Yamaha NS1000 crossover Tweaks

I just obtained a pair of NS-1000M for $500 that my friend a master cabinet / furniture refinisher, who works in the homes of multi-millionaires refinishing scratches in their mega-buck tables etc. Is going to completely sand down and refinish in the color Oxblood with a high gloss cover, as a favor for me.

I compared these NS-1000M directly against my Fostex FE208ES-R drivers with Fostex T-900a tweeters in Sachiko double-back-loaded horns and to say I was amazed at how good the NS-1000M sounded, would be an understatement! I was so impressed want to first rebuild the XO with today's high-quality components and if I like what I hear as much as I believe I will, I'll purchase a second pair of NS-1000M and stack & invert them on top of the first pair! So it will be W-M-T T-M-W on each side! Has anyone tried this yet? If so, what were the pros and cons of doing this sonically?

I'm listening to: For The Moment by Bob Mintzer Big Band

Thetubeguy1954 (Tom Scata)

Great score and good luck on the project! They should look great. I've never stacked them, I foolishly missed a chance to get another pair.

-Kent
 
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Joined 2002
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As I did with mine...
I did measure the old caps, and those 3,5uF did have nearly +/-1 uF difference. (each)
(I also mounted a pair of modern binding-posts, picture is before hot-melt-gluing)

Arne K
 

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I just obtained a pair of NS-1000M for $500 that my friend a master cabinet / furniture refinisher, who works in the homes of multi-millionaires refinishing scratches in their mega-buck tables etc. Is going to completely sand down and refinish in the color Oxblood with a high gloss cover, as a favor for me.

I compared these NS-1000M directly against my Fostex FE208ES-R drivers with Fostex T-900a tweeters in Sachiko double-back-loaded horns and to say I was amazed at how good the NS-1000M sounded, would be an understatement! I was so impressed want to first rebuild the XO with today's high-quality components and if I like what I hear as much as I believe I will, I'll purchase a second pair of NS-1000M and stack & invert them on top of the first pair! So it will be W-M-T T-M-W on each side! Has anyone tried this yet? If so, what were the pros and cons of doing this sonically?

I'm listening to: For The Moment by Bob Mintzer Big Band

Thetubeguy1954 (Tom Scata)

Check out Yamaha-NS1000
 
Yeah, I have long questioned the wisdom of a stacking. I guess it comes down to what you are after. It will work for a "wall of sound", but not for precise audio reproduction.

I, personally, rarely sit down in the sweet spot to try and extract the ultimate pinpoint imaging of the respective instruments (which is not to say that I don't appreciate it). I usually listen with the music wafting through the house while I'm doing something or other. I guess I'm one of those who would not find the inverted stacking of speakers objectionable. Until I sit down to listen critically.
 
Magnet

decca4 (hopefully you see this post, as the thread is seemingly dead).

I'm really taken with your magnet mod. I plan to start inquires today, aiming to acquire an applicable magnet.

I have the impression magnets are not intended to come off - how did you remove the magnet from its base (I assume they are permanently glued)?

Your info and pic: much apprreciated.
 
Hello jvd,

It is quit some time since I did this but this is my recollection of how I went about it.

As I recall the magnet together with the pool piece at the rear was not glued to the basket/cage. However the pool piece was glued to the magnet.

I took a thin medium sized knife and placed the edge at the perimeter where the magnet and pool piece meet. Then I used a hammer to hit the knife. Then I proceeded around the perimeter. This way the I managed to break up the glue joint. The magnet still sticks to the pool piece quit strongly and to separate those parts I used a hydraulic press. This was a rather easy task. If you don't have access to a press I suggest that you use some small wedges and press those into the gap you get when the knife is located between the magnet and the pool piece.

After separating the two pieces you will probably find that the surface of the magnet is somewhat uneven. This is of no consequent for it's function is this application.

If this is not totally clear please don't hesitate to come back with your questions.

The procedure is really not that difficult. The reward is a much tighter and more energetic low end.

Stefan
 
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It's great you've replied Stefan, THANKYOU.

I visited my local speaker 'doctor'. I made a cardboard template of the 1000 rear plate: he plans to find me old or new magnets to suit (and remagnetize if necessary). I shrunk a bit when he said that. Ooouch this is not going to be zero cost as I thought. But cost is not an issue with this hobby is it!
Said you can fit them, but you need to glue them in place, to allow for bump, transportation, earthquake etc. You don't want a magnet to fall onto a cone do you, he said, with a slightly concerned/wise look.
I'm out of town till next week so nothing will happen before then - a work in progress.
 
Step 5, a ring magnet was added to the woofer. At some point I replaced the dreadful binding posts with some proper ones.

Dear Sir
Can you eloborate on the point about adding a ring magnet to the woofer

what was the ring magnet you added, the polarity and function

I have seen a ring magnet on JBL woofers, I assumed it was for

cancelling stray magnetic field from Woofer Magnet

Robert Bose
 
Hi,
This is a very nice thread.
I've made my Yamaha NS-1000M's future proof and I hope my writing is of any interest to other Yamaha owners:

1) I took away the damping material behind the woofer and replaced it with 50 gramms of Twaron. Result: more bass. Not deeper, but more power and kick and detail; highly recommended. I think the original amount of glass wool behind the bass driver was a lot and added acoustically to the weight of the cone;
2) Then I replaced the glass-wool in the upper part of the cabinet behind mid and tweeter with 150 gramms of Twaron. Unfortunately this made the bass become less dramatic again, but still more bass and a bit deeper;
3) I rebuilt the filter and put it outside the speaker. I modeled the entire speaker to see where I was heading to while changing crossover values. The tweeter cap bevame 2,8 uF because the coil is a standard 0,27 mH/0,43 Ohms (in stead of the hard to find 0,3 mH/0,1 Ohm) and that alters the response slightly, a dB less under 3K so that's fine;
4) I've changed to 3rd order lowpass on the woofer with 4,7mH, 68uF+1,5 Ohms and 2,2mH. Coils are only 0,2 + 0,1 Ohm. This decreases the 200 Hz bump, bass sounds dryer now and a little deeper. If you like that high-bass sound then you better stay with the original 2nd order low pass.
The rest of the crossover has the original values. The caps are Obbligato MKP and Audyn Sn.
I think the speakers sound incredible, maybe like when new. Highs don't sound splashy at all anymore.

