This is effectively my first scratch build of a speaker system. I'm downsizing from a pair of Cambridge R50 TL clones, to a sub and two smaller speakers. The sub is a seperate project for now; a TC Sounds 15" TC2000 in a LT'd sealed box. I plan to cross the sub actively to the mains at around 50hz, this will depend on the mains capabilities I guess...
For the mains i've got a pair of Visaton GF200 8" woofers and Vifa D27TG-35-06 tweeters.
Visaton Specs
Vifa Specs
Looking at the drivers responses, It looks like the XO might be around 2khz, however I know very little about XO design.
It would be nice to build the main enclosures as to offer a better bass response when not in use with the active crossover/sub config. However integration with the sub is more important at the moment, I figured a box F3 of 50hz would be practical. Is this possible in a sealed enclosure? I'm thinking simple standmount monitor, size isnt too much of an issue but smaller the better 🙂
As for woodworking and electronics experience, I can get my head round tutorials quite easily. building the boxes and crossovers should be painless(ish!) I just need some design ideas to get the ball rolling! thanks!
For the mains i've got a pair of Visaton GF200 8" woofers and Vifa D27TG-35-06 tweeters.
Visaton Specs
Vifa Specs
Looking at the drivers responses, It looks like the XO might be around 2khz, however I know very little about XO design.
It would be nice to build the main enclosures as to offer a better bass response when not in use with the active crossover/sub config. However integration with the sub is more important at the moment, I figured a box F3 of 50hz would be practical. Is this possible in a sealed enclosure? I'm thinking simple standmount monitor, size isnt too much of an issue but smaller the better 🙂
As for woodworking and electronics experience, I can get my head round tutorials quite easily. building the boxes and crossovers should be painless(ish!) I just need some design ideas to get the ball rolling! thanks!
Have a look at the enclosures the GF200 is used in on the visaton page, plenty of clues there for how to proceed;
the VIB 2000 GF is a 2-way.
Pete McK
the VIB 2000 GF is a 2-way.
Pete McK
take the step initially and go active with your crossover. With this in mind you can incorporate your LT for the sub. You could even LT sealed monitor cabinets which could be advantageous because the LT is supposed to improve phase performance as well as extend bass response. Then you must establish the acoustic behavior of the drivers in question. ie, the acoustical rolloff will sum with the electrical so taking the acoustic response into effect is key. It is regarded that leaving an octave on either side of the crossover point of smooth FR will keep things safe though in the case of large peaks such as break up, more attention must be paid.
My next project will be to LT my sealed subwoofers. an extra octave of superb bass, yay!
My next project will be to LT my sealed subwoofers. an extra octave of superb bass, yay!
Why not first model a box using Unibox at FRD Consortium? From the spec, I think this woofer will require rather large a box even with a sealed design. F3 of 50 Hz is not necessary if you use a sub with them. A sealed design will integrate better with your sub.
For XO, I'd try asymmetric Likwitz-Riley acoustic 4th order crossed at around 1800 Hz. Lower XO point is better for an 8" woofer.
For XO, I'd try asymmetric Likwitz-Riley acoustic 4th order crossed at around 1800 Hz. Lower XO point is better for an 8" woofer.
Time to update on whats happening! My original intention was to build a sub and monitor pair to use together for music production. Well I've built the sub, crossed it over and EQ'd it with a linkwitz transform and its a monster. however its enormous, along with the crown amp to power it. I'm going to stick to a pair of full range speakers for the music production and leave the sub for foundation demolition or something... (pic included for good measure)
Thanks for the tip Pete, their design includes a crossover network set at 2.5khz with a parralel resonant circuit to flatten the midrange. I dont know what order or type their crossover is, could someone elighten me?
Visaton suggested crossover
Their design would work ok, as my tweeter matches the sensitivity. However the GF200 seems to break up immediately after 2.5k.. and my Vifa tweeters can go much lower than the visatons.
So would it be easy to modify it to cross at a lower frequency? Could i get away with a 1.8 cross?
