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Protecting Yamaha NS-1000M woofer with active high-pass filter?
Protecting Yamaha NS-1000M woofer with active high-pass filter?
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Old 5th October 2018, 02:03 PM   #11
chris661 is offline chris661  United Kingdom
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Quote:
Originally Posted by XScorpius View Post
Will try!





Hmm, you sure about this? I read a review where it was emphasised that closed enclosure of 1000m produces accurate bass because of its 12dB/oct slope and thus lowQ (0.5). Would LR4 mess up this?


Subs are being integrated beautifully already with dSpeaker antimode
If you want to protect the speakers from very low frequency signals, you need to add another layer of filtering. Since you're running a MiniDSP, it ought to be pretty easy to try adding the filter and see what you think.

That said, if you're happy with how the system sounds at the moment (ie, the only sign of trouble is when you play a full-level 20Hz sine tone), my advice would be to stop worrying! Direct-radiating speakers will tell you if they're distressed.

Chris
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Old 5th October 2018, 02:43 PM   #12
fatmarley is offline fatmarley  England
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Originally Posted by XScorpius View Post
Please read my original post. Adding port to my speaker, (especially to NS-1000M) is suboptimal solution at best..
So you've never tried it. The simulations say it will improve things with no negatives but you know best. Fair enough, you want to do it with dsp but for anyone else who's reading this and hasn't got a closed mind, try it. It's not "a suboptimal solution" at all.
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Old 5th October 2018, 02:49 PM   #13
chris661 is offline chris661  United Kingdom
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Originally Posted by fatmarley View Post
So you've never tried it. The simulations say it will improve things with no negatives but you know best. Fair enough, you want to do it with dsp but for anyone else who's reading this and hasn't got a closed mind, try it. It's not "a suboptimal solution" at all.
I'm afraid you're mistaken.
A ported box will reduce cone excursion around the port tuning frequency, but the woofer is no longer protected by the cabinet air-spring. Below the port tuning, it will flap around a lot more than the sealed box, meaning damage is actually more likely.

Check your work by extending the frequency axis to 10Hz.

Chris
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Old 5th October 2018, 03:23 PM   #14
marco_gea is offline marco_gea  Italy
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Quote:
Originally Posted by chris661 View Post
I'm afraid you're mistaken.
A ported box will reduce cone excursion around the port tuning frequency, but the woofer is no longer protected by the cabinet air-spring. Below the port tuning, it will flap around a lot more than the sealed box, meaning damage is actually more likely.

Check your work by extending the frequency axis to 10Hz.

Chris
Correct. But, there is no input at 10Hz to begin with, in a fully digital front end!
With vinyl there is, as I said before, and then active filtering is required.
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Old 5th October 2018, 03:40 PM   #15
Zvu is offline Zvu  Serbia
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How does the port resonance influences the sound with such long ports ? It is always quite low and thus almost omnidirective at that frequencies.

I know about the effect but never tried it because i never worked with woofers that are good for sealed cabinets.
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Old 5th October 2018, 04:24 PM   #16
chrisb is offline chrisb
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I’d be inclined to trust that the original designers at Yamaha had good reasons for going with sealed, and wouldn’t second guess them. The NS1000, or even the 690 and 670 had to my ears very well balanced performance across their entire range- certainly more so than some of the larger ported Marantz multi-ways that we’re in the showrooms when I was in retail in the mid - late 70s.

Richie00boy’s numbers probably couldn’t hurt.
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Old 5th October 2018, 05:14 PM   #17
marco_gea is offline marco_gea  Italy
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Originally Posted by chrisb View Post
I’d be inclined to trust that the original designers at Yamaha had good reasons for going with sealed, and wouldn’t second guess them. The NS1000, or even the 690 and 670 had to my ears very well balanced performance across their entire range- certainly more so than some of the larger ported Marantz multi-ways that we’re in the showrooms when I was in retail in the mid - late 70s.

Richie00boy’s numbers probably couldn’t hurt.
Those Marantz multi-ways probably employed Woofers with very different Thiele-Small parameters, housed in Reflex boxes tuned much higher (I'd guess around 40Hz).

Bottom line: you shouldn't automatically assume that all bass-reflex alignments sound the same ;-)
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Old 5th October 2018, 05:56 PM   #18
chris661 is offline chris661  United Kingdom
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Originally Posted by marco_gea View Post
Correct. But, there is no input at 10Hz to begin with, in a fully digital front end!
Sure there is. Church organ CDs, recording studio mistakes, etc etc.

I have a spectrum analysis of a close-mic'd kick drum somewhere. 16Hz is -3dB on 32Hz.

Chris
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Old 5th October 2018, 06:09 PM   #19
richie00boy is offline richie00boy  United Kingdom
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Protecting Yamaha NS-1000M woofer with active high-pass filter?
Whether porting is best or not, these are legendary and expensive speakers, and opting to cabinet is going to slaughter their monetary value. So in this case electronics is the solution. An electronic solution will also protect the voice coil, porting can never do that.
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Last edited by richie00boy; 5th October 2018 at 06:11 PM.
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Old 5th October 2018, 06:38 PM   #20
fatmarley is offline fatmarley  England
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Originally Posted by richie00boy View Post
Whether porting is best or not, these are legendary and expensive speakers, and opting to cabinet is going to slaughter their monetary value. So in this case electronics is the solution. An electronic solution will also protect the voice coil, porting can never do that.

Thought this was obvious, but I'd only suggest a port if someone was going to build new cabinets, or if there was somewhere on the cabinet that could be used as a port without damaging anything (L-pads holes?).

Why would you need to protect the voice coil? Are the voice coils known to be easily damaged on NS1000s?
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