seas thor crossover redesign help

[planet10]

Thanx Jim,

What would one change to tweak the amount of BSC (or the placement if someone was using these on a 9" wide Thor, ie ~100 Hz higher)?

Having the facility to approach the new TLs without the 9" wide restriction would be a big boon in terms of creating a footprint that isn't as deep.

dave

[jimangie1973]

Thanx Jim,

What would one change to tweak the amount of BSC (or the placement if someone was using these on a 9" wide Thor, ie ~100 Hz higher)?

Having the facility to approach the new TLs without the 9" wide restriction would be a big boon in terms of creating a footprint that isn't as deep.

dave

I put both the 10" width baffle and the 9" width baffle into Baffle Diffraction Simulator. The difference is the 10" step begins at a slightly lower frequency. The steps are very close, varying about a quarter dB from 250 Hz 700 Hz. I could make a difference magnitude file and put that into my simulation and match the current response.

Reducing the baffle step seems a little trickier to me. I'm not sure how to slope the reduction. As a fixed persentage of the total baffle step over the entire range, or use some other weighting.

I think the full baffle step would sound best with the stock Thor boxes since they are bass shy to begin with. I can't say that's true with the alternate boxes with the correct TL sizes (Small Thor, Fat Thor, etc).

[Finleyville]

One more thing, I closed up the rear port to make it a sealed response. The impedance plot reflects this. The W18E001s work perfectly in 1.2 cu ft sealed. The bass was a bit too prominent with the port.

I am very interested in this rework! Great job!

So if you closed up the rear port using your aforementioned x-over then there is no reason to use the original Thor cabinet schematic? I could just design a sealed floorstanding 1.2 cu ft internal volume enclosure? If I do what would be the front baffle width 9" or 10"?

[jimangie1973]

I am very interested in this rework! Great job!

So if you closed up the rear port using your aforementioned x-over then there is no reason to use the original Thor cabinet schematic? I could just design a sealed floorstanding 1.2 cu ft internal volume enclosure? If I do what would be the front baffle width 9" or 10"?

Correct, you can use a sealed 1.2 cu/ft cabinet stuffed. If you want better bass extention, use one of the alternate Thor transmission line cabinets designed by guys over at diyaudio (Short Thor, Small Thor, Fat Thor):

Short Thor cabinet design:

http://www.diyaudio.com/forums/attachment.php?s=&postid=863487&stamp=1141724985

Small Thor cabinet design:

http://www.diyaudio.com/forums/attachment.php?s=&postid=902727&stamp=1146169099

Fat Thor cabinet design:

http://www.diyaudio.com/forums/attachment.php?s=&postid=902738&stamp=1146169785

Information on the designs can be found in various threads at diyaudio. Search 'Thor' in thread titles.

One last thing, I'm working on a version of the crossover with 1-2 dB less baffle step compensation which I will be trying out before the end of the week. This should work better for speakers placed near a back wall.

Edit: I forgot to address your question about the baffle width. I am using 10" width with 0.5" radius roundovers on the sides. It should work fine with the 9" baffle as well, as there's only a quarter dB or so of difference in the midbass/lower midrange, with the 10" having having the higher energy in that band.

Jim

[KarlXII]

One last thing, I'm working on a version of the crossover with 1-2 dB less baffle step compensation which I will be trying out before the end of the week. This should work better for speakers placed near a back wall.
Jim

Hi Jim,

great work with the Thor/Odin XO!
Any idea when the above tweak is ready for publishing...?

I'm starting a Small Thor project, and since they´re going to stand close to the wall....well, it would very appreciated. I'm planning to order the components to the XO soon. Naturally, I'm going with your solution.

[Brian Bunge]

I swung by Jim's place a couple of Fridays ago and heard the updated crossover. Not having heard both versions within a close time frame I can't speak to how differently they sound. All I can say is that they both sounded very good.

I imagine he should be ready to post it soon. That is unless he's done more tweaking since then!

[jimangie1973]

Yes, the crossover is complete, no more tweaks in the future. The change I made to get 1 dB less BSC was to use Madisound 16 AWG sidewinder coils instead of the Erse 14 AWG. Values are the same, 2 mH and 0.7 mH. I am using the Madisound coils now in my system and prefer it. This is the configuration Brian listened to the second time he stopped by. ... and another benefit, it saves about $50.

See the schematic above done by planet10, but substitute in the Madisound coils.

[KarlXII]

Yes, the crossover is complete, no more tweaks in the future. The change I made to get 1 dB less BSC was to use Madisound 16 AWG sidewinder coils instead of the Erse 14 AWG. Values are the same, 2 mH and 0.7 mH. I am using the Madisound coils now in my system and prefer it. This is the configuration Brian listened to the second time he stopped by. ... and another benefit, it saves about $50.

