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So there I am with noise coming from my speakers. I did use those 1875's I had lying around. (a tube full I picked up for R20). How can you not take it? The brand, BoomTech, didn't sound promising. But at less than 50c a chip. Why not give it a go? Each channel's 2 way active crossovers with...

Well I finally got some nice Seas Drivers for a workshop active crossover build. The Drivers were originally from a pair of Musical fidelity MF40s. Thank you Facebook marketplace. If anyone is interested in a single MF40 case, let me know The midbass drivers are Seas P17RC4Y H 509...

Ok, so DACMan1 convinced me to do simulation of the difference based active crossovers.  The result : A flat response curve, but a rate of 6dB/Octave for the calculated channel, even if the filtered one is 12 or 24 dB/Octave. The continuous phase correcting nature of the difference channel...

New, probably only be made after the 3ways, but putting out there to get some feedback. Does it have what you'd want? This one features individual filters as opposed to the Sallen key topology.

After a number of requests I decided to look into a simple +12V to +5V and -5V regulated supply board, to power the active crossover filter board. The active crossover board does not use much power, so a simple voltage ladder should be good enough. Designing this board with this specific purpose...

I am putting together a design based on the prior 2 way active crossover design. This one is designed to support a sub-woofer, while still aiming for a flat total system response. The target audience is those with 2 way systems speaker including 1 or more subwoofers. Here is the current design...

I had this project going for a while and have sold some crossovers. Here is a new revision for comments. Now using new PCB services and SMD parts. The input and outputs are now via RCA plugs. Adjustable crossover frequency. A new low price for this initial run of 10, R120 per active crossover...

Hi there guys. I finally made my active cross over into an open source product. The design chosen ensures a flat total system response, reduced distortion at the cross over frequency, and minimizes the requirement for high tolerance parts. Please have a look and tell me what you think. Good or...

Hi Guys. I am experimenting with a brand new topology. I?ve never seen anything like it, perhaps someone out the may have seen something similar and provide some feedback or ideas. The basic idea is that the power stages of an amplifier are, ideally, mostly linear, and mostly with a...

Lots of cheap transformers out there, catch is that they are all 11.5VAC 50W. String 6 together and you get a center tapped +/- 34VAC, 300W transformer. (remembering to double check phase) A lot of people are replacing 50W halogen units with LEDs and throwing the old 50W transformers away. I...

Has anyone seen anything like this before? An idea I am toying with. http://s15.postimg.org/qiwvg01xn/Screenshot_from_2015_09_07_13_38_00.png If you can actively monitor the current through each stage, you can actively control the DC bias. Perhaps it would be even better if a DC servo...

Has anyone tried one of these? http://www.mi.com/en/miheadphones/  They supposedly have 50 mm 2um berilium drivers. Xiaomi have a reputation for exceptional bang for buck.

The 2 kids are now able to reach the tweeter. Time for a grill. (Click links for larger pictures) [img=http://s8.postimg.org/9gqxjsidt/DSC07718.jpg] Notice the magnet in place. They are flush on the grill. Remember to check the polarity, also, I drilled the magnet holes through the...

Hi guys. In case a project needs massive amounts of glue... My favorite low cost provider occasionally stocks Black Mamba wood glue. Looks like alcolin, Ive used it on odds and ends and it seems to work well. 500ml under R30.

Has anyone had any experiences with combined negative voltage and positive current feedback amplification? Here's the basic design : active crossover, normal voltage feedback amplifier directly connected to driver. A current sense element on the return from the load sends a small amount of...

Anyone tried a standard switchmode supply for audio, perhaps with a 1000uF or so on the output? They're very affordable, I think in part because of the reduced shipping weight, and you don't need massive caps on the outputs. Here is an example...

Has anyone tried one of these L20 designs that's all over ebay and dhgate? Specs Quoted as Power 200W (8R) 350W (4R) Voltage: DC + - 65V THD = 0.009% 1K HZ 50W 8R SR = 35V / US Noise 92DBU That's pretty good for a assembled PCB for R320 / mono. (and half of that is shipping) If you take 10...

I am thinking of experimenting with a motion feedback active subwoofer. The basic idea is you use one coil to drive the speaker and the other to sence the position of the driver. You will get some cross coupling, but you will also get some motion data on the emf of the sence coil. Here is a...

Having ordered a commercial speaker kit from Madison i was struck be the obvious and not so obvious mistakes made in the placement of their crossover inductors. The obvious being that inductors should be placed far apart and at 90 degrees to reduce cross coupling. The not so obvious being...

Here in JHB we have 14% less air mass. Does anyone factor this in? Are our simulations all out? I guess the reflex port should be 14% longer but the box? And how does this lower air mass affect the resonant peak of the driver? Thoughts? Murray.