Hope it is OK to ask this here in "Full Range" since to the best of my knowledge, the "WAW Institutional Knowledge" lives here in "Full Range"
I'm interested in setting up a WAW-type of arrangement in my Jeep - using Fountek FR59EXE 2" fullrange drivers in small sealed pods, facing the listener, on top of the dashbord and 6" KW-1 Morels down in the "knee-facing" location [I know that the knee facing location is far from ideal, but it's what I have to work with, which is why I'd like to extend the smaller drivers, above, as low in XO, as I safely can)
Fountek FR59EXE - 2.5" Full-range
I want to use __passive 6 dB series-configured__ crossovers and will be running 45WPC, Class D.
I am "set" on using passive series-configured XO-s -- I have enough going on in other parts of this project that I don't want to get into line level crossovers and extra amplification channels.
My goal here is sound quality and not max dB though I would like to be able to not have to curtail enthusiasm in turning it up, within reason (I don't need way loud, been there, done that with a Hafler 500 in my teens, trying to generally preserve the hearing that I have left).
The back of the FR59EXE are marked "15w" though some other data shows "10w" power handling. I assume that is in somewhere near full-range frequency spectrum.
My question is "how low can I go" in __crossover frequency__ at 45WPC, with the 6 dB series crossovers, at sane but satisfying listening levels, without being at high risk of either thermal damage or over-excursion damage to the FR59EXE 2" drivers?
I expect that my answer lies somewhere in the power distribution within music at the various frequencies, and partly in the fact that even a 6 dB crossover is actually starting to throttle off power throughput to the HF driver _above_ the nominal XO frequency, but I am not grokking it all fully-enough to really get where that gets me in the "how low can I go" answer for XO Hz.
Thanks very much in advance!
I'm interested in setting up a WAW-type of arrangement in my Jeep - using Fountek FR59EXE 2" fullrange drivers in small sealed pods, facing the listener, on top of the dashbord and 6" KW-1 Morels down in the "knee-facing" location [I know that the knee facing location is far from ideal, but it's what I have to work with, which is why I'd like to extend the smaller drivers, above, as low in XO, as I safely can)
Fountek FR59EXE - 2.5" Full-range
I want to use __passive 6 dB series-configured__ crossovers and will be running 45WPC, Class D.
I am "set" on using passive series-configured XO-s -- I have enough going on in other parts of this project that I don't want to get into line level crossovers and extra amplification channels.
My goal here is sound quality and not max dB though I would like to be able to not have to curtail enthusiasm in turning it up, within reason (I don't need way loud, been there, done that with a Hafler 500 in my teens, trying to generally preserve the hearing that I have left).
The back of the FR59EXE are marked "15w" though some other data shows "10w" power handling. I assume that is in somewhere near full-range frequency spectrum.
My question is "how low can I go" in __crossover frequency__ at 45WPC, with the 6 dB series crossovers, at sane but satisfying listening levels, without being at high risk of either thermal damage or over-excursion damage to the FR59EXE 2" drivers?
I expect that my answer lies somewhere in the power distribution within music at the various frequencies, and partly in the fact that even a 6 dB crossover is actually starting to throttle off power throughput to the HF driver _above_ the nominal XO frequency, but I am not grokking it all fully-enough to really get where that gets me in the "how low can I go" answer for XO Hz.
Thanks very much in advance!
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Hos low depends on how loud you need to play and how big your sealed box is.
A 0.15 litre butterworth sealed box will have an F3 of about 275Hz. One can then use the 2nd order sealed roll-off and use it with a second order on the woofer.
Adding more orders — 1st order would take it to 3rd order — will allow greater volume. Use with a complimentary HP on the woofer.
A passive xo will be difficult as you are trying to XO that low you are dealing with the system resonance, There is a whole class of sealed alignments with a series cap, so that may be useful info. Typically used on speakers that are trying to go octaves lower, this is much higher, and 4Ω means much smaller caps which means you can avoif bi-polars. A PLLXO should work well here.
dave
A 0.15 litre butterworth sealed box will have an F3 of about 275Hz. One can then use the 2nd order sealed roll-off and use it with a second order on the woofer.
Adding more orders — 1st order would take it to 3rd order — will allow greater volume. Use with a complimentary HP on the woofer.
A passive xo will be difficult as you are trying to XO that low you are dealing with the system resonance, There is a whole class of sealed alignments with a series cap, so that may be useful info. Typically used on speakers that are trying to go octaves lower, this is much higher, and 4Ω means much smaller caps which means you can avoif bi-polars. A PLLXO should work well here.
dave
Well the easy answer is twice the free air resonance at a minimum [ 300Hz] but much safer to go at least a half octave higher, so around 400/500Hz.
But that is an educated guess; nothing more and personally I'd not be using a single cap in series but using some sort of second order configuration and certainly not crossing any lower that 400 even so
But that is an educated guess; nothing more and personally I'd not be using a single cap in series but using some sort of second order configuration and certainly not crossing any lower that 400 even so
Thanks Dave, and thanks Moondog
The pods that I am interested in using are quite small, not sure exact internal volume, but they are the same ones shown here:
FR59EXE as a wideband in my 2015 F150 | DiyMobileAudio.com Car Stereo Forum
I realize that I may end up running the 2" more in a "moderately low reaching mid-tweeter" rather than than true wideband. Still would like that to be as close to fullrange as possible. I like the character of series 6db crossovers although I suppose their benefits as to phase are kind of moot in my currently planned location where the widebands and the woofers are a distance from each other and firing in different directions.
