I would stick with a decent iron core for the bass driver. That'll keep the DCR nice and low. A 4.5mh air core inductor with a suitable gauge wire to keep the DCR low will be massive! You could still use an air core for the 2mh coil. Having two massive air cores (which will be is close proximity) could cause interaction issues. It's only for the bass driver so any smearing that an iron core may introduce probably won't be audible. Anyway, Oliver stole the show for me....!
Oliver is the star ❤. Yeah kinda what I said in the video. However client want air core which I do understand. I've wound both and got the DCR low enough. Interaction / induction, not really. They will be at 90 deg to each other plus there part of the same signal path. Also that stupid sized shunt capacitor gets replaced with something small so there is room. The 4.5mH air core ended up about 80mm x 40mm so not to bad
@@haycrossaudio5474 Yep, getting rid of the crazy sized caps will give you a bit more room. It wasn't obvious how much space there was in the bottom of the cabinet, and being able to mount the coils at 90 degrees to each other solves the interaction problem. Well done for winding the coils and keeping them at a sensible size. I haven't got round to winding my own coils yet. To get the values I need I buy bigger ones and unwind. And another thing... why is it that some designers put silly big expensive caps in shunt?? In the signal path yes.... but not in shunt... What a waste. Size doesn't always matter 😁
@@patrickgrantham8800 Agreed. Shunt capacitors are not as critical. I try and use decent but not silly capacitors. Inductors in Shunt are a bit different though. Iron core can smear but dumping the discharge into the driver when the signal field collapses. Air core all the way except for the lower frequencies. Pointless. Laminated core is fine below 500Hz in my eyes
@@RobWhittlestone Yeah it would be better but I can get away with it. Normally I'd do critical measuring outside but Normally do the basics inside. If the weather improves I will take final measurements. 🤩
Nice touch to place the tweeter off center, distributing the edge diffraction in frequency. I would try to put the attenuating resistors closest to the drivers to omit a lot of heat loss and lower distortion a bit. Current driving the voice coils.
The attenuation resistor for the tweeter circuit needs to be first in circuit otherwise adding it between the high pass and the tweeter will upset the impedance the filter will see and alter its tuning frequency. You would then need a correction resistor to. Forming an L-pad would be a bad idea. The resistor placed in the PCB is fine. These are 10watt rated and there not covered in insulation. Given the low power and current in the HF circuit heat is not an issue.
@@haycrossaudio5474 I figured you knew that, and chose to keep the values. For a design from scratch you can save some energy loss and distortion through the crossover region by playing with the attenuation series R closest to the driver. Also there’s the possibility to add an inductor (or cap in the LR-shunt) in the RC-shunt. Making it RCL. Then you can control the q of the knee independent on variations of the driver load, even dynamic ones like heating of voice coils and unlinear flux in the magnet gap. Great work!👍🤓
Love the cat. And cats LOVE hi-fi..... sitting on it !!
So interesting. Thanks. I'm amazed by those measurements!
Oliver's a great addition to the channel.😊
Nice job. That waterfall is fantastic. ATCs are usually horribly low in sensitivity.
@@mfr58 I'm seeing about 87db with 2.83v at 1 meter at 1kHz. Good components in these which helps the CSD
I would stick with a decent iron core for the bass driver. That'll keep the DCR nice and low. A 4.5mh air core inductor with a suitable gauge wire to keep the DCR low will be massive! You could still use an air core for the 2mh coil. Having two massive air cores (which will be is close proximity) could cause interaction issues. It's only for the bass driver so any smearing that an iron core may introduce probably won't be audible.
Anyway, Oliver stole the show for me....!
Oliver is the star ❤. Yeah kinda what I said in the video. However client want air core which I do understand. I've wound both and got the DCR low enough. Interaction / induction, not really. They will be at 90 deg to each other plus there part of the same signal path. Also that stupid sized shunt capacitor gets replaced with something small so there is room. The 4.5mH air core ended up about 80mm x 40mm so not to bad
@@haycrossaudio5474 Yep, getting rid of the crazy sized caps will give you a bit more room. It wasn't obvious how much space there was in the bottom of the cabinet, and being able to mount the coils at 90 degrees to each other solves the interaction problem. Well done for winding the coils and keeping them at a sensible size. I haven't got round to winding my own coils yet. To get the values I need I buy bigger ones and unwind.
And another thing... why is it that some designers put silly big expensive caps in shunt?? In the signal path yes.... but not in shunt... What a waste. Size doesn't always matter 😁
@@patrickgrantham8800 Agreed. Shunt capacitors are not as critical. I try and use decent but not silly capacitors. Inductors in Shunt are a bit different though. Iron core can smear but dumping the discharge into the driver when the signal field collapses. Air core all the way except for the lower frequencies. Pointless. Laminated core is fine below 500Hz in my eyes
Nice work Matt. It would be interesting to see the measurements in a much larger room. Subscribed. All the best, Rob in Switzerland
@@RobWhittlestone Yeah it would be better but I can get away with it. Normally I'd do critical measuring outside but Normally do the basics inside. If the weather improves I will take final measurements. 🤩
Impressive stuff, again.
🖤well chuffed old chap..!
♣is there some BBC in your genes..🔥👍
Nice result Matt, I guess quality drivers makes your life easier
@@kjbunnyboiler yeah. You don't end up needing tons of parts to correct things
@@haycrossaudio5474 have you pulled the drivers yet? The midrange and bass drivers have some serious motor / magnet assemblies!
Nice touch to place the tweeter off center, distributing the edge diffraction in frequency. I would try to put the attenuating resistors closest to the drivers to omit a lot of heat loss and lower distortion a bit. Current driving the voice coils.
The attenuation resistor for the tweeter circuit needs to be first in circuit otherwise adding it between the high pass and the tweeter will upset the impedance the filter will see and alter its tuning frequency. You would then need a correction resistor to. Forming an L-pad would be a bad idea. The resistor placed in the PCB is fine. These are 10watt rated and there not covered in insulation. Given the low power and current in the HF circuit heat is not an issue.
@@haycrossaudio5474 I figured you knew that, and chose to keep the values. For a design from scratch you can save some energy loss and distortion through the crossover region by playing with the attenuation series R closest to the driver. Also there’s the possibility to add an inductor (or cap in the LR-shunt) in the RC-shunt. Making it RCL. Then you can control the q of the knee independent on variations of the driver load, even dynamic ones like heating of voice coils and unlinear flux in the magnet gap. Great work!👍🤓
I love cats 🐱