Some highlights on how I got hear from my starting point... Your suggestion worked to point, but I was having a hard time deciding on the enclosure, ultimately decided the super bright speakers were a bad choice for a total newb so I destroyed them to learn what I can and can't do.
Upgraded to a pair of slightly more expensive 2-way coax JBL speakers. While waiting for those to arrive I found these oem-replacement midrange speakers which actually listed most of the T/S parameters and what size sealed and ported enclosures to use (having that volume is a huge plus). Did a quick google search in store, saw that midwoofers and coax can be used together in a car, assumed it would also be fine in a home setup. These midrange speakers sound amazing (deep rich warm), the JBLs are thin on bass/lower mids but overall are much more well rounded than the other coax speakers I tried, very clear and crisp.
My childish expectation was that; since the woofers on coax speakers don't have a filter, adding another woofer the same diameter fixes the thin mids and bass without needing any additional crossover. At most Id need to run the coax open baffle to thin out the lows/mids, and the midwoofers in a ported enclosure to get a deeper bass response.
If I can't run the JBL speakers full range while using the midwoofers, there's no point using the JBL's at all. Inversely, the midrange woofers roll off at 7.5k so I can't just use tweeters off a different set of speakers, since they usually filter at 1.5-2khz... id still have the same overlapping frequency issue.
You could use tweeters such as those! Tweeters can be filtered at a higher frequency without fear of damage, but not lower.
The way to reduce the overlap in frequency between mid/woofer and tweeter is by using a more advanced crossover circuit than just a capacitor in series with the tweeter.
Attached is the simplest form of crossover network that would do the job.
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Without TS parameters you really are flying blind and any decision will be purely a guess. There is a lot of good advice above as far as general rules go but without the TS a small change can have a large affect on the freq response.
Here are 2 examples of a resp curve, one is with the midbass designed at 1 cubic feet and the other is 1.5 while both specs are "within manufacturer recommendations" there is an obvious advantage to the 1cuft design, the 1.5 cuft design has a big peak that you are going to have to try to get out with EQ or some kind of complicated notch filter.
Considering our time is valuable and building a nice enclosure can take a good bit of time, I would go to parts express and grab an overnight sensations kit. It has a good crossover network included and the drivers are decent. OR grab yourself a DATS and get some measurements but a DATS is like 130 bucks and a kit is 160 so unless you plan on building in the future the kit might be the most cost effective solution.
Regarding the open baffle aspect those can sound fantastic but a solid crossover design is critical AND the biggest issue is they need to be about 3 feet from a wall which kinda makes them hard to place in a room. In the images I included a set i built a while back and they were fantastic about 2.5 feet from wall but when i got them slide back to a position where they actually work in the room they sounded like garbage. So unless you can really place them in the correct location i would not advise that route. But GR Research on YT has a ton of information about open baffle designs, super bright guy.
Good Luck!
Here are 2 examples of a resp curve, one is with the midbass designed at 1 cubic feet and the other is 1.5 while both specs are "within manufacturer recommendations" there is an obvious advantage to the 1cuft design, the 1.5 cuft design has a big peak that you are going to have to try to get out with EQ or some kind of complicated notch filter.
Considering our time is valuable and building a nice enclosure can take a good bit of time, I would go to parts express and grab an overnight sensations kit. It has a good crossover network included and the drivers are decent. OR grab yourself a DATS and get some measurements but a DATS is like 130 bucks and a kit is 160 so unless you plan on building in the future the kit might be the most cost effective solution.
Regarding the open baffle aspect those can sound fantastic but a solid crossover design is critical AND the biggest issue is they need to be about 3 feet from a wall which kinda makes them hard to place in a room. In the images I included a set i built a while back and they were fantastic about 2.5 feet from wall but when i got them slide back to a position where they actually work in the room they sounded like garbage. So unless you can really place them in the correct location i would not advise that route. But GR Research on YT has a ton of information about open baffle designs, super bright guy.
Good Luck!
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Since starting this thread I got a pair of woofers that seem great. If I can figure out the right port and enclosure size to get res. freq to 80hz, I can incorporate my subwoofer (40hz-80hz).
According to the spec sheet F0 is 110hz in a sealed 0.32cu. ft sealed enclosure, F0 is 53hz in a 1.02cu. ft ported enclosure. They don't provide a port size, or xmax. But I believe I have the other t/s parameters. If I can figure out the right ported size enclosure combo I can incorporate my powered subwoofer (goes upto 80hz)
I could buy a pair of tweeters and crossovers for $20-$50 and be done.
The problem I need to resolve before I just buy pair of tweeters + crossovers is: I'm a stubborn dumb-a** who has a hard time letting go can't let go of a bad idea 🤔
I want to use the ported woofers but with 2way coax car speakers instead of a tweeter. Pretty much a 2.5 way? A pair 6.5" woofers in a tower looks more impressive than a 6.5" and a 1". The tweeter on the car speaker already has a high pass filter. The woofer on the coax has a resonant frequency of 115hz in open air. Why not make a rectangular enclosure so the standalone woofer is in a ported compartment and the coax have a foam back (so it's open air and soundwaves moving backwards are dampened). I'm using a splitter anyway for the subwoofer, so Id run the sub+modwoofers with one amp. The coax with the other amp turn the bass down a bit on the coax's amp... done (but not really because it sounds wrong, but I just adding a crossover between the two speaker to disable the woofer on the coax defeats turns it back into a 2 way so IDK. I have 2 weeks to figure it out or return the coax speakers)
with that much mixing you are going to have massive phase issues that you would spend way more than needed to correct with a crossover.
What is your ultimate goal for the audio setup?
Loud boomy bass or an accurate musical response?
I'm designing a 3 way myself right now for my living room and just to give you an idea of the cost, the crossover components are right at $90, and that is just the baseline, that isn't factoring that i may have to make some additional tweaks to the crossover once i start testing in the room. So just the crossover can easily go 100+.
Seems like you need to identify your goals for this project and go from there. But if it was me the only way i would use a coaxial midbass tweeter combo in a car or a house is if I had no other choice. (a few small exceptions to that, hybrid audio makes a coaxial set that has a phase plug and tweeter mount that works well)
Here is a link to Audio Judgement's Box Modeler Excel Sheet. Edit the yellow fields... dont touch the bass reflex page https://docs.google.com/spreadsheet...ouid=113514127576244839082&rtpof=true&sd=true
I like DIY, but I'm not an audiophile. I've never listened to a high-end speakers, or even one that has a crossover more complex that a single capacitor on a tweeter. The goal is the make of a usable pair of DIY Frankenstein speakers. I'm fully aware it will be crappier than what any of you have made.
I know what $70 bookshelf speakers from amazon/walmart sound like. Anything that's slightly better than those is sufficient as long as I get to design and build it (no kits). Dialogue should sound crisp and clear upto 12 feet away, it shouldn't clip, I want the resonant frequency to be 80hz or less.
So; "phase issues" smearing, comb filtering ...all the same sort of thing and why I can't use 2 woofers. Right? That's fair enough.
Appox. what crossover cutoff frequencies should I be using for each woofer 2.5way?
OR...
If I drop the coax. speaker. Just use the woofers and add tweeters (both 4ohms). Would a cheap crossovers like these be good enough?
Why not touch the bass reflex page? The woofers need a 0.32'cu. sealed 1101hz F0. OR 1'cu. ported for 53hz.
I'm shooting for an F0 of 70-80hz.,, need to build a ported enclosure (if I can figure out the port)
A crossover like this will not be optimal for your chosen drivers, but would perform the purpose of separating the frequency ranges of the mid/woofer and tweeter.
At the same time, it will attenuate the tweeter which is necessary as the tweeter is usually louder than the mid/woofer (note the white attenuating resistor which is fitted).
The big problem with this crossover is that the crossover frequency is not stated in the description - perhaps it is on the manufacturer's website.
That crossover would only be used if I keep the midwoofer. Add a separate tweeter. No coaxial car speaker at all. Boring ol' 2 way.
You could use such a crossover (of suitable crossover frequency) to combine your home mid/woofer with the car coaxial speaker.
Boring 2 way, OK you want wild. So there are two main ways you can go about crossing this. One is to try things and listen... in time, things will improve up to the limits of what can be done. Thoroughly recommended for the experience it gives.
The alternative with a 'unique' system is to take comprehensive measurements, and for that you need a plan which you don't have today.
The alternative with a 'unique' system is to take comprehensive measurements, and for that you need a plan which you don't have today.
I want to thank everyone again for all the input.
