Articles
   
       
       
Pics/Video
   
       
       
Shop
Search
 
 
 
 
 
Home   Articles   Pics/Video   Gear   Wake 101   Events   Community   Forums   Classifieds   Contests   Shop   Search
WAKE WORLD HOME
Email Password
Go Back   WakeWorld > Boats, Accessories & Tow Vehicles

Share 
Reply
 
Thread Tools Display Modes
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 8:44 AM Reply   
So I think I messed up! So last year I built a 1.7 cu.' trapazoid sealed box for my jl 12w6v3 pushed with a hd 750/1. It sounds ok.... But thought I'd get alot more out of it. Thinking I should have done a hull faced mount. Can anybody with expierence in the 2 applications give me pros and cons? Thanks.
Old    "G" (grant_west)      Join Date: Jun 2005       02-25-2014, 9:23 AM Reply   
Building a sub box is pretty straight forward. Getting the MOST out of it is a Art.
The size and shape, ported or sealed. Fireing into the hull or against a seat back or into open air are only a few of the diffrent options. We haven't even gotten into what sub or what amp and you have already thrown in so many variables to make someone's head spin. No wonder why W/W has - 50 to 1 ratio when it comes to tower speakers Vs sub box threads.

My advice is to build a box as small as you can with in spec. Don't make a super nice one just a box. Use this as a test mule. Put the box in as many diffrent locations and fire it into and off of all the diffrent directions you can think.

This will give you a better Idea what direction the sub sounds best. Once you have figured out the direction the sub firing sounds best I would start to try and "Vent" open up as many seats or remove as many sound blocking devices as you can. This again will give you a better idea what's holding your sound back. The inside of your boat is like a guitar. You need to tune the inside of your boat to work with the sub. By moving things around and opening things up you can change the sound and increase the output.
This advice go's for any and all boats. This is somthing that takes time and their is no set guide lines on "do this and do that" and your done.

If your trying to get the most out of your sub you need to go threw the process. Also some pics of your boats interior and it's layout would help give you some advice
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 9:28 AM Reply   
Well I did state my equipment above and my box is what my sub is speced for. I have a v210 and am putting it under the helm. I guess I could try fitting it sideways to see if it fits and what it sounds like. Doesn't really need to be pretty buy the side facing boxes with the plexi glass do look nice
Old    David (DavidAnalog)      Join Date: Sep 2013       02-25-2014, 9:43 AM Reply   
Quote:
Originally Posted by Dmac420sj View Post
So I think I messed up! So last year I built a 1.7 cu.' trapazoid sealed box for my jl 12w6v3 pushed with a hd 750/1. It sounds ok.... But thought I'd get alot more out of it. Thinking I should have done a hull faced mount. Can anybody with expierence in the 2 applications give me pros and cons? Thanks.
You have the right subwoofer and the right amplifier driving it. But you do not have the correct enclosure. That is the starting point with your situation.
A rectangular enclosure with different side dimensions is to your advantage. An extremely elongated enclosure that is too far removed from square is not good. Beyond that, the exact shape is not critical, whether all corners are 90s or a wedge shape.
Your enclosure is too large. It should be closer to 1.0 cu.ft. net after driver displacement is removed in a sealed application.
Too large of an enclosure will give you deeper bass extension but in an area lower than most material and will sacrifice energy in the meat of the bass. A sealed enclosure that is too small sounds dead and lifeless. Too small sounds live but peaky with a single note character. Either extreme reduces power handling. There is an optimum middle ground.
So begin by building the right size enclosure with a 'Qtc' in the .8 (minmum) to .9 (maximum) range per JL Audio specs.
Then follow Grant's suggestion for experimenting with different locations. You can also do the inverse by resting the enclosure on the driver's seat and move your head around the boat, in different nooks, and hear different results.
If I saw the boat I could predict the results with certainty and without the test.
Using the boat boundaries for effectively loading the sub can make a big difference.
Bass-reflex requires a sizable increase in the enclosure but is the easiest +3 dB you'll ever gain.
Btw, it's an open boat so don't take all the gusto out of the bass by tuning it the same as you would in an enclosed cabin of a car, truck or SUV.
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 10:02 AM Reply   
David I know your a wizard at this but could you please dumb it down a bit for me? Lol. So my box is too big? It is a longer box with the back about a 75 degree angle and obviously the sub facing forward. I hope I'm not expecting too much in a open air environment and never will be satisfied because all that does is get expensive.
Old    David (DavidAnalog)      Join Date: Sep 2013       02-25-2014, 11:02 AM Reply   
Quote:
Originally Posted by Dmac420sj View Post
David I know your a wizard at this but could you please dumb it down a bit for me? Lol. So my box is too big? It is a longer box with the back about a 75 degree angle and obviously the sub facing forward. I hope I'm not expecting too much in a open air environment and never will be satisfied because all that does is get expensive.
Yes, if the information that you provided is correct (1.7 cu.ft. inside) then your box is definitely too big.
For a 'Qtc' of 0.8 that woofer wants a sealed box of 1.0 cu.ft. internal net (after removing the woofer displacement), which happens to be 1.56 cu.ft. external if using 0.75" thick stock. That 'Q' will give you really deep bass, barely rolling off at 40 Hz, and some great upper bass attack. It will have a very wide and smooth response. Great bass SQ and pitch accuracy also.
Much of that potential is lost if the execution isn't perfect in the box construction, placement, tuning, etc.