See the schematic above done by planet10, but substitute in the Madisound coils.

Thanks Jim!

XO's are really weird science. :B

At least for a newbie like myself.
So what you´re saying is that just by changing brand of coils - same specs otherwise - you get the desired 1 db reduction?
That's a bit disturbing since I was planning to use some other brand altogether. Jantzen are available here, but I haven't found neither Erse nor Madisound.
I naively thought by just using components with same specs I'd be home free.
Oh well...I'd better check up on how to order and deal with customs.

[Brian Bunge]

I think you'd be just fine using different coils as long as the values and DCR's are the same. I think Jim was being more cost conscious than anything else.

[jimangie1973]

The coils don't need to be the Madisound ones specifically, sorry for the confusion. Any 16 guage coil will most likely be very close to the target DCRs.

Here's the target DCRs:

2.0 mH coil --> 0.52 Ohm
0.7 mH coil --> 0.28 Ohm

Any values close to these will work perfectly.

Good luck and keep us posted on your progress.

[Dennis H]

So what you´re saying is that just by changing brand of coils - same specs otherwise - you get the desired 1 db reduction?

No, he's saying he went from a 14 ga. coil to a 16 ga. coil which has thinner wire and higher DC resistance. That's what made the difference.

[KarlXII]

Thanks guys. I didn' t quite catch the gauge part. We're talking millimeters here.
Plus I didn't realize that thickness of wire had that effect. ops:

Did some conversion, seems that 14 ga = 1,68mm and 16 ga = 1,29mm
Nice conversion page, if you ever need it: http://www.mogami.com/e/cad/wire-gauge.html

I'll keep you posted.
It will be a while before I start on the XO; I've just started on the box.

[kappa546]

is this design simply a replacement of component values or complete redesign of the filters?

[KarlXII]

Ooookay.

I got the parts for the XO now. Unfortunately it´s impossible to find the same components as in Jim´s design.
These are the diffs:

Capacitators:
4 uF replaced by 3,9 uF
30 uF replaced by 33 uF

Resistors:
2,2 Ohms replaced by 2 Ohms

Coils:
Erse 14 GA=1,63mm replaced by noname 1,4 mm = close to 15 GA
Jantzen 20 GA replaced by noname 20 GA
Jantzen 18 GA replaced by noname 20 GA
All other values are the same.


What do you think about this?
To me, looking at it, this could make up a completely different XO.
Is it? Any ideas how this may change speaker output?

[jimangie1973]

Hi Karl,

What I will do is provide you with a difference frequency plot between what you have and what I currently have. I'll do this tomorrow when I get to work.

The two components that stand out as potential problems are the 33 uF cap and the 2 Ohm resistor. I originally had a 33 uF and lowered it to 30 uF for a smoother response.

I use an 18 uF and 12 uF in parallel to get the 30 uF value.

Also, you can parallel a 4 Ohm and 5 Ohm and get 2.22 Ohms which would be very close.

Do you have access to any of these values?

Jim

[KarlXII]

Hi Karl,

What I will do is provide you with a difference frequency plot between what you have and what I currently have. I'll do this tomorrow when I get to work.

The two components that stand out as potential problems are the 33 uF cap and the 2 Ohm resistor. I originally had a 33 uF and lowered it to 30 uF for a smoother response.

I use an 18 uF and 12 uF in parallel to get the 30 uF value.

Also, you can parallel a 4 Ohm and 5 Ohm and get 2.22 Ohms which would be very close.

Do you have access to any of these values?

Jim

Warm thanks for your swift reply, Jim.
I really appreciate it.

Capacitator steps over here are:
...10, 15, 22, 33 uF... Seems I'd be home free with two 15 uF in parallel then. :T

Looking in the catalogue, resistor steps are:
...1,50 , 1,80, 2,20 , 2,70...
Perhaps I got the right one there, although it´s printed "RSS10W 2Ω2J"...

It'll be really interesting to see what the coils will do.


Again: Many thanks! ;x(

[Dennis H]

2Ω2 or 2R2 is the same as 2.2 ohms. Just a European numbering convention.

[KarlXII]

2Ω2 or 2R2 is the same as 2.2 ohms. Just a European numbering convention.

Thanks for the clarification!

This means that once I get the 33uF exchanged for 2 x 15 uF the only bogey on the horizon are the coils..

[ThomasW]

Clarity cap makes a 33mfd unit, it's pretty $pendy though...

[jimangie1973]

Thanks for the clarification!

This means that once I get the 33uF exchanged for 2 x 15 uF the only bogey on the horizon are the coils..

So it sounds like you have everything exactly correct, with 15 guage coils. That should work well. If the DCRs are anything close to what the Jantzen 15 guage DCRs are, they will be very close to the Madisound 16 guage.

