PDA

View Full Version : Building up - Where to add first?



Todd_Droz
05-02-2010, 10:19 AM
I'm looking to spend around 600-700 on stereo upgrades and am not sure where to add first. I've read a lot around on here and have seen all kinds of opinions and ideas, some of which I'll likely adopt along the way, but I'm looking for opinions on what will make me happiest right now.

I've have new Polk db651s as my cabin speakers and will be upgrading to a dual battery set-up regardless (though the recent thread on the Perko switch vs. an automatic switch kinda has my head spinning).

So, I'm wondering if I should put the money into an amp for the cabin and add a subwoofer first? I would be doing the install myself I have a buddy just looking for a reason to use his cabinet making skills if i want a custom enclosure. OR, should I add tower speakers with amp for those right now since I don't have any tower speakers at all?

I've resolved that I won't be able to afford all the top-of-line stuff I've seen others rave about, but have seen others here say they have spent less and been happy too. I welcome any thoughts and ideas and appreciate the overall friendliness on this board (don't seem to see that too often in the message board world!)

sandm
05-02-2010, 11:04 AM
biggest question you have to ask yourself is if you want tunes while boarding right now, or would rather have a better system within the boat. my personal choice would be better tunes in the boat right now. for your $700, you could get a decent sub and 5ch amp and still have some coin left over to save toward a 2ch amp and towers down the road.

you don't have to spend wetsounds money either to have a good system. the kicker amps are very good and seem to be found online for some great prices and a good 10-12" sub can be had for under $175. sounds like your buddy is ready to make the box, just be sure and use the proper wood and make it water resistant.
good luck and remember to do your research..

mmandley
05-02-2010, 11:24 AM
biggest question you have to ask yourself is if you want tunes while boarding right now, or would rather have a better system within the boat. my personal choice would be better tunes in the boat right now. for your $700, you could get a decent sub and 5ch amp and still have some coin left over to save toward a 2ch amp and towers down the road.

you don't have to spend wetsounds money either to have a good system. the kicker amps are very good and seem to be found online for some great prices and a good 10-12" sub can be had for under $175. sounds like your buddy is ready to make the box, just be sure and use the proper wood and make it water resistant.
good luck and remember to do your research..

Second all this. I was in your situation last summer i only have 600 to spend on the stereo and i made a pretty great sounding system for last summer. I was able to salel almost all of it for 50% of what i paid to add that to the new system i installed this winter.

Id do a sub and amp for the boat, My findings is that even though i have this great tower set up it means nothing when my driver doesn't turn it on LOL. I drive almost all the time when we are pulling folks so at least in the boat i can jam out and i always remember to turn the tower on for my riders LOL.

viking
05-02-2010, 11:36 AM
Good advice mmandley and sandm!

I started last fall in your situation as well and really read and researched alot. I had a budget that allowed me to go all out on the tower or cabin but not both. I decided to spend the $$ in the boat and bought used stuff for the tower. Plan on upgrading the tower later and planned my amps and system to do that. Figured the core of the system is the first step.

If you want to project music for the riders - spend your money there.

If you want to have a good sounding system in the boat - look at amps and sub.

But remember - if your looking to build it all up over time make sure and not skimp on the amps. for either application.

Todd_Droz
05-03-2010, 11:36 AM
Thanks guys -

I think thats the way I was leaning anyway - improving the cabin first and building towards the tower set up i want. I've read where a lot of people have liked the Kicker 700.5 for their cabin amp. I know a lot have put a 12" sub too, but I was thinking of using a 10". Will that still sound pretty good?

Also, when you say use the proper wood - which is best for marine application? I would figure MDX would not be since moisture can wreak havoc with that.

mmandley
05-03-2010, 11:45 AM
a 10 will work just fine. Lots of people are running the 10s and they make a lot of really nice ones that pound really hard.

You can make the box out of MDF but you have to make sure its coated really well with a water proofing agent. Then make sure when you mount it your not drilling holes water can get to.

sandm
05-03-2010, 11:53 AM
I did a jl 12w6 and realisically, a 10 in the same series would have been fine. you're choice on subs should depend on your musical preferences. 80's and classic rock don't need a very large sub. rap/hiphop thrive on a larger sub. pick what works for YOU.
700.5 would be an excellent amp for a modest system with cabins and a sub. just make sure that you get an additional amp when you do towers. don't run them off the same amp. Ideally your towers and sub should be on separate amps since those are the 2 sets of speakers in a boat that are going to tax the system the most..

good luck..

Todd_Droz
05-03-2010, 12:04 PM
Awesome - I'm getting anxious to get to work on it now.

One other thing though - I've looked at pics that people have done on their installs and I know everyone's setup is different, but what type of board are you mounting your amp to? And also, HOW are you mounting it to the boat? I'm mounting in an '03 Mobius LS, and in that area behind the passenger seat, I can see pretty easily three decent contact points (the floor, the one beam on the outside) but don't know where or how else. Any special screws I should be using? I don't want to screw into something (or with something) that I shouldn't.

Thanks again for the advice guys.

philwsailz
05-03-2010, 12:23 PM
Guys-

I want to jump in here briefly and attempt to dissuade you guys from using MDF in your boat for sub boxes.

My background: In addition to doing the stereo stuff, I am a wood boat collector. I have a frustratingly good understanding of what wood and water does, and what it doesn't. When you get wood wet it swells. When you put dry wood in a humid environment, it swells. What is the material that swells a lot? MDF.


The reaon MDF is used for loudspeaker construction has to do with its acoustic properties. It has a uniform density, and therefore a uniform resonance, and also a uniform damping characteristic; i.e. its ability to not "ring". This property is very important when designing and building full-range loudspeakers, in particular for home and studio use where other materials are less than ideal and will ring in the critical midrange frequencies. This ringing is due to standing waves which can develop in the actual cabinet material, with resonant frequencies whose wavelengths can be measured in inches, not feet.

For a subwoofer and the frequencies we are trying to reproduce, the wavelengths of the sound we are recreating are measured in tens of feet.... WAY too long to create a standing wave in the cabinet material. There is no acoustic benefit in using MDF for a sub enclosure; the benefits of MDF don't apply.

Whe you build a sub enclosure out of MDF, you are building a precisely engineeered sponge. If you coat it, you delay water intrusion, but with a coating, WHEN the water gets in, there is no way for it to get OUT. My analogy is the old wood boat that someone misguidedly adds a fiberglass skin to. They think they are keeping the boat dry, when in fact they are keeping the boat wet. The water gets in and can't get out, and it rots away very quickly afterwards.

There is no way to totally seal an MDF box. You are putting screws in, it is bouncing around, it is flexing, both due to vibration, but also due just to environmental humidity. No matter what you use and how dilligently you apply it, a crack will eventually develop in your coating, and the box will start to swell, making more cracks and accelerating the process.

The proper material to use when constructing a marine sub enclosure is a good quality 13-ply void-free plywood. Many places advertise it as Birch plywood. These days, the adhesive in all but the cheapest of plywoods is not water soluble. When you build with plywood, you get domensional stability and much less swelling. Plywood also will not crumble like MDF. We see boat builders routinely using plywood to build boats, entirely out of wood... I don't know of anyone building MDF boats....

I recently bought good loudspeaker plywood at my local mega home improvement store, so it is out there and available. Just do not buy that cheap rough decking plywood though; it is often full of voids and will buzz... you want the good stuff, 13 plys, not 7... no little foootball-shaped voids in the middle... Smooth knot-free skin.. Get this wood, and you will be real happy with it andf you will build a sub box that will last a LOT longer than the MDF, even with NO sealing treatment.

Phil
Kicker

mmandley
05-03-2010, 12:25 PM
Make the amp board out of some kind of plastic. 1/2 inch HDP works very well. Get some 3m super sticky spray in a can at the local hardware. Use carpet to match your boat and it will look really flush.

As for mounting there is a trim rail along the bottom of the hull where the floor meets. This is the same spot your most likely looking at already. As for the top look there the rub rail is screwed into the boat. Not sure on yours but the 06 has a black square looking rail on the inside the factory screw the rub rail into. This is the top mount for your amp. You will only need 2 screws on the top and bottom to make this connection.

Also the screws only need 1/2 inch to bit and that's all you need is bite. No need to screw them in really fare.

If you cant find the upper rail then pull the carpet down from the inside of the hull and you should be able to see where the screws go in.

