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Down firing SUB on pontoon?


minnmarker

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So I've got a new to me WS XS-12 sub that's destined for the pontoon along with four old 6.5 Sony speakers from the Bu that'll be mounted under seat fronts and two 8" patio speakers that will be hung from the hard top canopy.  I'm perplexed about what to do with the sub.  I could mount it in an enclosure in the helm station but it would be facing backwards - away from most of the floor space - and I'm afraid that in the open environment most of the sound would be "lost overboard."  Any comments??

Objective is to have good full range sound for R&B, Pop, Classical - not necessarily a lot of boom or volume.

As an alternative what does everyone think of building a suitable down firing enclosure with a top on it (table or cooler)?  I have 2 down firing subs at home and they work very well in a room setting.  What adjustments to box volume, if any, should be made?  How far off floor should the speaker be?

Pontoon forum was useless BTW!

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18 minutes ago, skyskier said:

Think about how you would power that sub keeping in mind the small alternator on your outboard.

I should have added that it's a 29 foot toon with a 4.3 Merc I/O with a 70 amp alternator and I'll be putting in a dedicated deep cycle battery with isolator.  75 watts to each of the smaller speakers and 300 W to the sub.

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minn,

You will have to accept some compromises from what you describe.

Bass is said to be non-directional. That's not true. It is simply more fluid and less directional than higher frequencies. The best bass SQ scenario would be with the woofer aimed in the direction of the listeners and focused on a specific area rather than omni-directional distribution. The boat layout and the position of the occupants may not permit that.

Down-firing subs are great in the home on a concrete slab. It's different on a pontoon. The sole of the pontoon is not near as rigid or acoustically inert. When you down-fire you couple to that surface. The entire surface is excited. And every point of that surface radiates energy a bit out of phase with the original woofer energy. So it will never be as tight. But it will definitely yield more output. That's the biggest trade-off that you have to reconcile. A little experimentation before committing to a final approach might go a long way.

In an open field environment like a boat, versus a car, I never like to see a reduction in radiating surface area. So in a down-firing set-up you should elevate the peak of the woofer's surround 3 inches off the sole for a 12-inch driver. In a down-firing bass-reflex enclosure I would place the port on the downside also to get maximum output and place a round port in a corner of the baffle surface, but removed from any other surfaces too close to the enclosure.   

minn,

I know you said 'not necessarily a lot of volume'. But this is worth adding. In this open environment and without the sub setting deep in the typical bathtub within confining gunnels, you are going to lose a lot of bass energy. So anything that you can do to add some acoustic leverage, perhaps like down-firing or reinforcement from some surrounding plane, will keep the woofer and amplifier from working as hard. The subwoofer and amplifier that works less always sounds the best.   

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1 hour ago, David said:

Down-firing subs are great in the home on a concrete slab. It's different on a pontoon. The sole of the pontoon is not near as rigid or acoustically inert. When you down-fire you couple to that surface. The entire surface is excited. And every point of that surface radiates energy a bit out of phase with the original woofer energy.

In an open field environment like a boat, versus a car, I never like to see a reduction in radiating surface area. So in a down-firing set-up you should elevate the peak of the woofer's surround 3 inches off the sole for a 12-inch driver. 

Thanks for the knowledge David!  Would it help if I mounted my woofer enclosure on top of a thick piece of HDPE at the recommended 3" off?  To make it cheap, simple, waterproof and somewhat disguised I'm thinking of fixing a QBOMB box inside something like this: http://www.amazon.com/gp/product/B00013BUW8?colid=1ZSKJZD8CUEIL&coliid=I1ASMUE4NZO9FU&ref_=wl_it_dp_o_pC_nS_ttl

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14 hours ago, minnmarker said:

Thanks for the knowledge David!  Would it help if I mounted my woofer enclosure on top of a thick piece of HDPE at the recommended 3" off?  To make it cheap, simple, waterproof and somewhat disguised I'm thinking of fixing a QBOMB box inside something like this: http://www.amazon.com/gp/product/B00013BUW8?colid=1ZSKJZD8CUEIL&coliid=I1ASMUE4NZO9FU&ref_=wl_it_dp_o_pC_nS_ttl

I'm not sure. But it might be worth a try first with an inexpensive substitute. The HDPE floor separated by 3" could be part of the sub enclosure and decoupled from the pontoon sole with rubber feet.

