I was after some beginners 3 way crossover advice but I've been planning as below.
Briefly I've got Seas 27TFFC, MCA15RCY and CA22RNX drivers. I've planned a ported box using Winspeakerz of net 49 L after adjustments for internal bracing and V(b) increases due to filing, giving an F(b) of 26 Hz and F3 of 40 Hz (all theoretical). The plan was to build a test speaker with all 3 drivers, with a 1st order on the Woof/Mid and a 3rd order on the Mid/Tweet. Then rig it up to some test equipment and tweak the crossovers.
The help I needed was just getting some info on 3 way crossovers (plenty on 2 way) to get me started, found the site (I mentioned in my first post) which seemed ideal but incorrect. Thought I'd ask you guys just if you could confirm the site was in error or not which seemed to upset a few members ? I suppose if my questioning upsets some members maybe they don't have to answer ?
I'll leave it there on this subject but thanks for your help.
Briefly I've got Seas 27TFFC, MCA15RCY and CA22RNX drivers. I've planned a ported box using Winspeakerz of net 49 L after adjustments for internal bracing and V(b) increases due to filing, giving an F(b) of 26 Hz and F3 of 40 Hz (all theoretical). The plan was to build a test speaker with all 3 drivers, with a 1st order on the Woof/Mid and a 3rd order on the Mid/Tweet. Then rig it up to some test equipment and tweak the crossovers.
The help I needed was just getting some info on 3 way crossovers (plenty on 2 way) to get me started, found the site (I mentioned in my first post) which seemed ideal but incorrect. Thought I'd ask you guys just if you could confirm the site was in error or not which seemed to upset a few members ? I suppose if my questioning upsets some members maybe they don't have to answer ?
I'll leave it there on this subject but thanks for your help.
Add links:
H0881-06 27TFFC
H1262-08 MCA15RCY
H1288-08 CA22RNX
The xo is the hardest part, what's your plan, do you have schematic, is that what you are asking?
Edit: check this out, a good place to start and very reasonably priced:
http://www.madisoundspeakerstore.com/xover-design
H0881-06 27TFFC
H1262-08 MCA15RCY
H1288-08 CA22RNX
The xo is the hardest part, what's your plan, do you have schematic, is that what you are asking?
Edit: check this out, a good place to start and very reasonably priced:
http://www.madisoundspeakerstore.com/xover-design
Last edited:
Agreed, some posters/members not so kind also...
You know and might agree with me that there's a lot of small talk, not saying is the case, you can look at my first post of this thread. So no one else to criticize me much less you (with coffee or without). I addressed the question that was posted first.
In my second post I addressed the abusing by some members. It's not only a few times this happens and is needless to say but some more members get upset by it, in this thread also and they where confused with such a broad and misguiding statement of a site that everybody go's check. It's right that there are some MISTAKES, I SAID THAT.
I feel confident that the OP looked at the issue and addressed that very well.
I usually address posters questions. Is just a reminder.
As an example I can mention the "white van speakers" and the way that some people believe that they have good speakers and come here for an upgrade. It's only a matter of fair and balanced judgment...
I feel sorry for you, you have no reason to get upset it's how things are.
You stay with your cup of tea...
Sorry I guess I misread your intent and meaning in your post. It appeared to myself that you were jumping on Fradbut. Your sarcasm was lost on me, the wording only became clear after going back and re-reading your post. I apologize. I drink both coffee and tea btw
Fradbut,
I'm going to re-iterate my previous suggestion - read through that link I gave you before and familiarize yourself with FRD and ZMA files and how to manipulate them in various freeware programs, especially a passive crossover designer, the most popular of which is probably PCD right now. It will take you some time and effort but it will be worth it - it is miles above the trial and error approach you are proposing now. If you can take measurements, so much the better.
You've selected some nice drivers. Look at the speakers that giralfino has linked to above for some xo examples but understand that unless your baffle (and box volumes) are exactly the same, your xo's will need to be a little different.
