Found a great little bass extender - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 22nd January 2007, 01:38 PM   #1
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Default Found a great little bass extender

I've placed this in the loudspeaker forum as I thought this could benefit a lot of loudspeaker builders. This circuit is available in kit form at this site.

I was looking for something to add some lower bass to a large pair of bookshelf speakers (Peerless 850122 woofers) that's used secondary system. The idea was to have extra extension when playing some DVD's with good musical soundtracks (not action flicks as there's a HT setup for those). The system does not warrant a small sub, even though it had one in the past that was rarely used, so this seemed a good solution. Bass extenders I have heard in the past tended to sound like a bad loudness button.

The BassXt was first tested with a small loudspeaker that's in an undersized box where the F3 is 62Hz but 48Hz in the correct size box. The woofer is the PAE 14WG08 (Vifa BC14WG49-08) which has limited power handling so would be a good candidate to see if there would be any over driving. Not only did the BassXt restore the lower end bass, it improved on the larger box extension as well as controlling the woofer better. There were no crazy excursions and it was very well controlled. So the bass went lower and the power handling capabilities went up. The tonal quality of the bass was very good (depends on the driver of course) and natural with no boom or one note qualities. The same happened when tried with the Peerless 850122 woofer design and the F3 went from 47Hz down to well below 40Hz which is enough to enhance the selected movies where I wanted better bass from the soundtrack. This speaker now sounds more like a floorstander with a fuller sound in the bass.

In these speakers, it was not implemented to replace a subwoofer, but to extend and enhance the bass capabilities that were already there. I'm sure that port tuning (lower Fb) to give a under damped response would have even more gains but no port re-tuning was done during my tests and final use.

The circuit and layout is extremely simple with a 12VAC (plug pack) in, power switch, in RCA and out RCA. In the final application it's placed in the tape circuit so hitting a monitor button on the amp will put it in or out of the signal path. In the first test it was placed between the CD player and the pre amp but one will be built into the pre amp so it can be switched in as required.

I am not affiliated with the designer but I got quite excited with the results so thought this could be a great solution for those looking for a bit of extra bass extension. It worked out cheaper than a small woofer and the box was built from scrap material.... woohoo.
Attached Images
File Type: jpg gbbassxt.jpg (93.5 KB, 956 views)
__________________
No longer DIY active
  Reply With Quote
Old 22nd January 2007, 01:40 PM   #2
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Default .... and the inside

Made from scrap material and am stoked with the results sonically and visually.
Attached Images
File Type: jpg gbbassxt_inside.jpg (73.8 KB, 1061 views)
__________________
No longer DIY active
  Reply With Quote
Old 22nd January 2007, 01:59 PM   #3
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Interesting ...... could you please tell about the controls, how they work
  Reply With Quote
Old 22nd January 2007, 04:05 PM   #4
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
There's some info on it here.

Each pot does the adjustment of a 6dB peak between 20 - 50 Hz on each channel to restore the F6 to flat. As the pot changes position, the resistance is changed and alters the active filter network. There is a steep sub-sonic filter that works in conjunction with this to stop the driver going nuts with too low frequencies.
__________________
No longer DIY active
  Reply With Quote
Old 22nd January 2007, 04:12 PM   #5
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

To make it more flexible you should tune ports lower when using
such a device, though it should be fine with sealed boxes.

The whole thing can be modelled in WinISDPro.

/sreten.
  Reply With Quote
Old 22nd January 2007, 07:03 PM   #6
Andy G is offline Andy G  Australia
diyAudio Member
 
Andy G's Avatar
 
Join Date: Apr 2002
Location: Newcastle, Australia
But Peter, if you built the cabs the right size in the first place ;-)))))

  Reply With Quote
Old 22nd January 2007, 08:08 PM   #7
diyAudio Member
 
Join Date: Feb 2002
Location: Western Sydney
I think this is probably a good alternative to the Linkwitz transform circuit? Someone posted circuit details of a similar unit here on DIY Audio (maybe the same one?)
I think this unit would be good for cheap guys like me, who have drivers with large Vas, but don't want to go the expense & effort of building large cabs (but you knew that already, eh Andy...) e.g. I have a pair of Peerless 840146s which have Vas of 144 L, currently in 40 L cabs. For me it's a lot easier to make a small circuit such as Greg's than to build 90-120 L cabs (OK, my woodworking ability sucks too...)
cheers,
Pete McK
  Reply With Quote
Old 22nd January 2007, 09:19 PM   #8
diyAudio Member
 
Join Date: Jan 2006
Location: Wisconsin....what did you expect?
Send a message via AIM to Spasticteapot
Yet another reason why my next pair of speakers will have an active crossover, and be bi-amped.

(I also found that LM3875's are now cheaper than most good-quality inductors - and, if all else fails, paying $50 for the 41hz Amp9 will give you four channels in a tiny package.)
  Reply With Quote
Old 22nd January 2007, 09:28 PM   #9
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
I would not say this circuit is suitable for too-small closed boxes, as unlike the Linkwitz Transform is does not correct the large resultant peak in response, in fact it would probably add to it to a degree.
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more.
  Reply With Quote
Old 22nd January 2007, 11:19 PM   #10
freddi is offline freddi  United States
diyAudio Member
 
freddi's Avatar
 
Join Date: Aug 2005
very nice for our old friend the assisted 6th order reflex - some cases just step down Fb by 1/2 octave..

can it be purchsed with box and jacks?
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New Bass Extender amplifierguru Solid State 31 8th October 2008 07:43 PM
qualities of a great bass amp? mitchyz250f Solid State 8 26th February 2008 05:34 AM
Wow! Great Bass! johngalt47 Multi-Way 0 17th December 2004 05:20 AM


New To Site? Need Help?

All times are GMT. The time now is 04:10 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2