A plan would be nice, Are the crossover cutoff frequency just preference? IE If I make a 2.5 cross woofer 1 at 2000hz Low Pass, woofer 2 at 4000hz, Low Pass, Tweeter at 4000 high pass. Is that none sense or a plan? -6db passive high pass and low pass is very straightforward. 2.5way with crossover should sound cleaner than my original plan of letting both woofers full range... but what's the prevent the same issues from happening at the overlapping frequencies.
Your crossover frequency questions are all good, however if there isn't a reason for these things then all I can be sure of is that it's random.
So OK, you want a plan. I think the 2.5 way is pretty cool, I've done a few of those and they can be easy and successful. First things though, I'd start out with both woofers in regular boxes (ie closed or vented but not open).
Next I'd have to ask whether the car coaxial is at the same sensitivity as the other woofer. There's not much sense having them backing each other up in the bass if one is loud while the other is quiet.
Thirdly, since your car speaker is likely to be 4 ohms and the other 8 ohms, you'll have less than 3 ohms, possibly dropping closer to two. Will your amp be ok with this?
So OK, you want a plan. I think the 2.5 way is pretty cool, I've done a few of those and they can be easy and successful. First things though, I'd start out with both woofers in regular boxes (ie closed or vented but not open).
Next I'd have to ask whether the car coaxial is at the same sensitivity as the other woofer. There's not much sense having them backing each other up in the bass if one is loud while the other is quiet.
Thirdly, since your car speaker is likely to be 4 ohms and the other 8 ohms, you'll have less than 3 ohms, possibly dropping closer to two. Will your amp be ok with this?
The don't touch is the bass reflex alignments page, its the tables page, its the page that has all the calculation tables in it. Use whichever design you would like. I personally prefer ported so using bass reflex is probably best imo.
As far as multiple drivers, of course you can hell some line arrays have 40 drivers in them or more, you just have to account for the phase issues and correct them in the design stages.
Link doesn't work.
here is a setup you could use that I have crossovers designed for already... You would still be DIYing it and I don't mind sharing my design at all. The crossover components are about 52 bucks, the drivers are about 130ish so out the door you would be 180 and have a setup that is better than anything you could buy retail. If you want i can share the details and the freq response charts and all. Sometime this week im going to design a little cheaper setup, the goal is under $100. Working on the video slowly as I get time for my YT channel.
Here is a response curve for a 2.5 way that I am designing, you can see the crossover points in this for a 2.5 way. This still needs work, I have some peaks to sort out, but the crossover points are pretty close.
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I really like this, thank you.
If you don't mind bearing with me picking your brain a little longer..
Did you design this crossover then buy the parts or did you get here through trial and error?
-If it's trial and error how are you testing? (ie are you soldering/unsoldering parts, afaik there is too much power for an adjustable bread board but too many small parts for alligator clips ).
And your specific design:
what is that middle C2 and C5 doing?
what is R1 doing?
Well, I don't have an anechoic chamber to test real world. So I design in XSIM order the components and assemble them. Then test far-field measurements in the room with REW and use Equalizer APO to adjust any room issues...If a big issue happened I would modify the crossover with trial and error but that has not happened yet to me.
C2 and C5 prevent the midbass from playing too low. I wired 2 150uf in series because a 300 is more expensive than 2 150s
r1 is a resistor and brings the tweeter amplitude down a little bit
C2 and C5 prevent the midbass from playing too low. I wired 2 150uf in series because a 300 is more expensive than 2 150s
r1 is a resistor and brings the tweeter amplitude down a little bit
Ok makes sense, This is a practical and simple enough to create something similar.
Using 2 different pairs of woofers is going to give me trouble regardless right? (even if it's not a car speaker)
are you going to try to have them play the same frequency range or a 2.5 type setup where 1 driver just reinforces the lower end frequency?
The one pair of woofers has a rich bassy sound to it, the other is bright and crisp. Theirs no working plan other than to figure out where dialogue sounds clearest and music still has rich bass to to.
Ie 2k and 4k as a starting point.
If I'm ordering inductors and caps from parts express, I can forgo the car woofers and get the cheap 6.5" hone theatre woofers.
attached is shopping list for the setup, ignore the subwoofers. They are for my upcoming tower build. But im doing this exact setup for my living room... as a 2.5 way but you can omit the sub stage.
