Sealed vs I/B Sub

[redcamel]

So essentially after reading I have arrived at the inevitable I'm going to have to cut on the boat. I was hoping to put a sub under the seat and call her good, but I understand the sound quality will be terrible. I'd rather have quality sound, not looking for the shakes.

So I'm over the cutting and drilling thing. I have an AR240 2012. Please advise the pros and cons.

Option 1. Run a 10" sealed enclosure (probably port side under rear seat.) Not sure where to port to, maybe under the glove box by the convertible seat, open to other suggestions.

Option 2. Run a 10" I/B sub starboard side under rear seat. Hoping I still have cooler room. Also worried about water on the deck, as I've dropped the nose on purpose I have had 2" of water on the deck for a few moments....fun I guess I could live without...lol.

Which route do I get the best quality sound?

 

[veedubtek]

You can't beat a sealed enclosure for quality.

With that said, I like good sound, but I wouldn't consider myself an audiophile, but better than average I guess? I'm perfectly content with 2 IB subs in the cooler compartment, and the cooler still fits.

 

[David Analog]

If both the infinite baffle (using a true IB woofer) and acoustic suspension subs are direct-radiating (not concealed within a compartment) and both are executed correctly (rarely do I see IB subs correctly executed) then there is no real difference in sound quality until you reach higher output levels. Acoustic suspension is a more linear form of control and allows for greater excursion....so tighter sound at peak output levels.
However, unless you have an exposed acoustic suspension woofer that sandwiches the wall with a sealed enclosure inside the console, you no longer have direct-radiation. With a concealed and externally vented acoustic suspension sub/enclosure you have lost the advantage of acoustic suspension. Due to losses the sub and amplifier have to work harder. Also the transients, attack and much of the sharp tonal construction is filtered leaving you with a more tactile and less articulate sounding sub.
Plus, a sub/enclosure within an expansive enclosure (seating console for example) and externally vented creates a substantial phase delay making integration with the in-boat coaxials a little less coherent.
With a larger sealed 12-inch sub, a bass-reflex 10 or 12-inch sub, concealed and externally vented, and driven by more power, you can make a more authoritive bass statement. But you will always lose sound quality as compared to a direct-radiating version.

 

[redcamel]

But you will always lose sound quality as compared to a direct-radiating version

I see your point. I think the best bet would be the seal enclosure with the exposed woofer through the wall. I'm a little scare on the execution of getting the box right on the port side.

The I/B on the starboard side seems easy to execute. I was considering the Rockford PM210S4. If I were to go down that road do recommend any modifications to the cavity under the rear seat. I admit I'm not an audiophile....but I'm a quick study. Looking forward to your advise.

 

[txav8r]

As far as ease of execution, I can definitely attest to the IB sub being easier than the enclosure. The trick in our boats, if finding a location that gives you enough flexibility to miss a little and still get the box to line up with the woofer. I have done both. I put both in the starboard seat compartment. In the 2012 240, I hated that recess for the floor cooler as it was in the way of storage, I didn't use the hard cooler. So I filled in that hole. You can mount an IB sub in that wall easily. But...your going to have to get inside surface smooth, either by grinding it down, filling it, or both. My recommendation on any audio upgrade is to use as high a quality equipment as you can use. I use JL Audio equipment for good reason. Their best marine rated 10" IB sub is the M10iB5. You will need about 180W of clean rms to drive it. It can handle more and operate on less, but the peaks will overun it with higher and if not tuned properly, it is risky. And powering with less is leaving too much on the table for the investment. Another angle to look at it too...your cutting a hugh hole in the boat that won't be easily covered or repaired should you have to make a change. Lesser equipment will have not only lesser performance, but less lifetime, and the riggors of a boat expose them to issues, so a bulletproof woofer was in my plans all the way. You can check my thread on the Blue Yonder Stereo upgrade. I used the enclosure rated sub for this install, but it links my other install on the Nauti Dawg. You can find good info in the thread. I don't have pics with me but have plenty of the IB install if you want them too.

 

[David Analog]

I see your point. I think the best bet would be the seal enclosure with the exposed woofer through the wall. I'm a little scare on the execution of getting the box right on the port side.

The I/B on the starboard side seems easy to execute. I was considering the Rockford PM210S4. If I were to go down that road do recommend any modifications to the cavity under the rear seat. I admit I'm not an audiophile....but I'm a quick study. Looking forward to your advise.

The Rockford Fosgate PM 210S4 is a good sub but I like the JL Audio M10IB5 better. Here's why. JL Audio fully commits to infinite baffle with a higher 'Q' woofer, in that it is better self-damped/controlled. JL Audio offers a different model sub for acoustic suspension (small sealed box) applications. RF tries to play it down the middle with a jack-of-all-trades subwoofer, ie: sealed, vented & IB. So it's a bit of a compromise for two of the three and dead wrong for vented.

 

[redcamel]

I don't have pics with me but have plenty of the IB install if you want them too.

I sent you a pm with my info....could your share. Also your install on the Blue Yonder is really really nice. Gave me some good ideas. I like the box, but I want to keep run in that area....I like having a spare cooler there. Also, I'm some what question my ability to pull it off, well and make it look that good,

 

[redcamel]

I like the JL Audio M10IB5 better

I've been a fan of JL for a long while. I was draw to RF mainly for the tower pods (yeah bad reason). Plus I have a pair of the M262-Wake and buddy gave me in the winter for my b-day. Maybe I'll go all JL in the tub and go RF on the tower only.

