New Member, site to buy components?

Get to know these two online speaker builder's sources:  https://www.madisound.com/ and https://www.partsexpress.com/

For your first build, which can be a successful learning experience, I'd suggest using some of the lower-priced drivers you'll find on those sites.  Look through the buy-outs and closeouts, or other specials.  Also, look at high efficiency midbass drivers so that you can get a good system up with that available power.  Even some of the lower end Goldwood speakers at PartsExpress might fit the bill in that department.  And the Dayton brand is of higher quality than the price implies.

For the crossovers, look at PartsExpress'  Dayton brand for a good quality at less-than-audiophile pricing.  Dayton polypropylene capacitors, Jansen 18 or 20 gauge coils, and audio-grade resistors from either source can be had for reasonable pricing.  Wiring the crossover together:  I learned that using the pre-made crossover boards were more pain than pleasure, and now make them to fit MY plan...not a pre-arranged layout.  Use some high quality primary hookup wire to link the components of the crossover...I use 16 ga. silver plated teflon coated primary wire from https://www.hndme.com/storeteflonwire.html for crossover construction, and regular 16 ga.primary hookup wire for the runs to the drivers.

Here are some speaker design programs you may not have found yet:

https://www.pvconsultants.com/audio/frdgroup.htm  Of these, I use SPL Trace to copy the manufacturer's response graphs, which then are imported to the design programs.  Unibox helps you design the enclosure for the woofers.  Speaker Workshop will enable you to design the complete crossover.  These programs will share common files, so you can move results of one to another.  This is an appproach that is quite accurate and will allow you to build a network without having all of the equipment the pros use.  See https://www.rjbaudio.com/Audiofiles/FRDtools.html

And some very handy online calculators:

• https://www.mhsoft.nl/spk_calc.asp#top
• https://www.1728.com/pythgorn.htm
• https://www.troester.org/ls/lpad.html
• https://www.easysurf.cc/cnver7.htm#inmil3
• https://ourworld.compuserve.com/homepages/Bill_Bowden/r2.htm
• https://www.carstereo.com/help2/Articles.cfm?id=31

Good luck at OU.  I grew up not too far from there on the WV side of the river, and my son is graduating from that other Ohio school in Columbus this year.  He's a designer (industrial), so I foresee some collaboration with him on some things in the future.  I wish I had the foresight to get into something like you are doing at that time of my life.  Gold mining just didn't pan out  ;)

I'd suggest this one instead, as it is a 4 ohm driver designed for auto use.  Use one 4 ohm woofer with one 4 ohm tweeter on each side for your car's front soundstage for stereo sound.  The crossover will control the impedance when you have it designed properly.  The drivers connected via crossover are not in parallel, they are controlled by the crossover.  Use the impedance for each driver that you want as the final network impedance, e.g. 4 ohm for car, 8 ohm for home....and variations thereof.

The response graphs for all of the Dayton drivers are given, so they are easy to work with using those programs I told you about.

Take your time learning...take your time designing...build your system...listen and enjoy.  You will know the answer to that question after listening to yours and to other's systems.  Vague?  Sure.  The answer could go either way.  You will know right away that the actual components you are working with are superior to the ones in the premade crossover, but you don't know as of yet how to put them all together the best way.  You can still ruin the sound even if your crossover is worth 20 times more than the premade one...if you do something wrong.

You have to start somewhere if this is to become one of your hobbies/ passions.  This sounds like a good time!

I'm sure Steve will add his input, but my opinion is you can approach system design from any angle you want.  If you want to try a specific woofer or tweeter, then you build everything around that.  If you want to try a different crossover topology (like Bessel VS Linkwitz VS a series crossover) then you can design that first and choose drivers to fit.  Or, you can start with a desired system outcome, like "I want to be able to play undistorted at reference levels (110db) with a 50-watt per channel amplifier," then choose speakers that will achieve this and design the crossover to match them up.

My usually approach is to start with a specific speaker I want to try, whether it is a woofer or a tweeter... and once in a while I'll have both in mind and devise a system to make them work together.    I just finished a home theater subwoofer system for a friend that was designed to meet a specific system performance goal, and I'm now working on a center channel for a client that uses a specific speaker to match his existing stereo main set.

Speaker system designing and building is an additive (and can be very expensive) hobby, but it's also one that can be turned into a profession if you are good at it.

DYohn got me addicted to it!    

It would be beneficial to become familiar enough with those software programs (if you are thinking of trying that route) so that you can input some different woofer/tweeter combinations to see how they will work together.  Of course, that can take a lot of time as there's plenty of work to do just getting one set of drivers up and running to the point you can start experimenting with different things.  My approach has been (so far) to somehow find myself in possession of the drivers and then do my damnest to make them work together!  Not the best way to approach it, but I've had fun with it.  Actually, sort of like that...where I look at the parameters of drivers I want to match together and look at their published test responses (and the most important thing: price!), and make a judgement of whether I should try to use them together or not.  But I just do this type of thing for my own enjoyment and the learning experience, sort of like you are planning to do on this project.

The drivers freq ranges have to cross over each other at points where both drivers can easily accept the power at that level and are responding the way they should.  You'll find a lot of tweeter with an Fs of about 1,800 Hz and some others lower at 900 to 1000 Hz.  You'll probably note that the lower Fs models cost a little more than some of the others.  These are usually better in two-way systems because you can cross over at 3,500 Hz and be at over 1.5 octaves above the resonance freq.  You'll know by doing this that you can try a variety of different crossover topologies and the tweeter will likely not be in danger of receiving too much power at Fs.  Using a tweeter with a higher Fs would force you into a higher crossover point, and that is where you look at the woofer response at one octave above the target xover and see if it is still responding smoothly.

The woofer we looked at above would work with a lot of tweeters and will also give you good midbass that will cross well with the subwoofer.  You'll find tons of good information in those sources (much of it within the programs themselves e.g. Speaker Workshop), and if you have some free time between finals and all those things, look through this forum for posts from DYohn on driver selection.  But give yourself as much time as you can to absorb all the concepts.  With your EE studies, you'll be past my knowledge level in no time!  Stick with the forum...er, I see you've done that...but participate from time to time.  I'll be asking you questions before too long.

I've got the p17wj-00-08.jpg as the midbass in my 3-way main speakers at home, which crosses over to a subwoofer at 80 Hz.  The tonal quality is wonderful.  It's an 8 ohm driver (should be the last double-digit designation) but you should be able to incorporate it into the car system.  Perhaps not, though, with your power availablity.  I'm not sure what the difference is in models WJ and WG.  It cost me $44 each from PartsExpress, I remember that. 

https://editweb.iglou.com/eminence/eminence/pages/params02/params.htm is a good source of info and history on speaker parameter data.

In the Vifa designation system, "G" stands for a 1" voice coil and "J" stands for a 1-1/4" voice coil.  "W" means woofer.

https://www.d-s-t.com/link/main/tech/codes2.htm

I've used both the Vifa PL17 and the Peerless (they are made in the same factory by the way) and they sound excellent.  The Peerless CSCX will handle a lot more power.

The way to know if you can cross at 2600 Hz is to find a tweeter that will handle that.  Look for one with an Fs of 1000Hz or lower.  Then you will need to attenuate the tweeter to match the sensitivity of the woofer.  The Peerless is listed as 90db/2.83 volts/meter, but since it is a 4-ohm speaker that is equivalent to 87db per watt/meter.  If you choose a tweeter with, say, 91db/watt/meter, then you will have to pad it down to the woofer's 87db.  Follow?  Also, I recommend a high-pass on the midbass @ 80Hz, which can be the active filter on the amplifier.

saturnsubohio wrote:

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so basically because the tweeter is producing max sound @ Fs you want to keep it higher than that to prevent damage to the actual driver?

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No, a speaker does not produce "max sound" at Fs.  It is at resonance at Fs, the point where the frequency exactly balances the mechanical components of the motor system.  The impedance goes to max and the output goes down and can become erratic.  You can damage a tweeter and many mids by operating at or below Fs since almost all the energy will go into heat build-up in the voice coil and none (or very little) of it goes into producing sound.

Woofers are harder to damage at Fs, and indeed I used to work for a company that designed subwoofers to operate below Fs intentionally.

I don't think he will answer that question.  But I will say that it was impressive.

BTW, some more good resources on speaker design can be found here: https://forum.carstereos.org/showthread.php?t=54763  and in my above sticky thread on advanced front speakers.

haemphyst wrote:

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Capacitors, YES, absolutely! Inductors, not quite so much, but there are things you will still want to keep in mind when choosing either component...

Caps are better chosen if you stick with poly types - either styrene or ethylene types, or something equally fast. "The Purple Caps", or "The Yellow Caps" is what we call them (colloquially) in my audio circle. Solen makes the best ones IMO. Electrolytics of any sort should NEVER be used in any audio circuit AFAIAC. They are good for AC ripple filtering, and nothing else... Quality caps WILL make a difference in the quality of your crossover, and they are more stable at temperature, and do not suffer value drift over time.

Resistors should all be carbon-pile, or NON wire-wound types. Those types of resistors will add absolutely minimal inductance to the circuit, and your other component values can be more accurate in their function, once implemented...

Inductors. Well, MOST IMPORTANTLY, avoid iron-core. Those will be smaller, but they are not linear in their response curves, and their distortions are unacceptable to me. Choose inductors with the LARGEST wire you can find, to avoid excess DCR in your circuit. I like copper foil inductors as well... larger, but VERY linear in their response, and lower distortion levels. Parts Express sells Jantzen caps and coils, a decent brand name. Look up the name in their search function.

Your topology will also make a difference. If you have two inductors close to one another (less than, say 3 to 4 inches), make certain they are NOT on the same physical plane. Make certain that you align them on the X Y and Z planes. This will prevent hysteresis interaction between them. Some people will tell you it won't make a difference, but it does.

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Here's a couple more suggestions for you.  $40 is a hard price point to stay below...

Peerless 6.5" Autosound woofer, Vifa 6.5" Autosound woofer

The Adire Extremis is readily available in the 8-ohm version, with a 4-ohm car audio version soon to hit the streets.  But I suspect the mounting depth will be too great for this application (at almost 4".) 

saturnsubohio wrote:

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Those Peerless look solid too, hmm those coupled with those Morel Tweets, looks like a good choice.   also these will now be powered by a Kicker KX200.2 amp which does 50x 2 @ 4ohms and 100x2 @ 2ohms
any thoughts?

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Go for it.

Those components values should be fine for your low-pass filter, although I would recommend a higher guage for the inductor (like 14 or at least 16 AWG.)  For the high-pass portion, you'll want a 5.9uF cap and a 0.75mH inductor, and since you're looking at second order don't forget to reverse the electrical polarity of the tweeter.

-edit- when choosing component values, you are generally OK within +/-10% of theoretical.

I haven't followed this entire thread and don't know what all you've accomplished here, but I could add a couple comments.  The sensitivity you described above...is that correct?  The woofer is higher sensitivity than the tweeter?

And have you taken a look at Speaker Workshop?  It would help you put the crossover together with more clarity of the result.

DYohn was kind enough to give me much the same advice he gave you in crossover construction.  Some of what you learn though is going to be through working it up with the ability to make changes later.  Here's three examples of crossovers I've built through the learning process:

On the above, I tried to conform to premade PCB boards.  I found it difficult and confusing, and this shows that I didn't grasp the concept of coil alignments.  The pre-printed layout of circles for the coils added to my confusion.  Two of these coils have to be stood on end at 90 degree angles.

With suggestions made by DYohn, I started to get the concept of using other materials for the board.  This made the process much easier as I could put the crossover network together as it looked in the Speaker Workshop schematic.  You see here that I still didn't understand coil layout and it was pointed out that I had two coils together in the same plane.  For this layout, I used his recommendation of high grade 16 ga. silver-coated connecting wire.  I found it to be wonderful for soldering.

By the time I built this one i had enough experience and foresight to put it together without the sleepless nights.  For this, I used the fiberboard you see on the back of clipboards, cut to size.  Used hot glue to secure the components.  I used the Speaker Workshop schematic and re-drew it onto a paper the size of the actual board.  Then I just copied what I drew onto the real board.

There will always be the availability of tweaking your crossover, so don't worry so much that it is perfect from the get-go.  Sometimes you just can't know, such as decibel loudness difference between the mid and tweeter.  You have to be able to allow yourself to make some changes.  Already, after listening to the speakers that this last crossover and its twin is in, I will be trying out a different pair of resistors for the tweeter.  The db drop will be barely 1 db, but I will try higher grade resistors as well.  That's a very subtle change in the overall sound but it's a privilege you are afforded when you are building your own passives

With what you described above insofar as relative sensitivity of the drivers, there is no need to put in padding on the tweeter as it is already less sensitive than the mid.  If you haven't purchased the tweeters yet, consider using a 6 or 4 ohm version, or match the mid in that regard.  Your final impedance of the crossover should be no lower than 4 to 6 ohms for quality car audio output from your amplifier.  It doesn't  make sense to use quality components and build it yourself only to run your amplifier at its dirtiest output.

saturnsubohio wrote:

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the sensitivity is exactly 2dB @ 1W/m apart.

