First time DIY XO build, random questions

[Verdinut]

So first is just a rough placement... couple resistors and a cap are missing.

Then the two options I described above, spacing is about 1” (my index finger) and is about as far as I can move it on the rough in above.

Thoughts, please.



Sent from a handheld device using a silly little app.

From the above photos, I would fix the steel laminate coil vertically rather than horizontally, and I would keep the air core one as is. Keep them as far as possible from each other.
EDIT: I mean: I would put the air core on its edge as in the bottom picture and the steel laminate perpendicular to its shown position .

 

[ryanosaur]

Yes. For this build I’m just doing it by the provided specs. A majority of the components are salvaged from the original board and the woofer circuit is supposed to be unchanged.

 

[ryanosaur]

@Verdinut
Is this what you had in mind?

Spacing between the two parts is about 2” in this photo.

Sent from a handheld device using a silly little app.

 

[Verdinut]

@Verdinut
Is this what you had in mind?

Spacing between the two parts is about 2” in this photo.

Sent from a handheld device using a silly little app.

Yes!

 

[Verdinut]

@Verdinut
Is this what you had in mind?

Spacing between the two parts is about 2” in this photo.

Sent from a handheld device using a silly little app.

@ryanosaur

Looking at them again, I think it's preferable to install the air core one flat on the board so the coils will be perpendicular one from the other.

 

[ryanosaur]

Looking at them again, I think it's preferable to install the air core one flat on the board so the coils will be perpendicular one from the other.

Understood.
If I may extend this for greater clarity:
Does the solid core itself affect the magnetic field? Or is it the direction of the coil around the core that would dictate alignment?

(In the latter example, and by your suggestion here, it would seem the coil direction is the key.)
Thank you!

 

[Verdinut]

Understood.
If I may extend this for greater clarity:
Does the solid core itself affect the magnetic field? Or is it the direction of the coil around the core that would dictate alignment?

(In the latter example, and by your suggestion here, it would seem the coil direction is the key.)
Thank you!

Right. You're quite welcome.

 

[TLS Guy]

Understood.
If I may extend this for greater clarity:
Does the solid core itself affect the magnetic field? Or is it the direction of the coil around the core that would dictate alignment?

(In the latter example, and by your suggestion here, it would seem the coil direction is the key.)
Thank you!

Its like this.

 

[ryanosaur]

Its like this.

Thank you! Excellent illustration.

 

[ryanosaur]

One more question that I caught late last night when I was heading off to bed:
In the Woofer circuit schematic, a 6-element circuit, the path starts with that Solid Core 2mH Inductor. Following the path, the first shunt to ground is a resistor, the .5mH Air Core Inductor and a Cap. The second shunt to ground is a resistor and the NP Electrolytic Cap, then the woofer.
On the board, the first shunt has the 3 components in series as Resistor:Cap:Inductor(AC).

Does that change in order do anything to the circuit?

Thanks.

 

[TLS Guy]

One more question that I caught late last night when I was heading off to bed:
In the Woofer circuit schematic, a 6-element circuit, the path starts with that Solid Core 2mH Inductor. Following the path, the first shunt to ground is a resistor, the .5mH Air Core Inductor and a Cap. The second shunt to ground is a resistor and the NP Electrolytic Cap, then the woofer.
On the board, the first shunt has the 3 components in series as Resistor:Cap:Inductor(AC).

Does that change in order do anything to the circuit?

Thanks.

A circuit like that changes the Q of the filter. The roll off starts more gradually.

However I have to ask what is the value of that resistor? Usually that resistor represents the DC resistance of the coil. In any event you should measure the resistance of the coil and the resistor you add should be no higher than the sum of the DC resistance of the coil and the value if the resistor you add.

It is the same thing with the electrolytic cap. You can not easily measure the resistance of the cap, but it should be in the specification of the cap. Likely the resistance will be frequency dependent to a degree.

This whole issue is where people get into trouble recapping crossovers.

This is another issue with three ways, with the components being so large you have to handle the resistance of the components correctly.

 

[ryanosaur]

A circuit like that changes the Q of the filter. The roll off starts more gradually.

However I have to ask what is the value of that resistor? Usually that resistor represents the DC resistance of the coil. In any event you should measure the resistance of the coil and the resistor you add should be no higher than the sum of the DC resistance of the coil and the value if the resistor you add.

It is the same thing with the electrolytic cap. You can not easily measure the resistance of the cap, but it should be in the specification of the cap. Likely the resistance will be frequency dependent to a degree.

