DIY Cheap crossover parts effect on frequency response


If anyone on these forums can help, I'd appreciate it.

I'm building my first set of speakers. I have done months of research on drivers, designing crossovers, cabinet considerations, so let's please leave that aside.

I thought I would be clever and buy much cheaper parts than what I was planning on buying with equivalent specs to confirm the theoretical changes I was seeing in VituxCAD. I made three measurements using REW and my UMIK-1:

1) No crossover

2) Proposed first order crossover

3) First order crossover with a 1.5Ohm resistor in the woofer circuit intended to bring down a 100Hz peak.

The resulting sweeps are telling me that the crossover I designed does not have an effect below 1k Hz.

(Trying to eliminate other variables) The room is poorly treated, the results are still consistent within the room. I am confident that my wiring/soldering skills have not derailed this circuit. Am I missing anything else?

Is it really just the cheapness of the parts? If I'm going to spend hundreds of dollars on parts, I want to have some amount of confidence in their effectiveness. The cheaper attempt already cost $75, and getting entry-level audio components before buying what I wanted in the first place makes me uneasy.

Thanks

ricksgiving

Just becasue you have similar valued components and Even possibly Name brand components. Not all are created equal. Just some basics, Get ONLY capacitors and inductors that are made for speakers (not just musical type systems). Then If you look at just one brand of caps, Mundorf, you will find that they will have numerous caps of the exact same value, but for different intended purposes. Thankfully there is a page that gives one mans breakdown  (his opinion) of what each capacitor of a certain value sounds like. Inductors.
https://www.mundorf.com/audio/en/info/Service/Capacitor/


 I ONLY use ribbon wound inductors.
Then You mentioned the Resistor. Those also can act differently but even more is How you are applying it. It sounds like you are trying to get past the Resonate Bass Spike which needs more than just a resistor. That resistor by itself does not create a Zobel Network. His is a page that gives very simple explanation and calculator.

Speaker Zobel / Impedance Equalization Network Circuit Calculator (diyaudioprojects.com)
And then a much more elaborate page discussing the Zobel.
Zobel network - Wikipedia

I also use ONLY Silver Solder for my connections in side of a speaker.

Thank you for your input. I guess I am having a difficult time communicating the problem in a way that is able to be solved.

Parts values determine how crossovers operate. But the quality of crossover parts affects things like dynamics, transparency, etc. Also 1st order crossovers demand very high quality, wide band drivers. Otherwise they will still have significant output beyond crossover points where they are probably breaking up badly. Higher order crossovers use more parts which, of course adds to cost, but they handle the areas where drivers, even costly ones, behave badly. That's why there are very few 1st order crossovers. At least go to 2nd order. And 4th order Linkwitz/Reilly crossovers are an even safer bet. 

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If your crossover design is defective, better parts will not fix that.

I think you need to provide a lot more detail on your overall design - drivers being used - and the crossover design to get any useful feedback.

My technical question that I should have asked before is if the circuit is not effective, how can I have the components in-line and still have the speakers produce sound? Wouldn't something short?

Is VituxCAD really that different from XSim? I found the interface of the former a lot more accessible than the latter.

I would have liked to have posted pictures, but having to link to another site is a hassle. Would a verbal description of the circuit be helpful?

Thank you both.

  • DIYaudio is a much better place for this
  • You need something like XSim crossover simulator which will better help you model your changes.
  • Part costs don't matter, but changes in equivalent DCR or ESR do!

Cheap parts shouldn’t cause your crossover to fail unless they are different values that you used in your design.

many high end speakers use embarrassingly cheap parts in their crossovers.

I’d say review your design, there is an error.

Jerry

PS  fixing errors are part of the process.  I'm not being critical.