Cases for NS1000 Cross-Overs

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reffc
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Re: Cases for NS1000 Cross-Overs

Post by reffc » Mon Mar 11, 2019 11:26 pm

Be careful with that. Measuring suspect pots can yield false news ;)

To measure...use multimeter and first measure series connections (ie for mid...measure in "normal" switch setting between orange and yellow wires for series values and between orange and black for parallel).

YNWaN
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Re: Cases for NS1000 Cross-Overs

Post by YNWaN » Tue Mar 12, 2019 9:06 am

MTPapaDan wrote:
Mon Mar 11, 2019 10:11 pm
How would one go about cleaning those "tone controls" correctly? Hose them down with circuit cleaner while turning them full range? I ask because mine seem a bit "scratchy". When "tuning" them I discovered a couple of dead spots in each control in each speaker? Probably were set there by previous owner. Perhaps I should just remove them like Mark did? I'll have to find where he explained how to choose values for the "new" circuit.
Yes, to clean them you squirt switch cleaner into any gaps and give them lots of turns back and forth - not much else you can do. I'm concerned you are finding dead spots though - that certainly suggests a good cleaning is required! They will always feel a bit scratch as they consist of a wiper arm moving over a wire wound coil (rather than the conductive plastic film of many potentiometers). I just adjusted mine to the position at which I preferred the sound and then measured them (the pots that is - directly at their terminals after removing them - just as Paul recommends above). I also adjusted the individual resistor values to give a true 8Ohm load rather than the close approximation the pots provide.
Mark

reffc
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Re: Cases for NS1000 Cross-Overs

Post by reffc » Tue Mar 12, 2019 1:16 pm

The Lpads shouldn't really sum to 8 Ohms. This might be the stated nominal impedance, but the system impedance curve at both crossover points is well away from this. LF/Mid crossover impedance value is circa 6 Ohms and mid inpedance at HF crossover is about 7 Ohms. HF is circa 6 ohms at crossover, rising to 7 Ohms at 20KHz. I'll post accurate individual impedance values next week when I set up the simulation model.

reffc
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Re: Cases for NS1000 Cross-Overs

Post by reffc » Tue Mar 12, 2019 4:44 pm

Progress photos:


Image

Image

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ChrisOH1
Posts: 147
Joined: Tue Jan 02, 2018 9:58 am

Re: Cases for NS1000 Cross-Overs

Post by ChrisOH1 » Tue Mar 12, 2019 4:50 pm

Looking very smart Paul :-)

karma67
Posts: 222
Joined: Sat Sep 08, 2018 12:19 pm

Re: Cases for NS1000 Cross-Overs

Post by karma67 » Tue Mar 12, 2019 5:13 pm

top work paul,nice ash veneer too.
by the way,after reading your comments about the pot positions i tried adjusting mine,i normally have the hf at 10 to 12 and mid at 5 to 12.
after reading i turned them both to their minimum setting and slowly adjusted them till i got a good balance (learning to trust my ears).
guess what,i found the same as you,i ended up with the hf at just below normal and the mid at just above -3db. with this setting there appears to be a lovely balanced sound,i should have done this ages ago!

MTPapaDan
Posts: 436
Joined: Fri Oct 25, 2013 7:52 pm

Re: Cases for NS1000 Cross-Overs

Post by MTPapaDan » Tue Mar 12, 2019 6:52 pm

YNWaN wrote:
Tue Mar 12, 2019 9:06 am
MTPapaDan wrote:
Mon Mar 11, 2019 10:11 pm
How would one go about cleaning those "tone controls" correctly? Hose them down with circuit cleaner while turning them full range? I ask because mine seem a bit "scratchy". When "tuning" them I discovered a couple of dead spots in each control in each speaker? Probably were set there by previous owner. Perhaps I should just remove them like Mark did? I'll have to find where he explained how to choose values for the "new" circuit.
Yes, to clean them you squirt switch cleaner into any gaps and give them lots of turns back and forth - not much else you can do. I'm concerned you are finding dead spots though - that certainly suggests a good cleaning is required! They will always feel a bit scratch as they consist of a wiper arm moving over a wire wound coil (rather than the conductive plastic film of many potentiometers). I just adjusted mine to the position at which I preferred the sound and then measured them (the pots that is - directly at their terminals after removing them - just as Paul recommends above). I also adjusted the individual resistor values to give a true 8Ohm load rather than the close approximation the pots provide.
When I said scratchy I was referring to the sound as I adjusted them. None the less, they still need cleaning. I've always left them at normal position and used the Anthem preamp ARC initially and it's DSP finally to tailor sound. Suddenly :o I am convinced I need to get the nominal ohms values for HF and Mid and remove the LPads from the circuit. Is any old switch cleaner OK? Any one recommend a certain brand? Some are just cleaners and some also include lubricants? Our only Radio Shack closed 3 years ago and I have to order on line.

YNWaN
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Re: Cases for NS1000 Cross-Overs

Post by YNWaN » Tue Mar 12, 2019 6:54 pm

Oh, really, scratchy when adjusting them! Mine definately didn’t do that, so it seems like a thorough clean would be a good idea.

I mainly removed mine as a statement of purity rather than a genuine belief that they harmed the sound. Having said that I can easily make you some blancking plates if you want to remove them and replace them with fixed value resistor networks (I created blanking plates for mine but filled the holes in instead - I still have the CAD drawings though and can easily laser cut acrylic replacements.
Mark

MTPapaDan
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Joined: Fri Oct 25, 2013 7:52 pm

Re: Cases for NS1000 Cross-Overs

Post by MTPapaDan » Tue Mar 12, 2019 6:58 pm

Paul, really like those crossovers your building. Sharp!

MTPapaDan
Posts: 436
Joined: Fri Oct 25, 2013 7:52 pm

Re: Cases for NS1000 Cross-Overs

Post by MTPapaDan » Tue Mar 12, 2019 7:10 pm

YNWaN wrote:
Tue Mar 12, 2019 6:54 pm
Oh, really, scratchy when adjusting them! Mine definately didn’t do that, so it seems like a thorough clean would be a good idea.
I will clean them. I really wish I had the time and finances to build external XOs. Unfortunately I don't have the time as I spend most working on the Galaxie. I really should post pix of the progress. Most improvements are under hood and in frame/suspension. She doesn't look that different externally. I did however color sand at 1500 and 2500 grit and rebuff entire car to get rid of those horrible vertical paint marks. My neighbor says it's now a 2 footer. You have to get within 2 feet to see any paint defects. That's a whole lot better than $15 to $20 K paint job.

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