Some advice: I don't think a 1st order LP will work well on that woofer. Look at the resonance spike at about 3000Hz in the graph below. You want that to be well below the combined drivers' summed output level, but with only a 6dB per octave slope that's not going to happen.
Look at the woofer's FR. It looks like the SPL at 100Hz after some baffle step loss (solid line I believe is an in-box measurement) is about 86/87dB. The peak at about 3000Hz is at about 95dB. Lets call it an 9dB difference. Now lets say you put your xo at 350Hz. Three octaves above that is 2800Hz, right about at the resonance peak. So that will be 18dB down at that point. So plus 9dB to start with minus 18dB means that it will only be 9dB down. Now you could use a notch filter to pull it down more or perhaps lower your xo point, but it's easier (and better?) to just add an extra capacitor and make it a 2nd order electrical (12dB/octave). But depending on what values you choose, the acoustic slope may end up being closer to 3rd order (18dB/octave) which would be even better.
As a comparison, Troel's has that peak down about 20dB in the 3-way Classic and it looks like more than at least 30dB in the Poor Man's Strad.
Also, the mid tends to improve in a 3-way when you ask it to do less on the bottom end - there's less intermodulation distortion. (You get less bottom end with higher order xo's or a higher xo point or both.)
That's also an interesting choice on the woofer alignment. Did you pick those Vb and Fb values for a specific design purpose?
I'm going to re-iterate my previous suggestion - read through that link I gave you before and familiarize yourself with FRD and ZMA files and how to manipulate them in various freeware programs, especially a passive crossover designer, the most popular of which is probably PCD right now. It will take you some time and effort but it will be worth it - it is miles above the trial and error approach you are proposing now. If you can take measurements, so much the better.
You've selected some nice drivers. Look at the speakers that giralfino has linked to above for some xo examples but understand that unless your baffle (and box volumes) are exactly the same, your xo's will need to be a little different.
Some advice: I don't think a 1st order LP will work well on that woofer. Look at the resonance spike at about 3000Hz in the graph below. You want that to be well below the combined drivers' summed output level, but with only a 6dB per octave slope that's not going to happen.
Look at the woofer's FR. It looks like the SPL at 100Hz after some baffle step loss (solid line I believe is an in-box measurement) is about 86/87dB. The peak at about 3000Hz is at about 95dB. Lets call it an 9dB difference. Now lets say you put your xo at 350Hz. Three octaves above that is 2800Hz, right about at the resonance peak. So that will be 18dB down at that point. So plus 9dB to start with minus 18dB means that it will only be 9dB down. Now you could use a notch filter to pull it down more or perhaps lower your xo point, but it's easier (and better?) to just add an extra capacitor and make it a 2nd order electrical (12dB/octave). But depending on what values you choose, the acoustic slope may end up being closer to 3rd order (18dB/octave) which would be even better.
As a comparison, Troel's has that peak down about 20dB in the 3-way Classic and it looks like more than at least 30dB in the Poor Man's Strad.
Also, the mid tends to improve in a 3-way when you ask it to do less on the bottom end - there's less intermodulation distortion. (You get less bottom end with higher order xo's or a higher xo point or both.)
That's also an interesting choice on the woofer alignment. Did you pick those Vb and Fb values for a specific design purpose?
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+1
See the links from Giralfino, use those designs as guidelines because Troels has already worked with those drivers.
So from Troels designs we see a 2nd order electric on woofer and mid, 3rd order on tweeter.
Definitely get a measurement mic and together with Holmimpulse you'll see what you're doing.
Guys, you've been very helpful. I had originally based my design on Troels 3 way classic but thanks giralfino, I'd missed out that he's used the same drivers in the Poor Mans Strad. I'll be looking into Troels crossovers as a starting point and adapting them to fit my box design but try out the other links and suggestions you've made. A lot to think on
Many thanks.
Many thanks.
Not when your woofer has a rising response and a +10db cone breakup at 3khz.
A first order is not sufficient, with a 1st order you'll be listening to the nasty distortions of the woofer cone breakup instead of your nice mid.
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