This whole issue is where people get into trouble recapping crossovers.

This is another issue with three ways, with the components being so large you have to handle the resistance of the components correctly.

Thank you...
The schematic would read as follows:
Positive => 2.0mH S.C.Inductor => Shunt1, in series: 3 Ohm Resistor: .50 mH A.C.Inductor: 4.7uF Cap: Ground => Shunt2, in series: 25 Ohm Resistor: 100uF N.P.E. Cap: Ground => Woofer+: Ground.

(Hope that makes sense!)

As I described above, the actual circuit I have had the .5mH Ind and 4.7uF Cap switched in order with the Cap coming first after that 3 Ohm Resistor.

All the Caps, resistors and industors are to his specification. Nothing is changing in terms of the Inductors (all salvaged from original board, Janzen labels on the Air Cores, and the Steel Laminate is Erse, I believe). I'm sticking with same brand of caps, Audyn Q4, and Resistors, Dayton Sand Cast Non-Inductive.

 

[TLS Guy]

Thank you...
The schematic would read as follows:
Positive => 2.0mH S.C.Inductor => Shunt1, in series: 3 Ohm Resistor: .50 mH A.C.Inductor: 4.7uF Cap: Ground => Shunt2, in series: 25 Ohm Resistor: 100uF N.P.E. Cap: Ground => Woofer+: Ground.

(Hope that makes sense!)

As I described above, the actual circuit I have had the .5mH Ind and 4.7uF Cap switched in order with the Cap coming first after that 3 Ohm Resistor.

All the Caps, resistors and industors are to his specification. Nothing is changing in terms of the Inductors (all salvaged from original board, Janzen labels on the Air Cores, and the Steel Laminate is Erse, I believe). I'm sticking with same brand of caps, Audyn Q4, and Resistors, Dayton Sand Cast Non-Inductive.

So he has modified the Q of the filters.

 

[ryanosaur]

A circuit like that changes the Q of the filter. The roll off starts more gradually.

So he has modified the Q of the filters.

If I extend this correctly and understand the concept, then it would be appropriate to say he is lowering the Q and lessening the knee.
I "know enough" to "understand" that the circuit can be manipulated in ways... I don't get, yet. (Epistomology is a b!tch, ain't it... "You can know nothing if you cannot articulate it." Hence the "lazy" quotations! )
I think it was Toid123 that did one of his videos on a way of manipulating a particular circuit to achieve three different goals in the XO. I'll have to search on this and re-watch. Perhaps it applies here: perhaps not.

Please, Mark, correct my earlier inference if it is wrong. I appreciate greatly your taking the time to engage here. Thanks!

Cheers!
R

 

[ryanosaur]

Crazy update time!

First, life on the West Coast is nuts right now. I am on the supervisor team at the Coffee Company I'm working for. Our landlord for the location I'm assigned to is clearly a MAGA-head with a Drill-Baby-Drill mentality as it regards the pandemic. He is "encouraging" our owner to expand operations at that location; damn the torpedoes....
And now there are the fires.
It's a crazy flippin' scene out here, and sanity is a wild thread whipping in the Diablo Winds.

I've finished putting together the tools I need to build cabinets. My Router Bits and Table were delivered yesterday. I also picked up a Brad Nailer as it seems many cats are using that to help in cabinet assembly.

And then: I have a friendly acquaintance who insists I use the best XO components when I do my project. He is not familiar with Speaker Design. I politely told him no, that there is no actual difference in the premium components, but he insisted that I at least try ditching the Solid Core Inductor and the Electrolytic Capacitor. He laid cash in my hand for them. And so, I present the grand experiment:
I'm going to assemble two test cabinets, one with the "regular components, and one with the "special" components. I will test each. and check them out in a Double Blind, Level Matched scenario.
While I do not expect to hear anything different, I figure why not. This is a good time to play, as I'll be able to have my tests compared to the original modified speaker.
Whee!
Some comments starting at this post over on that other site.

Philharmonic Audio - Dennis Murphy

www.avsforum.com

Also, as it has been officially cleared, I am doing the + mod to the Affordable Accuracy speakers. Dennis has OK'd putting images up, so a few will follow.
I purchased a B-stock pair of AAs with the Dayton Silk Tweeter back in 2018. Since I was going to be using them for Rears or Atmos, I wasn't too concerned about the improvements the Morel version gave, and I was putting the "extra" loot saved into the Phil 3s.

