Interesting affordable active Xover

mcgsxr · « **on:** 20 Apr 2007, 08:03 pm »

I have been thinking more and more about how to integrate my single ended EL84 amp, and my plate subwoofer amp. The Maggie amp loves to be relieved of the low bass, and shines when this is allowed to happen. Although I have tried running the signal from SB3 to plate amp to Maggie, I am not deluded into thinking that the Xover in my plate amp is very good.

Available historically decent line level solutions have included Mirage/Energy/Paradigm/Outlaw active Xovers for subs. Usually still more than $200 or so, used.

I notice that CSS is currently carrying the Reckhorn series of active Xovers and amps.

http://www.creativesound.ca/index.html

This one looks interesting, and for $57 delivered, could solve my issue with my current setup, about how to incorporate 2 amps, with only my modded SB3 as the pre/source.

Anyone have any knowledge/advice/experience or opinion with these?

http://www.reckhorn.com/index.php?ln=en&prod=f1

Rudolf · « **Reply #1 on:** 20 Apr 2007, 09:02 pm »

I am following a german forum discussion about the B1 http://www.hifi-forum.de/viewthread-159-2034.html. According to that the B1 doesn´t work according to specs and has quality problems (resistors with wrong values put in). I would hesitate to buy their products without the opportunity to test them with scrutiny in advance.

mcgsxr · « **Reply #2 on:** 21 Apr 2007, 11:10 am »

Arghh, that is too bad, it certainly looks like a handy tool, and quite affordable too.

But, if it doesn't work...

Scott F. · « **Reply #3 on:** 21 Apr 2007, 02:22 pm »

Hey Mark,

Heres a cheap one that works......

http://www.allaudioexpo.com/i/pyramid_pr3000_home-studio_electronic_cr.html

Its the Pyramid PR3000. It is an active 2 or 3 way. I've seen it sold under several different brand names for around $60. It is designed for the DJ or maybe a band with no money.

I bought one of these a few years ago just to see what it sounded like. The thing I like most about it is the fact that is a very simple crossover, no extra features like time delays or anything else to pollute the signal path. Here are its features.

# 3 Way 6 Channel Crossover for Home or Club Use
# On/Off Switch w/LED Indicator
# Low Frequency: Low Pass: 50Hz,90Hz,180Hz,360Hz,720Hz
# Mid Frequency:
High Pass:50Hz,90Hz,180Hz,360Hz,720Hz,Flat
Low Pass: 1K, 2K, 4K, 6K, 8K, Flat
# High Frequency: High Pass: 1K, 2K, 4K, 6K, 8K
# 12dB per Octave Slope
# Low/Mid/High Output RCA Jack
# Pre-Amp RCA Input
# 110/220 Volt AC Switchable
# Dimensions:19''W x 2.375''H x 8.5''D

Inside it is built reasonably well considering its cost. The actual crossover portion has the resistor and caps board mounted with a rather unique slide switch (not a variable pot). Each of the bands has its own opamp and there is an input gain opamp. The pots and RCA's are the usual inexpensive ones.

This thing has some serious potential IF you are handy with a soldering iron. It's problems are twofold. First are the opamps. It uses the the super cheap and veiled sounding LM inline opamps. A simple swap out of the LM's for a decent DIP would improve the sound of this immensely.

The second issue is the power supply. Though it is linear, it's cheap and under built. An external 12 volt (I think it was 12 volt, might be 14v) Elpac would do wonders for the sound.

Beyond that, if you wanted to change out the resistors and caps for something better sounding, they are board mount and very easy to get to.

If somebody was a chronic tweaker and wanted to get into an active XO cheap and have something (pretty much) equivalent to the better crossovers out there, I'd have look at this one.

Russell Dawkins · « **Reply #4 on:** 21 Apr 2007, 04:49 pm »

Scott, is that Pyramid a mono item?

ryno · « **Reply #5 on:** 21 Apr 2007, 07:28 pm »

How about this from marchand
http://www.marchandelec.com/xm46.html
Low level passive your choice:
2-way in a case
1-way in a little box
just the boards
Only problem is it's not adjustable, you need to know the frequency you want.
Perfect if you just need a high pass to pull the bass out of your mains, then use the adjustable low pass on your subs amps.

Raw carries the reckhorn sub amp/xover, maybe you can ask him how it sounds.

I've heard that this
http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=248-664&CFID=9471248&CFTOKEN=53583693
sounds good. Never tried it though.
Ryan

scottw · « **Reply #6 on:** 21 Apr 2007, 08:45 pm »

Quote

Posted by: Rudolf
I am following a german forum discussion about the B1 http://www.hifi-forum.de/viewthread-159-2034.html. According to that the B1 doesn´t work according to specs and has quality problems (resistors with wrong values put in). I would hesitate to buy their products without the opportunity to test them with scrutiny in advance.

I've been thinking about getting the B1 to control an amp for stereo subs; and trying to read through the linked thread through an online translator. I can't seem to download the schemo that is linked on the first page of the thread (of the F1). Did you happen to download it and is there any way you could post it here?