 

[txav8r]

Eric, I thought I would post them here since the thread pertained to an IB install. First off, I did it exactly as @David Analog suggested it be done. By sandwiching the wall of the compartment between the woofer and the birch speaker ring that I made per his instructions as well. I coated the ring with resin to waterproof, then painted it white to match the back of the woofer.

I drilled and countersunk my holes, including the 4 holes to mount the ring to the back wall. I cut the hole to size with a jigsaw on that install almost to my cut line, then I finished it to the line with a drum sander wheel on my drill. It would have been easier to take my 1/4" MDF jig and screwed it to the wall, then taken a plunge router flush trim bit and followed it to finish all at once.

Radius the edges of your hole so it won't splinter or crack, as well as the countersunk holes to prevent the same.

On my 230, I was able to mount this in the wall facing the driver as you will see.

But with the 240, your going to want to mount it like I mounted the acoustic suspension sub on the seat compartment wall facing the isle, because the wall facing the driver has way too much radius to cut bezels and support easily. The more rigid the mount the better. You will also need to buy a baffle cup to enclose any mid cabin or aft cockpit speaker as they are so close to the woofer, that it will drive them. Pics of that as well here...

I hope this helps...you can get the speaker rings from Earmark Marine in Plano, TX, as well as the baffle. This is a pretty straight forward install, but measure 3 times and make sure your woofer fits on the wall without any of the curves interfering with the mounting of it.

 

[Earmark Marine]

A well-installer free-air sub can give you great performance. David Analog and txav8r made some great points. Let me know if you have any questions, I can get you everything you need to do great sounding sub install on your Yamaha, including detailed instructions for the DIY installer.

Odin

 

[internationalmarinemike]

Very nice pictorial and very nice job on the installation. If anyone needs the rings cut in almost any material let me know. We have an in house CNC that does these and it is reasonable. Again thank you for sharing the pictures, I enjoy looking at all the installations. We post our in our installation gallery on our website, Facebook, and Instagram pages. I will put up a few here as well.
@txav8r

 

[Geiger41]

@txav8r Are those baffle cups really necessary. I dont have them on my 2 JL IB's, and they sound great. Will they help the subs sound even better or are they for another reason. My other speakers in the boat replaced the stock ones and in the same stock locations in the front and back of the boat.

 

[GTBRMC]

@txav8r Are those baffle cups really necessary. I dont have them on my 2 JL IB's, and they sound great. Will they help the subs sound even better or are they for another reason. My other speakers in the boat replaced the stock ones and in the same stock locations in the front and back of the boat.

The baffle cup goes on the other speaker(s) that share the same air space with the sub(s)... they minimize the magnitude of the relatively large pressure waves coming from the sub that reaches the coaxial driver.
More simply stated, the baffle cup keeps the sub from driving the coaxial.

I don't believe it does anything significant for the sub performance - although, in theory, it might... but the power, surface area, and excursion differences between the coaxial driver and the sub tells me the coaxial's chance of back-driving the sub are infinitesimal.

 

[txav8r]

The baffle cup is on the 6.5" speaker that is in the same compartment as the IB sub. If your coaxial is in the same compartment, you need to isolate it from the massive sub, because the way a speaker works, it must move to reproduce the sound. When the midrange cone moves on the IB sub,, it will literally overpower a close by coaxial. So the baffle cup just encloses the smaller driver so the bigger one can't do that.

 

[txav8r]

Yeah, the small coaxial won't drive the larger sub

 

[Geiger41]

Im good then Subs are in a separate area then the 6.5's.

 

[txav8r]

Again, if the coaxial is not in close proximity in the same compartment, the baffle isn't necessary. However, if your IB is in the starboard cockpit seat compartment, and the coaxial is in the wall area of the same compartment, it is. I don't know if the 240's with the speakers in the rear corners would be so affected, but it would be close. And the amount of affect it has may not be perceptible...but if your spending well north of $1000-1500, spending an extra $25 (don't remember cost) to make sure it doesn't seems reasonable.

 

[Geiger41]

My 6.5's are in the front and rear corners of the boat, subs behind the driver seat facing inward, and the other right across also facing inward.

 

[David Analog]

My 6.5's are in the front and rear corners of the boat, subs behind the driver seat facing inward, and the other right across also facing inward.

When you add a subwoofer to your system and highpass the coaxials you immediately notice how much cleaner the midbass and midrange is. The isolation pod on the coaxial can have a similar impact. But you want to be careful to only use it when there is a legit need.
A subwoofer in very close proximity and sharing the same air space as a coaxial will cause the coaxial midbass driver to become a sympathetic radiation and modulate out-of-phase with the woofer. This wasted excursion creates distortion and detracts from the sound quality in several respects.
On the flipside, the compact isolation pod serves to raise the coaxial speaker resonance and limits its midbass reach.
So it's much like selecting the leper with the most fingers and knowing exactly when and when not to apply it.
The collective size of the seating compartment and adjoining gunnel cavities raises the compliance of the air space plus the increased distance both serve to minimize the negative effect. So if the two aren't in very close proximity in a tight air space then I wouldn't recommend using the isolation pods. Mel has a legit need where the pros clearly outweigh the cons.

The other reason to use isolation pods is when the coaxial is mounted right at the edge of an open coaming pocket or similar situation. The pod restores front to rear acoustic isolation thereby increasing power handling, decreasing wasted excursion, improving damping, and cleaning up the midrange. But this is not a scenario found on a Yamaha.

 

[txav8r]

I couldn't have said it that good if I was drunk! @David Analog