Thinking about adding a 2nd Sub. - AVS Forum
Forum Jump: 
 
Thread Tools
Old 12-30-2003, 08:38 PM - Thread Starter
Senior Member
 
MarkMSM's Avatar
 
Join Date: Apr 2003
Location: Tampa, FL
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
My receiver only has one mono LFE pre-out. I currently have a Y-adaptor at the end of the run plugging in to the sub L & R inputs.

I have a Velodyne DLS-4000 Sub (12"/200 Watt RMS). I previously had the CHT-15. The CHT-15 was very very loud, but was too boomy for my taste.

The DLS-4000 is much smoother and tighter, but not as loud (not as earth shaking as the CHT15 was).

What happens when I use a Y-Adapter to two separate subs? Will the signal be split in half? If so, I'm wondering if the AUTO on feature would not work since the subs may not detect a weaker signal....

I'm just wondering if the split signal would cancel out any gains from the second sub.

...or would the signal remain about the same (same voltage, lower impedance), and would I get almost double the LFE effect in the room?
MarkMSM is offline  
Sponsored Links
Advertisement
 
Old 12-31-2003, 07:04 AM - Thread Starter
Senior Member
 
MarkMSM's Avatar
 
Join Date: Apr 2003
Location: Tampa, FL
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Bump
MarkMSM is offline  
Old 12-31-2003, 07:14 AM
AVS Special Member
 
Tweakophyte's Avatar
 
Join Date: Jan 2001
Location: Boulder, CO, USA
Posts: 3,361
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I believe the signal might drop a little so you'd need to boost the level on the sub(s) or the receiver. The AUTO feature would benefit by turning up the receiver. I rememer reading that splitting a mono signal into the L and R inputs boosts the sub's sensitivity to the signal, but you are not getting anything that you couldn't get by turning up the levels.

Are your sub levels currently maxed out?
Tweakophyte is offline  
Old 12-31-2003, 08:32 AM - Thread Starter
Senior Member
 
MarkMSM's Avatar
 
Join Date: Apr 2003
Location: Tampa, FL
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I currently keep the sub gain/volume at around 10 o'clock on the dial for regular TV viewing. When I watch movies, I crank it up from 1 o'clock to 3 o'clock. Sounds good, but not as loud as the CHT-15 was.

My room is rather large (15x15) that opens up to the kitchen (also 15x15) so the total area to pressurize is about 15x30.

I'll run some tests with a Y-Adapter and only one side connected to my one sub to see what happens.
MarkMSM is offline  
Old 12-31-2003, 08:38 AM
Senior Member
 
Armand28's Avatar
 
Join Date: Dec 2002
Posts: 207
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
It shouldn't be a problem.

I'm splitting my LFE signal, then have Y-adapters to each of my subs, and one of them has 20' of RCA cable to go through and still spits out a great sound.
Armand28 is offline  
Old 12-31-2003, 01:49 PM
Senior Member
 
HTJunkie1's Avatar
 
Join Date: Dec 2003
Location: ~The Lone Star State~
Posts: 259
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Try connecting your 2nd sub to the speaker terminal inputs. I tried it and it sounded good, but let me also say that I have since moved on to just 1 better sub and the sound is even better than when i had 2 or more subs inline. Good Luck. Johnny:D

On The 8th Day, God Created Home Theater.
HTJunkie1 is offline  
Old 01-01-2004, 09:18 AM - Thread Starter
Senior Member
 
MarkMSM's Avatar
 
Join Date: Apr 2003
Location: Tampa, FL
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally posted by Armand28
It shouldn't be a problem.

I'm splitting my LFE signal, then have Y-adapters to each of my subs, and one of them has 20' of RCA cable to go through and still spits out a great sound.

This is exactly what I was planning.

I did some tests yesterday. When I split the one LFE signal with a Y-Adapter, I lose about 3 db. This was easily compensated for by turning up the gain on the sub about a quarter turn.


The auto sense feature seemed to be pretty much unaffected. Looks like the auto sense feature may work on voltage, rather than audio signal.
MarkMSM is offline  
Old 01-01-2004, 09:49 AM
AVS Special Member
 
Tweakophyte's Avatar
 
Join Date: Jan 2001
Location: Boulder, CO, USA
Posts: 3,361
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The 3db is the loss number I remeber. That's a feature of the gain on the amp. My thought about using a splitter on one sub to input into the L/R is you're adding a chance for signal corruption.

I would not use the speaker-level input because you should be running your sub with your speakers electronically x-overed.
Tweakophyte is offline  
Old 01-01-2004, 11:08 AM
AVS Special Member
 
John Robert's Avatar
 
Join Date: Sep 2003
Location: Las Vegas
Posts: 3,526
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
You can split you LFE with no problem. You do lose some gain but get extra headroom and possible better distributed bass. If you are not careful with placement and calibration, you get the opposite effect - cancellation and overall bass problems.

One common solution is to stack both subs on top of each other in a selected corner for additional reinforcement. Some "experts" swear by this.

If you search under "two subs" or "multiple subs", you'll get an overload of info, including links to some fairly technical papers on number, location and crossover freq for subs.

Regards,

John

"What happens in Vegas..."
John Robert is offline  
 
Thread Tools


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