As for the cabinets, i'm aiming around 35 litres in a ported alignment. I may try a slot port too as KRK use on their monitors.
Thanks for the tip Pete, their design includes a crossover network set at 2.5khz with a parralel resonant circuit to flatten the midrange. I dont know what order or type their crossover is, could someone elighten me?
Visaton suggested crossover
Their design would work ok, as my tweeter matches the sensitivity. However the GF200 seems to break up immediately after 2.5k.. and my Vifa tweeters can go much lower than the visatons.
So would it be easy to modify it to cross at a lower frequency? Could i get away with a 1.8 cross?
As for the cabinets, i'm aiming around 35 litres in a ported alignment. I may try a slot port too as KRK use on their monitors.
Attachments
electrically, tweeter xover is 3rd order (although it looks like the 6.8 ohm resistor is tweaking the slope a little); woofer is 2nd order with notch as you note;
I should be easy to cross over a bit lower, maybe even tweaking one of the components in the woofer xover will get you what you want (the 33u cap a bit larger? )
You would need to recalculate the tweeter xover parts values for the impedance of the vifa tweeter at the xover point anyway
cheers,
Pete McK
I should be easy to cross over a bit lower, maybe even tweaking one of the components in the woofer xover will get you what you want (the 33u cap a bit larger? )
You would need to recalculate the tweeter xover parts values for the impedance of the vifa tweeter at the xover point anyway
cheers,
Pete McK
Hi,
Nice design for an old school 2-way, I guess. Well maybe not since you are using a double voice-coil with the Visaton GF 200. You could test a 1200Hz xover (+/-) for that effect dj.
Conservative upper limit is for a 8" 1,23K. Keep in mind that this will cut the voices mid-band in a half, this is just for purists. Highest recommended frequency with this woofer will be the band 1-2k, because of break-up as you said and there is enough room to play.
note: Svante do you remember if the parameters for this GF 200 are right from their website Visaton factory work sheet (?), I remember they messed with parallel and series connections.
Nice design for an old school 2-way, I guess. Well maybe not since you are using a double voice-coil with the Visaton GF 200. You could test a 1200Hz xover (+/-) for that effect dj.
Conservative upper limit is for a 8" 1,23K. Keep in mind that this will cut the voices mid-band in a half, this is just for purists. Highest recommended frequency with this woofer will be the band 1-2k, because of break-up as you said and there is enough room to play.
note: Svante do you remember if the parameters for this GF 200 are right from their website Visaton factory work sheet (?), I remember they messed with parallel and series connections.
Update
in "Driver recommendations - Vifa"
http://ldsg.snippets.org/vendors/vifa.php
it's always the same... %&/($)/ new drivers from China. They are not even measured in the factory, unless they run out of ferrofluid ?!...
dj do you have the new kit from PE to measure impedance vs frequency in speakers?
in "Driver recommendations - Vifa"
http://ldsg.snippets.org/vendors/vifa.php
it's always the same... %&/($)/ new drivers from China. They are not even measured in the factory, unless they run out of ferrofluid ?!...
dj do you have the new kit from PE to measure impedance vs frequency in speakers?
The only measurement tools I have are a digital multimeter and an oscilloscope. I've not looked into measuring impedance before..
I bought the tweeters approximately 2 years ago, perhaps they're not the chinese ones?
2-way designs with 8" woofers can't be terrible as Visaton offer the GF 200 in such a config. I know of many studio monitors with 8 inchers too...
Rod Elliot's pages have some useful information on passive xover design that I can understand. Its probably easier to design the xover from scratch than modify Visaton's suggested plans. If the Vifa's Fs is 650 then a 2nd order at 1.8khz seems reasonable.
I only bought the GF200's because I got them very cheap, if I could get a pair of P13's that'd make an awesome 3-way, but i'm quite determined to nail a 2-way design.
I bought the tweeters approximately 2 years ago, perhaps they're not the chinese ones?
