I am looking at these SEAS drivers to use as my mid for a little Kitchen 3 way.
There are two types. The woofer style which has a power limit of 60rms and sealed F3 of 170hz. This says it has the symmetrical drive. The Mid one doesn't say that but I assume its the same motor. I think this is the same motor tech used in the revelator and the wavecor drivers.
https://www.madisoundspeakerstore.c...e-ca12rcy-h1152-4.5-coated-paper-cone-woofer/
Then they also have this same woofer as "mid range". Now it has an RMS of 100 and sealed F3 of 105hz
https://www.madisoundspeakerstore.c...tige-mca12rc-h1304-4.5-coated-paper-midrange/
I'm going to buy the mid range of course. Since I am using it as a dedicated mid range.
But this begs the question: "what do they do to the driver to make it a dedicated mid range"?
Anybody know?
There are two types. The woofer style which has a power limit of 60rms and sealed F3 of 170hz. This says it has the symmetrical drive. The Mid one doesn't say that but I assume its the same motor. I think this is the same motor tech used in the revelator and the wavecor drivers.
https://www.madisoundspeakerstore.c...e-ca12rcy-h1152-4.5-coated-paper-cone-woofer/
Then they also have this same woofer as "mid range". Now it has an RMS of 100 and sealed F3 of 105hz
https://www.madisoundspeakerstore.c...tige-mca12rc-h1304-4.5-coated-paper-midrange/
I'm going to buy the mid range of course. Since I am using it as a dedicated mid range.
But this begs the question: "what do they do to the driver to make it a dedicated mid range"?
Anybody know?
Supposedly because it excels at delivering the midrange frequencies, and my guess is that it has lower distortion than say, a comparable full-range. Still, those specifications are contingent on your selection of tweeter, woofer and crossover points. Based on the information above I’d pick the bottom one because 1) it has a lower F3, 2 it has higher wattage rating, and 3) is cheaper, though not by much. I prefer wide-range midranges that can go from 300 to 3k HZ, (even if I don’t use them in such a wide frequency range) but the trade off is often lower efficiency, (rms per watt) and higher distortion at the lower frequencies.
A midrange driver has relatively high efficiency, high power handling, high resonant frequency, small displacement and no low frequency extension compared to a "full range" or midwoofer driver of similar size.
If one opts for a midwoofer in a 3 way (there are a lot more midwoofers around than midranges) the relatively low efficiency would cause problems matching the woofer. A fairly common solution is to use a pair of midwoofers instead of a single midrange.
If one opts for a "fullrange" driver in a 3 way the low power handling and low efficiency would mean either using multiple drivers, perhaps 4 or so, or limiting the clean SPL of the speaker to whatever the "fullrange" can deliver.
What should I expect for increased low frequency distortion? I was planning on crossing these over around 350-450hz. I could cross them higher if I needed too.
I guess I'm not 100% on what frequencies are actually considered "mid range". Don't humans vocals start at like 100hz?
That is about where I planned to run this mid. What frequencies should I expect to cross when using a cone driver designed for "mid range duties".
Always seemed to me that the term, mid range, is kind of a grey area
I sometimes get pessimistic towards drivers that are slightly modified to give two versions for mid-bass and (supposedly) dedicated mid. The latter 'can' just mean a cut-down version (e.g. smaller magnet and shorter coil, since large excursion isn't needed), but with little or no benefit in sensitivity or distortion.
In the specific case of the drivers here, well the sensitivity is no different and the price is very similar. So i'd want to investigate distortion, which manufacturers rarely quote, to see if the midrange version really does bring the kind of advantages one would expect from a dedicated mid driver..
In the specific case of the drivers here, well the sensitivity is no different and the price is very similar. So i'd want to investigate distortion, which manufacturers rarely quote, to see if the midrange version really does bring the kind of advantages one would expect from a dedicated mid driver..
Not sure I understand the question about increased low frequency distortion. Your crossover frequency looks to be in the right ballpark for a 4-5" midrange cone driver. Might need tweaking depending on what you discover but seems a reasonable place to start.
I am most leery of two versions of a driver where one driver is higher output than the other. In this case the dedicated mid has 3 times the power handling. This, to me, kind of indicates that some loudspeaker manufacturer needed a whole bunch more power out of a unit and SEAS agreed to make it. It could very well be that it can handle 3x times the power now because it isn't designed to put out less low frequency tones. Not sure
The MCA12RC-H1304 midrange with .9mm Xmax has only .25kG magnet weight, the CA12RCY-H1152 woofer has .42kG magnet weight and 3mm Xmax.
Lighter cone, higher Fs, shorter voice coil, less inductance.
Expect ~10% second harmonic distortion at Xmax.
With only .9mm Xmax, the midrange driver would reach 10% distortion at only 86dB at 100Hz.
Some bass vocalists like J.D. Sumner could actually sing below the low E on a four string bass (41.2Hz).
I can sing down to an F2, 87.3 Hz, 1/2 step above the low E on a 6 string guitar.
Most pop lead vocals are an octave or more higher.
Usually the second harmonic is far louder than the fundamental in low range singers, though it may be equalized to fatten it up.
The difference between 60 and 110 watts is less than 3 dB.
If I recall correctly, the IEC 268-5 power ratings are based on the recommended frequency range and conducted free air, the mid-woofer would reach it's Xlim of 9mm peak to peak at 200 watts 45Hz, while the midrange only has to survive 400watt peaks above 400Hz.
If the woofer was crossed over higher, it probably would be rated for more power than the midrange driver.
Art
Don't worry about trying to grasp the hidden meaning between the lines. It's not like that 😉
I happen to notice the mid is smoother in the upper region, although this is inconclusive. Simple resonances are not a concern, and the 'polars' (3 responses shown) are not resolving enough to give a clue about breakup. I'd feel I was buying these blind until proper measurements could be taken. Of course, that's quite a common thing.
What frequencies are we talking about?
Speech frequencies typically range from 85 Hz to 255 Hz, covering the fundamental frequencies of human voices. However, for clear speech intelligibility, the most important frequencies are between 300 Hz and 3,400 Hz, which is the range commonly used in telephony
Midrange audio frequencies typically fall between 500 Hz and 2 kHz. This range is crucial because it contains the core frequencies of most instruments and vocals, making it essential for clarity in music and speech. And then there's what is defined as lower midrange and upper midrange...
Speech frequencies typically range from 85 Hz to 255 Hz, covering the fundamental frequencies of human voices. However, for clear speech intelligibility, the most important frequencies are between 300 Hz and 3,400 Hz, which is the range commonly used in telephony
Midrange audio frequencies typically fall between 500 Hz and 2 kHz. This range is crucial because it contains the core frequencies of most instruments and vocals, making it essential for clarity in music and speech. And then there's what is defined as lower midrange and upper midrange...
I feel like this is always the case in a way. Measurements never tell the whole story and everything has a tone. What one person likes another might not. So you just buy it and see if you like it I guess. Too few of us all spread out over the world to meet and listen to each other's drivers.
This was actually helpful to me. The lower and upper midrange....yeah, who knows
Seems Troels used this mid in a design.
Crossed at 700 and 2800. That seems usually high for the high pass and oddly low for the low pass. Unless I am missing some key piece of knowledge. My plan was to cross 200-250 hz lower and another 1khz higher
Crossed at 700 and 2800. That seems usually high for the high pass and oddly low for the low pass. Unless I am missing some key piece of knowledge. My plan was to cross 200-250 hz lower and another 1khz higher
These are the simple resonances I spoke about. We would plan to equalise them, so the tone shouldn't be a factor.
What I'd be concerned about is reports from those who don't manage the tone themselves, and leave it to chance. Drivers are more similar to each other than the stories seem to suggest.
Most of it is marketting to the system integrator.
We need to define our target frequency range, SPL and directivity before we can choose wisely.
For sure, if we just want to be boys with toys, by all means just buy and sample.
However, in that case we are just consumers. Buy and try, like fine wine/dine.
