Hi all,
I can see there’s a lot of experience of the NS1000M here, so maybe someone can help me?
I’ve just joined the club with a really nice lateish pair, and want to start tweeking them. I want to initially go active on the bass, and use a simplified crossover on the mid/tweeter. I will use an active crossover for bass to mid at 500hz LR 4th order, so don’t need a low pass on the mid. And I want a simple mid HP filter / tweeter LP filter, 2nd order, with no L pads.
So what is the consensus for cap and inductor values for what I want to do:
1) Stick with the Yamaha values as they are now?
2) Or is there a better crossover point to aim for? If so what are the values I need.
I’ll be using low power class A on the mid/high, and class D for the bass.
Cheers,
Jonathan
I can see there’s a lot of experience of the NS1000M here, so maybe someone can help me?
I’ve just joined the club with a really nice lateish pair, and want to start tweeking them. I want to initially go active on the bass, and use a simplified crossover on the mid/tweeter. I will use an active crossover for bass to mid at 500hz LR 4th order, so don’t need a low pass on the mid. And I want a simple mid HP filter / tweeter LP filter, 2nd order, with no L pads.
So what is the consensus for cap and inductor values for what I want to do:
1) Stick with the Yamaha values as they are now?
2) Or is there a better crossover point to aim for? If so what are the values I need.
I’ll be using low power class A on the mid/high, and class D for the bass.
Cheers,
Jonathan
If you stay with the current values then it's possible they make a good rolloff. Your active version is less likely to be correct unless you follow the output of the speaker, not the filter.
Maybe you could measure them. There are different ways, some easier. Or maybe you'd prefer to tune it by ear?
Maybe you could measure them. There are different ways, some easier. Or maybe you'd prefer to tune it by ear?
Thanks for this.
Can you clarify what you mean by the active version being less likely to be correct please?
The active crossover I use is easy to change for slope and frequency, so I can easily measure the combined response of the bass / mid. I could measure the drivers individually too I guess, but that's a lot more work.
There is a lot more than just slope and cut-off frequency. The filter transfer functions of an xover in a (good) real-world loudspeaker is usually (very) different from a simple textbook filter. You'll want to measure the transfer function of the woofer filter and then replicate this with your new active filter to get the correct result.
But... why do you want to do what you described (active bass, simplified mid/tweeter filter)? What do you want to achieve?
But... why do you want to do what you described (active bass, simplified mid/tweeter filter)? What do you want to achieve?
That is kind of a step in the right direction.
Any chance you'd want to measure the electrical response to your woofer to know where to set your filter?
Are you talking about the electronic filter transfer function as measured at the terminals of the drivers, or about the acoustic response of the drivers?
Getting a good measurement of the electronic transfer function is easier than the acoustic response.
Sure. But the data of the "transfer function" for the woofer filter already exists. So I'll be copying that in the active domain, adjusting the filter slopes too, and then measuring the actual results. And because the parameters can be so easily changed its straightforward to get the optimal filter settings this way.
I don't really get the point you're making with this question. But overall I'm wanting to assess the maximum potential of the Beryllium drivers, to see what SQ they're capable of. They certainly aren't maximised at the moment, and going active on the bass also allows the mid/top to run at their full efficiency.
Yes, though that information already exists, so I already know where to set it.
But to be honest, if the mid/top provides the level of performance I'm looking for, I'd change the bass driver anyway, as that seems to be the weak point on these. And so by going active with a modern 12" driver in a slightly larger cabinet would be where I'd probably end up.
Yamaha made such a model NS-500YST (Yamaha Servo Technology), which I have in my Beijing basement, though I've never opened them up to check the XO/amps. Perhaps information can be found online. I ran the beryllium-coated mid+hi with tubes or 30W Class A Luxman, and added a super-tweeter.
Can you show the filter transfer function of the woofer here? I'd be interested to see if/how this can be approximated by setting the cutoff frequency and filter slope only.
If you replace the passive woofer filter with an active filter+amp, the mid+tweeter will still work exactly the same as before. If you want to improve the efficiency, you'll have to change the mid/tweeter xover, possibly revise it substantially. Can you show the xover schematic here?
Follow up question: why do you need higher efficiency from the mid+tweeter? Do you have a "weak" amp and want to go louder?
If you replace the passive woofer filter with an active filter+amp, the mid+tweeter will still work exactly the same as before. If you want to improve the efficiency, you'll have to change the mid/tweeter xover, possibly revise it substantially. Can you show the xover schematic here?
Follow up question: why do you need higher efficiency from the mid+tweeter? Do you have a "weak" amp and want to go louder?
The drivers not loses it"s efficiency, the crossover just changes how many electrical power is delievered to them. Maybe you can remove attenuator resistors from the mid/high crossover section (but this is not at all certain) if you convert the bass to active, but otherwise I guess Yamaha did a good job to maximize the potential of these Be drivers.
mbrennwa is already ahead of me with the questions I would ask, so to just quickly expand on the first point.. you may possibly want multiple filters to roll off the woofer rather than just one.
A general response given the replies here so far. I posted my questions to those who had experience with the NS1000, having seen a number of posts here about folks wanting to improve the performance of their own speakers.
What I feel that I'm getting so far are questions or comments based on the theory of operation of crossovers active or passive, rather than any real experiences being shared.
Can anyone help me that has actual experience of these having made crossover changes either passive or active? And I don't mean just pointing to those who make passive replacements of the whole crossover! 👍👍
What I feel that I'm getting so far are questions or comments based on the theory of operation of crossovers active or passive, rather than any real experiences being shared.
Can anyone help me that has actual experience of these having made crossover changes either passive or active? And I don't mean just pointing to those who make passive replacements of the whole crossover! 👍👍
I have no direct experience with the NS1000, but I do know a thing or two about xovers. If what you want to do has been done successfully before just go ahead and repeat those changes. Otherwise, no one will be able to provide detailed step-by-step instructions to modify the xover circuit. There will be no way around a (partiall) re-design of the xovers in your speakers.
Well, a quick search of NS-500YST vs NS-1000M shows the 10" YST active server with feedback goes much deeper 22hz vs 40hz and has greater sensitivity 92dB vs 90dB.
https://www.audiokarma.org/forums/index.php?threads/yamaha-ns-500yst-opinion.942886/
https://audio-heritage.jp/YAMAHA/speaker/ns-500yst.html
http://audionostalgia.co.uk/yamaha-ns-1000-m-review/ (with images of components)
Adjusting the pots then measure & replace with fixed-value Rs should help.
https://www.audiokarma.org/forums/index.php?threads/yamaha-ns-500yst-opinion.942886/
https://audio-heritage.jp/YAMAHA/speaker/ns-500yst.html
http://audionostalgia.co.uk/yamaha-ns-1000-m-review/ (with images of components)
Adjusting the pots then measure & replace with fixed-value Rs should help.
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p.s. NS-500YST 30+120+250mm XO 250hz, 4khz (12dB/oct) according to the Japanese page (which I cannot read); NS-1000 Monitor 30+88+300mm XO 500hz, 6khz.
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Thanks, interesting to know, I didn’t know about these.
Although they’re a similar concept to what I’m wanting to do, unless they had exactly the same drivers as the NS1000 and were driven using line level inputs, it’s not going to help me unfortunately. That’s aside of the fact that I can’t find any info of the electronics online!
Although they’re a similar concept to what I’m wanting to do, unless they had exactly the same drivers as the NS1000 and were driven using line level inputs, it’s not going to help me unfortunately. That’s aside of the fact that I can’t find any info of the electronics online!
I do appreciate your input, though as you say with no experience of what I’m trying to do it doesn’t help me get a quick solution.
I too know a thing about crossovers, having been making speakers for 40 years now. I also know how much time DIY’ing things from scratch takes, hence me asking for experience with these!
The mid and tweeter are being attenuated to match the bass driver. Even though the two attenuators imply otherwise! That’s just one reason why I want to modify them.
The other being that I want to remove the passive crossover parts that affect sound quality the most.
I’m sure Yamaha did the best job they could in the 70’s given the budget levels they were aiming for. But many improvements can be made now, especially since improved components and understanding about crossovers. Linkwitz and Riley hadn’t even published their paper at that point!
Maybe the quickest solution would be to measure the electronic filter transfer functions of all three drivers, and replace the entire passive x-over with an active system that implements these filter functions. Should be relatively easy to do with a DSP based active filter.