2-way designs with 8" woofers can't be terrible as Visaton offer the GF 200 in such a config. I know of many studio monitors with 8 inchers too...
Rod Elliot's pages have some useful information on passive xover design that I can understand. Its probably easier to design the xover from scratch than modify Visaton's suggested plans. If the Vifa's Fs is 650 then a 2nd order at 1.8khz seems reasonable.
I only bought the GF200's because I got them very cheap, if I could get a pair of P13's that'd make an awesome 3-way, but i'm quite determined to nail a 2-way design.
dj_smilee said:
I think the problem here was originaly the ferrofluid. (Again, I can be wrong.)
Type 1 w/out ferrofluid fs=1000Hz and type 2 with ferrofluid fs=650Hz.
The type 1 ones: D27TG0506, D27TG1506.
The type 2 ones: D27TG3506, D27TG4506.
They are used in various set-ups like Kefs and other pro stuff. You will be fine.
We should try 2 or 3 different set-ups/x-overs (and be patiente) before some good results.
Now if you agree (I don't want to be pretencious here) I would make a first shot on a 1.order/3order x-over and if "I" would not like it (meaning you) or you found it unreasonable we would then change it for a 1.order/1.order or 2.order/2.order. There's plenty of material to work on. But probably I would finish with 2 x-overs at the end to chose from or something similar.
Hi, dj,
I didn't forget about you, as promised.
I just got your "first series" x-overs, the first implementation for this pro experiment. A brand new design, completely out of the "schoolbook" as Ingvar would say (from the GURU thread that was killed), so don't expect to much from it. A second order/second order is conforming to the "textbook" here.
So, as I was saying, You might like it or not, but you should experiment because is out of normality. Next step will be to check BS baffle step, box size, size of baffle and that I leave with you. It might need some low end reinforcement (+/- 100Hz). The xover will make the two drivers in phase, aligned. I will keep checking this all the time, with all the x-overs I design and others from the factory, to see if one speaker needs to be reversed or not, meaning the poles reversed as for a typical 2.order/2.order.
This xover is also out of the ordinary because it will add up all the frequencies for the woofer and the tweeter, between 2K and 8K (really 5K in this case not the announced 8K Hz on the woofer). The other xovers subtract frequencies and you first listen to the woofer or/then to the tweeter in it's pass band, woofer is on it's stop band. Not in this case, because is more like a first order for the woofer. You can then vary (change) the resistor R2 on the Lpad, that will be provided as the best simulated attenuation (around -3dB's) already, that is -5dB to 86dB's +/- from the 91/92 Spec. and to mate the woofer one, lower by 3db's in general.
Any ideas?
Visaton GF 200 2 X 4 Ohm (5.8Ohm/Re Spec in series)
Vifa D27TG-35-06 (4.6Ohm/Re Spec)
I didn't forget about you, as promised.
I just got your "first series" x-overs, the first implementation for this pro experiment. A brand new design, completely out of the "schoolbook" as Ingvar would say (from the GURU thread that was killed), so don't expect to much from it. A second order/second order is conforming to the "textbook" here.
So, as I was saying, You might like it or not, but you should experiment because is out of normality. Next step will be to check BS baffle step, box size, size of baffle and that I leave with you. It might need some low end reinforcement (+/- 100Hz). The xover will make the two drivers in phase, aligned. I will keep checking this all the time, with all the x-overs I design and others from the factory, to see if one speaker needs to be reversed or not, meaning the poles reversed as for a typical 2.order/2.order.
This xover is also out of the ordinary because it will add up all the frequencies for the woofer and the tweeter, between 2K and 8K (really 5K in this case not the announced 8K Hz on the woofer). The other xovers subtract frequencies and you first listen to the woofer or/then to the tweeter in it's pass band, woofer is on it's stop band. Not in this case, because is more like a first order for the woofer. You can then vary (change) the resistor R2 on the Lpad, that will be provided as the best simulated attenuation (around -3dB's) already, that is -5dB to 86dB's +/- from the 91/92 Spec. and to mate the woofer one, lower by 3db's in general.
Any ideas?
Visaton GF 200 2 X 4 Ohm (5.8Ohm/Re Spec in series)
Vifa D27TG-35-06 (4.6Ohm/Re Spec)
Attachments
update
😡...(really 5K in this case not the announced 8K Hz on the woofer that is by now at 66dB's with the xover attenuation/ tweeter at full power 89dB's (+/-) with xover attenuation@8kHz).
😡...(really 5K in this case not the announced 8K Hz on the woofer that is by now at 66dB's with the xover attenuation/ tweeter at full power 89dB's (+/-) with xover attenuation@8kHz).
Sorry, the phase was wrong. I was doing it with wrong parameters.
I will ask the administrator to erase my last picture were it says "Check the phase here:" Thanks.
Is never to easy. Back to basics.
I will ask the administrator to erase my last picture were it says "Check the phase here:" Thanks.
Is never to easy. Back to basics.
xover visaton-vifa
here it is, dj, are you there?!
i am looking at the best components for the tweeter...
Do you prefer more baffle step for stronger bass line and a more even tweeter with lower output (-1dB) or the oposite, a little less bass and a stronger tweeter (+1dB)? You can always do the twikings yourself later, as you like (as with the box for the speakers, size of baffle, etc). Just to have a starting point from your pro preferences.
here it is, dj, are you there?!
i am looking at the best components for the tweeter...
Do you prefer more baffle step for stronger bass line and a more even tweeter with lower output (-1dB) or the oposite, a little less bass and a stronger tweeter (+1dB)? You can always do the twikings yourself later, as you like (as with the box for the speakers, size of baffle, etc). Just to have a starting point from your pro preferences.
Attachments
Hello Inductor! sorry for the delay, very busy at the moment 
I really appreciate you taking the time to come up with these designs!
As to your questions; I only have a basic understanding of the possible tweaks for personal taste. My main goal is for flattest possible response, with baffle step correction. As you say, I can adjust it after. I plan on constructing a microphone for measuring response which should help a lot!
Do you think the woofer will behave adequately? I couldnt understand your comments in previous posts regarding the attenuation of the woofer towards breakup..
I really appreciate you taking the time to come up with these designs!
As to your questions; I only have a basic understanding of the possible tweaks for personal taste. My main goal is for flattest possible response, with baffle step correction. As you say, I can adjust it after. I plan on constructing a microphone for measuring response which should help a lot!
Do you think the woofer will behave adequately? I couldnt understand your comments in previous posts regarding the attenuation of the woofer towards breakup..
Those previous considerations were for a xover of a 1.order/3.order type that has not seen the light of the day. The idea was to have a good phase between drivers and no cancellation. You can start readind were I said "Back to basics". Sorry.
Take this last one as a serious implementation.
Just post your questions there's a lot of people w. a good knowledge around.
Take this last one as a serious implementation.
Just post your questions there's a lot of people w. a good knowledge around.
Thanks for clearing that up. Could I include the notch filter from visaton's design in order to level out the midrange?
http://www.visaton.com/bilder/frequenz/gross/vib2000gf_fs.gif
that is visaton's measurement of their 2-way design with the crossover above and GF-200.
I will be designing and building the cabinets in a few weeks. I'll let you know how it goes! Thanks for your help Inductor
http://www.visaton.com/bilder/frequenz/gross/vib2000gf_fs.gif
that is visaton's measurement of their 2-way design with the crossover above and GF-200.
I will be designing and building the cabinets in a few weeks. I'll let you know how it goes! Thanks for your help Inductor
dj_smilee said:
What do you mean? (What midrange?) The design of this xover has in consideration the overlap band of the tweeter and "levels" the Visaton just before xover and stop band, and the band after xover of the tweeter with a boosting output at high frequencies.
Hear it to believe it!
If you want is possible to change it like for use without BSC if you use your subs. That's about 2/3 more dB, what means double the output with the same power. But that's another new xover.
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