Hi everyone,
i am in the middle of a project and i want some help with the crossover design and the bass reflex size. I have currently designed the enclosure for the speakers based on the dynaudios heritage special and the size of the contour 1.3 in which, i assume, the drivers came in from dynaudio.
The cabinet is 13.5 liters, subtracting the volume of the inside reinforcement piece and the speaker, and will be made from 20mm plywood. In the dynaudio dataset they have used a 15 liter enclosure with a 45mm x 80mm port for their measurements, should i use the same size port?
Regarding the crossover, i have found this thread and tested the referenced designs in Xsim, but i cant get a nice frequency response. I will attach the frd and zma files for the drivers. Can anyone help me with the design? I have uploaded a test based on the designs i have found on the thread.
i am in the middle of a project and i want some help with the crossover design and the bass reflex size. I have currently designed the enclosure for the speakers based on the dynaudios heritage special and the size of the contour 1.3 in which, i assume, the drivers came in from dynaudio.
The cabinet is 13.5 liters, subtracting the volume of the inside reinforcement piece and the speaker, and will be made from 20mm plywood. In the dynaudio dataset they have used a 15 liter enclosure with a 45mm x 80mm port for their measurements, should i use the same size port?
Regarding the crossover, i have found this thread and tested the referenced designs in Xsim, but i cant get a nice frequency response. I will attach the frd and zma files for the drivers. Can anyone help me with the design? I have uploaded a test based on the designs i have found on the thread.
Attachments
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That was a fun old thread.
Question arises do you have the 4 or 8 ohm woofer.
The Zobel is 4R7/15 and 6R8/20 respectively.
You'd use 0.9mH for 4 ohm and about 1.5mH for the 8 ohm.
First order tweeter is probably a mistake. Won't go loud.
Lojzek is excellent. If you don't crib the Dyanaudio design, I see nothing wrong here:
10-15L is recommended for this speaker. Tube shouldn't be very critical.
Question arises do you have the 4 or 8 ohm woofer.
The Zobel is 4R7/15 and 6R8/20 respectively.
You'd use 0.9mH for 4 ohm and about 1.5mH for the 8 ohm.
First order tweeter is probably a mistake. Won't go loud.
Lojzek is excellent. If you don't crib the Dyanaudio design, I see nothing wrong here:
10-15L is recommended for this speaker. Tube shouldn't be very critical.
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Thanks a lot for the reply 
I have the 8 ohm version.
Ok so i tried the 1st order for the woofer and 2nd order for the tweeter as you said but i had to use big capacitors for the tweeter to counter a dip @1000-2000hz which didnt go away even if i invert the tweeter:
Do you think i should use the impedance correction circuit?
I have the 8 ohm version.
Ok so i tried the 1st order for the woofer and 2nd order for the tweeter as you said but i had to use big capacitors for the tweeter to counter a dip @1000-2000hz which didnt go away even if i invert the tweeter:
Do you think i should use the impedance correction circuit?
I think you are going wiildly wrong here.
No need to cross so low. 20uF and 39uF? Far too big.That 1.3kHz dip is just what woofers often do. It's a cone-edge resonace to do with the rubber surround. Quite inoffensive usually. Dips are better than peaks.
We have got good results with Morel and Dyanudio woofers with a simple bass coil. But Zobels can help. They have built in rolloff and no terrible breakups.
Can't believe Lojzek has gone far wrong. He's a good modeller. Is your time-alignment correct?
No need to cross so low. 20uF and 39uF? Far too big.That 1.3kHz dip is just what woofers often do. It's a cone-edge resonace to do with the rubber surround. Quite inoffensive usually. Dips are better than peaks.
We have got good results with Morel and Dyanudio woofers with a simple bass coil. But Zobels can help. They have built in rolloff and no terrible breakups.
Can't believe Lojzek has gone far wrong. He's a good modeller. Is your time-alignment correct?
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The 20uF etc is way off.
I own a few Dynaudio speakers with various filter topologies which I have modified and mostly settled on a similar structure to this MurphyBlaster Productions without knowing it had been done before.
You can play with the values to adjust for specific versions of each speaker (there are many btw), obviously your 8 ohm woofer choice is different as all higher quality Dynaudio originals are 4 ohm so you need to factor this in copying/designing the filter.
You can also add a small resistor to C1021 further tweaking the slope and I have added a Zobel of 1-1.5uF and 6.8-10 ohms depending on the D260 version/generation/baffle/room and what not.
The xxw75 have some issues around 5khz and earlier versions of the D28 and D260 at 10khz so if you want it really nice you need to manage that as well which adds to the filter.
I own a few Dynaudio speakers with various filter topologies which I have modified and mostly settled on a similar structure to this MurphyBlaster Productions without knowing it had been done before.
You can play with the values to adjust for specific versions of each speaker (there are many btw), obviously your 8 ohm woofer choice is different as all higher quality Dynaudio originals are 4 ohm so you need to factor this in copying/designing the filter.
You can also add a small resistor to C1021 further tweaking the slope and I have added a Zobel of 1-1.5uF and 6.8-10 ohms depending on the D260 version/generation/baffle/room and what not.
The xxw75 have some issues around 5khz and earlier versions of the D28 and D260 at 10khz so if you want it really nice you need to manage that as well which adds to the filter.
Thanks a lot for the advice guys
i have played around a bit and concluded to this design, what do you guys think?
Should i worry about the impedance?
i didnt see A 8's answer when i did this, but i think i implemented some of the things you said. I am designing a crossover for the 1st time so the advices that you game me helped a lot. If you have any other suggestions please feel free to share
i have played around a bit and concluded to this design, what do you guys think?
Should i worry about the impedance?
i didnt see A 8's answer when i did this, but i think i implemented some of the things you said. I am designing a crossover for the 1st time so the advices that you game me helped a lot. If you have any other suggestions please feel free to share
Looks like a good structure/start but C9 will not work as is, maybe with a 10 ohm resistor in series to ground. I don't have any experience/knowledge of simulations but with my hands on experience I can't help think something is not right if you get that 2.2uF to ground on the tweeter.
You also need to get more detailed on the coils including their DC resistance.
In the end and once you have a the right structure you need to tweak the values live so to speak meaning you measure the actual output and impedance.
Why a 8 ohm woofer?
It will sort of mess up your overall system, you will need to bring the tweeter down more and get a bigger and more expensive coil to the woofer.
You also need to get more detailed on the coils including their DC resistance.
In the end and once you have a the right structure you need to tweak the values live so to speak meaning you measure the actual output and impedance.
Why a 8 ohm woofer?
It will sort of mess up your overall system, you will need to bring the tweeter down more and get a bigger and more expensive coil to the woofer.
This filter should do reasonably well for the 17W75xl-4 and D28/2.
woofer 2nd order electrical lp filter: 1mH; 15uF
tweeter 3rd order electrical with padding before x/o: 4R7; 6.8uF; 0.22mH; 10uF
Modify padding resistor to better suit your taste.
You said your tweeter was D28. That would mean the one with a small horn?
woofer 2nd order electrical lp filter: 1mH; 15uF
tweeter 3rd order electrical with padding before x/o: 4R7; 6.8uF; 0.22mH; 10uF
Modify padding resistor to better suit your taste.
You said your tweeter was D28. That would mean the one with a small horn?