Thomas, it's actually a 30 uF that he needs.

[KarlXII]

So it sounds like you have everything exactly correct, with 15 guage coils. That should work well. If the DCRs are anything close to what the Jantzen 15 guage DCRs are, they will be very close to the Madisound 16 guage.

Thomas, it's actually a 30 uF that he needs.

Ah great, that´s good news! :T

So now it's just the assembly.

What's your recommendation so put the components on?
I've seen circuit boards with lots of holes, I 've seen people building on pieces of board and masonite...
I was thinking of maybe using acrylic glass - although it maight be really tricky not to melt it while soldering.
Any ideas on how to make the XO "look good"?

[Finleyville]

Any ideas on how to make the XO "look good"?

To me, I am ecstatic if it just "sounds good!"

[kappa546]

whats the total cost for the new xo's?

[jimangie1973]

whats the total cost for the new xo's?

$125 - $150 with Madisound 16 AWG coils in series with woofers, Solen Caps, Eagle resistors, and Madisound or Jantzen higher gauge coils.

[88clipper]

I have two Thors & three Odins since 5 years & now I'm upgrading all of them by rebuildind the cabinet of 2 new fat sea thors ( from scottmoose ), also the updated Xover from jimangie. Can any one provide any suggestion ? Is changing Xover good enough for Odin as I prefer to stay with the old Odin cabinet. Thanks

[jimangie1973]

I have two Thors & three Odins since 5 years & now I'm upgrading all of them by rebuildind the cabinet of 2 new fat sea thors ( from scottmoose ), also the updated Xover from jimangie. Can any one provide any suggestion ? Is changing Xover good enough for Odin as I prefer to stay with the old Odin cabinet. Thanks

Yes the regular Odin cabinet will work fine. You may want to experiment with stuffing the port. I have the ports on mine stuffed making them very close to a sealed system. The bass response is smoother this way.

Also, I would start out with 2 crossovers and give them a listen before going all out.

Good luck with the project.

[KarlXII]

Hi Jim,

just finished up the Small Thors - here's the result:




The filter with your design resides in the foot. After putting it together, it looked like this:



And of course, the birdnest underneith:




I'll get back when I've had a few hours listening done.

[Quwiksilver]

Very sexy finish!

[kesa32]

will be good to hear your comparisons of stock vs modded thor.............l'm looking at doing mods next year myself to improve things too.

cheersken

[jimangie1973]

Awesome job Karl. Beautiful work. I'm jealous. I'd like to have the bass extention you're going to get.

If you can, try to place them out from the back wall a little bit, since the crossover implements the full baffle step.

... and make sure the tweeter is connected with reverse polarity.

[KarlXII]

Awesome job Karl. Beautiful work. I'm jealous. I'd like to have the bass extention you're going to get.

If you can, try to place them out from the back wall a little bit, since the crossover implements the full baffle step.

... and make sure the tweeter is connected with reverse polarity.

Holy smoke!
It really is a big difference to the better. 8O
I thought the diff would be subtle, but it is another speaker altogether..



Thanks. Yes, I do keep the out from the wall like on the picture.
Start building, Jim. Don't wait just go. You have the drivers and the XO, now take the last step to Nirvana...

Again, many thanks for your very competent work. ;x(

[Brian Bunge]

Karl,

Nice work!

Awesome job Karl. Beautiful work. I'm jealous. I'd like to have the bass extention you're going to get.

If you can, try to place them out from the back wall a little bit, since the crossover implements the full baffle step.

... and make sure the tweeter is connected with reverse polarity.

Jim, all we need to do is add bass bins to your MTM's! A pair of ported RS 10" subs would work nicely! :T

[jimangie1973]

Great news Karl. I'm glad you like the sound. If on extended listening you find something you would like to change, such as treble level or whatever, just let me know and I'll work with you.

I would like to make those small thor boxes sometime. Your build really looks fantastic with the excel drivers.

Hey Brian, that is another very good option for sure. I'll talk with you about it.

[KarlXII]

Great news Karl. I'm glad you like the sound. If on extended listening you find something you would like to change, such as treble level or whatever, just let me know and I'll work with you.

I would like to make those small thor boxes sometime. Your build really looks fantastic with the excel drivers.

Hey Brian, that is another very good option for sure. I'll talk with you about it.

Thanks.

Yes, it's a lot of work but sure worth it. Besides, it's great fun too.
Worst part was the paintjob. I decided to spraypaint myself, and I underestimated the workload there..jeez.

To do the boxes is not hard at all.
And they do have such a potent bass you won't even need those bass bins.

[kesa32]

glad to hear they are a better speaker now, what are your thoughts now you've had awhile to do some extended listening?

cheers ken

[KarlXII]

glad to hear they are a better speaker now, what are your thoughts now you've had awhile to do some extended listening?

cheers ken

They sound just great. They do have a really neutral sound,fast, with a very potent bass. Sometimes I find myself wishing for a stronger top. It will probably give me fatigue in the long run, but just for the resolution and a better atmosphere...

