infinia said:
Hi,valleyman said:
Yes, that's why I suggested the Vifa P13. It has a good response right up to 5k and will be tolerant of some crossover mistakes. In the correct size box, it will roll off nicely at the bottom, even without a high-pass.
Yes, I hope N10 does come back. It's always a shame when the local bullies gang up on the new guy.
Hi
As long as you got Unibox running try these,
What about 75 liters 29 Hz? I think that would be the best compromise.
What freq. does the vifa run out of steam (full range) using closed box Q=0.6
edit>F-3 doesn't look all that great but equals 100 liter design at -8 dB or so i.e shallow slope between EBS and closed box. As I mentioned before Group Delay is key here.
Nice to know the limits for the Vifa mid to wisely pick Xover freq.
As long as you got Unibox running try these,
What about 75 liters 29 Hz? I think that would be the best compromise.
What freq. does the vifa run out of steam (full range) using closed box Q=0.6
edit>F-3 doesn't look all that great but equals 100 liter design at -8 dB or so i.e shallow slope between EBS and closed box. As I mentioned before Group Delay is key here.
Nice to know the limits for the Vifa mid to wisely pick Xover freq.
infinia said:
I did a sample calculation for a second order Bessel low-pass for this woofer using the dreaded calculator.
At 300Hz, plotted impedance is 9.5ohms from Parts Express. No Zobel needed as the frequency is low enough to be below the big rise.
32uF cap and a 8.8mH coil. A low DCR iron core inductor would be fine here.
Hi Infinia,
Still good, but I like the 70 litre at the higher tuning > gives a lower F3 and higher port resonance.
Attachments
infinia said:
No, the calculator uses the impedance at the corner frequency. Re will not give a usable result. Do you have the Le of the woofer?
I considered matching the lower crossover frequency with the baffle step - 300Hz, therefore the higher efficiency of the woofer (92db) would work well with the efficiency of the mid (88db) to give 4db of baffle step compensation without a correction circuit or adding another woofer. Often 4db will be enough.
Higher efficiency of the tweeter could be padded down to match.
infinia said:
I think we are talking about different things. I have done the illustration below to show what I'm talking about.
The woofer has a sensitivity of 92db or 4db greater than the midrange. This extra "loudness" is the baffle step compensation.
The 2nd order Bessel is the low-pass filter for the woofer. The corner frequency for this is 300Hz or about the same as the baffle step calculated for a 15" wide baffle.
Attachments
the Vifa Mid is not available
So we could use Tang Band W5-704D 5-1/4" Woofer
same specs
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-850&ctab=2#Tabs
use in
Fb 9 liter closed chamber
f-3 120 Hz
Fres 85 Hz
Q=0.57
So we could use Tang Band W5-704D 5-1/4" Woofer
same specs
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-850&ctab=2#Tabs
use in
Fb 9 liter closed chamber
f-3 120 Hz
Fres 85 Hz
Q=0.57
Attachments
MJL21193 said:
Mmmm lets see then on Super Tuesday!
I'd don't know the tang bang looks pretty sweet, half the price, and has ext response.
PM me if you have a Xover between the woofer and mid. Use real inductors and caps ( ie standard values with Rdc)
Don't forget the mid LF rolloff and baffle step. I'll put it in SPICE to check you.
Attachments
Slightly OT…
Also being a beginner in speaker design, one of the best resources I’ve found on the web is the Visaton site. Full technical/construction details of dozens of professionally designed speaker systems to study here:
http://www.visaton.com/en/bauvorschlaege/2_wege/index.html
http://www.visaton.com/en/bauvorschlaege/2_wege/index.html
http://www.visaton.com/en/bauvorschlaege/mehrwege/index.html
Cheers,
Glen
Also being a beginner in speaker design, one of the best resources I’ve found on the web is the Visaton site. Full technical/construction details of dozens of professionally designed speaker systems to study here:
http://www.visaton.com/en/bauvorschlaege/2_wege/index.html
http://www.visaton.com/en/bauvorschlaege/2_wege/index.html
http://www.visaton.com/en/bauvorschlaege/mehrwege/index.html
Cheers,
Glen
Alrighty guys....you haven't scared me off yet!
Sorry it took me a while to post today, but I'm very much here and I do need to catch up on all the forum chatter here on this post before I get down to business again.
To help you guys, I'll explain my stance on the build I first proposed (now with the edits from MJL21193 for mid, tweeter etc..)
I would very much like to see the design come to fruition, so for the sake of directing further posts, If we could end the suggesting of established designs and boxes, it'd be good.
I did look at those designs and some others I found via the internet however none was very appealing to me.
I have no problem either using a stock crossover or a custom built one, if it's custom (and it very likely will be) then I've got more reading to do then what this forum can offer and it'll take some time, and I'll for sure ask here before I go and start buying the parts for that. However, that won't prevent me from ordering speakers or starting to build the cabinets....that I can do without all the nitty gritty wiring.
I appreciate everyones answers and suggestions, but I do want to focus on this design and get it off the ground --- even if it doesn't sound as good as it could be. First builds never are as good as the evolution of builds years later. The wright brothers flew a few hundred feet at first. Does that mean they didn't fly at all? It's the same here. It's producing decent sound isn't it? If it's not matching the spec graph, or the optimal output, does that mean it's a terrible speaker?
