Underground Sub - Page 5 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 March 2013, 11:54 AM   #41
Ile is offline Ile  Finland
diyAudio Member
 
Join Date: Sep 2011
Location: Jyväskylä
You need to separate front and back sub arrays to different back spaces with DBA, because back array is driven with inverted phase. With same back space to all drivers you wont get any output from sub, because of acoustic cancellation.

I guess DBA theory is based to rectangular room, so no one cant predict how it works in that shaped room. Probably still better than some other system.
  Reply With Quote
Old 22nd March 2013, 02:09 PM   #42
diyAudio Member
 
Join Date: Feb 2012
Location: Brisvegas
Keeping the back space separate shouldn't be a major problem.

I have reworked the room a bit to restore a more rectangular shape and get the size down a bit. Current rendition is 12 meters long by 8 meters wide.

It means having to use a combination of back space and some under slab space to cut 2 meters off the width.
Attached Images
File Type: jpg Home Theatre Room 15.jpg (79.2 KB, 117 views)
  Reply With Quote
Old 22nd March 2013, 06:49 PM   #43
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

worked with the 18" LMS Ultra and 15" LMS of TCSounds.
Both drivers are true Killers in their class. Unlike most of these very heavy and longthrow drivers, they show exceptional good lowlevel resolution. If pushed hard they will deliver.
After my taste they work best in CB. Their parameters are very well suited for rather small volumes and bass-eEQued (kind of ELF). Just keep it straight and simple. No fancy casings are required. CB in a inWall situation is perfectly ok.
You need a powerful amplifier though. A class-D amp comes top mind. See for example the Powersoft Digimod1500 and 3000PFC.
Powersoft also offers a interesting new motional feedback concept with specialised B&C drivers, dedicated amp and FB-sensor, the IpalMod.

jauu
Calvin
  Reply With Quote
Old 23rd March 2013, 12:27 AM   #44
diyAudio Member
 
Join Date: Feb 2012
Location: Brisvegas
Hi Calvin, I have something similar to what you suggested already... I have 1 x RB1092 Home Theater System Surround Sound Amplifier DVD Player - Rotel PRODUCT SPECIFICATIONS and 1 x RB1091 Home Theater System Surround Sound Amplifier DVD Player - Rotel PRODUCT SPECIFICATIONS

To date I have yet to be impressed with the TC Sounds Pro 5100s but that is largely due to how I am using them, in a plain OB baffle the barely move more than 1mm or 2mm (perhaps too stiff).

I think in a closed box or something that provides a bit of resistance they could really shine. From what I have read, with the amp I have powering them, they should be delivering a lot more than they do. If I turn off the RB1092 I barely notice them gone (slight exaggeration but not too much).
  Reply With Quote
Old 23rd March 2013, 07:31 AM   #45
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

open baffle, or smaller sized folded dipoles are imo not really suitable for home cinema. The here regularly occuring very low signal frequencies would require impractically large membrane areas and excursions. Still though sonically a dipole can´t supply for the desired ´pressure´ and slam. A more classical approach as subwoofer, i.e. a monopole, just used below the lowest room mode (hence working under very efficient room pressurization, hence it should be a CB) offers all one could wish for. Precision, resolution, dynamic range and reasonable power efficiency.

I don´t wonder that You didn´t achieve positive results with the Pro5100 in a dipole configuration. It´s parameters suggest a BR casing or similar. The three only parameters suitable for a dipole useage would be its size, the long excursion and its Fs. Teh needed EQuing is quite heavy. Wo EQ I don´t wonder at all, that You hardly notice any difference betwen On and Off.
For a true Subwoofer playing from the infrasonic range up to max. 50Hz the 18" LMS Ultra5400 and the LMS-R15 feature a superior set of parameters.

