Sub Install, Setup Thoughts

[scarabscs]

Ok, so I have a nice set up for mids and highs.  2 Polk MM series 6.5's and 2 Polk MM series 5x7's powered by an, with an alpine D class 4.100 amp pushing them.

Im ready for my wife to back her @ss up on the bow of the boat, so it needs some bump.  Im thinking of 3 x 10" Polk MM's with dual voice coil, pushed by another Alpine amp.  I would use the 1.600 D class amp, and hook the subs up in series so they are running around 2.3 ohm.  Topped off with a 2 Farad cap.  I will build a box similar to Johns in the front of the bow.

What do you think about the setup, and what size secondary battery do i need to install.  I want both batteries on a Perko, so I can select which is doing what.  I prefer to isolate all of the stereo to one large battery.

Thoughts?

 

[shimp]

Ok, so I have a nice set up for mids and highs.  2 Polk MM series 6.5's and 2 Polk MM series 5x7's powered by an, with an alpine D class 4.100 amp pushing them.

Im ready for my wife to back her @ss up on the bow of the boat, so it needs some bump.  Im thinking of 3 x 10" Polk MM's with dual voice coil, pushed by another Alpine amp.  I would use the 1.600 D class amp, and hook the subs up in series so they are running around 2.3 ohm.  Topped off with a 2 Farad cap.  I will build a box similar to Johns in the front of the bow.

What do you think about the setup, and what size secondary battery do i need to install.  I want both batteries on a Perko, so I can select which is doing what.  I prefer to isolate all of the stereo to one large battery.

Thoughts?

Sounds good, BUT save your $$ and don't buy the cap, unless you just want another pretty lightup voltmeter, the caps do nothing.  Noone uses them anymore except the stereo shops that are just greedy and/or don't know what they are doing.  Your amp has plenty of caps inside of it on the B+ side of the power supply transformers.  If you don't believe me, which I am pretty sure you won't, as most people don't because the caps have become a mainstay of installs, go to a competition, look at the 20,000 watt + setups, the one's that know what they are doing may have 1 cap just to have a voltmeter in the area they need it in to monitor voltage during charging of their battery banks.  More battery is always better.  Get the biggest/best you can fit/afford, that's really the best advice.  For the sub box, for the tightest sound, use a sealed box, but it will suffer in low freq range repro, a vented box, properly tuned, will be on average 6dB louder on the low freq bass (below 40Hz).  6dB increase in audio means 4 times louder to the human ear.

 

[shimp]

If you do decide to go with a Bass Reflex (vented) subwoofer enclosure, be sure to use good materials and add some bracing inside the enclosure.  Even though there is a "hole" in the speaker box, the pressures inside a vented enclosure will be significantly higher than the pressures inside a sealed enclosure, don't want to blow your box apart .. I have done it!

If you want beautiful sound (or just sound, then ignore this) You may need some midbass drivers (6-10") to supplement the freq ranges between the top freq of the rolloff of your sub enclosure, and the bottom end of your current "midrange" drivers...

Also be sure to set the Subsonic filter on the amplifier properly to the bottom of the rolloff freq of the enclosure, don't want to unload your subwoofers at really low frequencies (some music does have really really low bass) and see them moving to their mechanical limits, at which point soon the triple joint (the part where the cone, spider, and coil meet and are glued together) will separate, and you will need to buy new woofers or have those reconed at that point. 

Or just skip all the madness and do a sealed box, however, the low freq repro of a properly designed vented enclosure is phenomenal compared to a sealed box.  Just my $0.02...  Been doing car audio off and on since mid 80's. 

 

[blazeracer]

Check on the Hz range of the sub. A pair of 2,000 watt 15 inch subs that only reach 30Hz won't sound nearly as good a one 350 watt 10 inch sub that will hit 20Hz. I have a Pioneer going in mine that was in my car. People used to be amazed at the high quality sound it put out. Then again, if you want to shake the windows you need size.

For best subwoofer sound placement, the human ear hears down to about 24Hz. The 24Hz sound wave needs about 6 1/2 feet to mature. Place the sub so it's at 6 1/2 feet from the cone is the center of the boat and the bass will hit so damn hard you'll be amazed. Most guys just throw them in there and 6 1/2 feet will be behind the back seat or something. I know with a jet boat the distance will be hard to reach, but you can reflect the wave off of the side. It's not prefect that way, but it will be MUCH better than having a round sub cannon shooting straight back into the gunwhales.

I'm doing a custom enclosure on mine, NOT vented. 10" 350 watt sub with a range down to 20Hz, 1.2cf of space inside the enclosure per Pioneer specs. Center of the cone 6 1/2 feet from the middle of the boat with one deflection being pushed by a Directed Audio 350 watt crossover amp. It will sound awesome if I ever get time to do it!!

 

[Patchman]

Wow I'm lost, I guess buying the truck box at Wally world isn't going to cut it anymore! :smile25:

 

[scarabscs]

Shimp, Blazerracer, thanks for the comments.  I would like to build a vented box, but i do not have the know how to do it.  Its going to be some tricky angles just to build a sealed encloser that matches the contours of the bow of the boat.  Im going to go do some measurements today, and try and getan idea of what im looking at.

These subs are 86dB with a frequency of 28-200hz.  RMS = 270w Peak = 540w.

I could install 2 mid bass drivers under the rear seat, but the sub setup is going to tap my budget for now. 

Any pointers on building the sealed box?  Sould I leave it open inside with no baffels?

 

[blazeracer]

Wow I'm lost, I guess buying the truck box at Wally world isn't going to cut it anymore! :smile25:

There's nothing wrong with a truck box from Walmart to get the job done. It will still sound good. If you want audiophile results that's a different story. I'm bumping a Pioneer TS-W256C with a freq response of 18-2500Hz. Here it is.

http://shopping.yahoo.com/7486003-pioneer-ts-w256c-car-speaker/specs 

But i'm looking for high end results, not loud results.

 

[blazeracer]

Shimp, Blazerracer, thanks for the comments.  I would like to build a vented box, but i do not have the know how to do it.  Its going to be some tricky angles just to build a sealed encloser that matches the contours of the bow of the boat.  Im going to go do some measurements today, and try and getan idea of what im looking at.

These subs are 86dB with a frequency of 28-200hz.  RMS = 270w Peak = 540w.

I could install 2 mid bass drivers under the rear seat, but the sub setup is going to tap my budget for now. 

Any pointers on building the sealed box?  Sould I leave it open inside with no baffels?

A vented box actually needs a bigger rear space.. hence more wood, hence more weight... BUT like Shimp said, a vented band pass will ROCK OUT done right. I had a band pass box with two cheapo 12's in my old S10 Blazer and it would shake the windows on Burger King as you drove past. Shoot, I have a band pass box sitting here next me with two 10's in right now that I have no idea what to do with. It's my sons and he went back to his mom's in AZ.

As far as pointers, seal it from the inside and let it set overnight before installing the sub. My Pioneer calls for a 1.2 cubic feet of space behind it, which is not a lot. I'm making mine out of fiberglass so it's custom fitted, hugs the hull tight, and weighs almost nothing. When I did the floor I pre glassed in two mounting blocks for the sub.

 

[shimp]

I don't have the time to build a box, plus my fears of the skil saw these days after cutting my thumb.  BUT, if you could give me the measurements of what you have to work with as far as size/space for the box, and if the T/S parameters are availible for the woofers you are using I can design the box for you.  I use WinISD for the design, and usually use google sketchup for the layout, cuts, measurements, etc.  Would make it easy for you to have a badass sub box as long as you can build it yourself.  You'd be suprised, 1 10" woofer in a vented box will easily outperform 2 10" woofers in a sealed box, and 2 would very easily outperfom 3, etc...  Vented boxes are usually required to be larger volume than sealed though, so the box size would be the same in the end, but more sound from less woofers.  Also the power handling of the woofers will go up siginifigantly in a vented enclosure, especially near resonant freq.  The sound can be boomy though, and also if you don't watch the amount of air velocity at the port (during the design phase) you can get some very annoying "port noise", sounds like wooshing air, or chuffing sound.  But done right it's bad ass.  I may put 1 8" woofer in my boat in a vented enclosure one day, but the sound system is low on the priority list. 

 

[shimp]

A vented box actually needs a bigger rear space.. hence more wood, hence more weight... BUT like Shimp said, a vented band pass will ROCK OUT done right. I had a band pass box with two cheapo 12's in my old S10 Blazer and it would shake the windows on Burger King as you drove past. Shoot, I have a band pass box sitting here next me with two 10's in right now that I have no idea what to do with. It's my sons and he went back to his mom's in AZ.

Bandpass boxes are more gimmic (for looks) than for their usefulness, the bandwidth is too narrow, they will be loud, but not over a broad spectrum.  And they take up too much space.  Regular Vented is the way to go, best overall performance and size.

About dividers:
You don't necesarily have to baffle/divide between the subs in a sealed box or otherwise, if they are all the same woofers (therefore their suspensions compliance is the same) and they are on a single mono amplifier channel, they will not "fight" with each other much.  I have 3 10's in my caprice, vented, no divider, all the same woofers, on a single 1500 watt amp and have 0 problems.

 

[shimp]

Check on the Hz range of the sub. A pair of 2,000 watt 15 inch subs that only reach 30Hz won't sound nearly as good a one 350 watt 10 inch sub that will hit 20Hz. I have a Pioneer going in mine that was in my car. People used to be amazed at the high quality sound it put out. Then again, if you want to shake the windows you need size.

A REAL 2000 watt subwoofer in 15" cone size would never have a problem reproducing 30HZ unless the enclosure was way too small.

Car Stereo stuff these days is such a "big lie".  What it says on the specs is a joke, the price is a joke, etc.  The 2000wrms woofers that I deal with are 100lbs each.  I laugh when I go into a place like best buy and see 2000wrms subs that only weigh around 30-50lbs.  That's a joke. 

If anyone ever needs advice on buying car stereo equipment, i.e. what's junk and what's not, the price is almost always a dead giveaway, but feel free to call me I will help you Chris 281-454-9496.  Will probably answer as "dBr" but it's me, ask for Chris to be sure.  http://www.db-r.com is our website.  We do repair on amplifiers (not all, just the good stuff, and it's not what most people think of when they think of good, again times have changed in this industry and most people are clueless to it)  and we have an Online Store.  Not everything is listed there, we can get much more stuff, even the Best Buy brand junk (like Kenwood, Fosgate, Kicker, Sony,  etc) that is so popular, but it's no longer the best stuff.

 

[blazeracer]

A vented box actually needs a bigger rear space.. hence more wood, hence more weight... BUT like Shimp said, a vented band pass will ROCK OUT done right. I had a band pass box with two cheapo 12's in my old S10 Blazer and it would shake the windows on Burger King as you drove past. Shoot, I have a band pass box sitting here next me with two 10's in right now that I have no idea what to do with. It's my sons and he went back to his mom's in AZ.

Bandpass boxes are more gimmic (for looks) than for their usefulness, the bandwidth is too narrow,they will be loud, but not over a broad spectrum.

I guess I meant vented, not bandpass. But they are loud. Now loud and good.. two different animals. I'm about good, I have no need for loud. A regular county/rock bass guitar's lowest note is C at 33hz. Some hip hop and funk bands will tune the low string to B at 31hz. But hip hop music's deepest driving electronic syntesized bass tones will get down 18Hz and I can reach it.

To get both loud and good you'll have to pay price in size and weight, and prolly a BIG shot on the wallet too. If you want to go all out here is something. Not my info, a quote...

"MTX Jackhammer

The largest production subwoofer intended for use in automobiles is the MTX Jackhammer by MTX Audio which has a 22-inch (560 mm) diameter cone. The Jackhammer can take a total of 6000 watts sent to dual voice coils moving within a 900-ounce (26 kg) strontium ferrite magnet. The Jackhammer weighs 369 pounds (167 kg) and has an aluminum heat sink. The Jackhammer has been featured on the television show Pimp My Ride."