I'm fully aware how uneducated I am in the world of speakers, but I was the same way with computers when I built mine. Now I could tell you all the parts and what they do and for what reason. I hope to someday be able to do that with speakers.
Anyways, I'm going to read over these posts and figure out the direction we'll go from here. But unless someone has an extremely glaring problem with the suggested parts so far, I'll probably start purchasing them within the next few weeks as funds allow...
N10
Sorry it took me a while to post today, but I'm very much here and I do need to catch up on all the forum chatter here on this post before I get down to business again.
To help you guys, I'll explain my stance on the build I first proposed (now with the edits from MJL21193 for mid, tweeter etc..)
I would very much like to see the design come to fruition, so for the sake of directing further posts, If we could end the suggesting of established designs and boxes, it'd be good.
I did look at those designs and some others I found via the internet however none was very appealing to me.
I have no problem either using a stock crossover or a custom built one, if it's custom (and it very likely will be) then I've got more reading to do then what this forum can offer and it'll take some time, and I'll for sure ask here before I go and start buying the parts for that. However, that won't prevent me from ordering speakers or starting to build the cabinets....that I can do without all the nitty gritty wiring.
I appreciate everyones answers and suggestions, but I do want to focus on this design and get it off the ground --- even if it doesn't sound as good as it could be. First builds never are as good as the evolution of builds years later. The wright brothers flew a few hundred feet at first. Does that mean they didn't fly at all? It's the same here. It's producing decent sound isn't it? If it's not matching the spec graph, or the optimal output, does that mean it's a terrible speaker?
I'm fully aware how uneducated I am in the world of speakers, but I was the same way with computers when I built mine. Now I could tell you all the parts and what they do and for what reason. I hope to someday be able to do that with speakers.
Anyways, I'm going to read over these posts and figure out the direction we'll go from here. But unless someone has an extremely glaring problem with the suggested parts so far, I'll probably start purchasing them within the next few weeks as funds allow...
N10
Hi N10
Here is an idea for a cabinet and what the crossover could look like.
http://www.troelsgravesen.dk/PMS.htm
Here is an idea for a cabinet and what the crossover could look like.
http://www.troelsgravesen.dk/PMS.htm
I have been wondering what Pauls "Eathers" would sound like with a 12 inch woofer, and if you can get Vifa P-13's may be an option, you get to design your own speakers but why not take insoiration where you can.
http://undefinition.googlepages.com/diy-aethers
Regards
Ted
PS these are on my short list using a quad of 10 inch woofers front and back firing
http://undefinition.googlepages.com/diy-aethers
Regards
Ted
PS these are on my short list using a quad of 10 inch woofers front and back firing
3 way
N10,
As you have decided to do it the harder way just a few points one does not often find in more popular books.
1. put woofer in a separated enclosure; consequently
2. midrange will have its own enclosure. That gives you much greater flexibility for further choices. The box may be trapezoid with slanted back cover (second best to the spherical). Make that cover removable so you will be able to compare sealed versus sort of open baffle. Of coures separate box makes accoustic alignment of accoustic centres easier;
3. with passive xo do the calculation for operational temperature of voice coils;
4. Sealed enclosures should not be perfectly sealed. One of the reasons is that variation in air pressure will be forcing the piston away from the central position. It does not matter much for long throw woofers but pure midrange drivers are more affected.
Remember to design boxes in such a way that compression and expansion are as identical as possible for the same sine wave test. You will find that in better books. Plus a lot of other things you have to discover so happy reading.
cheers,
N10,
As you have decided to do it the harder way just a few points one does not often find in more popular books.
1. put woofer in a separated enclosure; consequently
2. midrange will have its own enclosure. That gives you much greater flexibility for further choices. The box may be trapezoid with slanted back cover (second best to the spherical). Make that cover removable so you will be able to compare sealed versus sort of open baffle. Of coures separate box makes accoustic alignment of accoustic centres easier;
3. with passive xo do the calculation for operational temperature of voice coils;
4. Sealed enclosures should not be perfectly sealed. One of the reasons is that variation in air pressure will be forcing the piston away from the central position. It does not matter much for long throw woofers but pure midrange drivers are more affected.
Remember to design boxes in such a way that compression and expansion are as identical as possible for the same sine wave test. You will find that in better books. Plus a lot of other things you have to discover so happy reading.
cheers,
Crossovers Active vs. Passive
Alright, no comments further on the drivers, I guess now I'm ready to ask about these crossovers.
Active vs. Passive, and from what I've read, active seems to be the better, albeit more expensive choice.
I read up from this website here .
Active crossovers, they seem to be....simpler to build? Looking at the diagrams, I did get that feeling, but correct me if I am wrong.
How much more expensive are active crossovers than passive ones to construct?
Alright, no comments further on the drivers, I guess now I'm ready to ask about these crossovers.
Active vs. Passive, and from what I've read, active seems to be the better, albeit more expensive choice.
I read up from this website here .
Active crossovers, they seem to be....simpler to build? Looking at the diagrams, I did get that feeling, but correct me if I am wrong.
How much more expensive are active crossovers than passive ones to construct?
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