Jordan JX92s and Dome Tweeter Crossover in Minipod enclosure
Hi! Can anybody recommend a schematic and or crossover points for a Jordan JX92s and a dome tweeter helper?
Thinking of using a first order crossed at around 5-8khz to allow the Jordans a wide range of frequencies to cover.
Enclosure will be a Blueroom minipod fiberglass enclosure. https://futureshapeofsound.com/
Would want to have a minimalist crossover with a single inductor for the jordans and a resistor and single cap for the tweeter if possible. If not a crossover with as few components possible is preferred.
Backstory: Got these minipod speakers for a song but the woofers and tweeters are out of spec (rubber surrounds have dimples and probably need replacing and the tweeters aren’t putting out the same level) having it repaired will cost about the same if I just pull out the drivers and replace them. Jordans became available in ebay and are a direct fit with no modifications with the minipods.
Tweeters that will fit in the enclosure are:
https://www.parts-express.com/Peerl...Radiator-XT-Tweeter-4-Ohm-264-1642?quantity=1
https://www.parts-express.com/LaVoce-TN100.70-1-Soft-Dome-Neodymium-Tweeter-8-Ohm-293-738?quantity=1
https://www.parts-express.com/Dayto...mium-Tweeter-Element-4-Ohm-275-053?quantity=1
Leaning towards the daytons.
Any help appreciated.
Thanks in advance!
EDIT: Ill be using a 2x4 minidsp to smoothen out the response and cross it to a subwoofer.
Hi! Can anybody recommend a schematic and or crossover points for a Jordan JX92s and a dome tweeter helper?
Thinking of using a first order crossed at around 5-8khz to allow the Jordans a wide range of frequencies to cover.
Enclosure will be a Blueroom minipod fiberglass enclosure. https://futureshapeofsound.com/
Would want to have a minimalist crossover with a single inductor for the jordans and a resistor and single cap for the tweeter if possible. If not a crossover with as few components possible is preferred.
Backstory: Got these minipod speakers for a song but the woofers and tweeters are out of spec (rubber surrounds have dimples and probably need replacing and the tweeters aren’t putting out the same level) having it repaired will cost about the same if I just pull out the drivers and replace them. Jordans became available in ebay and are a direct fit with no modifications with the minipods.
Tweeters that will fit in the enclosure are:
https://www.parts-express.com/Peerl...Radiator-XT-Tweeter-4-Ohm-264-1642?quantity=1
https://www.parts-express.com/LaVoce-TN100.70-1-Soft-Dome-Neodymium-Tweeter-8-Ohm-293-738?quantity=1
https://www.parts-express.com/Dayto...mium-Tweeter-Element-4-Ohm-275-053?quantity=1
Leaning towards the daytons.
Any help appreciated.
Thanks in advance!
EDIT: Ill be using a 2x4 minidsp to smoothen out the response and cross it to a subwoofer.
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Strictly at a glance and presuming the 2500 Hz usable BW is based on a 2nd order XO, then it's -24 dB @ 2500/2^2 = 625 Hz, so for 1st order it in theory requires a 625*2^4 = 10 kHz XO.
Jim Griffin had a design using the jx92 with a ribbon tweeter some years ago. You might do a search and find his crossover design.
Hi hornwannabe, I would like to make just few comments and please take them as "personal" opinions.
My experience is reduced to a pair of Jordan JXR6HD, but I think they are fairly similar to the JX92S (in gross lines).
IMHO what they need is help on the low frequency range and their high frequency output is acceptable to me without a tweeter; but you got the cabinets and a properly "crossed-over" tweeter will not hurt.
Do you have means to measure impedance and acoustic frequency response?, it will be very useful if not a need to have them.
First order/simple filters as you propose are interesting but not as easy to implement as one may initially think.
The first step is to add an impedance compensation in parallel with the drivers to make them as "resisitive" as possible over the range where you are planning to cross them, this is made with a resistor in series with a cap (usually this is enough, search the web for "impedance compensation"). Maybe the tweeter will not require it, but you will need it for the Jordan for sure.
If you want to "tune or voice" the response, you may also need to add some EQ components and measure response again (like an inductor in series with the 92s to cause a gently roll off in high frequencies, etc.).
Then you measure your drivers and chose a frequency point where both overlap nicely and flat in despite of level, which can be easily adjusted provided the tweeter is more efficient than the Jordan.
There are different opinions, but using a simple cap as high pass for the tweeter (6dB/oct.) asks at least for a crossover freq. around two octaves above its resonance freq. unless you are willing to further complicate the filters adding some "resonance trap" in parallel with the tweeter.
I hope this helps without adding confusion 😉
My experience is reduced to a pair of Jordan JXR6HD, but I think they are fairly similar to the JX92S (in gross lines).
IMHO what they need is help on the low frequency range and their high frequency output is acceptable to me without a tweeter; but you got the cabinets and a properly "crossed-over" tweeter will not hurt.
Do you have means to measure impedance and acoustic frequency response?, it will be very useful if not a need to have them.
First order/simple filters as you propose are interesting but not as easy to implement as one may initially think.