On my 08 it was just fiberglass. No plastic was there so i mounted some HDP squares tot he inside of the rub rail area and mounted my racks to that.

sandm
05-03-2010, 01:09 PM
phil, good points, but you forgot medex. I have used this in the housing trade for exterior treatments around doors when people want fluted columns and the such. expensive for a sheet, but works just like mdf, however has some water RESISTANT properties. notice not waterproof.. still need to have some treatment, but will outlast mdf 10 to 1.
it can be used, but the precautions I would take are to treat the entire box with some water repellent and ensure it's in a location that won't see direct contact and raised off the carpet..

btw, sweet boat :)

philwsailz
05-03-2010, 01:11 PM
Correct on medex; my bad. I know of a garage cabinet outfit that uses medex for cabinets that need high moisture resistance. It would be a reasonably suitable material for enclosure building, and yes, it lasts a lot longer than MDF...

thanks for the nice comment on the boat. I have a few more of them, wanna buy one? :rolleyes:

Phil
Kicker

sandm
05-03-2010, 01:57 PM
so to further this conversation a little and hope I can learn something, the school of thought has always been to use mdf in the automotive arena, and I believe that kicker has used this in the past on sub boxes? why then if it does not matter does mdf continue to be the material of choice, especially when 95% of auto installs use mdf strictly for sub boxes and the surrounding amp racks?

I was of the belief that it was superior to other forms of "wood"

philwsailz
05-03-2010, 02:27 PM
Acoustically, it is best for full range enclosures. It is largely irrelevant for sub boxes.

The driving forces for use of MDF or HDP in enclosures are history, price and machinability. Frankly, speakers have been made from MDF for a LONG time. Plants were cranking out full range speaker enclosrues long before the advent of the mobile audio phenomenon. There was familiarity on behalf of the enclosure manufacturers.

MDF in an enclosure plant is easily milled, and provides a smooth cut finish when compared with other materials. There are no fuzzy - furry splinter edges that would require sanding. It is a very flat product that almost never warps or twists in a plant and has an EXTERMELY uniform thickness from sheet to sheet making it easier for machines to handle.

Finally, MDF delivers good perfornance in the acoustics and machining departments at a price that is as much as 50% to 75% lower when compared with an appropriate plywood material. The last sheet of 13-ply void-free wood I got was about $40.00 as I recall. In a plant where I used to do enclosure engineering, I recall that we could get a comparable sheet of MDF for about $16.00. It is higher at retail, about $30.00 for a similar sheet, but the savings are still there.

Phil
Kicker

sandm
05-03-2010, 03:07 PM
thanks :)

viking
05-04-2010, 01:51 AM
To play the devils advocate.............why not use MDF and seal it really good! Also install it above the ground so no direct water seeps in. Yes, eventually moisture will get in. That's a given. But "eventually" could be years down the road. In most cases (and I speak from experience) owners are going to upgrade and change, build a new box, trade in the boat on a new one, and the cycle continues. Many members on here have MDF sub enclosures and with good experience i think?

If you happen to have the ONLY boat you are going to own, and want to install the "system of your dreams" then I say you are 100% correct.

But be ready to invest the $$.

Just food for thought!!

Brianinpdx
05-04-2010, 02:58 AM
Oh I cant resist a good game of devils advo :)

Viking. I'll side with Phil on this one. I'd banter back, the very answer to your Q is the same reason that you bought a Moomba, "the boat doesnt have any wood in it to begin with..." (I wonder why? insert whistling dixie icon here).

In all honesty, moisture will attack much faster than people realize. If you can afford it... go with a composite material. No 40 year financing on the box tho.

ok, I'll head back to the peanut gallery.

-Brian @ Exile

sandm
05-04-2010, 09:03 AM
viking

I would say that many members have mdf boxes here and have had very good luck with them, but almost all of them are less than 1.5 years old, with a vast majority of them less than a year. lets see how they look at the 3-4 year mark.

I bought medex from a local lumber yard. it was $23 for a sheet of 3/4" mdf, and the medex was $75. small price to pay for peace of mind, especially in a rig that cost more than some spend on a car..

EarmarkMarine
05-06-2010, 03:44 PM
Todd,

If I was building on a budget I would follow a couple of basic issues.

1.) Simple Perko switch. Its manual but you can protect your batteries and alternator by understanding just a few things.

2.) The tower is another zone for the benefit of those outside of the boat. I would begin with a balanced in-boat system. Even if you are not a 'bass head' you need a subwoofer or you'll be missing two octaves of important musical fundamentals.

3.) Forget about power handling and instead focus on maximizing system efficiency through the right system choices including balanced components and system tuning. In many of the systems I hear, I can immediately tell that roughly a third of the system potential is wasted through insensitive subwoofers, mismatched equipment selections, bad system tuning and poor voltage management.

4.) Do it in order. Look at your options in the context of your particular boat. The boat should dictate the type of sub box which will dictate the correct subwoofer which will dictate the right amplifier.

5.) Do it right the first time so that nothing becomes obsolete in the future, especially when adding a tower system later. Choose your fusing, wiring, amplifier panel and more based on the final projected system and not just to get by for today. In the long run forward thinking will save.

6.) Its not how much you save that determines the value and performance. Cheap gear with empty specs will not sound good and will not last. You can still buy quality within your stated budget.

David
Earmark Marine

Todd_Droz
05-07-2010, 03:10 PM
David -

Thanks for the point by point help. I do have a couple questions though.

1) "Simple Perko switch. Its manual but you can protect your batteries and alternator by understanding just a few things."

Why this versus the Blue Sea automatic switch (7650 Add a Battery)? I know the Blue Sea one is like $100 more, but does it not automatically switch to your house battery when you are just sitting around? (This is why all the battery threads had me confused)

2) "Forget about power handling and instead focus on maximizing system efficiency through the right system choices including balanced components and system tuning. In many of the systems I hear, I can immediately tell that roughly a third of the system potential is wasted through insensitive subwoofers, mismatched equipment selections, bad system tuning and poor voltage management."

Lost me. I can I be assured I have a balanced system? The only component I have right now is the stock Kenwood HU and just put in the Polk db651s. I have an '03 Mobius LS which has plenty of room in the driver floorboard area (picture attached). I have someone that can build whatever enclosure we want and have seen some good ideas posted here.


I'm all about doing it right, and making it flexible for growth, so I do want to make sure I do it right, but still within a reasonable budget.

-Todd

EarmarkMarine
05-07-2010, 06:48 PM
Todd,

I definitely like ACR/VSRs (you can't beat the convenience) but am a larger advocate of an AC shore charger and an ACR/VSR will in most situations create more dependency on a charger. I don't like the approach taken by some of the ACR/VSR manufacturers. In order to provide total dual bank isolation (independent profiles and programs on two banks with decidedly different impedances due to different usage) a supplemental switch is often required. So if you're on a budget and have a limited tolerance for technology a simple dual battery switch is fine. In fact with a fundamental understanding of charging systems a single switch can be used to manage alternator protection, extend battery(s) lifespan and provide AC charging isolation. There's no such thing as a perfect charging system and every design has inherent conflicts but we try to minimize them.

Here's just one small example of system efficiency and the resulting cause and effect. Say we take a woofer with a 2000 watt thermal rating. Its beefed up to take alot of abuse. The surround, cone, spider, voice coil are all much heavier as a result so it takes 1000 watts to reach its potential. That's alot of mass and inertia that has to change directions 200 times a second not to mention the finer nuances multiplexed within the big signal. So its kind of clumsy and inarticulate from a musical standpoint although with enough power it can seriously move air and ultimately play very loud. And this comes with a major premium in current draw. As a result the 14 plus volts at the alternator are only 12.5 volts at the amplifier primary inputs when the sub is driven hard. As voltage drops so does the real power of an unregulated amplifier and thus the entire system is affected including the highpass amplifiers. Not everyone can afford four stereo batteries and an upgrade 150 amp alternator to stiffen the voltage and overcome an inefficient design.

There are numerous areas where you can profoundly impact system efficiency. A more efficient system is immediately recognized by a more open and dynamic sound and may actually sound better than a much larger or expensive system. When you're operating within a budget you can ill-afford system design and implimentation errors compared to someone who is throwing away more resources that tend to mask some of those flaws. The best sounding systems make far less waste and eliminate the performance bottlenecks that choke the other components. Balance and selection is part of it. System tuning is huge. Hope this helps.

David
Earmark Marine