I use 15" LMS15 in a small EQed CB (global shaped, monolithically cast concrete, see pic) driven by 1500W@4Ohms class-D modules and it seems this power is just sufficient. The 18" requires more, something like the afore mentioned Powersoft 3.4kW module.
500W is what I would try with a 12" driver.
All that of course with the idea of home cinema in mind. For home hifi I´d accept less powerful amps.

jauu
Calvin
Attached Images
File Type: jpg Subwoofer.jpg (66.6 KB, 93 views)

Last edited by Calvin; 23rd March 2013 at 07:41 AM.
  Reply With Quote
Old 23rd March 2013, 12:02 PM   #46
diyAudio Member
 
Join Date: Feb 2012
Location: Brisvegas
Don't get me wrong the sound that does come out of the Pro 5100s is sweet, but a 10" in a closed box could probably do the same job.

Toying up between these two drivers for the job of the eight IB subwoofers.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-455
and
http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-468
Thoughts?

Like your spherical concrete sub.

Last edited by Silent Screamer; 23rd March 2013 at 12:09 PM.
  Reply With Quote
Old 24th March 2013, 08:12 AM   #47
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

the RSS390 would be suitable for a nice CB alignment. Very well built and equipped and probabely very capable too. I only worked with smaller Dayton drivers like the RSS225 and 180 and they proofed to be extremely priceworthy.

The other driver is intended for infinite/open Baffle useage, hence nothing You want for home cinema.

jauu
Calvin
  Reply With Quote
Old 24th March 2013, 10:15 AM   #48
diyAudio Member
 
Join Date: Feb 2012
Location: Brisvegas
I've heard the Dayton's in a closed box and they lack the clarity I am looking for in LF bass, I have no issues in buying a lot more of them to get depth with clarity / control I am looking for without the thumpiness normally associated with boxed speakers.

I really would like to keep the Pro 5100s in an OB / IB configuration but at $2500 landed with taxes I can't afford to buy a whole lot more of them to get results, but at < $200 each (plus freight + tax) for the Dayton's, that isn't so much an issue.

So while IB isn't the most efficient way to go, I do believe it will deliver the cleanest results.

Last edited by Silent Screamer; 24th March 2013 at 10:18 AM.
  Reply With Quote
Old 25th March 2013, 06:53 AM   #49
Ile is offline Ile  Finland
diyAudio Member
 
Join Date: Sep 2011
Location: Jyväskylä
These are made for IB...
IB318 - Fi Car Audio Store
Best price/liter ratio.
  Reply With Quote
Old 25th March 2013, 07:15 AM   #50
Calvin is offline Calvin  Germany
diyAudio Member
 
Calvin's Avatar
 
Join Date: Nov 2004
Location: close to Basel
Hi,

I haven´t worked with the Pro5100, since I was searching for a very capable driver in a rather small CB. So I tested the Ultra5400 even though it is terribly expensive. Cost and dynamic-wise a pair of the LMS15R are similar to a single Ultra5400. The pair of 15" requires slightly more volume than the single 18", but is easier in handling and allow for effective mass-momentum cancelation.
The 18" weighs incredible 36kg(!!) which asks for a mounting fixture and helping hands. The 16kg of the 15" are already something to really struggle with if You´re alone. It might also be easier to find good amps in the 1kW-1.5kW class than in the 3kW-4kW class.
So far I never pushed the pair of 15" to their 60mm excursion limits. Room, cubboards, closets and ears always gave up first.
The concrete casing, the sperical shape and the momentum-cancellation are so effective that one can´t sense any vibration of the casing by touching.
Probabely the ´quietest´ commercial Subwoofer.
These extreme-longthrow drivers enjoy and require a really really tight fixation to the casing and a extremly stiff casing with highest damping (in contrast to absorption). I´d rather discard wood as building material.
If You mount several of these drivers mechanically parallel into a wall, You need to waste some thoughts on how to keep the wall quiet.

jauu
Calvin
  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
Unheard, Underestimated, Underground Music zayne742 Music 18 16th February 2008 05:20 PM
There is water flowing underground.... ptwining Multi-Way 10 8th August 2006 03:49 PM


New To Site? Need Help?

All times are GMT. The time now is 07:45 PM.


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