Look, the identical equipment will never be as impressive in an open field environment as it will in the confines of a vehicle cabin. In open air the bass energy flash dissipates in a 360 degree sphere. In a car the four sides of the cabin are folded around the subwoofer. Not only are you containing that energy but the reflected energy is often reinforcing the direct energy. Below 80 Hz in a car is like having sixteen times the sub power with a perception of nearly four times as loud. So you cannot afford mistakes in a boat.
Loading into the hull will get you one of those four folded surfaces within the context of the bathtub (in the boat).

You should always be able to depend on your mobile electronics dealer to guide you through every step to make sure you are getting the maximum return on your equipment investment. Stuff like system tuning really matters. Good equipment only gets you so far. Optimum performance is in the execution.
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 11:07 AM Reply   
Would you say a hull pointed sub on say a 30 degree angle down to get more reflection help in any way.
Old    David (DavidAnalog)      Join Date: Sep 2013       02-25-2014, 11:41 AM Reply   
Quote:
Originally Posted by Dmac420sj View Post
Would you say a hull pointed sub on say a 30 degree angle down to get more reflection help in any way.
Sure, as opposed to direct radiating. However, if that area in front of the woofer is too tight, or too restrictive, or you have decreased the radiating surface area through that pathway, then you have hurt the bass. You might increase the tactile feel in the boat a bit but it will reduce more impactful or transient bass. So for a 12-inch sub for example, just make sure the sub face is at least 6" away from any adjacent surface, whether hull or sole. Then you will get a positive increase without the negatives.

The big bass killer is when the sub/enclosure is concealed in a closed & expansive helm or bench seat console and vented out through a relatively small grill. In contrast, the helm console (underdash) of many towboats are completely open in the front plus the cavity is relatively small. So a side-firing sub in this later scenario constitutes direct-radiating and maintains many of the same direct-radiating sound characteristics. You are fortunate if you have this type boat. But again, do not choke off the woofer's radiating surface area.
Old    Robby Elliott (Elliottsx80)      Join Date: Feb 2012       02-25-2014, 2:24 PM Reply   
this is my solution/steps to proper subs and proper sub placement if you skip a step, your system will suffer!!!! step 1 have lots of MONEY… step 2 have HAVE VERY LARGE SUBS…. step 3 use VERY LARGE AMPS…. step 4 this one is really important CUT VERY LARGE HOLES IN YOUR BOAT…. step 5 this is the step i always hate, if it still doesn't sound right, sell the boat and start over from step 1
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 3:30 PM Reply   
i Robby I'm screwed!
Old    David (DavidAnalog)      Join Date: Sep 2013       02-25-2014, 4:15 PM Reply   
I think for the most part Robbie is kidding. But I have seen many boats where the approach was to cut a hole in every flat surface and fill it with a speaker with no regard for phasing or acoustics. Turning a boat into swiss cheese with too many subwoofer origins is definitely not the answer.

In Robbie's previous boat he had dual 13.5" subs in separate bandpass enclosures where the two ports were collected into one and were direct-radiating into the cockpit. The exposed vent/grill only had to be a little larger than two slotted ports. It takes a huge boat with some huge seating consoles to pull that off.
Old    Robby Elliott (Elliottsx80)      Join Date: Feb 2012       02-25-2014, 6:31 PM Reply   
My previous post was more or less for humor, but there was some truth to it
Old    Bryce Pool (bryce2320)      Join Date: May 2012       02-25-2014, 6:34 PM Reply   
Maybe step 1 needs to be, work at NASA
Old    Robby Elliott (Elliottsx80)      Join Date: Feb 2012       02-25-2014, 6:39 PM Reply   
Gave up on the NASA gig, im now a self employed underwater basket weaver!
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-25-2014, 7:40 PM Reply   
Ok David f it I'm gonna give you my dimensions and I need you to build me a box. Cool let me know how much.
Old    TJ (Houstonshark)      Join Date: Jan 2011       02-27-2014, 5:53 AM Reply   
I think we need to see pics of this subwoofer enclosure.
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-27-2014, 7:55 AM Reply   
The one David is gonna build or the one I built?
Old    TJ (Houstonshark)      Join Date: Jan 2011       02-27-2014, 8:28 AM Reply   
The one you built.
Old    David (DavidAnalog)      Join Date: Sep 2013       02-27-2014, 8:36 AM Reply   
Quote:
Originally Posted by Dmac420sj View Post
The one David is gonna build or the one I built?
Hey, Chris,
I can't tell if you are serious or not. But I don't work in the audio industry and I don't build boxes.
Although I am happy to give advice if someone else is doing all the hard work.
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-27-2014, 9:42 AM Reply   
Ill build it you direct me. What info do you need? Dimensions?
Old    David (DavidAnalog)      Join Date: Sep 2013       02-27-2014, 1:05 PM Reply   
Quote:
Originally Posted by Dmac420sj View Post
Ill build it you direct me. What info do you need? Dimensions?
The JL Audio 12W6v3 needs a sealed enclosure made built from 0.75" thich stock of 1.5625 (1.6) cu.ft. external and 1.1074 (1.11) cu.ft. gross internal. 'Gross' means before deducting the woofer's displacement. So 'gross' will be the actual internal volume.
So take any height, width & depth dimensions that will equal the 1.6 cu.ft. external. There are 1728 cu.in. per (1) cu.ft.
The tricky part is when you are building a wedge or trapazoid box.
So split the box into two parts, the large rectangle and the triangle (having a single 90 degree).
Calculate the volume of the rectangle portion. That will be HxWxD divided by 1728. That will be (A).
Create a mirror image of the triangle so that now you have a rectangle. Calculate the volume of that rectangle (comprised of two trangles) That will be HxWxD divided by 1728.
Now divide the volume of the rectangle (actually two triangles) into two. That will be (B).
Add (A) + (B).
That will be the displacement of your wedge/trapazoid enclosure.
You will have to trial and error a few times before you get the perfect size of enclosure that fits your boat.
Old    Danny Pacini (dp513)      Join Date: Jul 2011       02-27-2014, 2:18 PM Reply   
Chris get another w6. One in the locker one under the dash. Face them forward. My boat was a monster with that set up. When I faced mine towards the back of the boat it sounded weak
Old    Chris Dirty (Dmac420sj)      Join Date: Mar 2012       02-27-2014, 4:00 PM Reply   
I don't want to add another 12 just wanna maximize the subs potential. Got my amp rack and 2xdekas under the observer seat and don't wanna rerout it all. It's to pretty to change.
Old    Mikeski (mikeski)      Join Date: Aug 2003       02-28-2014, 5:53 PM Reply   
If I were you I would toss a 3" port in that box, maybe a different woofer too. You can always plug it back up.
Old    Sean Unrau (shunra)      Join Date: Aug 2008       03-14-2014, 2:02 PM Reply   
Quote:
Originally Posted by DavidAnalog View Post
In Robbie's previous boat he had dual 13.5" subs in separate bandpass enclosures where the two ports were collected into one and were direct-radiating into the cockpit. The exposed vent/grill only had to be a little larger than two slotted ports. It takes a huge boat with some huge seating consoles to pull that off.
Hi David,

Can you share a bit more about this setup. I am trying essentially accomplish 1/2 of this setup. I have a 13W6V2 on a PDX 1000.1

Last year I ran with a sealed enclosure in a vented storage locker and it was mediocre at best. So I would like to build a bandpass box and put it in the locker withe the bandpass port vented directly into the cabin.