Sometimes I feel like the world of video and digital communications has clear standards for improvement eg. resolution, contrast ratio, mega/gigabits per second etc.
"Audiophiles are what's left after almost all of the knowledgeable music and engineering people left the audio scene back in the 1980s. Audiophiles are non-technical, non-musical kooks who imagine the darnedestly stupid things about audio equipment. Audiophiles are fun to watch; they're just as confused at how audio equipment or music really works as primitive men like cargo cults are about airplanes.
"An audiophile will waste days comparing the sound of power cords or different kinds of solder, but won't even notice that his speakers are out-of-phase. An audiophile never enjoys music; he only listens to the sound of audio equipment."
(Excerpt from Ken Rockwell, on the "What is the Audiophile"
As DIYers, we are a small market and have really little influence in terms of market to the manufacturers. But in a way that also gives us an advantage in that we are free to share, discuss and debate the pro/cons of alternatives.
For instance, one of the things I can applaud SEAS for, is their frequency and impedance response datasheets graphs and datasheets in general, which are clear, unsmoothed and contain measurement conditions. And, as I've recently discovered, they know how to do spiders properly.^
But part of the problem is that midranges are a small market in C21. So it's just easier to just shorten the voice coil and call it a day. But something that only needs to move +/-2mm really doesn't need a surround like a midwoofer.
So increasing the cone area and reducing the surround will increase sensitivity.
But this requires investment of resources. Why don't they do it. It's a question of economics...
^(topic for another day)
We need to define our target frequency range, SPL and directivity before we can choose wisely.
For sure, if we just want to be boys with toys, by all means just buy and sample.
However, in that case we are just consumers. Buy and try, like fine wine/dine.
Sometimes I feel like the world of video and digital communications has clear standards for improvement eg. resolution, contrast ratio, mega/gigabits per second etc.
"Audiophiles are what's left after almost all of the knowledgeable music and engineering people left the audio scene back in the 1980s. Audiophiles are non-technical, non-musical kooks who imagine the darnedestly stupid things about audio equipment. Audiophiles are fun to watch; they're just as confused at how audio equipment or music really works as primitive men like cargo cults are about airplanes.
"An audiophile will waste days comparing the sound of power cords or different kinds of solder, but won't even notice that his speakers are out-of-phase. An audiophile never enjoys music; he only listens to the sound of audio equipment."
(Excerpt from Ken Rockwell, on the "What is the Audiophile"
As DIYers, we are a small market and have really little influence in terms of market to the manufacturers. But in a way that also gives us an advantage in that we are free to share, discuss and debate the pro/cons of alternatives.
For instance, one of the things I can applaud SEAS for, is their frequency and impedance response datasheets graphs and datasheets in general, which are clear, unsmoothed and contain measurement conditions. And, as I've recently discovered, they know how to do spiders properly.^
But part of the problem is that midranges are a small market in C21. So it's just easier to just shorten the voice coil and call it a day. But something that only needs to move +/-2mm really doesn't need a surround like a midwoofer.
So increasing the cone area and reducing the surround will increase sensitivity.
But this requires investment of resources. Why don't they do it. It's a question of economics...
^(topic for another day)
I would agree with this. I think the one outlier I have heard so far is the planar mid range. Utterly transparent and different from any cone. An absolute nightmare to work with though.
Being in manufacturing myself, I figured this was the case.
My last build I utilized a planar mid range. Absolutely fantastic sound. Makes more sense than use a cone from an engineering point of view. Barely has to move so why use all that rubber and spider and drive magnet, etc.
I considered using a 3". One of the Peerless full range drivers. Since eim using dual 7" woofers I could cross higher and then have a bit better cross to the tweeter and better power response.
This is all for a kitchen where people will be moving from place to place so off axis response is very important. I considered a mid dome, a small 2" one or even a 3", but I want a softer tone than a mid dome could supply
I'm not quite sure how to translate this description into perceived effects.. but knowing that cone drivers are capable of proper reproduction if used properly I can only advise against jumping to conclusions.