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

To take a pro 18" down to 20Hz
To take a pro 18" down to 20Hz
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 11th November 2015, 01:12 PM   #61
technofreak is offline technofreak  Estonia
diyAudio Member
 
technofreak's Avatar
 
Join Date: Dec 2006
Send a message via MSN to technofreak
I've been playing around with Equalizer APO for a few days to get room modes under control. Main culprit is 39 Hz boom. Also needed boosts at 24, 45 and 87 Hz (the last null being impossible to get totally rid of).

Overall, I'm pretty pleased with that driver; it blends in with the mains seamlessly, has good efficiency and very life-like sound with no audible distortion even below 20 Hz. The end result is this (no smoothing applied to graph):
Attached Images
File Type: png sub_EQ.png (34.4 KB, 131 views)
  Reply With Quote
Old 11th November 2015, 05:31 PM   #62
Inductor is offline Inductor  Portugal
diyAudio Member
 
Inductor's Avatar
 
Join Date: Feb 2006
Location: Cascais
I'm very curious about your last impressions. I will check about a more tight alignment, what should be Fb (?) for the same Vb (364L from #23). The peak is a blueprint from frequency of driver, symptom not that problematic with smaller volume probably (but a different project from yours.) What's the size of your room or venue?
  Reply With Quote
Old 11th November 2015, 06:34 PM   #63
technofreak is offline technofreak  Estonia
diyAudio Member
 
technofreak's Avatar
 
Join Date: Dec 2006
Send a message via MSN to technofreak
Hi Inductor,

My room is about 4,5x3,5 meters, listening position is about 1,4 meters from the back wall. If you run the numbers, the first axial mode is right at ~39 Hz. The null at ~45 Hz seems to be the second axial mode. And all these peaks and nulls have been here with any speaker setups

Here's a plot for different box tunings (~19 Hz as built, 25 Hz and 30 Hz), 30 Hz is optimal for maximum total SPL view, but, like all things in audio, it's about what compromises you are willing to make. I also added comparison between EQ-d and non-EQ-d response at listening position:
Attached Images
File Type: png tuning_comparison.png (72.7 KB, 119 views)
File Type: png sub_EQ_vs_noEQ.png (38.1 KB, 119 views)
  Reply With Quote
Old 11th November 2015, 07:50 PM   #64
Inductor is offline Inductor  Portugal
diyAudio Member
 
Inductor's Avatar
 
Join Date: Feb 2006
Location: Cascais
An alignment of 364L Vb and 12/14Hz looks like a viable option. This driver does subsonic fr easy go to 15 Hz with 800/1000W RMS power in speaker installed (ref 900/1800W from spec).
Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 Ohm
Taking the driver/CABINET SIZE/port to your spec, 364L/Vb (calibrated) u have (below). Have fun

(1) with (4x) port 10.3 cm (diam.), 14.0 Hz
Surface : 333.29 cm2 - length 126.26 cm

(2) with (3x) port 10.3 cm (diam.), 14.0 Hz
Surface : 249.97 cm2 - length 92.70 cm

(3) with (3x) port 10.3 cm (diam.), 15.0 Hz
Surface : 249.97 cm2 - length 79.18 cm (port resonance 217 Hz)
F-6 dB/F3 in room: 13.8 Hz
SPL 1m/1 speaker (60.54 V/812.4 W): 119.2 dB with thermal attenuation 114.5 dB.

Quote:
Originally Posted by technofreak View Post
Hi, Inductor,

364 is the net volume (driver, ports and bracing subtracted). Ports are 110 mm external (103 internal), sorry for mixup, I posted that while tired of a day full of woodwork. I aim for 18 Hz Fb.

And yes, home theater will be on the usage list of my sub.
Attached Images
File Type: gif DAYTON RSS460HO-4 v2015, VB = 364.0 L, FB = 15.0 Hz.gif (87.5 KB, 114 views)

Last edited by Inductor; 11th November 2015 at 07:58 PM.
  Reply With Quote
Old 12th November 2015, 01:06 PM   #65
technofreak is offline technofreak  Estonia
diyAudio Member
 
technofreak's Avatar
 
Join Date: Dec 2006
Send a message via MSN to technofreak
Yes, that Dayton is a great driver, pity it's so expensive here in Europe (261.78 USD on Parts Express; 384.54 EUR/412.65 USD on Europe Audio). And no other drivers that could match its U.S price while performing similarily, either.
  Reply With Quote

Reply


To take a pro 18" down to 20HzHide 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
Wanted: 1-2 18" pro subwoofers Spasticteapot Swap Meet 0 21st May 2014 09:38 PM
pro woofers 12" , 15" AND 18" DATASHEET? inertial Multi-Way 6 3rd August 2013 12:21 PM
BMS Pro Audio, 18", 8", horns, ultimate 3-way setup, mint mikey7182 Swap Meet 10 11th December 2012 06:21 PM
Rate this Pro 18" Woofer sonu Multi-Way 6 3rd July 2005 06:41 AM
Dayton pro 18" woofer w/4" VC rcavictim Multi-Way 8 27th November 2004 03:32 AM


New To Site? Need Help?

All times are GMT. The time now is 03:20 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