I don't have the pods yet.
I was originally planning on running the Founteks in the flat up-facing spot that the crummy OEM 2.75 paper tweeters are located, on flat adapters, open backs into the upper dash cavity, and crossing the Founteks fairly high - but have now got to thinking about using the pods to face direct at listener and crossing the Founteks at the lowest feasible frequency.
I have done another project with the FR59EXEs in some small nearfield monitors with small Dayton PRs and they sound stunning, and put out not only surprising SQ but also surprising amplitude for such tiny speakers.
'small wonder' fullrange mini monitor (beginner's luck)
I stocked up on a bunch of FR59EXEs to play with when Madisound had them on substantial discount at something like $10 each a year or two ago. Fountek now seems to be gone, at least in the USA, and the main Fountek website seems defunct.
The pods that I am interested in using are quite small, not sure exact internal volume, but they are the same ones shown here:
FR59EXE as a wideband in my 2015 F150 | DiyMobileAudio.com Car Stereo Forum
I realize that I may end up running the 2" more in a "moderately low reaching mid-tweeter" rather than than true wideband. Still would like that to be as close to fullrange as possible. I like the character of series 6db crossovers although I suppose their benefits as to phase are kind of moot in my currently planned location where the widebands and the woofers are a distance from each other and firing in different directions.
I don't have the pods yet.
I was originally planning on running the Founteks in the flat up-facing spot that the crummy OEM 2.75 paper tweeters are located, on flat adapters, open backs into the upper dash cavity, and crossing the Founteks fairly high - but have now got to thinking about using the pods to face direct at listener and crossing the Founteks at the lowest feasible frequency.
I have done another project with the FR59EXEs in some small nearfield monitors with small Dayton PRs and they sound stunning, and put out not only surprising SQ but also surprising amplitude for such tiny speakers.
'small wonder' fullrange mini monitor (beginner's luck)
I stocked up on a bunch of FR59EXEs to play with when Madisound had them on substantial discount at something like $10 each a year or two ago. Fountek now seems to be gone, at least in the USA, and the main Fountek website seems defunct.
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Lower impedance-smaller coil, bigger cap.
Why the resonance peak makes a simple cap HP so hard to tune.
Pick a frequency where the peak voltage of your amp will not drive it past xmax.
And go steep enough to protect it.
Why the resonance peak makes a simple cap HP so hard to tune.
Pick a frequency where the peak voltage of your amp will not drive it past xmax.
And go steep enough to protect it.
On a 2.5in I wouldn’t go lower than 500-600Hz. That helps keep the cone movement low to reduce distortion. Even on a 3.5in I go down to 900Hz with a first order - so more like 450Hz with 2nd order.
a 2.5" driver with a 6 dB crossover slope is a bad idea. You'd have to cross it high enough that you loose one of the main benefits of WAW: the ability to cross low such that dispersion matching or wavelength interference isn't a problem.
I suggest you bump to a second order 12 dB crossover, then you can get away with 600-800 hz with that driver.
I suggest you bump to a second order 12 dB crossover, then you can get away with 600-800 hz with that driver.
Hi kd1yt, I’m going to be doing a similar install in my wife’s car but with the SB65 2.5” wideband drivers. I am very happy with the quality of the ValiCar aluminium pods.
Is there any way you could cross over actively? I’ve chosen this route & gone with a minidsp Harmony amp/dsp combo, although I’m not looking forward to getting my tiny brain around setting it up but it does have lots of flexibility with xover slopes etc etc.
Is there any way you could cross over actively? I’ve chosen this route & gone with a minidsp Harmony amp/dsp combo, although I’m not looking forward to getting my tiny brain around setting it up but it does have lots of flexibility with xover slopes etc etc.
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Thank you all VERY much- I got sidelined with work and helping family and so am only now having a chance to respond to all of the great input.
I'd been stubbornly resistant to active crossovers and extra amplification channels, but you all (to my surprise, compared to when I'd asked) have helped me realize that the only way to let my widebands really operate wideband in this application will be if I _do_ use an active crossover.
I just ordered a new-old-stock Audio Control 2XS active crossover that can be configured for either 18 or 24db slopes, and at user-selectable crossover points, using swappable self-make-able DIP resistor networks, so I'll be able to try both different frequencies and different slopes. Yes, I know that someone is already asking "why not DSP?" - I can only stand being dragged into modernity gradually....
I'd been stubbornly resistant to active crossovers and extra amplification channels, but you all (to my surprise, compared to when I'd asked) have helped me realize that the only way to let my widebands really operate wideband in this application will be if I _do_ use an active crossover.
I just ordered a new-old-stock Audio Control 2XS active crossover that can be configured for either 18 or 24db slopes, and at user-selectable crossover points, using swappable self-make-able DIP resistor networks, so I'll be able to try both different frequencies and different slopes. Yes, I know that someone is already asking "why not DSP?" - I can only stand being dragged into modernity gradually....