A bit of a conundrum here, I'm designing a three-way, settled on a fifteen incher and a ceramic dome tweeter...The choices for the all important sounding mids are a three inch Tangband dome...and a six and a half inch high power, big magnet cone by Dayton.
Now, the high power of the cone is superfluous, but the surface area requiring less displacement...does it increase outright accuracy vs. a three-inch dome ? The factory supplied SPL graphing has a perfect match to the 800 hertz & 4500 hertz crossover points...I'm leaning towards the dome for accuracy. Yes the cone is going to be beaming grossly & won't match the ceramic dome tweeter. ???
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick
Now, the high power of the cone is superfluous, but the surface area requiring less displacement...does it increase outright accuracy vs. a three-inch dome ? The factory supplied SPL graphing has a perfect match to the 800 hertz & 4500 hertz crossover points...I'm leaning towards the dome for accuracy. Yes the cone is going to be beaming grossly & won't match the ceramic dome tweeter. ???
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick
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-depends on where you want the mid.s high-pass (I’m assuming the tweeter can except a lower high-pass).
Remember that with a cone mid. you likely won’t have to use baffle-step compensation on the woofer.
IF you want a low order crossover then use all 4 drivers.
Remember that with a cone mid. you likely won’t have to use baffle-step compensation on the woofer.
IF you want a low order crossover then use all 4 drivers.
I would also be taking a serious look at the volume displacement of the dome at Xmax, the desired high pass crossover frequency to it, the dome's maximum output there, and whether that's enough for what you expect from the speaker.
In the right implementation, domes just sound better…..period. But you have to consider all of your performance values like expected average SPL and as mentioned earlier, can your 15” woofer meet the high pass sweet spot of your dome?
You need a higher xover than 600 hz, even with a higher order slope if you want it to keep up with the 15. The other issue is the abrupt swing in dispersion at the 15" to mid dome handover, which can create uneven power response. The other big issue is the limited SPL capability of the mid dome if crossed too low. I wouldn't go lower than 800 - 900 hz 3rd order min if you want some hope of it keeping up.
That being said, if you get the xover right and make them combine well, a mid dome can sound better than a cone. I'm a huge fan of dome mids. I hope you're successful with the project.
That being said, if you get the xover right and make them combine well, a mid dome can sound better than a cone. I'm a huge fan of dome mids. I hope you're successful with the project.
That mid dome (if its the 3" version) looks similar to the ATC SM75-150, have low Fs and high xmax (for a midrange). For good polar match to the 15" woofer I think you can cross as low as 350-400 Hz with 4th order (24 dB/octave) acoustical slope, shallower slopes are not recommended IMO. Easy with active xo. Probably needs an impedance flattener circuit if you plan using passive xo.
ATC using its dome, even combined with two 15".
What would be the woofer?
ATC using its dome, even combined with two 15".
What would be the woofer?
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I've been looking at these domes for ages they've just come back Into stock at a lower price than previously as well . I vote for the above suggestion of using both and making it a r way . alternatively a diffraction slot over the woofer could improve its dispersion at the crossover frequency .
From a polar response POV the mid-bass/mids lines up real close at 976 Hz, so 1.0 kHz is close enough and with a 260 Hz Fs, should be fine re power handling.
Since the math only goes up to the ~1450 Hz VC dia. frequency, can't do an HF match to the tweeter.
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That is precisely why Genelec, KEF, JBL M2, the late Siegfried Linkwitz, Dutch & Dutch, Grimm and many many others invariably use dome mids.......
That Tang Band mid dome can't be compared to the ATC, which is more voltage sensitive, handles way more power and has more xmax. The biggest issue for me is the price - $180 for this newer version of Tang Band mid PE sells is really steep.
I've used both the older version of the Tang Band mid (75-1558SE) and the ATC SM75-150 (non S version) . The 75-1558SE doesn't even come close to the ATC in almost every way. The similarities end with both mids being 3" domes.
As a comparison, I used the Scan Speak D7608-9200 in a few builds and it needs to be crossed above 800 hz 3rd order to just about keep up with the capabilities of a 12" woofer. The 1558SE can be crossed a little lower at about 600hz 3rd order if you dont need 100+ dB playback levels, but even then it starts to sound strained and shouty. A decent 5" cone mid will blow it out of the water and can be crossed an octave lower.
So I'm not trying to discourage the OPs efforts in using a 3" dome mid for his project. I'm trying to keep him from wasting a fair chunk of money on drivers that won't live up to their factory published specs.
The only other currently available high output 3" dome I'm aware of, which can be crossed lower than 600 hz and keep up to a 15" LF driver, is the Volt VM752.
The size difference just seems too big. A nominal 5" would be my starting point, possibly going as high as 8" if I want something like an underhung Visaton, and then put a wavenguide on the tweeter.
Yes, the TB have lower sensitivity/efficiency but how much xmax the ATC dome have? We still don't know what 15" woofer would the OP use for the project and what max SPL have in his mind.
Al lot also depends on the directivity you're looking for.
Geddes has been using a 2-way design with a 15 inch with just a horn to great succes. (plus multi-sub)
If that is the soundstage you like, it can definitely be a solution.
Geddes has been using a 2-way design with a 15 inch with just a horn to great succes. (plus multi-sub)
If that is the soundstage you like, it can definitely be a solution.
Power response is gonna suffer no matter what with the large difference in baffle size assuming an 18” baffle minimum for a 15” woofer unless there’s some creative baffle sculpting in place…..the side and back response of even a 6-7” mid is gonna be very fwd balanced. Me?…..I’d do a side stand mounted three way with the dome mid and tweet fitted vertically along side the 15” woofer…..no THAT is a speaker I could dig!……sadly we’re all pre programmed for the up and down instead of side to side…..we missed Mr Miagi’s lesson! Lol
You're basically describing a large nearfield monitor style 3 way, but listened to and balanced for midfield.
Most of the 4 ways I build are actually 3 ways with subs underneath them and 2 x 6" - 8" midbass side by side with the mid and tweeter vertically situated above the MB drivers. I dont cross the MB high enough to start lobing, so they behave as one driver, with the benefits of a few dB sensitivity gain. You don't need a particularly sensitive mid driver for this thanks to overlapping gain of MB and HF. This makes the mid more of a filler driver depending on xover.
Most of the 4 ways I build are actually 3 ways with subs underneath them and 2 x 6" - 8" midbass side by side with the mid and tweeter vertically situated above the MB drivers. I dont cross the MB high enough to start lobing, so they behave as one driver, with the benefits of a few dB sensitivity gain. You don't need a particularly sensitive mid driver for this thanks to overlapping gain of MB and HF. This makes the mid more of a filler driver depending on xover.
I have a 15” woofer in a 3cuft sealed box along with a morel mdm55 midrange, and a morel tweeter, cross over between woofer and mid is at 750 Hz, sounds good to me
Even if the 15 was smooth to 600 box nodes might impact response. run the numbers here: http://www.mh-audio.nl/Calculators/standingwaveinbox.html crossover below the first box node.
Looking at the dome, surround and motor structure, I don't see how that is physically possible.
How close are the Volt domes to these?