91 Woofer/89 Tweet respecitively.

im going to have to add a "pad" on the tweeter to reduce it to a 4ohm Req. it is an 8 ohm tweeter i want to have a 2 ohm load @ the amp for 100 W.

Anything wrong with this? i couldnt think that there was except finding a decent sized resistor? or does that not even matter?

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First the impedance.  No, you are not correct.  You do NOT want to try and change the impedance of any of your speakers.  Your chosen tweeter is an 8 ohms unit.  Your amplifier will be loaded by the woofer @ 4 ohms below the crossover frequency and by the tweeter @ 8 ohms above the crossover frequency.  This is how a crossover works, the speakers are not in parallel.  Do not suffer from the typical car audio misconception about seeking maximum power.  Ignore it.  You will be fine.  This is normal.

The purpose of a pad in a crossover is to match the sensitivity of the speakers.  The speakers you've chosen should work really well together without need for any pad.  The Peerless woofer is rated @ 91db, but this is at 2.83 volts into its 4-ohm impedance.  To convert that into a standard 1W/1m rating, subtract 3db so the actual rating is 88db.  The tweet you've chosen is 89db @ 1W/1m.  These ratings in effect match.

Good info from Steve above, and thanks for posting your pictures!

OK, actually the speakers ARE electrically in parallel, it's just the only time both are receiving a signal is in the crossover transition band.  As frequency rises, the woofer signal is being attenuated and the tweeter signal is increasing (in your case at 12db/octave) so the net impedance placed on the amp will never drop to what the two speakers would net in parallel.  Does that make sense?

2.83 volts = 1 watt @ 8-ohms.  2.83V = 2W @ 4-ohms.  The sensitivity difference between 1W and 2W = 3db.

DYohn] wrote:

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OK, actually the speakers ARE electrically in parallel, it's just the only time both are receiving a signal is in the crossover transition band. As frequency rises, the woofer signal is being attenuated and the tweeter signal is increasing (in your case at 12db/octave) so the net impedance placed on the amp will never drop to what the two speakers would net in parallel. Does that make sense?

2.83 volts = 1 watt @ 8-ohms. 2.83V = 2W @ 4-ohms. The sensitivity difference between 1W and 2W = 3db.

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You meant to say "coil" for that second formula, but speaking for myself, there are things in audio that I will gladly let stay above my head where they belong.  Those formulae are two of them. 

This chart from Rod Eliott's site may be of some help:

Use the crossover freq and the crossover orders that you have selected along with this chart to find percentage of power to each driver.  You may be starting to worry a bit too much about the varying impedance load...just my impression.   But then, that is an area my brain was not meant to get into.

That's correct.  That's why a tweeter isn't getting 100 watts at 4000 Hz.  It'll probably never get more than 10 watts of power.  The more that the frequency spectrum relies on the tweeter to produce the primary sound, the more power goes to the woofer and the less to the tweeter.  That's where the "robbing" of power due to the coils etc. come into play because of their impedance ( I think...heh heh).

er, at least I mean to say that the chart is correct.  Use it to see that at 2400 Hz the power is NOT split 50/50.

edit to add:  IIRC, this chart was used so that you can have some help in determining power values of resistors used at the various frequencies.  This showed that in most cases a 5 watt resistor is fine for the tweeter, if I remember Rod's words correctly.  https://sound.westhost.com/lr-passive.htm#7.0

Again, don't concern yourself with power utilization.  As long as your woofer and all the crossover components are rated to handle the power output from your amplifier, you are OK.  As far as the tweeter is concerned, like Steve mentioned most tweeters never see more than 8-12 watts no matter what because of the frequencies they reproduce.  There is NO point in your system where "amplifier power is shared 50/50" by the two speakers.  It will never happen, nor do you want it to happen (as you would blow your tweeter.)

Power utilization as a function of frequency is what Rob's chart that Steve posted illustrated.  If you look at that chart, 80% of the amplifier's power goes into reproducing frequencies below 2KHz.  Also, don't worry about Rob Elliot being down on inductors.  While what he says is true, he tends to exaggerate the importance of some things to reinforce his own personal biases (in this case, his bias towards preferring active filters VS passive crossovers.)

The component values I listed are standard textbook values for a Butterworth 2nd order filter @ 2400Hz into an 8-ohm tweeter.

The network you posted includes Zobel circuits for the speakers, which you will not need to concern yourself with.  It is also a crossover for two 8-ohm speakers: you are using one 8-ohm and one 4-ohm.