Just need a cherry picker to install it. That's my .02 on it. I think Shimp's more of an expert in this than I am.

 

[shimp]

Bandpass boxes are more gimmic (for looks) than for their usefulness, the bandwidth is too narrow,they will be loud, but not over a broad spectrum.
-----------

I guess I meant vented, not bandpass. But they are loud. Now loud and good.. two different animals. I'm about good, I have no need for loud. A regular county/rock bass guitar's lowest note is C at 33hz. Some hip hop and funk bands will tune the low string to B at 31hz. But hip hop music's deepest driving electronic syntesized bass tones will get down 18Hz and I can reach it.

To get both loud and good you'll have to pay price in size and weight, and prolly a BIG shot on the wallet too. If you want to go all out here is something. Not my info, a quote...

"MTX Jackhammer

The largest production subwoofer intended for use in automobiles is the MTX Jackhammer by MTX Audio which has a 22-inch (560 mm) diameter cone. The Jackhammer can take a total of 6000 watts sent to dual voice coils moving within a 900-ounce (26 kg) strontium ferrite magnet. The Jackhammer weighs 369 pounds (167 kg) and has an aluminum heat sink. The Jackhammer has been featured on the television show Pimp My Ride."

Just need a cherry picker to install it. That's my .02 on it. I think Shimp's more of an expert in this than I am.

Yeah, Bandpass boxes have 2 chambers, one in front of the woofer, and one behind the woofer.  Typically one is a small sealed chamber and the other is a vented chamber.  Usually there is a plexiglass piece so you can see the woofers "inside" the enclosure.  But plexiglass of course is not required.  It could be made where you cannot see the woofers inside at all, just the port coming out of the one chamber that is vented.  Here is an example of a large bandpass.  The back of this truck is filled with 48 10" subwoofers in a large sealed enclosure, and the back window has been removed, and is now the "port" that leads to the front of the truck.  Roll down the windows of the truck and you now have a bandpass enclosure (the truck).


48 10's in a Ford F-350 Bandpass, front chamber is the truck itself... toward the end of the vid you can see the inside of the truck.

http://www.youtube.com/watch?v=ve3Iu1DjJ1c&feature=related

-- and yeah, I know it sounds like A$$ in the video, it's extremely loud, the camera mic is not buffered right for that type of SPL level, LOL, it would be like sticking your mic inside the header of your boat, it just wouldn't sound the same as it would out on the lake listening with the human ear instead.

26Hz, Ford F-350 about to fall apart:

http://www.youtube.com/watch?v=8ZeIeqPPShg&NR=1


The guys I deal with shake the ground literally (check vid) not just windows:

http://www.youtube.com/watch?v=hetLDhu47-8&feature=related



Honestly that jackhammer thing is junk too, so is 99% of what MTX sells these days, overpriced junk selling based on the success of the past using the name MTX to sucker in buyers, The jackhammers practicality is entirely limited to only the lowest bass notes, to which equal "loudness" or SPL Level could be achieved with a much smaller hit to the wallet and likely in a smaller space by multiple 18" drivers.  Some of the manufacturers that I deal with do make 21" subwoofers, but they don't sell good.  The practical bass reproduction pretty much ends with a 18" sub.  Anything bigger than that, is a waste of materials, for music reproduction, as you have stated.  My subwoofer box in my car is tuned at 32HZ (mechanically, driver is most loaded at 32HZ), it resonates at around 34-35Hz (actually highest SPL level, just above tuning frequency), so as you can see, a properly designed vented box will "play music" very well, and efficiently.  In SPL competition, efficiency is king, second only to the resonant freq of the internal space of the car being used, the higher resonant freq, the easier to "get loud" on the meter, but sounds like A$$...  60Hz tuning is puke, but it makes the SPL numbers easier to push upward for competition in the lanes where it's all about "the number on the screen of the meter".  Of course SPL systems don't generally sound good, most of them never even play music, just tones and try to put the biggest number on the meter. 

