Just a bump to get this back near the top. This is too good a thread to let it die.
EDIT: By the way, I'm nitpicking here, but this page:
http://mehlau.net/audio/multisub_geddes/
says
Because we are using 3 subwoofers, they do not need to be as powerful as a single subwoofer. Any decent active subwoofer (ported or closed design) with a 10" or bigger driver will do. It should have controls for
level (infinitely variable)
low pass frequency (infinitely variable)
phase (switchable or infinitely variable)
It makes more sense to say continuously variable rather than infinitely variable as infinitely variable declares an infinite range, which of course cannot be the case.
EDIT: By the way, I'm nitpicking here, but this page:
http://mehlau.net/audio/multisub_geddes/
says
Because we are using 3 subwoofers, they do not need to be as powerful as a single subwoofer. Any decent active subwoofer (ported or closed design) with a 10" or bigger driver will do. It should have controls for
level (infinitely variable)
low pass frequency (infinitely variable)
phase (switchable or infinitely variable)
It makes more sense to say continuously variable rather than infinitely variable as infinitely variable declares an infinite range, which of course cannot be the case.
Last edited:
Just a rather boring story - it's a typical peak caused by modes. When adding a subwoofer at a tri-corner, those peaks get boosted but the second sub "neutralizes" the peak. Looks like multiple subs work
Yep, moved to Switzerland. Smaller country but much bigger space (4.5m x 10m x 2.5m). The Nathans work pretty good in that room. Although there's no significant room treatments yet, the level of first reflections is low (<15dB).
Currently running 2 subs in parallel, final optimization with Audyssey. Combined with Dynamic EQ the sound is pretty impressive. I love black magic
Currently running 2 subs in parallel, final optimization with Audyssey. Combined with Dynamic EQ the sound is pretty impressive. I love black magic
Yes, important thread and there's a lot of design issues downstream from the speaker.
As I understand it, there are three components to bass irregularities:
1. something called "room gain" or the bass boosting people say you get inside automobiles - it that a myth?
2. room modes or resonances of the room which seems to have been studied nicely even before Welti's excellent paper, and
3. tied to room modes are seat locations which, just like woofer locations, can influence the bass you hear by positioning you relative to modes.
In the spirit of maximum mixing-and-matching, I've gotten very good results by adding a giant mid-wall OB to my corner true-horn Klipschorn woofer. Hard to think of a more polar-opposite mix. The OB has path difference from the front to the back ranging from about 5 feet to 9 feet.
http://www.diyaudio.com/forums/multi-way/123512-ultimate-ob-gallery-21.html#post2363110
As I understand it, there are three components to bass irregularities:
1. something called "room gain" or the bass boosting people say you get inside automobiles - it that a myth?
2. room modes or resonances of the room which seems to have been studied nicely even before Welti's excellent paper, and
3. tied to room modes are seat locations which, just like woofer locations, can influence the bass you hear by positioning you relative to modes.
In the spirit of maximum mixing-and-matching, I've gotten very good results by adding a giant mid-wall OB to my corner true-horn Klipschorn woofer. Hard to think of a more polar-opposite mix. The OB has path difference from the front to the back ranging from about 5 feet to 9 feet.
http://www.diyaudio.com/forums/multi-way/123512-ultimate-ob-gallery-21.html#post2363110
Setting up a multiple woofer system is (for anecdotal purposes) like sitting at an EQ and boosting everything until it is even. You've come along and decided to cut. Kinky
Last edited:
Setting up a multiple woofer system is (for anecdotal purposes) like sitting at an EQ and boosting everything until it is even. You've come along and decided to cut. Kinky
Can you explain that?
(A bit of Linkowitz-like bass boost EQ is always needed for OB bass. See my signature.)
No, but it requires a relatively sealed space with rigid boundaries in order to "pressurize" and provide that 12 dB/octave room gain below the lowest room mode. Most listening rooms aren't sufficiently "tight" or stiff enough to use simple predictions.
I think that one of the most interesting findings was that multiple subwoofers can actually underperform a single corner subwoofer in terms of the metrics used.
There's a fourth component that you didn't mention, which is SBIR or speaker boundary interface response, discussed in Toole's book as adjacent boundary effects.