Small or large sub for music


I've been using a pair of Velodyne HGS-10s to supplement KEF LS50s below 50 Hz, but I read that larger subs are better for music because the cone needs excursion.  Is there any truth to this?  I have a pair of HGS-15s that I could use to supplement the LS50s or Reference 1s (below 40 Hz) if I go there.  The HGS-15s do HT superbly.

db
Ag insider logo xs@2xdbphd
I hardly ever sit in the sweet spot. and I have never been concerned with getting the deepest bass. I can't think of any of my guests wanting to stack up on or behind the sweet spot either, but we all want to hear good sound wherever we are in the room, or house for that matter. Not to mention I disliked having my guests ask me about all the acoustic panels I had and why. They appreciate my art collection that hangs on the wall now much more. Thanks to the 4 box distributed array we can eat, drink and enjoy music. Room size is 14 x 20 so with their small footprint they fit quite nicely and nobody trips over them.
erik_squires:
" TBC, having the space and money to have 4 subs is not the normal music lover's situation."

erik,
     Understood.  I consider myself fortunate that I was able to accommodate the relatively small 4 Debra subs in my room without issue and inconspicuously.  As for the money, I don't have an abundance but I could afford $3K and consider it a bargain.

erik_squires:
"@mapman  was talking to that. He was not discrediting the use of 4 subs."
mapman:
" noble yes for 20 hz in large room you need at least 1 larger sub up to the task (check specs) or multiple subs or drivers. Distributed multiple subs or sub array allows more for smoother bass response throughout a room than extending low end frequency response." 

erik and mapman,
     Yes, I didn't think mapman was discrediting the use of 4 subs, either.  I just wasn't sure if he knew that the Debra/Swarm dbas are capable of reproducing deep bass down to 20 Hz +/- 3 dB in any sized room (running in mono and in combination) and that 'at least 1 larger sub up to the task' is not required to reproduce bass this deep even in a large room.

wolf_garcia:
" Why does anybody care if the bass is distributed evenly around the room? Is this so you can enjoy accurate bass while doing your yoga headstand against the wall?"

wolf,
     I find it disturbing that you're aware I enjoy accurate bass while I'm doing my yoga headstands against my wall.  
    As to why I care if the bass is distributed evenly around the room, see clio09's post and my reply below:


clio09:
" I hardly ever sit in the sweet spot. and I have never been concerned with getting the deepest bass. I can't think of any of my guests wanting to stack up on or behind the sweet spot either, but we all want to hear good sound wherever we are in the room, or house for that matter. Not to mention I disliked having my guests ask me about all the acoustic panels I had and why. They appreciate my art collection that hangs on the wall now much more. Thanks to the 4 box distributed array we can eat, drink and enjoy music. Room size is 14 x 20 so with their small footprint they fit quite nicely and nobody trips over them."

clio and wolf,
     I agree with clio, my guests and I all want to hear good sound wherever we are in my room.  There is just one 'sweet spot' seat in my room for best overall performance but I and my guests think music still sounds good throughout the entire room because it's full range everywhere, from as deepest bass to highest treble as the musical content possesses.  Yes, the very realistic, solid and stable sound stage illusion existing only at the 'sweet spot' seat is missing.  But the overall sound of well recorded music reproduced in high quality utilizing the actual complete audible range can still be enjoyed throughout the entire room, even when seated at a table in the adjoining dining room. 
      My wife, guests and I also enjoy the evenly distributed sota bass response for ht.  Our room has 6 seats with good views of a 65" plasma hdtv.  The 4 sub Debra dba is part of a 5.4 DD surround sound system that, along with the large hdtv, allows for very good A/V reproduction experiences to be enjoyed at each of these 6 seats.  I realize this ht capacity is not relevant to some of you but it is to me, my wife, guests and likely some readers of this thread.

Thanks,
  Tim
Is this so you can enjoy accurate bass while doing your yoga
headstand against the wall?


I don't need a wall for that.
Size and # drivers (including passive radiators) is often a general indicator of how low a sub might go but you really have to check the specs to get a good idea how a sub will perform

Also lower bass frequencies take exponentially more power to produce flat response so you better have plenty of good clean amp power in those subs too to carry the load. The more the better. Not enough power in reserve is perhaps the most common cause of bad sounding bass.

@mapman wrote:

"Also lower bass frequencies take exponentially more power to produce flat response so you better have plenty of good clean amp power in those subs too to carry the load. The more the better. Not enough power in reserve is perhaps the most common cause of bad sounding bass."

Well, it depends on the specifics. Some subs rely on aggressive EQ to go deep. The DEBRA and Swarm systems do not.

The DEBRA and Swarm systems use individual subwoofer modules whose native response is the approximate inverse of typical room gain from boundary reinforcement (which is +3 dB per octave south of 100 Hz, according to Martin Colloms). The Debra and Swarm subs have a native response that falls at about 3 dB per octave from 80 Hz down to 20 Hz. This is a more gentle rolloff that you can get from an unequalized sealed box.

In many smaller rooms this ends up giving you more low end than you need. One option is to invert the polarity of one of the four subs. Doing so often further improves the in-room bass smoothness in my experience. And since small rooms are the ones that usually have the most room for improvement in the bass region, this works out well. This is not the only trick the DEBRA and Swarm systems have up their sleeves - they are highly adjustable in the acoustic domain, and still have EQ available in their amplifier if needed.

One advantage of not relying on power-hungry EQ to go deep is, we’ve never had an amplifier fail due to being over-driven. And we’ve only had one woofer failure in twelve years.  That's less than 1%, and it was an 8" woofer (which we no longer use) in an early version of the Swarm.

Duke

Swarm designer