Regardless, I have everything largely together at this point and am ready to proceed with building some test cabinets. I will wire the XOs externally for test purposes. My hands on education begins!
Cheers!

 

[ryanosaur]

This is the roughed in XO board with the standard components.
The 2mH and 100uF parts are on the sides.

The two Inductors side by side.

And the two Caps.

By some dirty math, I estimated I would need to add about 1/4” to the internal depth of the cabinet if I were to actually install these components, just to make up for lost volume.

Anyway... stay tuned my friends for further updates as I am able.

And again, my thanks to all who have offered advice and wisdom!


Sent from a handheld device using a silly little app.

 

[Verdinut]

This is the roughed in XO board with the standard components.
The 2mH and 100uF parts are on the sides.

The two Inductors side by side.

And the two Caps.

By some dirty math, I estimated I would need to add about 1/4” to the internal depth of the cabinet if I were to actually install these components, just to make up for lost volume.

Anyway... stay tuned my friends for further updates as I am able.

And again, my thanks to all who have offered advice and wisdom!


Sent from a handheld device using a silly little app.

A small reduction of a cabinet volume will not affect the performance to the extent that you would hear a difference between the smaller and larger size. It's all a question of percentage of volume. The situation is the same for crossover components. They can vary by 10% from the project calculations without any important negative consequences.

 

[TLS Guy]

Crazy update time!

First, life on the West Coast is nuts right now. I am on the supervisor team at the Coffee Company I'm working for. Our landlord for the location I'm assigned to is clearly a MAGA-head with a Drill-Baby-Drill mentality as it regards the pandemic. He is "encouraging" our owner to expand operations at that location; damn the torpedoes....
And now there are the fires.
It's a crazy flippin' scene out here, and sanity is a wild thread whipping in the Diablo Winds.

I've finished putting together the tools I need to build cabinets. My Router Bits and Table were delivered yesterday. I also picked up a Brad Nailer as it seems many cats are using that to help in cabinet assembly.

And then: I have a friendly acquaintance who insists I use the best XO components when I do my project. He is not familiar with Speaker Design. I politely told him no, that there is no actual difference in the premium components, but he insisted that I at least try ditching the Solid Core Inductor and the Electrolytic Capacitor. He laid cash in my hand for them. And so, I present the grand experiment:
I'm going to assemble two test cabinets, one with the "regular components, and one with the "special" components. I will test each. and check them out in a Double Blind, Level Matched scenario.
While I do not expect to hear anything different, I figure why not. This is a good time to play, as I'll be able to have my tests compared to the original modified speaker.
Whee!
Some comments starting at this post over on that other site.

Philharmonic Audio - Dennis Murphy

www.avsforum.com

Also, as it has been officially cleared, I am doing the + mod to the Affordable Accuracy speakers. Dennis has OK'd putting images up, so a few will follow.
I purchased a B-stock pair of AAs with the Dayton Silk Tweeter back in 2018. Since I was going to be using them for Rears or Atmos, I wasn't too concerned about the improvements the Morel version gave, and I was putting the "extra" loot saved into the Phil 3s.

Regardless, I have everything largely together at this point and am ready to proceed with building some test cabinets. I will wire the XOs externally for test purposes. My hands on education begins!
Cheers!

The issue with electrolytics is not SQ per say, but much more to do with holding the correct spec. long term. If you avoid them your crossover will last a life time and beyond. Also they do have high forward resistance. I also try and avoid iron core inductors if possible, because of hysteresis core issues. They certainly can give rise to distortion at power. However any time I design a really powerful system I always use active crossovers. In that case it really does make a difference to SQ.

 

[Swerd]

When coming up with a crossover board layout, I find it useful to print a copy of this diagram and keep it nearby. Use alignment examples 1, 6, or 7. In your small 2-way, you might have a tough time finding 20 cm (8") as shown for #1. Do the best you can with the available space.

Align iron or steel core inductors with other inductors on the board the same as you would air core inductors. The iron or steel bar goes through the coiled wire hole in the same direction as you would look through the doughnut hole of an air core inductor.

You can find it here: http://www.troelsgravesen.dk/coils.htm

 

[Swerd]

By some dirty math, I estimated I would need to add about 1/4” to the internal depth of the cabinet if I were to actually install these components, just to make up for lost volume.

If you're really worried about that extra ¼" internal cabinet depth you would need because of the physically larger crossover parts, use a crossover board made with Masonite pegboard instead of the hardboard you show in your photos. All those holes in the pegboard should make the difference .