Done right the vented subwoofer enclosure, using the same driver as you are using (the Pioneer) could probably achieve 6dB+ gain at 32hz vs the same in a sealed enclosure, and sound equally well, in almost all regards.  I know it may not seem like I am right, but man I tell you, I built a lot of vented and sealed enclosures, when I used to be all about sealed I thought I'd never switch over to using vented, but once I did, and did it right, I was hooked.  It's nice to have 3 10's in my car that only take up 30% of my trunk space, and only have 1500 watts of power, and whoop the pee-pee out of these guys around here with 6 12's in sealed boxes in the trunk of their cars.... They never believe I just got 3 10's, always looking around trying to find more speakers in my trunk, but there aren't.

 

[Candygirl]

forget boxes and all that stuff. just build one of these and you're good to go. this is a redneck jukebox highly portable and looks cool too!

 

[Becket]

forget boxes and all that stuff. just build one of these and you're good to go. this is a redneck jukebox highly portable and looks cool too!

I'll try to get some pic's, my buddy built one like this, Gel cell bats, amp, all inside and a solar pannel on top to charge it, very nice and sounds perty good to, Not a show stopper but good.

 

[scarabscs]

Thanks for all of the info guys, some great feedback! 

That powerstroke is freeking sick.  Not something I would want to own, but its bad ass as hell as far as power and frequency!

I also diig the cooler stereo, im about o build one for the deel lease, and the river!

So, due to space limitation, and keeping theweight down, I am going to build a sealed box out of fiberglass.  Any thought on the type of foam i should use to make the mold?  Ill post some pics up shortly of the nose of the boat, where the box is going.

Finally.... anyone have a hook up on the stereo equipment im looking for?  :smile16:

 

[shimp]

Thanks for all of the info guys, some great feedback! 

That powerstroke is freeking sick.  Not something I would want to own, but its bad A$$ as hell as far as power and frequency!

I also diig the cooler stereo, im about o build one for the deel lease, and the river!

So, due to space limitation, and keeping theweight down, I am going to build a sealed box out of fiberglass.  Any thought on the type of foam i should use to make the mold?  Ill post some pics up shortly of the nose of the boat, where the box is going.

Finally.... anyone have a hook up on the stereo equipment im looking for?  :smile16:

No idea on the Foam.

I'll check to see if my wholesaler carries Alpine or Polk, but I don't think they do.

 

[Shrek]

The best way I've found to make a one off mold with foam is to use the white foam like the ice chests are made of.
You can get it at Lowes or Home Depot. I use 3M 77 to glue the foam together to the right size then start sanding with a DA sander or what ever you like to use. When you get it to the shape you want, then paint the mold with Latex house paint. This will keep the resin from attacking the foam.
Lay up your glass and wait for it to harden.
Now comes the really messy part, getting the foam out.
I usually gouge out as much as I can remove and then use gas or other solvent to clean the inside of the part.
This methos works very good for one part.

 

[scarabscs]

The best way I've found to make a one off mold with foam is to use the white foam like the ice chests are made of.
You can get it at Lowes or Home Depot. I use 3M 77 to glue the foam together to the right size then start sanding with a DA sander or what ever you like to use. When you get it to the shape you want, then paint the mold with Latex house paint. This will keep the resin from attacking the foam.
Lay up your glass and wait for it to harden.
Now comes the really messy part, getting the foam out.
I usually gouge out as much as I can remove and then use gas or other solvent to clean the inside of the part.
This methos works very good for one part.

Shrek,  thanks for the feedback.  The angles are pretty complex, and I think the foam is going to be the only way to make a well fit mold.  Im looking forward to getting started on this project, but I can tell its going to be a handfull!  how many coats of laytex house paint did you have to use?  I was pretty concerned with the resin attacking the foam.  That would be hell, after spending hours making the mold!!!

The pic of your boat in your signature looks great.  I love seeing top fuel stlye headers......

 

[scarabscs]

These are the angles im working with.