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

Subwoofer for an VOT A7
Subwoofer for an VOT A7
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 30th June 2020, 09:13 AM   #1
jakruby is offline jakruby  South Africa
diyAudio Member
 
Join Date: Jun 2007
Default Subwoofer for an VOT A7

I have a pair of A7s: 416C 902A+811B plus a Fostex A90 supertweeter all going through the JE Labs passive XO (1k6 I think) and 1.33uF direct to the supertweeter. Driven by either 6V6 triode PP at ~3W or EL84 UL PP at ~10W.

I would like a bit more bass (of course!!) any suggestions as to a matching sub design? Not too clued up on LS design but do build all my own electronics so not afraid pf dirtying the hands. Are horn subs possible?
  Reply With Quote
Old 30th June 2020, 12:34 PM   #2
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Subwoofer for an VOT A7
Before you go the sub route, what are the ports like on your cabinets? The stock port opening doesn't allow for much below 60Hz. Close them up to a more reasonable size and you can play down in the the 30s. Even lower with the right room and placement.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 30th June 2020, 04:32 PM   #3
jakruby is offline jakruby  South Africa
diyAudio Member
 
Join Date: Jun 2007
Interesting, I have followed many of your and others' discussions about Altecs on the forums and have never heard it said they could put out out much below 50Hz...

My port is a full-width slot of 800mm by 60mm - approximately 73 inches squared. Cabinets are in corners, glass wool on all interior surfaces. Cabinets are 828 style.
  Reply With Quote
Old 30th June 2020, 10:29 PM   #4
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
OK, your vent is already down in numerous DIYer's 'chosen' ~75"^2.

Lots of options, including a [sub] bass horn, so need complete info on the total acoustic space, especially if a [somewhat] open one like mine, where in room the speakers, 'sub [s]' can go [dimensioned floor plan, showing all available], any dimension limits within each space, signal chain and any other limitations not listed.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 30th June 2020, 10:45 PM   #5
John Busch is offline John Busch  United States
diyAudio Member
 
John Busch's Avatar
 
Join Date: Oct 2007
Location: Hill country, Texas
Do you have an actual A7 cabinet?
__________________
Commercial Website: https://manzanita-audio.com/
  Reply With Quote
Old 30th June 2020, 10:59 PM   #6
jdarg is offline jdarg  United States
diyAudio Member
 
Join Date: Aug 2005
Close off the ports completely and use a linkwitz transform. I'm able to get jbl 4560 loaded with 2220h down to 20hz in a small room this way. Using a 40w amp on the bass bins is good enough for my average listening levels and then some. I tried this first, then actually built two huge subs, and then ended up going back. This worked better for me I think because I didn't have a lot of places to put the subs and the response with the subs was way more ragged than without them. It might be kludge but these components can easily handle it when I'm only throwing a few watts at it anyways.
  Reply With Quote
Old 30th June 2020, 11:16 PM   #7
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: SW Florida
Subwoofer for an VOT A7
Yes, that's one way to do it. I ran the bass cabinets sealed with EQ for awhile and it wasn't bad. But fortunately for me vented did as well or better, so I used that. Also corner placement helped, but Jak has already done that.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 1st July 2020, 08:05 AM   #8
jakruby is offline jakruby  South Africa
diyAudio Member
 
Join Date: Jun 2007
Cabs not made by altec just to 828 spec

Thanks GM will do some measuring and report back.
  Reply With Quote
Old 1st July 2020, 10:57 AM   #9
eduard is offline eduard  Netherlands
diyAudio Member
 
Join Date: Sep 2002
Location: Holland
Send a message via Yahoo to eduard
Hello,
If i remember well Pano just like me has been in France, Paris where Jean Hiraga used these Altecs. From the information they published in their magazines they indeed advised to make the event smaller but their main target was to lower the impedance peak ( have to find the magazine in my library)
I know adding the wings make them go lower!
I know that Jean Hiraga uses or used a Magnat active subwoofer with his Altecs.
In my '' home cinema 2.1 '' set i use two active SVS subwoofers. The main speakers there have a 6 DB slope filter at 80 hertz inside the Virtue Sensation integrated amp and the SVS have been adjusted to the set/room by a DSP correction and a microphone.
What i wanna do is use a second DSP correction to integrate these 2 SVS subwoofers into my audio set. Just using the Altecs as a speaker that doesnt produce anything below a certain frequency . Let's say 50cycles and just tell the SVS to do everything below that frequency with its built in 12 db filter.
80 hertz/cps integrates VERY well in my home cinema . But there the efficiency of the system is well balanced. I can make the Virtue going into protection while the SVS couple are not running out of steam!
I think by choosing the cross over frequency as low as possible i might get a combination that will get me an improvement.
Greetings, Eduard
  Reply With Quote
Old 1st July 2020, 02:46 PM   #10
jakruby is offline jakruby  South Africa
diyAudio Member
 
Join Date: Jun 2007
My room is L-shaped. Approximately 25' by 15' for the main area that houses the hi-fi. 10' by 12' for the shorter part of the "L". The speakers sit at the top of the longer part of the "L". The space is actually bigger than that as there aren't many doors, but the substantive room is as described.
 

Reply


Subwoofer for an VOT A7Hide 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
FS in Los Angeles: subwoofer, subwoofer cabinet, oscilliscope, KEF center... taloyd Swap Meet 81 1st February 2020 09:46 PM
Overview about words largest Subwoofer Drivers/Transducers (SUBWOOFER BEAST) tiefbassuebertr Subwoofers 27 9th September 2012 09:42 AM
FS: Dayton Reference Subwoofer RSS315HF-4 12" Subwoofer Driver matevana Swap Meet 0 12th February 2012 02:42 PM
Subwoofer build - Morel UW1258, 12" Ultimate Subwoofer mantha3 Subwoofers 46 10th October 2011 01:11 PM
how to connect a non powered subwoofer to a stereo system without a subwoofer output JSD777 Multi-Way 4 20th September 2005 03:19 PM


New To Site? Need Help?

All times are GMT. The time now is 06:53 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki