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

Second Voice Coil For Bass Boost
Second Voice Coil For Bass Boost
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
Thread Tools Search this Thread
Old 16th June 2018, 09:16 PM   #11
anthonybisset is offline anthonybisset  Japan
diyAudio Member
Join Date: Aug 2007
Nice thought experiment. Seems easy enough to implement. Some accuracy is sacrificed however it's hard to say if it would really sound bad or not. "Good" is incredibly subjective, especially with bass reproduction. Given the desire for small volume enclosure it might be worth the trade off. In the interest of exploration, I say push forward if you like experimenting.

fwiw, there are many cabinet geometries that people enjoy which mangle the phase at least as badly as what you're proposing.
  Reply With Quote
Old 16th June 2018, 09:27 PM   #12
Einric is offline Einric  United States
diyAudio Member
Einric's Avatar
Join Date: Feb 2011
Location: Bozeman, MT
Second Voice Coil For Bass Boost
Thanks for the encouragement!
I may proceed with this thought experiment at some point once I clear my plate of more important projects.
  Reply With Quote
Old 16th June 2018, 09:28 PM   #13
Einric is offline Einric  United States
diyAudio Member
Einric's Avatar
Join Date: Feb 2011
Location: Bozeman, MT
Second Voice Coil For Bass Boost
.5 Woofer as in adding a second woofer to a 2way but rolling off the second woofer to compensate for baffle step losses.
Similar concept but using 2 woofers instead of 2 VC's on a single woofer.
  Reply With Quote
Old 16th June 2018, 09:33 PM   #14
scottjoplin is offline scottjoplin  Wales
diyAudio Member
scottjoplin's Avatar
Join Date: Dec 2015
Location: Penrhyndeudraeth
Gotcha, I can't see there being a difference as regards phase distortion, as Anthony says, may well not be noticeable
Woofer Assisted Wideband is the New Testament renounce the anachronistic acronym FAST
  Reply With Quote
Old 16th June 2018, 10:03 PM   #15
tsmith1315 is offline tsmith1315  United States
diyAudio Member
tsmith1315's Avatar
Join Date: Jul 2003
Location: Doerun, GA
Originally Posted by Einric View Post
However, if the natural F3 sealed of a single VC is 70hz and you add in the second VC at 1/2 octave below that around 50hz or so

Maybe I'm missing something....?
Originally Posted by scottjoplin View Post
The phase shift
And the change in driver Q if your filter knee is this low.
  Reply With Quote
Old 16th June 2018, 10:52 PM   #16
JMFahey is offline JMFahey  Argentina
diyAudio Member
JMFahey's Avatar
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Short answer: it wont do what you want.

It won+t "go lower" by any means: 2 boxes same size, same speakers, will sound the same, have same resonant frequency, rolloff the same, just will sound louder (but at same frequencies as before) because of acoustic cross coupling and plain old pulling more power out of your amp simply because halved impedance.

"Cheating" by making the crossover frequency lower than the rolloff point wont help much, if at all , because you are helping a weakened speaker (at that lower frequency) with another equally weakened speaker, so ....

There was an old proverb about "the blind leading the blind" .... some variation might apply here.

If anything, try putting your original speaker inside a doubled volume cabinet and see where that leads you.

After all, you *already* accepted a second cabinet.
Design/make/service musical stuff in Buenos Aires, Argentina, since 1969.
  Reply With Quote
Old 17th June 2018, 12:29 AM   #17
bentoronto is offline bentoronto  Canada
diyAudio Member
Join Date: Jan 2008
Location: Toronto and Delray Beach, FL
Second Voice Coil For Bass Boost
With the output of an accelerometer stuck to the dust cap, you could direct it to the second voice coil as corrective motional feedback.

Think about that.

HiFi aspirations since 1957. Currently working on motional feedback again... the final frontier in audio (also, see recent post with data on a 17-foot labyrinth sub)
  Reply With Quote
Old 18th June 2018, 02:36 AM   #18
Jared is offline Jared
diyAudio Member
Join Date: Sep 2002
Location: Raleigh NC
Send a message via AIM to Jared
This thread has me pondering what value there might be from using a larger woofer as a passive radiator, and then wiring some passive components to the passive woofer to adjust the response / tuning of the passive radiator.
  Reply With Quote
Old 20th June 2018, 09:35 AM   #19
wolf_teeth is offline wolf_teeth  United States
diyAudio Member
wolf_teeth's Avatar
Join Date: Mar 2006
Location: Indiana
Jared, look up the Sonus Faber Extrema version 2. That has an active coil PR with resistance across it.

As to the X.5 method with a DVC driver, Focal used to have kits like that in a 2-way. In terms of subwoofers, you'd get the +6dB below the Fc of the coil, just like in BSC, where the bass range halves the impedance. However, the Fc of the coil if low enough can cause an additional boost in combo with the driver's Fs. You might even get more output than expected, but the DVC will still only have the same Fs and Mms. It's likely more output can be put in a certain range if required, but actually going lower really can't be done unless changing the box or trying the 3rd order sealed response, or going with active means of some sort.

Photobucket picture pages: http://photobucket.com/Wolf-Speakers_and_more
Writeups/thoughts/blogs: http://techtalk.parts-express.com/blog.php?u=4102
  Reply With Quote


Second Voice Coil For Bass BoostHide 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
winding voice coil, reconing to bass guitar speaker, delta 10's, sdk-10, eminence 10 Flameworker Multi-Way 10 6th February 2015 03:07 PM
Voice coil Magnasanti Construction Tips 3 20th June 2012 12:37 PM
Voice Coil TheReaper Subwoofers 4 27th October 2011 06:11 PM
Single Voice Coil Vs Double Voice Coil Subwoofer kASD Car Audio 6 12th April 2007 07:36 AM
ASV voice coil ? Nihilist Multi-Way 4 1st October 2006 08:16 PM

New To Site? Need Help?

All times are GMT. The time now is 09:47 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio