3 way crossover design questions
I've been thinking of making a 3 way speaker using Dayton Audio Reference Series Drivers. I've never made a 3 way before!
Bass - 8" 8 ohm 90db/2.83v (Dayton Audio RS225p-8a)
Midrange - 6" (4" cone) 4 ohm 90db/2.83v (Dayton Audio RS150p-4a)
Tweeter - not sure yet, likely a 3/4" dome for good off axis dispersion
RS225p-8a datasheet
https://daytonaudio.com/images/reso...rs225p-8a-reference-series-specifications.pdf
RS150p-4an datasheet
https://daytonaudio.com/images/reso...rs150p-4a-reference-series-specifications.pdf
I intend to use the 8" woofer up to 300hz, the 6" woofer (with 4" cone) from 300hz to 2400hz, and tweeter 2400-20000hz.
If you look at the 8" woofer's datasheet, you'll see its response is ruler flat between 90 and 700hz, and its rolloff is very shallow.
If you look at the 6" woofer (with 4" cone), you'll see its response is ruler flat between 120 and 2400hz and is well behaved between 2400 and 4800hz. By well behaved I mean it's very flat up to 30 degrees off axis.
The reason I've chosen these drivers is I've had some good experience recently with the RS150p-4a. I used them to fix up some in wall speakers at my parents. I have them crossed over lower than I intend to cross mine at (2nd order at 1700hz), but I have a feeling they'll do fine crossed a bit higher.
As I said, I've never designed a 3 way before. I'm looking for some help choosing and possibly designing the crossover - I was thinking of a simple 2nd order bandpass, possibly 2nd order woofer to mid and 3rd order mid-tweeter, but I don't know. With these drivers, what would be best?
The woofer is ruler flat 1.33 octaves above crossover and is only down 1db ~1.6 octaves above crossover. The midrange is ruler flat 1.75 octaves past the low crossover point and flat 1 octave above the high crossover point. Is it suitable for 2nd order? I want very good off axis response
I've been thinking of making a 3 way speaker using Dayton Audio Reference Series Drivers. I've never made a 3 way before!
Bass - 8" 8 ohm 90db/2.83v (Dayton Audio RS225p-8a)
Midrange - 6" (4" cone) 4 ohm 90db/2.83v (Dayton Audio RS150p-4a)
Tweeter - not sure yet, likely a 3/4" dome for good off axis dispersion
RS225p-8a datasheet
https://daytonaudio.com/images/reso...rs225p-8a-reference-series-specifications.pdf
RS150p-4an datasheet
https://daytonaudio.com/images/reso...rs150p-4a-reference-series-specifications.pdf
I intend to use the 8" woofer up to 300hz, the 6" woofer (with 4" cone) from 300hz to 2400hz, and tweeter 2400-20000hz.
If you look at the 8" woofer's datasheet, you'll see its response is ruler flat between 90 and 700hz, and its rolloff is very shallow.
If you look at the 6" woofer (with 4" cone), you'll see its response is ruler flat between 120 and 2400hz and is well behaved between 2400 and 4800hz. By well behaved I mean it's very flat up to 30 degrees off axis.
The reason I've chosen these drivers is I've had some good experience recently with the RS150p-4a. I used them to fix up some in wall speakers at my parents. I have them crossed over lower than I intend to cross mine at (2nd order at 1700hz), but I have a feeling they'll do fine crossed a bit higher.
As I said, I've never designed a 3 way before. I'm looking for some help choosing and possibly designing the crossover - I was thinking of a simple 2nd order bandpass, possibly 2nd order woofer to mid and 3rd order mid-tweeter, but I don't know. With these drivers, what would be best?
The woofer is ruler flat 1.33 octaves above crossover and is only down 1db ~1.6 octaves above crossover. The midrange is ruler flat 1.75 octaves past the low crossover point and flat 1 octave above the high crossover point. Is it suitable for 2nd order? I want very good off axis response
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Two things:
- designing a loudspeaker system like this requires measurement gear and skills;
- a 1” tweeter might be a better match for the RS150. Even a shallow waveguide like the SEAS H1499 could be fine. That way the transition between mid and high will be better.
