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

Vintage JBL for subwofer
Vintage JBL for subwofer
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 14th March 2017, 10:56 PM   #11
conanski is offline conanski  Canada
diyAudio Member
 
Join Date: Mar 2013
Quote:
Originally Posted by academia50 View Post
Is it only possible to achieve sub bass tones with large Xmax and tremendous powers?
In general the lower the frequency the more driver xmax and amp power is required to reproduce it. How much power you need is directly related to the listening SPL you usually run at and your subwoofer design. If your design can reach the SPLs you need with only 20-70w then there is no need for more.. simple as that.


Quote:
Originally Posted by academia50 View Post
I'm thinking that instead of a classic cut of 6 db in a first order filter, it would be better 12 DB in the second order. The reason ? If there is too much bass overlap around the 80 Hz cut, I can invert the phase by 180 degrees (to compensate) by reversing the speaker connection)
Here is my 2 cents on that. You will want at least a 3rd order filter at 80hz because anything shallower allows too much midrange into the subwoofer, and same goes for your satellite speakers, at least a 3rd order high pass filter there too to eliminate the low bass that will just push those drivers to xmax even if they cannot reproduce any meaningful output at those frequencies. Because of this it's often easier to use an active crossover before the amplifiers and if you go that route get one with 4th order LR filters for best summing response.
  Reply With Quote
Old 15th March 2017, 08:33 PM   #12
academia50 is offline academia50  Argentina
diyAudio Member
 
Join Date: Jan 2013
Bear, and Conanski, thanks for your responses.

I have been reading and I see that each of the different topologies of the basic circuits of active filters have their pros and cons, there are no free lunches here .....

I understand that you have to go through some more elaborate commercial design with the possibility of controlling and adjusting the different variables, roll off, phases, gain, etc.

Any recommendations on this?
  Reply With Quote
Old 15th March 2017, 10:28 PM   #13
bear is offline bear
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Buy a plate amplifer with the built-in xover.

No need for a highpass filter, there's nothing down there unless ur running LP or some extraordinary CDs... maybe some video DVDs...
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]
  Reply With Quote
Old 17th March 2017, 10:33 PM   #14
academia50 is offline academia50  Argentina
diyAudio Member
 
Join Date: Jan 2013
Quote:
Originally Posted by bear View Post
Buy a plate amplifer with the built-in xover.

.......there's nothing down there unless ur running LP or some extraordinary CDs... maybe some video DVDs...

You have hit the nail ...... , this LP has very low frequencies .......


16 hertz are not audible but modulate to the lowest tones that we can hear ... also speak of using a subwofer to perceive in all its dimension the fantastic sound of these 6791 tubes.

Well, here I go then, DTQWTII exceeds in all audible parameters (they are excellent !) to these vintage JBL, less in the very low notes.

I think it's because the cabinet is a bass reflector. FS of the LE14C speaker and FB cabinet is much smaller than Eminence 2510 II.
Attached Images
File Type: jpg 014.JPG (843.8 KB, 188 views)
File Type: jpg 008.jpg (446.1 KB, 175 views)
  Reply With Quote
Old 17th March 2017, 11:17 PM   #15
bear is offline bear
diyAudio Member
 
bear's Avatar
 
Join Date: Apr 2002
Location: New York State USA
Best study up on reproducing 16Hz organ notes without doubling.

You can create the note with a single speaker as a direct radiator, but not the one you want to use, and not with much SPL down to the Fs of the driver. No free lunch to be had.
__________________
_-_-bear
http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]
  Reply With Quote
Old 18th March 2017, 05:24 AM   #16
Fenalaar is offline Fenalaar  Norway
diyAudio Member
 
Join Date: Apr 2011
When that filter is as much as $350, I'd use a MiniDSP 2x4 instead. It is much more flexible...

Johan-Kr
  Reply With Quote
Old 18th March 2017, 06:25 AM   #17
jazbo8 is offline jazbo8
diyAudio Moderator
 
jazbo8's Avatar
 
Join Date: Jan 2011
Location: In Transient
Vintage JBL for subwofer
For home use, just get a Behringer iNuke amp with built-in crossover and EQ.
  Reply With Quote
Old 18th March 2017, 08:41 AM   #18
bentoronto is offline bentoronto  Canada
diyAudio Member
 
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Vintage JBL for subwofer
Quote:
Originally Posted by academia50 View Post
You have hit the nail ...... , this LP has very low frequencies .......
Be skeptical (esp for LPs) until you've actually seen those low notes on a real-time analyzer such as included in REW (free or honourware).

The real low freq music you want to reproduce is the side drum as in Mahler's and Copland's 3rd symphonies. That's where the low note is to be found.

Exaggerated power and low freq requirements routinely pontificated on this forum without empirical basis.

B.
__________________
HiFi aspirations since 1957. Currently working on motional feedback again... the final frontier in audio (and just posted data for a folded 17-foot pipe sub)
  Reply With Quote
Old 18th March 2017, 08:25 PM   #19
academia50 is offline academia50  Argentina
diyAudio Member
 
Join Date: Jan 2013
Quote:
Originally Posted by Fenalaar View Post
When that filter is as much as $350, I'd use a MiniDSP 2x4 instead. It is much more flexible...

Johan-Kr

350 $ argentinos are 22 u $ s at this time. Not a great investment, but I will look for a better option, I have been convinced, it will not do much .......
I have this Yamaha 5.1 receiver, also the Prima Luna valvular amplifier that I use with DTQWTII, it has a bypass for HT ...... humm, and if I use the low level output of 5.1? This is for an active subwofer, I could use this option to go to the NAD 3020 / JBL, but I do not know how often the cut will be, nor the slope ....
I have to study this to see if it's possible

Any suggestions are appreciated!

RX-V520 - Stereo Receivers - Hi-Fi Components - Audio & Visual - Products - Yamaha United States


DiaLogue Two ? PrimaLuna USA
  Reply With Quote
Old 18th March 2017, 08:56 PM   #20
academia50 is offline academia50  Argentina
diyAudio Member
 
Join Date: Jan 2013
Quote:
Originally Posted by jazbo8 View Post
For home use, just get a Behringer iNuke amp with built-in crossover and EQ.
That is good news, Beringher is a very present brand here...

But they are products for PA, and something expensive for the investment I want to make at the moment ...


Behringer Inuke Nu-6000 Dsp Potencia Digital 6000w Usb - $ 17.990,00 en Mercado Libre



Friends, another question, class D (I do not know anything about the topology of these circuits ) admits to raising the loads in the output stage? I can use the JBL 8 Ohms as in a amplifier SS class AB without problems (losing power, which would be good for me ..... ) ?

Thanks in advance !
  Reply With Quote

Reply


Vintage JBL for subwoferHide 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
Reviving vintage JBL cabinets MichaelM86 Multi-Way 32 29th September 2014 02:02 PM
Vintage Richard Long Bertha/vintage JBL artscrafts14 PA Systems 6 5th July 2012 07:19 AM
FS: Vintage drivers- SEAS, JBL, Jensen, Bozak, etc GordonW Swap Meet 1 3rd April 2011 04:52 PM
Subwofer Filter Schematic Problem hernanstafe Parts 1 16th March 2007 09:15 AM
Scan Speak 21W8553 based subwofer. aeon Subwoofers 11 17th November 2004 05:50 PM


New To Site? Need Help?

All times are GMT. The time now is 05:12 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