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30 minutes ago, David said:

I'm not sure. But it might be worth a try first with an inexpensive substitute. The HDPE floor separated by 3" could be part of the sub enclosure and decoupled from the pontoon sole with rubber feet.

Excellent, a table/seat/woofer!  I've got some extra 3/4" plywood I can try it with.  Will run some bolts from the QBOMB thru the plastic box to the "floor' to some rubber feet.  If it works then will get the HDPE.

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  • 1 month later...

The beast is done.  WS XS-12 powered by a Kicker CX1200.1 (600 Watt RMS). 

First step was mounting four 3/8" x 6" carriage bolts into the face of a QBOMB box so the threaded portions extended outwards from the face.  Make sure you drill so the bolt head will fit into the interior corner of the QBOMB.  Nylock nuts and fender washers to hold in place.  Install your speaker.  Then cut a hole in the center of the base of the box (Suncast SS1000 Storage Seat) the size of the woofer and some 3/8" holes for the bolt.  Put 4 fender washers on top of the nuts.  Mount the box base on your QBOMB with the smooth side facing away from the QBOMB (that's the only way the QBOMB will fit in the box).  Four more fender washers and 4 more nylock nuts.  (Be careful not to twist your carriage bolts.  I held mine with some vice grips with hard rubber in the jaws.)


0502161153r.jpg.129d8c0e9eac6af3c2a47d3d

Drill a small hole in the base and take a long piece of speaker wire and attach it to the terminal and out through the hole.  I tied a knot in the wire to keep it from getting yanked out of the terminals.    Now assemble the sides of the box onto the base.  Since the base is upside down you'll have to cut some new holes for the box panel locking tabs (see picture). 

0502161153ar.jpg.310b5d95184d19b4e081694

Now cut your base and drill 4 3/8" holes in it for the bolts.  I used 3/4" HDPE (Seaboard) but marine plywood would work.  Put 4 more nuts and fender washers on your bolts, then the base, then 4 more fender washers and nuts.  Finally, screw 4 rubber feet to the bottom of the base and put the top on the box.  It sounds great in the shop and with 600 watts driving it this thing should fill the open pontoon with some good bass!

0502161210r.jpg.c457879b4887524dee653aca

0502161210ar.jpg.dfe6f8fa6dc6d1f31cc674a

 

0502161211ar.jpg.96dfb5dd06641379d0f4ce8

 

Edited by minnmarker
  • Like 4
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  • 1 month later...

The pontoon sound stage is done.  I know it's not a Malibu but maybe someone else has a pontoon and wants good sound and will find this in a search some day...

Two Kicker KM8 under the bow seats on a JBL 70 watt rms per channel.

Two Dual LU53PW mounted under the hard top canopy about half way from front to back also on the JBL.  Not power houses but they put out adequate mid range and highs.

One WS XS-12 powered by a Kicker CX1200.1. In the enclosure shown above.

Clarion EQS746 equalizer.  Sirius XM and AUX inputs.

It took some tuning to optimize - mostly letting the KM8s take over most of the mid bass (thanks multiple TMC threads) which seems to travel well down the interior of the boat.  The sub may be a bit too powerful and I turned down the gain since it overpowered (as David predicted) the other speakers.  Perhaps the sub/amp will find its way into the Malibu next Winter in exchange for the RF sub there now.  The low end really reaches every corner of the pontoon interior and even enough overboard (for floaters) to give a bit of bass outside on the water.  The CX1200.1 was probably overkill but I got a good deal on it.  A bit of room for more sub has been left on the equalizer in case we want more bass for floating once the water gets warmer.  The high mounted down facing Duals fill in the highs for people sitting in the back and floaters around the sides and back of the boat.

I knew I had something when all 3 dogs started running around the deck barking at the KM8s and sub!  The only other time I've seen this is with my home theater setup.

So we did a long cruise with 4 people and 3 dogs and everyone got to pick their music and volume level.  Funk to Mozart #41. All good!

0612161721br.jpg.15c6e2875daccb439d123e8

Sub under the picnic basket. Clarion under the black weather shield.

0612161721r.jpg.94331cd9a63239d5f5eb24cc

0612161730r.jpg.a8bcf04510ab36cb087b3d55

Lots of room under the helm.