The first step is to add an impedance compensation in parallel with the drivers to make them as "resisitive" as possible over the range where you are planning to cross them, this is made with a resistor in series with a cap (usually this is enough, search the web for "impedance compensation"). Maybe the tweeter will not require it, but you will need it for the Jordan for sure.
If you want to "tune or voice" the response, you may also need to add some EQ components and measure response again (like an inductor in series with the 92s to cause a gently roll off in high frequencies, etc.).
Then you measure your drivers and chose a frequency point where both overlap nicely and flat in despite of level, which can be easily adjusted provided the tweeter is more efficient than the Jordan.
There are different opinions, but using a simple cap as high pass for the tweeter (6dB/oct.) asks at least for a crossover freq. around two octaves above its resonance freq. unless you are willing to further complicate the filters adding some "resonance trap" in parallel with the tweeter.
I hope this helps without adding confusion 😉
Attachments
Jim Griffin XO notice the JX92S LPF/BSC is quite simple (7.5" ~190mm-wide baffle, 7L). I did briefly try both 1-way and 2-way in a (very) makeshift folded TL. The Jordan alone extended flat to very HF (possibly too flat in the 2-4khz loudness region hence actually recessed). He said somewhere, he made his MLTL (same XO) a "convertible" and 2-way had much better dispersion than 1-way (of course). After a brief listen and tone-sweep I used the XO parts for other projects....
p.s. LF reached quite low in my folded TL "space-capsule" (two cabs hole-to-hole secured with a slanted divider slab through both). But sound didn't move me. Just looked at the FR chart in the pdf and indeed 2-4khz was recessed.
p.s. LF reached quite low in my folded TL "space-capsule" (two cabs hole-to-hole secured with a slanted divider slab through both). But sound didn't move me. Just looked at the FR chart in the pdf and indeed 2-4khz was recessed.
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Well, from a 'textbook' POV, if the driver was rolling off at -6 dB/10 kHz or you use an inductor to do the same, then yes, but as already noted, this assumes matching impedance's and SPL's, which it won't normally, so will require tweaking.
Yeah, this is where percussive attacks, vocals recognition, hard consonants are, so not surprised.
What you should checked first is do cabinets and drivers match. Is cabinet volume and tuning optimum for Jordans?
I think first order x-over should work well in this case. Bear in mind it gives big overlap between drivers. For that reason my choice for crossing frequency would be 5kHz.
Low enough to avoid drivers working together at very small wavelenghts, but high enough to protect the tweeter.
I think first order x-over should work well in this case. Bear in mind it gives big overlap between drivers. For that reason my choice for crossing frequency would be 5kHz.
Low enough to avoid drivers working together at very small wavelenghts, but high enough to protect the tweeter.
]Thank you! Will check this. Planning to plug the port hole to make it a sealed enclosure and crossing it over to a subwoofer.
By using a coil and crossing the woofer at 5khz, should I also cross the tweeter at 5khz or 10khz and just have the frequency overlap take care of the frequencies in between them?
Again thanks!
By using a coil and crossing the woofer at 5khz, should I also cross the tweeter at 5khz or 10khz and just have the frequency overlap take care of the frequencies in between them?
Again thanks!
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I meant to cut both at 5kHz.
But its possible to use mismatched crossing freqs to tune the response. You'll have to experiment with that if you wish.
But its possible to use mismatched crossing freqs to tune the response. You'll have to experiment with that if you wish.
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Don't forget to listen to the JX92 full range without the tweeter but with proper BSC compensation, you may find that you don't need a tweeter. You can bypass the BSC with a small cap to lift the treble response. Say 1.5 mH and 6r for the BSC and 1 uF for bypass cap as a starting point. I played around a lot trying to integrate a tweeter with my JX92s with simplistic crossovers to find I liked them best alone.
My experience is the Jordan definitely benefits from steeper crossovers. The upper range is pretty zingy to a degree that easily overcomes a first order slope.
It's been months since last working on the speakers below but from memory both are second order, the HiVi RT1C-A on the right crossed around 5 kHz and the Peerless DA25TX00 under 1500. The latter measures very well with low distortion to 95 dB, even vertical dispersion and flat response across the band. The HiVi also measures well except for the limited planar vertical dispersion and unavoidable vertical nulls from such a high crossover point, hence the cabinet flip to point the largest null into the floor. Be aware the Jordan's dispersion begins to narrow significantly between 2 and 3 kHz.
Both low and high crossovers sound good but it stalled pending a better feel for which sounds more natural. Though the Peerless is far and away the more 'Olive accurate' I'm not convinced the midrange energy is realistic.
It's been months since last working on the speakers below but from memory both are second order, the HiVi RT1C-A on the right crossed around 5 kHz and the Peerless DA25TX00 under 1500. The latter measures very well with low distortion to 95 dB, even vertical dispersion and flat response across the band. The HiVi also measures well except for the limited planar vertical dispersion and unavoidable vertical nulls from such a high crossover point, hence the cabinet flip to point the largest null into the floor. Be aware the Jordan's dispersion begins to narrow significantly between 2 and 3 kHz.
Both low and high crossovers sound good but it stalled pending a better feel for which sounds more natural. Though the Peerless is far and away the more 'Olive accurate' I'm not convinced the midrange energy is realistic.
