Building up - Where to add first?
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!)
MDF and Boats = Oil and water
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.