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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Weogo Reed on May 19, 2021, 11:37:49 AM

Title: cardioid subs
Post by: Weogo Reed on May 19, 2021, 11:37:49 AM
Hi Folks,

    For smaller venues:

    A wall of big, horn-loaded subs might be the best sounding choice for
going low, loud, accuracy, and some directional control.   

    For events/venues without the space or budget for a wall of horns,
an omni front-loaded or tapped-horn sub(s) can sound good and work well.
Though with sound bouncing off of and being absorbed by various surfaces, the
actual low-frequency sound in a particular venue can sound good to not so good.
    With a cardioid sub or array, more of the sound compromises are made in the box(es), before
the sound goes out in to a venue, and may actually sound better than an omni box that has better specs. 

    For smaller venues, does all of the above sound reasonably correct?
Am I missing something significant?

Thanks and good health,  Weogo
Title: Re: cardioid subs
Post by: Helge A Bentsen on May 19, 2021, 01:30:03 PM
Directional subs needs space to breathe so the cancellation work, unless they have room enough around them on all sides (IME 1m minimum) you loose directivity and impact sound quality in a negative way. How much? Depends on the situation.
I prefer omni subs when space is an issue.

Don't get me wrong,  directional subs are a great tool when/if you need it and have space/budget for it.
Title: Re: cardioid subs
Post by: Weogo Reed on May 21, 2021, 09:56:10 AM
Hi Helge,

    Thanks for the reply, and good point about the space needed around cardioid subs.
One venue has a 42" tall concrete stage and a less than 60" to the first seat. 
Omnidirectional Danley TH28s that are less than 11" deep work really
well right against the stage wall.

    One of the subs I'm looking at is the Fulcrum CS212L which, at only 14" tall,
could sit on the front of the stage in many venues.
It has a useful 6~8db of broadband reduction at the rear and
doesn't require a brand-specific amplifier.

Thanks and good health,  Weogo
Title: Re: cardioid subs
Post by: Ivan Beaver on May 21, 2021, 01:12:12 PM
Hi Helge,

    Thanks for the reply, and good point about the space needed around cardioid subs.
One venue has a 42" tall concrete stage and a less than 60" to the first seat. 
Omnidirectional Danley TH28s that are less than 11" deep work really
well right against the stage wall.

    One of the subs I'm looking at is the Fulcrum CS212L which, at only 14" tall,
could sit on the front of the stage in many venues.
It has a useful 6~8db of broadband reduction at the rear and
doesn't require a brand-specific amplifier.

Thanks and good health,  Weogo

If you put a directional sub in front of a wall (ie solid stage front), it will not behave as it does in an open area.

In fact, you could make the sound out front worse, and lower in level, because of the phase of the rear direction, would be reflecting off of the boundary very close in time, and will cancel some of the forward energy.

This does not happen with a sub that has the same energy coming out of the front and the rear, since they are in phase, or close enough at the sub freq.
Title: Re: cardioid subs
Post by: Weogo Reed on May 21, 2021, 01:32:06 PM
Hi Ivan,

    Yep, I know this!
In venues like the one with the concrete stage front, subs like the
omni TH28s work well and I'll continue to use them there.

    What I'm wondering is if in some smaller venues, where cardioid arrays of
omni subs would be more than needed, and there may not even be space for them,
is it possible a cardioid sub could sound better?
Even though there are measurable compromises in the cardioid sound quality,
might the overall sound in the venue be better than an omni box sending energy all over the place?

Thanks and good health,  Weogo


If you put a directional sub in front of a wall (ie solid stage front), it will not behave as it does in an open area.
Title: Re: cardioid subs
Post by: Art Welter on May 21, 2021, 03:07:08 PM

One venue has a 42" tall concrete stage and a less than 60" to the first seat. 
Omnidirectional Danley TH28s that are less than 11" deep work really
well right against the stage wall.

One of the subs I'm looking at is the Fulcrum CS212L which, at only 14" tall,
could sit on the front of the stage in many venues.
It has a useful 6~8db of broadband reduction at the rear and
doesn't require a brand-specific amplifier.
The CS212L onstage, downstage would still take advantage of the 42" tall boundary, while reducing the onstage bass level considerably compared to an omni.
With amplified acoustic music, you could increase gain before feedback,  increasing LF level in the house 6~8dB without the bass and guitar players having to mute strings after every note.
The  Fulcrum CSP118 has quite a bit more 90 degree off axis pattern control, was quite impressed when I walked around it.  5 Hz lower response and 2 dB more output than the CS212L, but 2.3 times the size.

Art
Title: Re: cardioid subs
Post by: Weogo Reed on May 21, 2021, 09:31:06 PM
Hi Art,

    Good point about the concrete wall.

    I regularly work(ed) with a Keyboard player who wants more lows out on the dance floor and
less on stage.  Her wedge is high passed at 250Hz.
Then there's the muso that wants to drown in lows on stage.
And the band with one of each.  Good candidates for IEMs.

Thanks and good health,  Weogo
Title: Re: cardioid subs
Post by: Tim McCulloch on May 23, 2021, 01:09:01 AM
The Nexo CD-18 was my first exposure to self-contained directional sub.  The 6th order bandpass design, I expected to disappoint, but I was surprised.  Not small or lightweight, but they performed as advertised.  Nexo is still building subs with similar designs.