Thanks,

Scott

konut · « **Reply #7 on:** 21 Apr 2007, 08:59 pm »

Quote from: ryno on 21 Apr 2007, 07:28 pm

How about this from marchand
http://www.marchandelec.com/xm46.html
Low level passive your choice:
2-way in a case
1-way in a little box
just the boards
Only problem is it's not adjustable, you need to know the frequency you want.
Perfect if you just need a high pass to pull the bass out of your mains, then use the adjustable low pass on your subs amps.

That is what I use. Very transparent. Only 1db insertion loss.

Scott F. · « **Reply #8 on:** 21 Apr 2007, 09:17 pm »

Quote from: Russell Dawkins on 21 Apr 2007, 04:49 pm

Scott, is that Pyramid a mono item?

Hiya Russell,

Its stereo.

Russell Dawkins · « **Reply #9 on:** 21 Apr 2007, 10:45 pm »

I never thought I would ever see anything that made Behringer look up-market!

mcgsxr · « **Reply #10 on:** 21 Apr 2007, 11:48 pm »

For pure high pass, I would likely spend my dough here, on these, but I am not sure of the insertion loss on them?

http://www.audioc.com/accessories1/misc/hipass.htm An 85Hz 6db/octave would likely make the Maggie happy, and the price is certainly good.

Dmason · « **Reply #11 on:** 22 Apr 2007, 12:09 am »

The overall gains made by relieving the tubes, transformers, and B200's of bass duty will far outweigh insertion loss I would imagine. Those are handy little beasts. I say snag a pair of the 85Hz....but first ask exactly what they are using for resistors. Then ask if they could cobble you up a pair of 150Hz

Scott F. · « **Reply #12 on:** 22 Apr 2007, 01:24 am »

Quote from: Russell Dawkins on 21 Apr 2007, 10:45 pm

I never thought I would ever see anything that made Behringer look up-market!

Like I said, if someone were willing to do some heavy tweaks to this thing, I has the potential to be a pretty darned good XO. The architecture is solid, they just cheaped out on the parts.

The great part about this one is the signal path isn't polluted with all of those add on features like time delays, muting switches, phase reversal switches, subsonic filter switches, all that stuff that finds its way into the signal path. Not to mention the variable capacitor and resistor pots which generally sound bad. This one has real caps and resistors on selector switches. Wooo Hooo!

opnly bafld · « **Reply #13 on:** 22 Apr 2007, 02:31 am »

Quote from: mcgsxr on 21 Apr 2007, 11:48 pm

For pure high pass, I would likely spend my dough here, on these, but I am not sure of the insertion loss on them?

http://www.audioc.com/accessories1/misc/hipass.htm An 85Hz 6db/octave would likely make the Maggie happy, and the price is certainly good.

If you want something like these, but 12dB/oct instead of 6 and more freq. choices look here-
http://www.partsexpress.com search under Brand Name: Harrison Lab

Lin

konut · « **Reply #14 on:** 22 Apr 2007, 03:53 am »

We discussed those in this thread.
http://www.audiocircle.com/index.php?topic=38267.msg343354;topicseen#msg343354
The ACI look to be the same.

opnly bafld · « **Reply #15 on:** 22 Apr 2007, 04:24 am »

Quote from: konut on 22 Apr 2007, 03:53 am

We discussed those in this thread.
http://www.audiocircle.com/index.php?topic=38267.msg343354;topicseen#msg343354
The ACI look to be the same.

The same except the slope and choice of frequencies, I don't know how others feel, but I would prefer the amp feeding FR OB drivers to be down more than 6dBs at 40hz. With the 100hz hp Harrison Laboratory version for example, it would be down 12dBs at 50hz and one is able to choose higher cutoffs if desired.

Lin

zobsky · « **Reply #16 on:** 22 Apr 2007, 07:46 am »

http://www.t-linespeakers.org/tech/filters/passiveHLxo.html ...simple and cheap , ..this is what those Harrison Lab inline plugs are.

mcgsxr · « **Reply #17 on:** 22 Apr 2007, 12:53 pm »

I agree, those Harrison plugs are simply a commercial implementation of a line level Xover - but, for chumps like me, keeping a soldering iron out of my hand, is the best advice anyone could give!

I briefly experimented with solder slinging a few years ago, promptly burned a finger, and figured, hmmmn, this is likely something that I should either get into, or get out of.

$30 or so does not seem outrageous, in terms of cost structure - if you built them, what do you think it would cost? I figure loosely 30-50% of that, not bad.

Rudolf · « **Reply #18 on:** 22 Apr 2007, 08:00 pm »

Quote from: scottw on 21 Apr 2007, 08:45 pm

I've been thinking about getting the B1 to control an amp for stereo subs; and trying to read through the linked thread through an online translator. I can't seem to download the schemo that is linked on the first page of the thread (of the F1). Did you happen to download it and is there any way you could post it here?

scottw · « **Reply #19 on:** 23 Apr 2007, 01:02 am »

Thanks Rudolf,

A schematic is worth a thousand words.

Scott