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Discussion Starter · #1 ·
This is my first build and first time putting together a crossover, so I'm sorry for the total noob questions in advance. I purchased the kit from Meniscus and they provided a layout for the crossover, but I still need some clarifications as follows:

1. The layout (attached) has the inductors at 90 degrees (one standing, one laying flat) but they are still in-line with one-another on the board. I read one tip that said when you look through the hole of the standing coil, you should not be able to see the other. Should I be looking for an alternate layout?

2. In terms of connections, I've drawn in what I think I need to do (again, see attached). Could someone confirm that I have this correct?

3. How do I ground this? Do I need to ground this?

Thanks for your help, I have my cabinets assembled and I'm going to try my hand at veneering later this week. I'm really enjoying this build so far except the WAF hasn't been stellar. Hopefully they will look and sound great so that WAF increases enough for me to try another project...

-Carbon13
 

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Welcome to HTS!

I would agree with the rule of thumb you are referencing, I have heard it too. I'd turn your .35mH coil 90 degrees. Concern alleviated.

By visually inspecting your circuit, I see: 2nd order electrical LPF on the woofer with a tanking cap, and a 3rd order electrical HPF and L-pad attenuator on the tweeter . Is this what your plans describe? If so, you are good to go :T

And no, do NOT ground anything in your crossover. Leave it as if it were floating inside your speaker, the only connections are + and - to your amp outputs.
 

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Discussion Starter · #3 ·
Thanks for your reply. I'm glad to know I was on the right track.

So if I turn the .35mH coil 90 degrees, I'll probably have to move some of the other components (ie. 15 Ohm resistor) over a bit. I assume that wouldn't be a big issue?

Thanks again for your help.
 

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No need to move anything on the crossover; you were talking to knowledgable people at Meniscus and they didn't steer you wrong. First off, consider the distance between the coils. Then consider that being perpendicular makes them independent if they were next to each other.

But feel free to orient as you see fit - this is DIY - just don't imply that you got bad advice from the vendor.

Have fun,
Frank
 

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Discussion Starter · #5 ·
Thanks for the comments.

Don't get me wrong, I chose to get my kit from Meniscus because their service was fantastic, including a follow-up email to make sure I received everything in good order and that I was satisfied. I will definitely be buying from them again.

My question was because the crossover layout they recommend was counter to the rule of thumb that I read elsewhere (see my first post) and I simply don't know enough about electronics to know if this is really critical.

From what I read, placing the coils perpendicular will reduce any chance of interference. What I wasn't sure of was whether this rule of thumb that you shouldn't look through one coil and see the other is still critical to the orientation and possible crosstalk.

-Carbon13
 

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http://www.troelsgravesen.dk/coils.htm

I love when the internet provides data... The figure at the bottom was at the bottom of the page of the speakers I first built. Your crossover is a combo of Fig. 1 for distance, but in Fig. 6's orientation.
- Fig. 1 is worst case orientation, but at safe distance.
- Fig. 5 is best case orientation at minimum distance
- Fig. 6 is what you've got, but at minimum distance
- Fig. 7 & 8 are what you want to avoid.

The key is distance first, then orientation. But don't ignore the note at the bottom...

HAve fun,
Frank
 

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Discussion Starter · #7 ·
This is great! God bless the internet indeed!

So according to this site, the recommended layout could be problematic (or even very bad) since the coils are under 10cm apart (see configurations 4&5 at bottom of that page, not figures). So I think I will rotate 90 degrees so I have something that looks like configurations 6 or 7.
 

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Indeed. Perhaps it was a mistake in the Xover, or perhaps field coupling was deemed negligable by the person who did the layout. It doesn't really matter which, the important part is getting the most out of your own project-- which you have full control over. It's a tiny and simple change to make, I'd just do it and enjoy the extra peace of mind :)
 

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Discussion Starter · #9 ·
Thanks for all the help. I soldered my first board tonight with the small 90 degree change in the orientation of the small coil.

This was my first time soldering, so it's no work of art but it'll do (fingers crossed). I'm going to do my other board tomorrow and hopefully give the speakers a test run this weekend. Still have to veneer the boxes but that's a whole other topic :)
 

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Discussion Starter · #10 ·
All finished and I must say, these far exceeded expectations! The sound is amazing!

The veneering was the most difficult part ( probably because it was raw and not paper backed).

Great kit!

Also - just want folks to know that Meniscus was fabulous for customer service! They have my future business for sure.

-Carbon13
 

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Discussion Starter · #12 ·
Thanks, nice of you to say.

I'm really happy with how they turned out; and the sound seems to get better the more I listen to them.

Now I'm thinking about a 5.1 or 7.1 surround project for my home theater. Right now I'm thinking of sticking with Paul Carmody's design with the swopes. Or other possibilities are Statements or Zaph's ZA5.5tt. Have to investigate some more. Plus, it may be a while before the wife lets me do another project...
 

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There's a down side to sharing pictures - we see something you weren't intending, like your application. "Bookshelf speaker" is an oxymoron, acoustically, no matter how nice they look (and they do look very nice).

I won't tell you what to do or not do, but I will try to make you aware of the tradeoffs, or in this case, the pitfalls of loudspeakers on shelves. Take a look at this link, not so much for the speaker designs as for the lead-in... you have built a speaker with response like Figure 12.8a, ,but you are listening to 12.12a.
http://www.htguide.com/forum/showthread.php4?t=28655

The only remedy is a different location, which may not be practical. Regardless, when you will make a choice, I believe it should be an informed choice.

Frank
 

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Discussion Starter · #14 ·
Oh I don't consider it a downside to be informed! Thanks for pointing me here.

I actually moved the Overnights into my den where they sit on my desk and yes, a noticeable difference in sound quality. The shelves I showed in the picture are where I'm relocating my den (basement) and I will be placing a desk in front of them, so I could bring the speakers out of the cavity of the shelves.

That said - take a look at Pauls site and some of the pics of the O/S build threads. The second last one shows a nice pic of the Overnights in an pretty compact entertainment unit. Not saying it's correct, my point is that it's all relative (even in a cavity, these things still sound better than most of the cheap speakers I've owned in past!).

I think Paul even comments that they are better placed on a riser:

"I originally built these to sit on my desk, but since they have very full bass (or as some might say "full BSC"), they sounded best put up on a little stand or risor. Once I did that, I absolutely fell in love with listening to them in the nearfield."

I've also built mine with mini-spikes, don't know if that helps?
 
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