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

Cheap BG Radia BGX alternative?
Cheap BG Radia BGX alternative?
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 8th January 2018, 10:39 PM   #11
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Quote:
Originally Posted by 4real View Post
Well, there really is no point in using 3" drivers if you'd need a 100L box is there
Appropriately set up, shallow but large box could be as unobtrusive as paintings hung on the wall.

Examples here:
Optik

A sub could blend in better than these, since a painted cover / grille will not harm LF performance.
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 9th January 2018, 09:12 AM   #12
4real is offline 4real  Netherlands
diyAudio Member
 
Join Date: May 2004
Location: Steyl
Yes, that sort of the idea, but much more than 20~25L will still be quite obtrusive.

Meanwhile I tried some modeling using Hornresp and it looks like 12 of these make it to 100dB at 20Hz. They would obviously need some LT, but still, not to shabby.
__________________
Do diamonds shine on the dark side of the moon?
  Reply With Quote
Old 10th January 2018, 09:53 AM   #13
4real is offline 4real  Netherlands
diyAudio Member
 
Join Date: May 2004
Location: Steyl
Attached some of the simulation results. Last one is with some DSP'ing.
Attached Images
File Type: jpg Screen Shot 2018-01-10 at 10.47.13.jpg (103.3 KB, 25 views)
File Type: jpg Screen Shot 2018-01-10 at 10.46.45.jpg (71.1 KB, 25 views)
File Type: jpg Screen Shot 2018-01-10 at 10.49.49.jpg (79.2 KB, 25 views)
File Type: jpg Screen Shot 2018-01-10 at 10.49.09.jpg (68.4 KB, 24 views)
__________________
Do diamonds shine on the dark side of the moon?
  Reply With Quote
Old 10th January 2018, 11:09 AM   #14
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Hmm, the first graph is a bit louder / watt than I'd have guessed.

Because "the DC resistance reaches a value of approx. 2.2 ohms for 6 parallel-connected woofers", I think your resistance will be 4.4 ohms, and you need to drop the input down from 2.83V accordingly if you want to see the SPL at 1 watt.

My guess would be: 71dB for a single driver
+3dB per doubling of drivers = about 81dB
+9dB for corner loading = about 90dB

...so the best case scenario = about 87dB at 65Hz (the -3dB point)

Looking for 20Hz is a stretch, I reckon - the recommended eq is "HP filter 32Hz,> = 18dB / oct".

If the first graph is 77dB from (roughly) 2 watts at 20Hz, generating a 100dB 20Hz tone means you'd be putting ~400watts in (well, probably twice that, to overcome power compression), which would be a bit like running a hair drier in a shoe box.

I dunno if 400 watts would be OK in short bursts. I usually do low power builds, so this is an interesting opposite scenario for me
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 10th January 2018, 12:12 PM   #15
4real is offline 4real  Netherlands
diyAudio Member
 
Join Date: May 2004
Location: Steyl
I guess 400W would be okay for a short while. Also don’t forget that the slot lossing also adds efficiency. Hornresp says at 20Hz it is limited by displacement, not amp power, so the 20W per woofer should be fine I guess. Only above 40Hz is it limited by the amp (I modelled a 400W amp).
__________________
Do diamonds shine on the dark side of the moon?

Last edited by 4real; 10th January 2018 at 12:36 PM.
  Reply With Quote

Reply


Cheap BG Radia BGX alternative?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
47 Labs OTA, a cheap alternative? homer09 Chip Amps 86 15th July 2016 07:07 AM
sonarquest cheap alternative to furutech? zycomatique Everything Else 0 10th May 2014 06:47 PM
AE TD12M cheap alternative - Faital 12PR300? Defo Multi-Way 60 13th June 2009 01:21 AM
Cheap ERS Cloth alternative? zBuff Parts 1 16th May 2008 06:52 AM
Cheap alternative to EF86 Shoog Tubes / Valves 29 8th January 2008 11:15 AM


New To Site? Need Help?

All times are GMT. The time now is 03:47 AM.


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