2 x 15" sub design advice - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 8 Old 01-30-2013, 03:47 PM - Thread Starter
Member
 
nw06's Avatar
 
Join Date: Jul 2011
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 10
Hi

Currently running with a single Rythmik F12, but looking to upgrade for music & HT.

I am very space (& WAF) restricted at the moment, but will be moving into a bigger place eventually, so I want to do a single sub initially, and just add a second for the bigger room when the time comes. Keeping in mind it is always going to be in a normal-sized living room situation, and only required to hit maybe -10db reference max...

My choices come down to either a single 18 in about 5cf, or a 2 x 15 in about the same. Given the displacement advantage of the 2 x 15 option, it would be the preferable option if I could get it to work within my enclosure constraints.

So, can anybody confirm what the minimum sealed internal enclosure volume would be for a dual-opposed sub using TC LMS-R 15" drivers, to make it worthwhile? Would 5 cubic feet work? If not, are there any other recommended 15" drivers with great SQ suitable for small sealed enclosures?

I will be using a 2 x 2400/4 watt amp (1800 RMS). Will I be able to power each sub driver with one amp channel initially, and then when I make the second enclosure, power each enclosure with one amp channel?
i.e. two individual amp input connections in each sub enclosure, so each amp output will be 'y split' into the two input connections of the sub enclosure (assuming y split Speakon connections actually exist??) Would this change the ohms load to the amp?

Thank you in advance for your help!

Nathan
nw06 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 02-01-2013, 05:26 PM - Thread Starter
Member
 
nw06's Avatar
 
Join Date: Jul 2011
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 10
Bump. Any advice?
nw06 is offline  
post #3 of 8 Old 02-01-2013, 06:01 PM
AVS Special Member
 
jpmst3's Avatar
 
Join Date: Dec 2005
Location: Davidsville, PA
Posts: 8,286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 56 Post(s)
Liked: 218
With a sealed setup there is no exact specs. Small changes in enclosure size make very little difference. 5 cubic feet would work well dual opposed.
The larger you go, you get small increases in efficiency down low but not enough to warrant making the enclosure much larger.

You can choose to present whatever load you desire to the amp. You could choose to run the amp bridged, using both channels to power both cabs. However, with only 2400 theoretical watts on tap, you will run out amp long before you run out of excursion in 5cf enclosures.
Or you can run each channel to the pair of subs. It just depends on how you wire the voice coils and then subs together in each cabinet.

Google speaker wiring in parallel and series and you will see some examples.

______________________________________________
Joe = LFE Addict
Joe's LOWARHORN build
Dual LMS-5400 Ultra Endtables build
jpmst3 is offline  
post #4 of 8 Old 02-02-2013, 08:49 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 16,856
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 568 Post(s)
Liked: 1172
you could go as small as 4 cubic feet internal, but the low end sensitivity goes down a couple db as you do that.

what amplifier are you using/plan to use?

Listen. It's All Good.
LTD02 is offline  
post #5 of 8 Old 02-02-2013, 01:44 PM - Thread Starter
Member
 
nw06's Avatar
 
Join Date: Jul 2011
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 10
I was considering the funk audio 2 x 2400 amp, but am now getting conflicting reports on its real ability. So not sure what to do really. I assumed it would be enough, and Funk says that it measures very well. What REAL power do I need for 4 cubic feet?

Anybody know if the new Dayton UM15 driver is a competitor to the LMS-R 15? Keeping total driver and shipping costs under $1K saves me 15% in import taxes!
nw06 is offline  
post #6 of 8 Old 02-02-2013, 01:49 PM
AVS Special Member
 
jpmst3's Avatar
 
Join Date: Dec 2005
Location: Davidsville, PA
Posts: 8,286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 56 Post(s)
Liked: 218
You won't know how much is enough until you try it.

The LMSs are tough to beat.

How big is your room?

______________________________________________
Joe = LFE Addict
Joe's LOWARHORN build
Dual LMS-5400 Ultra Endtables build
jpmst3 is offline  
post #7 of 8 Old 02-03-2013, 01:27 AM - Thread Starter
Member
 
nw06's Avatar
 
Join Date: Jul 2011
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 10
Quote:
Originally Posted by jpmst3 View Post


How big is your room?

Approximately 2500 cubic feet.
nw06 is offline  
post #8 of 8 Old 02-03-2013, 08:16 AM
AVS Special Member
 
Martycool007's Avatar
 
Join Date: Jun 2011
Posts: 3,692
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 280 Post(s)
Liked: 172
Quote:
Originally Posted by nw06 View Post

I was considering the funk audio 2 x 2400 amp, but am now getting conflicting reports on its real ability. So not sure what to do really. I assumed it would be enough, and Funk says that it measures very well. What REAL power do I need for 4 cubic feet?

Anybody know if the new Dayton UM15 driver is a competitor to the LMS-R 15? Keeping total driver and shipping costs under $1K saves me 15% in import taxes!

Bump. I would like to know more about the UM15 compared to other drivers as well!
Martycool007 is offline  
Reply DIY Speakers and Subs

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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