enter image description here This is the schematic for 2-way crossover, the speakers I want to use are:

I wanted to use resistors in high-pass side of crossover to attenuate speaker by the value of 10dB. I chose my crossover frequency on 2.6kHz. With this bunch of information could you tell me if this schematic is correct and I can start to design a board?

  • \$\begingroup\$ Note that woofers larger than 10", especially 15" and 18" woofers, tend to have a muddy bass sound, as opposed to the tight bass an 8" or 10" can put out. Professional recording studios often use many speakers with 8" or 10" woofers to keep a very tight bass sound, such as the kick-drum. \$\endgroup\$ – user105652 Sep 18 '18 at 21:23
  • \$\begingroup\$ Sadly, I have to take 15” as I have a housing that was designed for 15”. Or maybe it is some way to put 10” into the hole for 15” (i dont know how to call it, adaptor?). But I think about if the design for 15” gonna be good for sound from 10”. \$\endgroup\$ – Radosław Majchrzak Sep 18 '18 at 21:41
  • \$\begingroup\$ I am going to skip this one. Sorry Radoslaw but everything seems to be a miss-match. Way over sized woofer with a single tweeter. No mid-range speaker. Series resistors for the tweeter? Inductors 1,000 times too small. Same for woofer capacitors. Can you show us your equations that got you these values? \$\endgroup\$ – user105652 Sep 19 '18 at 0:24
  • \$\begingroup\$ Unfortunately, I have housing to which I have to fit it. It has place for one 1” tweeter and 15” woofer, no place for mid speaker. I got my equations from this site: v-cap.com/speaker-crossover-calculator.php \$\endgroup\$ – Radosław Majchrzak Sep 19 '18 at 6:20

Many years ago (in my days as an EE student) I also messed with speakers and crossover filters. I remember using inductors with values measured in milli Henries, not micro Henries as is the case with yours.

So I think your inductors are at least a factor 1000 too small in value. Look at some typical crossover filter designs, for example this one. Note how all inductors have values of around a couple of milli Henry.

Will it work with a more sane crossover filter: very likely yes.

Will it sound any good: that depends on your standards. If you have low standards it will sound good. If you have high standards: don't waste your money on trying to build your own speakers. Buy some used speakers instead. Good speakers have been around for many many years. Decent speakers can be had for little money.

If you insist on building your own, then be prepared to experiment. Or get a pre-designed kit, that way you can be more sure the speakers will be a better match and the crossover filter will be tweaked for that combination of speakers.

  • \$\begingroup\$ Oh, thanks, I did it too quick, and type uH instead of mH, made an edit. And I my aim is to build my own speaker still, I wanted to do it for too much time to now give it up. \$\endgroup\$ – Radosław Majchrzak Sep 18 '18 at 20:29
  • \$\begingroup\$ Yeah I second this advice. I went through exactly this process in college. The speakers sounded great, except there must have been some gap in the crossover frequencies or something because there was always something slightly "wrong" with the sound. I never could fix it. \$\endgroup\$ – Drew Sep 18 '18 at 20:38
  • \$\begingroup\$ I want to have mine as a college project, that’s why it’s important to me. Gonna check out subOP links tommorow to know what to do. \$\endgroup\$ – Radosław Majchrzak Sep 18 '18 at 20:54
  • \$\begingroup\$ You could learn a lot using this article from Wireless World: keith-snook.info/wireless-world-magazine/Wireless-World-1979/… Speaker design with passive filtering is timeless. Of course if you modernize then you'd do it with op-amp filters and separate drivers. \$\endgroup\$ – Jack Creasey Sep 19 '18 at 4:13

The question is really a bit too broad to be capable of a direct answer. Things like choice of crossover frequency make and break speaker designs. You can do a paper/simulated design and think everything is good, but how it will sound is a whole other story.

The point here is that there is much more to it than designing an electric filter which (theoretically!) gives you flat frequency response. The crossover is a weak point in a speaker, because of the various odd phase and directionality anomalies that happen around the crossover point. Unfortunately our hearing tends to be most sensitive to these effects in the 1-4kHz range which is where xovers tend to want to be. (This is because we are evolved to hear speech, and most speech information is in this band.) You are slap bang in the middle of this.Some designers try to choose drive units to try to avoid this sensitive area.

Basically, to get really good results, you are looking at a lot of listening/measurement tests once you build the first prototype. These will tell you if you are somewhere close to correct.

In fact there are very good arguments that suggest that passive crossovers are a very sub-optimal solution anyway. Logically this makes sense : how did we end up trying to do subtle frequency tweaking at high power levels, and deliver the power to a very complex, low-ish impedance load? It doesn't make sense, from a system design perspective. Mostly its just done this way because it always has been. If you really want to tr to build a superior system - power amps are cheap, so consider powering each driver independently, and splitting frequencies at line level. You have far more options in terms of filter types, adjustment, and so on.

  • \$\begingroup\$ Thought about this 5 minutes ago, I went here and voila! Gonna figure it out. \$\endgroup\$ – Radosław Majchrzak Sep 18 '18 at 21:20
  • \$\begingroup\$ Linn did exactly that - a friend had a system with 6 power amps each driving a single speaker, I think they called it “active”, but I played a couple of my favourite records on it : so sad cos after that they never sounded so good, the sound on that system was just superb... \$\endgroup\$ – Solar Mike Sep 18 '18 at 22:25
  • \$\begingroup\$ This is called bi- (or tri-) amplification. A DSP chip can work wonders in terms of processing the line-level signals, pre-correcting phase and amplitude anomalies in the drivers -- and the enclosure, for that matter. If you're ambitious enough, you can design a system that "tunes" itself to the room as well \$\endgroup\$ – Dave Tweed Sep 19 '18 at 0:15

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