- designing a loudspeaker system like this requires measurement gear and skills;
- a 1” tweeter might be a better match for the RS150. Even a shallow waveguide like the SEAS H1499 could be fine. That way the transition between mid and high will be better.
Why do you say a 1" dome would be better to cross to the RS150P? I don't think I'd need to lower the crossover point. The RS150P is probably not even down 3db 80 degrees off axis at 2400hz - its cone is like 3.875". I did say I want great dispersion, but I consider flat up to 60 degrees off axis good enough, and I'd like to get 10khz up to 45 degrees off axis. I think a good 3/4" dome should be capable of enough SPL paired with the RS225p/RS150p in a 3 way design, no?
I chose the lower frequency drivers to simplify design: they had to have the same sensitivity and a flat frequency response in their passbands and for octave or two past crossover points. And an almost omnidirectional dispersion of all frequencies up to at least planned crossover points. Are you saying this was for nothing?
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I used to wonder that too but as the Le sums so does the impedance and there is no HF rolloff. I could have sworn you taught me that, many moons ago. 🙂
I also won't use a 3/4 tweeter, it's just to much push and pull with a 5 inch mid.
Although a good exception will be the SB19ST-C000-4
Otherwise take a good 4 inch mid, like the RS125 for example.
For filter advice, just simulate the whole thing in VituixCAD (or Boxsim) to get a feel for what it can do.
What orders etc to use, totally depends on a lot of things.
Although a good exception will be the SB19ST-C000-4
Otherwise take a good 4 inch mid, like the RS125 for example.
For filter advice, just simulate the whole thing in VituixCAD (or Boxsim) to get a feel for what it can do.
What orders etc to use, totally depends on a lot of things.
All that does is make the needed filter more simple looking. (The end result is the proper rollof regardless of what you started with)
On the other hand what matters is that the problem area, ie breakup, isn't just straightened but is also taken down with the rolloff.
Yes.
Yes.
The cone and surround of the rs150p is less than 4 inches, I measured. Look at the datasheet I linked to, you'll see it's performance. I also picked it (and the 4 ohm version of it) to exactly match the sensitivity of the 8 ohm woofer. The 125s aren't quite efficient enough
Edit: I saw that tweeter, am considering it. SB has a few decent 3/4" domes - that one looks best for dispersion, and the price is good too
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I'll be installing VituixCAD and trying out different crossovers. Will post results of a couple options
I guess what I'm getting at is will 2nd order attenuate the drivers enough within the 1-1.6 octaves they are well behaved past the crossover points?
Easy to do yourself. Check the 6dB xo cut off for mH ratings according to impedance. I am on the iPad so not so easy for an old guy like me to give a link. Google is your friend Mike.
I admit that my time learning such stuff is with tube amps and the higher the output impedance, the quicker the HF roll off, which HR shows when adding the resistance as [Rg], so have historically stated that series wiring yields the same, but don't believe I've ever done an all series hookup nor had it questioned and unable to properly compare in HR unless I'm missing something, so look forward to one of the EEs chiming in.
No, but it does sim a faster HF roll-off in a 0.7 Qtc sealed cab, supporting my HF roll-off, so now my 'burning' Q is why didn't it in an IB???
It use to be unbelievably helpful, but a massive change to severely limit the number of returns combined with totally unrelated sale ads + making all my old links either of no real use or flat out NLA, etc., makes it more frustrating than useful to me and searching
in various configurations yielded nothing of use.
If the speakers are identical, then if you apply a voltage across both in series, then the voltage across each one must be half of that, no matter what the frequency. So frequency response is not affected by the series connection, despite the total inductance doubling.
Google's trying to keep everyone stupid lol. Seems to me that from 2004 it's just been downhill. You used to be able to search forums, it was a tab in advanced, like "Images".
Unfortunately in its horrible state it's still the best search engine around 🙁
I swear the internet wayback machine (archive.org) has been sabotaged too