Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Protecting Yamaha NS-1000M woofer with active high-pass filter?
Protecting Yamaha NS-1000M woofer with active high-pass filter?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 5th October 2018, 06:48 PM   #21
fatmarley is offline fatmarley  England
diyAudio Member
 
Join Date: Aug 2003
Location: Cheltenham
Quote:
Originally Posted by chris661 View Post
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
Always thought cd was 20hz to 20khz. Assuming you're right, there may be the odd cd that goes below 20hz. Not that that means anything because it depends how loud it's recorded at that low frequency, how loud the person is listening, and also, the port isn't brickwalled at 20hz so does offer some protection below that frequency.

Subjectively I don't think it would make any difference. I can't even imagine how many ported speakers there are out there tuned much higher than 20hz and yet still have tight bass (the last two I built a perfect examples for me, and i'm a big fan of sealed boxes)

As I said before my tv speakers are tuned to 18hz and the bass is just as tight as when they were a sealed box. The proof in the pudding is in the eating, as they say.
  Reply With Quote
Old 5th October 2018, 08:50 PM   #22
chrisb is offline chrisb
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by marco_gea View Post
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 ;-)
I donít think I suggested that all BR alignments sound ed the same, some well engineered commercial systems may even lack the excessive kick-drum punch that was likely targeted to the intneted demographic market of the day. I simply found that all the sealed box systems in the store - AR, Advent, EPI, Burhoe, Genesis, KLH, Yammy, Dahlquist, to name just a few , had smoother bass extension, and were far less fatiguing over extended listening.

What Iíd be worried about is that in attempting to port a design that was quite likely optimally engineered as sealed, one might find the enclosure volume too small. With only one exception - those crazy large ear shaped plastic cones- I found the entire Yamaha Natural Sound series of the late 70s easily the equal of all the other speakers in the shop at each price point, and only surpassed by the Quad ESL, AR LST, and with sufficient budget for the required power and room, the Dayton Wright XG8.
__________________
on hiatus from active posting
  Reply With Quote
Old 5th October 2018, 09:51 PM   #23
goodlionaudio is offline goodlionaudio  United States
diyAudio Member
 
Join Date: Jul 2011
Location: Columbia, MD
Default I would worry more about the berylliums

Assuming your tube SET amp is significantly less powerful than your Luxman, I would not worry so much about the woofers; by the time it becomes an issue, the SET amps have run out of steam already.
  Reply With Quote
Old 7th October 2018, 03:47 PM   #24
XScorpius is offline XScorpius  Finland
diyAudio Member
 
Join Date: Dec 2013
Quote:
Originally Posted by fatmarley View Post
Why would you need to protect the voice coil? Are the voice coils known to be easily damaged on NS1000s?

Indeed, as far as I know, this is the case. Gavensen also mentioned this in his work:
"Left: Voice coils wound on paper doesn't allow excessive power handling and Yamaha wisely added a sticker to the rear of the speaker stating:
"Do not exceed the speaker's maximum input capacity". Should be on all speakers."


Quote:
Originally Posted by goodlionaudio View Post
Assuming your tube SET amp is significantly less powerful than your Luxman, I would not worry so much about the woofers; by the time it becomes an issue, the SET amps have run out of steam already.

I have active crossover, thus those pesky L-pads can be eliminated. My measures indicates that berylliums gained 7.2 dB (!!!!) sensivity due to fact that woofer - mid/tweeter are no longer necessary to balance with L-Pads. Those berylliums are very effective (93 dB sensitivity).


Which means I can use more than 4 times less power with same output...So my feedback-less SET tube amp (3W to Class A - 15W to Class B) is effectively 12W - 60W
  Reply With Quote
Old 11th October 2018, 10:53 PM   #25
goodlionaudio is offline goodlionaudio  United States
diyAudio Member
 
Join Date: Jul 2011
Location: Columbia, MD
Default series capacitor

It just dawned on me that you could add a series capacitor to reduce subsonic frequencies. If calculated properly,
it will extend the low frequency response, keep the alignment, and reduce ultra low frequencies from reaching the woofer. There are several papers describing this concept. The one I remember is from Thiele in AES (sorry have no reference handy).
  Reply With Quote
Old 12th October 2018, 07:38 AM   #26
chris661 is offline chris661  United Kingdom
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Quote:
Originally Posted by goodlionaudio View Post
It just dawned on me that you could add a series capacitor to reduce subsonic frequencies. If calculated properly,
it will extend the low frequency response, keep the alignment, and reduce ultra low frequencies from reaching the woofer. There are several papers describing this concept. The one I remember is from Thiele in AES (sorry have no reference handy).
It wouldn't keep the alignment. You'd get an 18dB/octave rolloff starting at a lower frequency.

Finding a decent-quality (ie, not electrolytic) cap in the 100s of uF range is tricky and expensive.

Chris
  Reply With Quote
Old 12th October 2018, 11:57 AM   #27
marco_gea is offline marco_gea  Italy
diyAudio Member
 
Join Date: Apr 2005
Location: London, UK
Quote:
Originally Posted by chris661 View Post
It wouldn't keep the alignment. You'd get an 18dB/octave rolloff starting at a lower frequency.

Finding a decent-quality (ie, not electrolytic) cap in the 100s of uF range is tricky and expensive.

Chris
Just for kicks, I modelled this option too:

see below for the effect that 660uF of series capacitance would have on the NS-1000's woofer frequency response and impedance (in the same 50L closed box).

Incidentally, four good quality MKP 330uF capacitors (two per side, parallel connected) would end up costing about £ 180, so yeah, not cheap.
Attached Images
File Type: gif NS-1000+cap FR.gif (17.1 KB, 16 views)
File Type: gif NS-1000+cap Z.gif (19.4 KB, 16 views)
  Reply With Quote

Reply


Protecting Yamaha NS-1000M woofer with active high-pass filter?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Yamaha NS-1000M active crossover? XScorpius Multi-Way 2 25th June 2016 05:19 PM
WTB: Yamaha NS-500M or Yamaha NS-1000M speakers Aerolite360 Swap Meet 0 28th February 2013 01:58 AM
Variable active high pass filter . lio nuite Analog Line Level 0 14th April 2012 05:44 AM
Active High-pass filter for Horn Subs Eddie Wolve Parts 5 21st July 2009 05:47 PM
high gain 2nd order high pass active filter topology sreten Solid State 21 23rd March 2006 01:26 AM


New To Site? Need Help?

All times are GMT. The time now is 05:15 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki