I’m converting 2-way speakers to 3-way. The 2-way speaker contains a 10” woofer and a 1” tweeter. I have a pair of 2” dome midranges: Dayton DC50FA-8 whom I’m going to use them for the midrange drive units. The specification is on attached. I decided to start designing crossover for the midrange units first. And I have some questions as follows:
1) Which data between frequency response and impedance response will you use for finding cut-off frequencies of the drivers?
2) If I’m going to create a 4th order acoustical slope, according to the spec sheet, can I set the cut-off frequency at the resonance frequency, 370Hz, where the amplitude response is naturally down 3dB around that frequency?
3) If it is possible, should I calculate the filter component values by 20 Ohms impedance based regarding the impedance curve?
I know the above questions are weird and I agree. I’ve read there’s a ‘trick’ suggesting the way for creating a steeper acoustical slope from the lower order crossovers i.e. 4th order acoustical slope from 2nd order electrical filter slope combining with 2nd order natural roll-off of the driver. And in this case, I find the -3dB of the driver is located around its resonant frequency. So this is the cause of the questions.
1) Which data between frequency response and impedance response will you use for finding cut-off frequencies of the drivers?
2) If I’m going to create a 4th order acoustical slope, according to the spec sheet, can I set the cut-off frequency at the resonance frequency, 370Hz, where the amplitude response is naturally down 3dB around that frequency?
3) If it is possible, should I calculate the filter component values by 20 Ohms impedance based regarding the impedance curve?
I know the above questions are weird and I agree. I’ve read there’s a ‘trick’ suggesting the way for creating a steeper acoustical slope from the lower order crossovers i.e. 4th order acoustical slope from 2nd order electrical filter slope combining with 2nd order natural roll-off of the driver. And in this case, I find the -3dB of the driver is located around its resonant frequency. So this is the cause of the questions.
What is the result of doing this, please? Actually, it's not near the mid's resonance but at the exact point.
Why is it easier? The resonance will become lower or it'll shift to other frequencies?
The impedance peak tends to give you a response peak, unless you manage to work with it which is not easy without a response measurement, or to tune a resonance peak filter to level the impedance peak which is not easy without impedance measurement.
It can be done all the same.
It can be done all the same.
Do you mean the 'series notch filter'?
But, so far, I intended to avoid it because I felt it create loss through the music. In short, I removed it and got better sound to my ears.
You need to look at the harmonic level in the range in which you want to use the speaker, and preferably look at the harmonic level at the volume at which you want to use the speaker.
As a rule, the harmonic level at the resonance frequency is high, and the gain that you want to get in the steepness of the frequency response cutoff will most likely be spoiled by the high harmonic level.
I would like to note that these harmonics will be modulated with the useful signal that this speaker reproduces.
As a rule, the harmonic level at the resonance frequency is high, and the gain that you want to get in the steepness of the frequency response cutoff will most likely be spoiled by the high harmonic level.
I would like to note that these harmonics will be modulated with the useful signal that this speaker reproduces.
Setting up a three-band speaker system is quite difficult, and calculating the correct passive filter without a microphone and CAD is even more difficult.
Without measurements and filter calculations in CAD, it is better not to make a three-band speaker system, it will simply be a waste of time.
Without measurements and filter calculations in CAD, it is better not to make a three-band speaker system, it will simply be a waste of time.
As I wrote in your other, similar thread: using a 2" dome with a 10" woofer is not the best idea.
You could use a bigger cone midrage.
And while we're at it: you could even try to use a 1" tweeter with a big waveguide and setting the crossover point low enough for directivity matching.
See this project:
https://www.donhighend.de/?page_id=1461
You could use a bigger cone midrage.
And while we're at it: you could even try to use a 1" tweeter with a big waveguide and setting the crossover point low enough for directivity matching.
See this project:
https://www.donhighend.de/?page_id=1461
It is similar in appearance, it's just used for a different purpose. It still reduces the response in a small band but in this case it doesn't remove a response peak, instead it prevents one.
I feel this would be because of the change in response. This doesn't mean that using a filter would cause problems if it done correctly.
Yeah, and they're all at least 40 years old.
The world has progressed and the knowledge about good speakers with it.
But no problem if you like a modern interpretation of vintage gear.
It's just that you seem to know very little (yet) about speaker design, so I offered some hints.
Where is your hint, please?
Anyway, even vintage JBLs had used 4-5.25” cone midrange, they had their 10-12” woofers cut-off frequency at higher point than my designs (10-12” woofers with 2” mid-dome) of about 1-1.5kHz compared to mine of 400-800Hz.
For modern gear, I also see ‘PMC’ uses the 2” dome in their 3-way speakers.
Hint 1: use a bigger than 2" mid (usually a cone)
Hint 2: if you like small domes try uding the 1"tweeter with a big waveguide.
Hint 3: Even disregarding the distortion issues that normally occur with a small dome near resonance, typical dome midranges don't have the volume displacement to run very low in frequency at high output. There are some outliers that do better at it, but they are not the norm.
Theoretical output of your driver at Xmax:
Each person has their own tastes, and your fondness for the mid-dome-based ADS speakers is well known, but here's Lynn Olson's take on the subject of soft-dome midranges: "These things are dogs! I've listened to the AR-3, AR LST, ADS systems, Audax 2", and the Dynaudio D-52 soft dome midranges, and they barked, they snarled, they chewed the rug, and made a mess on any loudspeaker they approached! They measure flat, all right, but they sound opaque, fatiguing, strongly colored, and 2-dimensional.
The first problem is that soft-dome midranges have a limited bandwidth resulting from restricted linear excursion (1-2 mm typical) and do not gracefully tolerate even a 500 Hz crossover, operating best over a limited 800 Hz to 3200 Hz range.
A second problem is that they are quite prone to side-to-side rocking modes, since there is no spider combined with the surround to force the movement into a linear back-and-forth motion.
A third problem is that the doped silk dome is just, well, too soft for the job it has to do in the power band of the midrange."
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Again, this doesn't mean it won't do what you want, but it's a configuration best handled carefully and with measurements, as others have said. But there are people that prefer to just put the parts together and listen to what they do. If you have the components already, that's an approach as well, but the results are less predictable.
Theoretical output of your driver at Xmax:
Each person has their own tastes, and your fondness for the mid-dome-based ADS speakers is well known, but here's Lynn Olson's take on the subject of soft-dome midranges: "These things are dogs! I've listened to the AR-3, AR LST, ADS systems, Audax 2", and the Dynaudio D-52 soft dome midranges, and they barked, they snarled, they chewed the rug, and made a mess on any loudspeaker they approached! They measure flat, all right, but they sound opaque, fatiguing, strongly colored, and 2-dimensional.
The first problem is that soft-dome midranges have a limited bandwidth resulting from restricted linear excursion (1-2 mm typical) and do not gracefully tolerate even a 500 Hz crossover, operating best over a limited 800 Hz to 3200 Hz range.
A second problem is that they are quite prone to side-to-side rocking modes, since there is no spider combined with the surround to force the movement into a linear back-and-forth motion.
A third problem is that the doped silk dome is just, well, too soft for the job it has to do in the power band of the midrange."
-------------
Again, this doesn't mean it won't do what you want, but it's a configuration best handled carefully and with measurements, as others have said. But there are people that prefer to just put the parts together and listen to what they do. If you have the components already, that's an approach as well, but the results are less predictable.
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