A bit silly, since I don't miss anything. And the treble really is silky smooth. Never a knife sharp "S", but not lacking detail either.
At least I would like to try it on for size.

Jim, what to do? Change the 3,9 (4) capacitator to....6?
Or does it take more than that?

No measurements yet, stilll holidays here. At the earliest next week. Exicting!

[jimangie1973]

They sound just great. They do have a really neutral sound,fast, with a very potent bass. Sometimes I find myself wishing for a stronger top. It will probably give me fatigue in the long run, but just for the resolution and a better atmosphere...

A bit silly, since I don't miss anything. And the treble really is silky smooth. Never a knife sharp "S", but not lacking detail either.
At least I would like to try it on for size.

Jim, what to do? Change the 3,9 (4) capacitator to....6?
Or does it take more than that?

No measurements yet, stilll holidays here. At the earliest next week. Exicting!

Hey Karl,

Funny you mention this. I was just playing around with this in my simulation yesterday.

You can change the 8 Ohm parallel with tweeter to a 10 or 12 Ohm, and change the 1.33 Ohm to a 1.2 Ohm (2 Ohm parallel with 3 Ohm). This will give some upper treble boost. I'll add the difference plot to show you the change in FR when I get to work today.

The extra bass you're getting from the TL is probably skewing the tonal balance a little bit.

EDIT: I've attached the plot showing how the change affects the frequency response. The blue curve is with the 12 Ohm, and the red curve is with the 10 Ohm. Y-axis is dB, X-axis is frequency in Hertz.

Jim

[KarlXII]

Hey Karl,

Funny you mention this. I was just playing around with this in my simulation yesterday.

You can change the 8 Ohm parallel with tweeter to a 10 or 12 Ohm, and change the 1.33 Ohm to a 1.2 Ohm (2 Ohm parallel with 3 Ohm). This will give some upper treble boost. I'll add the difference plot to show you the change in FR when I get to work today.

The extra bass you're getting from the TL is probably skewing the tonal balance a little bit.

EDIT: I've attached the plot showing how the change affects the frequency response. The blue curve is with the 12 Ohm, and the red curve is with the 10 Ohm. Y-axis is dB, X-axis is frequency in Hertz.

Jim

Great!
Funny that you already were playing with it. :B

So that'll be appx 1 dB starting from 3000Hz?
That could do it, but what if it isn't..?

What happens with the 1,33 -> 1,2 ohm change?

Edit: Perhaps I won't even have to go to the store.
This is a 12 ohm resistor, right? ops:




Edit..again!
Just measured it to 12,2 ohms. :T

[jimangie1973]

Great!
Funny that you already were playing with it. :B

So that'll be appx 1 dB starting from 3000Hz?
That could do it, but what if it isn't..?

What happens with the 1,33 -> 1,2 ohm change?

Edit: Perhaps I won't even have to go to the store.
This is a 12 ohm resistor, right? ops:




Edit..again!
Just measured it to 12,2 ohms. :T

Looks like a 12 to me. I'm anal so I always verify with an ohmmeter. If you have two 12 Ohms per channel, you can add the second one in parallel with the 1.33 Ohm to make 1.2 Ohm.

Lowering the 1.33 Ohm resistor raises the entire treble response. Raising the 8 Ohm value lowers the lower treble very slightly and raises the upper treble. The combination gives the best response from what I think you desire.

From my experience, a 1 dB raising of the upper treble level is not subtle. If it's still not enough, just let me know and I'll work with you.

Jim

[KarlXII]

Unfortunately I have only one per channnel - that would have been slick..
Many thanks, Jim. I'm starting right away.
Stand by for progress reports.

[KarlXII]

Houston, we got a problem. :roll:

Seems I'm already running the boosted treble - I've got 2 & 3 ohm parallell soldered in! I have a faint memory of the guy in the store saying it was no mentionable difference from the 2 & 4. :evil:

Anyway, this means I'm currently running the boosted treble and still want more.
I could still switch the 8 for the 12, but do you think that will do it for me or do we try something else?

[jimangie1973]

Yes, switch in the 12 for the 8. That makes the difference in the upper treble.

EDIT: Attachment shows difference from what you're currently running.

[KarlXII]

Yes, switch in the 12 for the 8.
That makes the difference in the upper treble.

Right away, sir. :T

[KarlXII]

Change implemented.

First impression:
This is not a subtle change.
Wow.

[KarlXII]

A lot more detail. Air.
Now all the small details in the upper region comes through.
This is exactly what I was looking for.

Now I just have to check that it isn't too sharp...