If you don't want to invest much money, you might as well just replace the damping behind the woofer with something more loose and replace the 2,7 uF cap with an MKP.

I didn't change internal wiring because the terminals on the domes seem too fragile to solder to me.
I had to change the rear plate. It's thick but vibrates more than the rest of the cabinet. Yamaha did a really good job here, using just 22mm. particle board but it is as dead as a dodo. How did they do that...
I noticed one tweeter is a little reduced in SPL. I've seen measurements of 4 tweeters at a german webmagazine that were all 4 very different. Thanks to the very good L-pad, I can increase the level of one of them.

An externally hosted image should be here but it was not working when we last tested it.
 
Reviving an old thread.
I am recapping a NS1000M using Polypropylene caps Audyn is what I am using through out.
Just for reference here is the Crossover schematic
An externally hosted image should be here but it was not working when we last tested it.


When I measured using my Capacitance meter all electrolytics measure more than their rated value...
C-1_1 = 55.4uF instead of 47uF
C-1_2 = 52.2uF instead of 47uF
C-1 Total = 105.6uF instead of 94uF
C-2=23.2uF Instead of 21uF
C-3=3.9uF Instead 3.5uF
C-4=4.7uF Instead of 2.7uF

So when I recap, should I use capacitance values close to there right now or just sticking with the values on the circuit diagram? Which is the better option?

I will have to add extra caps from 1uF to 10uF in parallel to stock circuit diagram values for different cases, if I want to reach the measured values.

Pics Below
C-1_1
IMG_2259_zpswh2hvbe7.jpg


C-1_2
IMG_2261_zpsxpn7vueo.jpg


C-2
IMG_2255_zpscm4ozbmg.jpg


C-3
IMG_2272_zpsiuibqqiu.jpg


C-4
IMG_2266_zps3uepktvn.jpg
 
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If it was me I would go for the values in the posted schematic. However I would also meausere the values for the inductances to see if these are the values in accordance with the schematic. Those coils ought to be very close to the original values as they are not likely to change over time as capacitors do.

When I recapped and changed the coils the result was far from satisfactory and I was disappointed with the result. However, I found that neither my new coils nor caps had the right values when meassured. So I had to buy more caps and adjust the values when not spot on. With the coils I had to ad a couple of turns and in some cases wind of a turn or two on some. The coils I changed to were air coils and that I would highly recommend. If you do go ahead with that project I highly recommend going for coils with the least possible resistance. They are not cheap but very well worth the cost IMO.

First I changed the caps and listended to the improvement and then changed the coils so that I could here how they contributed to the totality.

The above was my aproach but sound is highly personal and dependend on all the other components in your set up so if you think that everything sound fine now maybe you should stick with your meassured values.

I would also highly recumbend cleaning the I-pads with some cleaning fluid. It made a big difference regarding clarity in my system.
 
If it was me I would go for the values in the posted schematic. However I would also meausere the values for the inductances to see if these are the values in accordance with the schematic. Those coils ought to be very close to the original values as they are not likely to change over time as capacitors do.

When I recapped and changed the coils the result was far from satisfactory and I was disappointed with the result. However, I found that neither my new coils nor caps had the right values when meassured. So I had to buy more caps and adjust the values when not spot on. With the coils I had to ad a couple of turns and in some cases wind of a turn or two on some. The coils I changed to were air coils and that I would highly recommend. If you do go ahead with that project I highly recommend going for coils with the least possible resistance. They are not cheap but very well worth the cost IMO.

First I changed the caps and listended to the improvement and then changed the coils so that I could here how they contributed to the totality.

The above was my aproach but sound is highly personal and dependend on all the other components in your set up so if you think that everything sound fine now maybe you should stick with your meassured values.

I would also highly recumbend cleaning the I-pads with some cleaning fluid. It made a big difference regarding clarity in my system.

Thanks.... Especially for the link. I will read it now. I am just wondering whether the original designers used those +80 -20% tolerance caps and the design always took a mean value more than the printed value. Because even after 30years, caps are reading more than the printed value not less. That is why I wanted to know the best is to match at least the current measured value(which is higher) than what is in the schematic.
 
The Graveson kit comes with extra resistors to allow fine tuning of the MR and HF to suit your taste.
IMHO, you should always replace caps with schematic target values, not what you recently measured which could easily represent aging and drifting from target. Especially with electrolytics.

As far as I know, electrolytics only will lose capacitance won't increase the capacitance as they age. So yes they may have drifted from an even higher value. Definitely not from a lower value.... Hope you get the drift :)

And schematic values are even lower... So the effective capacitance is gonna be even lower than what was there before with electrolytics. That is my confusion.
 
I personally have measured vintage caps that have drifted upward. Some downward as well. The key point I tried to make is replace with values the same as printed on the cap you are replacing or on a schematic. DON'T trust measurements of vintage lytics as a guide for targeting uF values.
Don't forget ESR as well. That also drifts upward making the cap behave more like a resistor.