Drivers:
Vifa 18TC49-08 Woofer
Vifa D25AG-05-06 Tweeter
Just a few quick questions before I begin a shortlist...
I want to build a 2nd Order Crossover, but what is the best type for these type of drivers? Linkwitz-Riley, Butterworth, Bessel, Chebychev?
I am looking at a crossover frequency of 3kHz, as the woofer has a peak +2dB from 1kHz to 3kHz.
Looking at the response for each driver, is a Notch filter necessary? (I'm inclined to say yes to the woofer and no to the tweeter)
I am using formulas from this website. Specifically.
Box...
My current speaker that I am replacing the tweeter (upgrading), is a floorstander, however has a separation piece inside the cabinet. The upper enclosure (where the drivers are at), is 47 litres. By removing most of the wood by cutting, will I improve the bass low-end - effectively making it 94litre? (Not that I want to do it!)
-Final thoughts-
I am going to add a Zobel network, and Attenuator resistors. The drivers will be positioned woofer over tweeter, on a 25mm baffle.
Much appreciated if you can shine your knowledge on this newbie
(and fill the blanks too)
Thanks. Mike
Vifa 18TC49-08 Woofer
Vifa D25AG-05-06 Tweeter
Just a few quick questions before I begin a shortlist...
I want to build a 2nd Order Crossover, but what is the best type for these type of drivers? Linkwitz-Riley, Butterworth, Bessel, Chebychev?
I am looking at a crossover frequency of 3kHz, as the woofer has a peak +2dB from 1kHz to 3kHz.
Looking at the response for each driver, is a Notch filter necessary? (I'm inclined to say yes to the woofer and no to the tweeter)
I am using formulas from this website. Specifically.
Box...
My current speaker that I am replacing the tweeter (upgrading), is a floorstander, however has a separation piece inside the cabinet. The upper enclosure (where the drivers are at), is 47 litres. By removing most of the wood by cutting, will I improve the bass low-end - effectively making it 94litre? (Not that I want to do it!)
-Final thoughts-
I am going to add a Zobel network, and Attenuator resistors. The drivers will be positioned woofer over tweeter, on a 25mm baffle.
Much appreciated if you can shine your knowledge on this newbie
(and fill the blanks too) Thanks. Mike
I've done a bit of reading and researching and found a project with the same tweeter and a similar woofer, using a 4th order Linkwitz-riley xover - http://www.gti.net/wallin/audio/vifabook/vifabook.html.
Just finished a crossover diagram with an attenuator section, zobel network and contour network.
Any feedback before I order this gear (in a few days) would be appreciated.
Attached the crossover diagram. Fc = 3kHz.
Just finished a crossover diagram with an attenuator section, zobel network and contour network.
Any feedback before I order this gear (in a few days) would be appreciated.
Attached the crossover diagram. Fc = 3kHz.
Attachments
octopus said:
Octopus,
Be very careful about using crossovers for "similar" woofers and presumabley cabinets and expecting great results. I have attached a frequency response plot for a TC18SG49-08 I measured on my baffle. So here I have a slightly different baffle, and a slightly different woofer and use the crossover network you posted. As you can see it's got quite a peak in the 1500Hz range.
I'm not saying you won't get good results, but be prepared to tweek the crossover to your final liking.
Scott
Attachments
I went ahead and did a lot of hard work (okay, so I pushed the "optimize" button and drank coffee) and did a curve fit to a true LR response. I'm not saying to use these values either, but you can look at the differences between the two schematics to see what range of component values to expect.
Attachments
Thank you Scott, its good to get some feedback for my first crossover...
I mentioned that I followed a design of another speaker with not exact the same drivers. I did not in anyway take any of the design of that crossover, but just based mine on its type - 4th order Linkwitz-Riley.
I used a spreadsheet program, Passive Crossover Design Calculator to get my last xover design. I have also downloaded WinISD, and Crossover Simulator, but since I don't have the FRD files (and no sound testing software), I can't use them very much.
Your crossover design looks somewhat similar to mine - many of the values close to 10% within range...
As you mention I should experiment, and getting more crossover components doesn't hurt (well its only money!) so I can 'experiment' by changing values and doing it by ear.
As you mention the baffle step - what size baffle was this? My current cabinets have curved edges so I expect this to reduce it.
I mentioned that I followed a design of another speaker with not exact the same drivers. I did not in anyway take any of the design of that crossover, but just based mine on its type - 4th order Linkwitz-Riley.
I used a spreadsheet program, Passive Crossover Design Calculator to get my last xover design. I have also downloaded WinISD, and Crossover Simulator, but since I don't have the FRD files (and no sound testing software), I can't use them very much.
Your crossover design looks somewhat similar to mine - many of the values close to 10% within range...
As you mention I should experiment, and getting more crossover components doesn't hurt (well its only money!) so I can 'experiment' by changing values and doing it by ear.
As you mention the baffle step - what size baffle was this? My current cabinets have curved edges so I expect this to reduce it.
Bricolo said:
I don't know, for the amount of time and money it has saved me, and the power it has it's reasonably priced. The version I have new costs around $500 U.S. I didn't pay quite that much because I was a very early adopter of the program and took advantage of initial offerings for savings. There is a demo I think, but it is limited in various ways.
Scott
octopus said:
My baffle is 9" wide. Curved edges will *not* do that much to reduce baffle step, they will only reduce diffraction related ripple. Baffle step is caused by the driver radiation going from full space to half space.
Unless the baffle geometry is quite extreme, then you will see some baffle step. The radius should be at least 3/4" to start seeing some effect, and more is better.
Scott
Yes there is a demo version, and it is limited only in the box modelling section (can only use supplied drivers), however crossover simulation is full working.
However, if you want to use response and impedence files for specific drivers, you will have to search them out or create them yourself using something like Speaker Workshop.
Cheers
No time limit - all crossover functions active. Demo version just limited in box modelling. There are a couple of different full versions, and after playing around with the demo you will probably think seriously about buying one of them - it is good.
Can't remember download url, but Google search on lspcad will find it.
Cheers
Can't remember download url, but Google search on lspcad will find it.
Cheers
Wow, the gear came very quick! I only ordered it on Tuesday!!
The new tweeters look good, I hooked them up with the old crossover and sound better already. I've finished the crossovers and are ready to run-in. Unfortunately I ordered two extra 0.4mH inductors
The crossovers during testing...
The new tweeters look good, I hooked them up with the old crossover and sound better already. I've finished the crossovers and are ready to run-in. Unfortunately I ordered two extra 0.4mH inductors
The crossovers during testing...
Attachments
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