe]

Ok i've asked this before several times and i got answers that were not so useful, and after reading some information about the subject, i'm getting more and more confused.

This is the thing; i built a 10" vented subwoofer cabinet, the speaker goes inside the cabinet, facing up, and the enclosure has 2 vents behind the speaker, if i'm not wrong that's a 4th order bandpass enclosure, i think.

I need an active filter, which also sums up both L and R channels. Some people on the forum reccommended me Rod Elliot's Project Nº 48, but i just read it's USELESS FOR VENTED CABINETS plus the schematic is incomplete on the page (some caps are missing).
So here i am again with nothing and wondering what should i use to filter and sum up channels. Does anyone know a working, suitable ACTIVE filter? I've been looking for one on the net for quite some time but i can't find it

PS: I remind it should also sum up both channels.

Cheers!!

 

[dswiston]

Rod Elliots P48 is absolutely not for your vented speaker.


I'd suggest looking at P09 on Rod's site, specifically the "low" portion of the circuit.


To sum the channels, the easiest way is to simple use a resistive summer. (Just hookup the two channels together through resistors) A better way would be active mixer, look at figure 1 on P71 on Rod's site for that. You don't necessarily need the second opamp there either.

 

[CSS/XBL]

You might want to consider one of the Reckhorn products, either the F-1 or the B-1 (http://www.reckhorn.com/index.php?ln=en&prod=b1).

These will be available in North America next week when my shipment arrives. These units are 120V but 220V are available from Germany.

Bob

Creative Sound Solutions

 

[Cal Weldon]

I picked up the Reckhorn B-1 from Bob at CSS and am very happy with the overall control it gives me. As far as summing the channels, why not consider dswiston's suggestion?

 

[hernanstafe]

ok thank for the replies guys, about those devices coming from germany, i'm from Argentina, i don't think we'll get them here Bringing them here from USA would be horribly expensive.

About Rod's projects, the mixer is fine, the Figure 1 on P71, i was wondering if that schematic is complete? or there are also some coupling caps missing?

Still looking for athe filter tho

 

[dswiston]

I don't see anything missing from Rod's mixer circuit. Looks OK to me.

 

[CSS/XBL]

Small packet air (up to 2 KG) is quite reasonable from Canada but I don't have any 220V versions.

Bob

 

[hernanstafe]

ok the mixer circuit will do then, now i have to find the filter!!

 

[mikee55]

Its all there

You just have to look.

Mostly building blocks. In the downloads section the crossover calculator is there

This program (ESP-LR12.EXE) is the actual executable file. This is version 1.2 of the program, and is just under 67k, so it is not too big. There are no setup programs or such like, so you simply have to decide where to put it, and create your own shortcut. Feel free to distribute the program to friends, since I have released it as freeware - just don't change the program in any way is all I ask.

Cheers mikee55

 

[hernanstafe]

just wondering, what are those 3 opamps in the lower part of the schematic?

 

[TwisterZ]

I'm not sure if your looking for a project or a simple solution but here is what I used in my system, BEHRINGER CX2310 CROSSOVER, paid $64USD shipping included. It has 2 inputs & 5 outs, L&R high out, L&R low outs & a summed low pass mono sub out.

 

[DorinD]

... Does anyone know a working, suitable ACTIVE filter? I've been looking for one on the net for quite some time but i can't find it

PS: I remind it should also sum up both channels.

Cheers!!

Yes Hernan, I know one. Mine. If you have some hands on electronics see here:

http://www.hi-fi.ro/fhifi/download.php?id=12620

or

http://www.hi-fi.ro/fhifi/viewtopic.php?t=10640&postdays=0&postorder=asc&start=45

my "summing/crossing@70Hz/phasecontroll" device built with discret components on air. Cheers!
Dorin

 

[dswiston]

just wondering, what are those 3 opamps in the lower part of the schematic?

First one is a buffer, the second two make up the low-pass filter.

Seeing as how you are having numerous questions with this stuff, may I suggest taking it slow and working on understanding what is going on step by step. There are three or four threads with you asking similar questions, try to keep this to one thread so progress and previous question/answers can be tracked so someone isn't giving you the same answer or suggestion 4 times.


Circuits you might find anywhere on the web often leave out the power supply section, simply speficying +/- X Volts at some point on the schematic. They often leave out bypassing caps for the supply lines. These are normally understood to be needed / included. So if you ask someone "Is that all of the circuit", you'll probably get a "yes".

It sounds like you might want to find something predesigned and on a PCB with a BOM (Bill of Materials) that you can simply assemble. I'd suggest looking for this as a start, you'll more than likely have to spend some money buying the PCB/design.

 

[trip-pcs]

active crossover

Hi,

you could try this one. The circuit was designed by some members of a German hifi-forum and me as active crossover for sub/sat systems with variable crossover frequency, either with pluggable resistors or a rotary switch. Gain is variable for sub- and sat-channels.
Moreover it offers summing of both channels for subwoofers or mono use, this can be configured with a jumper.

Voltage supply is included on the printed circuit board, only standard components are used. MKP condensors should be selected to ensure tolerances of at most 5%. Such types are also available at electronics distributors.

The whole thing is quite easy to build, costs are about 30$ without enclosure.

If interested, ask for further information.

Ciao Phil

 

[hernanstafe]

trip-pcs i'm really interested in that circuit it looks nice. The only thing i'd like to know is if there are any pcb layout available. Thanks for your help btw!!

 

[Hornlover]

Here is a great sounding crossover. Available as a bare board or kit. It includes an on board regulated power supply, which most kit types omit.

http://www.audio-kits.com/page/page/4071180.htm

 

[trip-pcs]

Of course there is a pcb. I tried the circuit, it works well.

 

[trip-pcs]

Unfortunately I can't upload files with high resolution here.

You get all information needed in a zip-file here:

http://www.file-upload.net/download-174181/hifi-forum-aktivweiche.zip.html

A picture of my design can be found below...

 

[hernanstafe]

After a long time of not working on this (because i was busy with college) i'm going to keep working on my amp/pream projects. I'm going to build trip-pcs filter, but i'd like to know if you could help me understand what you sent me since i really don't understand that language!!
Thanks in advance