I am trying to design the box but don't really know what center frequency I should try to tune it for, and how much pass band ripple is an acceptable trade-off for pass band gain and bandwidth.
Old    David (DavidAnalog)      Join Date: Sep 2013       03-14-2014, 2:23 PM Reply   
I'm no longer associated with the dealer so I don't have access to the 'one-off' design for Robby's boat. But I am still good friends with the people at Earmark Marine. They typically design the enclosure exclusively for their customers.

You are on the right track using a shallow manifold to directly couple a subwoofer output to the open cockpit and completely seal it off from the storage locker. This avoids big time output losses and serious phasing issues. This could apply to a bandpass, sealed acoustic suspension, or both the port & woofer in a bass-reflex enclosure.

A bandpass actually has two tuning frequencies. One for the sealed enclosure and one for the ported enclosure. Either too close together or too far apart have negative consequences. And some of it depends on whether you are prioritizing maximum peak output or maximum sound quality. The Earmark Marine subs in Robby's boat focused on SQ since the bandpass in the most conservative alignment was still good for a solid 6 dB increase in output over sealed. Add in the two compounding 13.5" bandpass enclosures port to port, and it was impressive. The only thing missing was that it probably could have used an HD1200/1 per sub versus an HD750/1.
Old    Sean Unrau (shunra)      Join Date: Aug 2008       03-17-2014, 12:12 PM Reply   
Quote:
Originally Posted by DavidAnalog View Post
I'm no longer associated with the dealer so I don't have access to the 'one-off' design for Robby's boat. But I am still good friends with the people at Earmark Marine. They typically design the enclosure exclusively for their customers.

You are on the right track using a shallow manifold to directly couple a subwoofer output to the open cockpit and completely seal it off from the storage locker. This avoids big time output losses and serious phasing issues. This could apply to a bandpass, sealed acoustic suspension, or both the port & woofer in a bass-reflex enclosure.

A bandpass actually has two tuning frequencies. One for the sealed enclosure and one for the ported enclosure. Either too close together or too far apart have negative consequences. And some of it depends on whether you are prioritizing maximum peak output or maximum sound quality. The Earmark Marine subs in Robby's boat focused on SQ since the bandpass in the most conservative alignment was still good for a solid 6 dB increase in output over sealed. Add in the two compounding 13.5" bandpass enclosures port to port, and it was impressive. The only thing missing was that it probably could have used an HD1200/1 per sub versus an HD750/1.
HI David,

Sounds like I am on the same track. I hear that a sub box for an open environment such as a boat should in general be tuned to a higher frequency than you would for an enclosed environment such as a car. I am trying to understand what "higher" means. How much higher? What do you think of the picture I attached? The blue line is a 4th order bandpass of my design. The green is close to JL's suggestion for a slot ported box, and the yellow is close to JL's suggestion for a sealed box.

Looks like I could get close 5db of pass band gain but with a reduced bandwidth, and with a pretty small enclosure. However without building the box I have no idea how it would actually sound.

Changing the design I can quite easily tune the over all response higher (shift to right), but I don't really know how much a shift I should be aiming for, or if I should keep the response pretty close to the recommended JL Audio curves.

Any insight?
Attached Images
 
Old    Brad Morring (BradM07SS)      Join Date: Jul 2011       03-17-2014, 12:47 PM Reply   
In the 4th order I would increase the front and rear volume. Ported volume 50 and sealed volume 30 and tune around 50hz
Old    Timmy! (timmyb)      Join Date: Apr 2007       03-19-2014, 9:05 AM Reply   
How accurate is that software? I downloaded it and was playing around with it. On your vented enclosure, look at what the graph does when you bump the tuning up around 40 hz. For the 12W7 I was working with, it bumped the gain up to 5db and had a smoother rolloff.

Reply
Share 

Thread Tools
Display Modes

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 On



All times are GMT -7. The time now is 9:46 PM.

Home   Articles   Pics/Video   Gear   Wake 101   Events   Community   Forums   Classifieds   Contests   Shop   Search
Wake World Home

 

© 2012 eWake, Inc.    
Advertise    |    Contact    |    Terms of Use    |    Privacy Policy    |    Report Abuse    |    Conduct    |    About Us