0612161722r.jpg.fc05f3413508b57af50abe66

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  • 1 month later...
  • 2 weeks later...
  • 8 months later...
On 5/3/2016 at 10:22 AM, minnmarker said:

The beast is done.  WS XS-12 powered by a Kicker CX1200.1 (600 Watt RMS). 

First step was mounting four 3/8" x 6" carriage bolts into the face of a QBOMB box so the threaded portions extended outwards from the face.  Make sure you drill so the bolt head will fit into the interior corner of the QBOMB.  Nylock nuts and fender washers to hold in place.  Install your speaker.  Then cut a hole in the center of the base of the box (Suncast SS1000 Storage Seat) the size of the woofer and some 3/8" holes for the bolt.  Put 4 fender washers on top of the nuts.  Mount the box base on your QBOMB with the smooth side facing away from the QBOMB (that's the only way the QBOMB will fit in the box).  Four more fender washers and 4 more nylock nuts.  (Be careful not to twist your carriage bolts.  I held mine with some vice grips with hard rubber in the jaws.)


0502161153r.jpg

Drill a small hole in the base and take a long piece of speaker wire and attach it to the terminal and out through the hole.  I tied a knot in the wire to keep it from getting yanked out of the terminals.    Now assemble the sides of the box onto the base.  Since the base is upside down you'll have to cut some new holes for the box panel locking tabs (see picture). 

0502161153ar.jpg

Now cut your base and drill 4 3/8" holes in it for the bolts.  I used 3/4" HDPE (Seaboard) but marine plywood would work.  Put 4 more nuts and fender washers on your bolts, then the base, then 4 more fender washers and nuts.  Finally, screw 4 rubber feet to the bottom of the base and put the top on the box.  It sounds great in the shop and with 600 watts driving it this thing should fill the open pontoon with some good bass!

0502161210r.jpg

0502161210ar.jpg

 

0502161211ar.jpg

 

Great idea!!

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  • 3 years later...
On 6/14/2016 at 3:36 PM, minnmarker said:

The pontoon sound stage is done.  I know it's not a Malibu but maybe someone else has a pontoon and wants good sound and will find this in a search some day...

Two Kicker KM8 under the bow seats on a JBL 70 watt rms per channel.

Two Dual LU53PW mounted under the hard top canopy about half way from front to back also on the JBL.  Not power houses but they put out adequate mid range and highs.

One WS XS-12 powered by a Kicker CX1200.1. In the enclosure shown above.

Clarion EQS746 equalizer.  Sirius XM and AUX inputs.

It took some tuning to optimize - mostly letting the KM8s take over most of the mid bass (thanks multiple TMC threads) which seems to travel well down the interior of the boat.  The sub may be a bit too powerful and I turned down the gain since it overpowered (as David predicted) the other speakers.  Perhaps the sub/amp will find its way into the Malibu next Winter in exchange for the RF sub there now.  The low end really reaches every corner of the pontoon interior and even enough overboard (for floaters) to give a bit of bass outside on the water.  The CX1200.1 was probably overkill but I got a good deal on it.  A bit of room for more sub has been left on the equalizer in case we want more bass for floating once the water gets warmer.  The high mounted down facing Duals fill in the highs for people sitting in the back and floaters around the sides and back of the boat.

I knew I had something when all 3 dogs started running around the deck barking at the KM8s and sub!  The only other time I've seen this is with my home theater setup.

So we did a long cruise with 4 people and 3 dogs and everyone got to pick their music and volume level.  Funk to Mozart #41. All good!

0612161721br.jpg.15c6e2875daccb439d123e8

Sub under the picnic basket. Clarion under the black weather shield.

0612161721r.jpg.94331cd9a63239d5f5eb24cc

0612161730r.jpg.a8bcf04510ab36cb087b3d55

Lots of room under the helm.

0612161722r.jpg.fc05f3413508b57af50abe66

 

 

WHAT QBOMB BOX DID YOU USE?

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On 6/28/2020 at 7:54 PM, barwick803 said:

 

 

WHAT QBOMB BOX DID YOU USE?

The 12" sealed.   Its pretty much a cube.

Put it on a new pontoon last year.  Still sounds great paired with two 8" and two 6x9 Kickers.  100 rms to each Kicker.

Structurally holding up very well.

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