Newbie here....got a few questions about speaker building....

[yelo]

First.....This is a great Forum and a wonderful resource, I'll be spending a great deal of time here learning!!!


OK, here's the questions....

1. In multiple woofer floor standing speakers how do speaker builders get around the Vas requirements for the indiviual woofers (three 8" woofers with a Vas of 1.8 cu. ft. ea. all together in a 2 cu. ft. box ??), This may be a really stupid question but I'm stumped

2. How do you make three 8 ohm woofers show an 8 ohm load to the amplifier ??? (I know my electronics pretty well and I'm stumped on this as well...)

3. How do you calculate D'appolito spacing ???, I've searched 'till my eyes hurt trying to figure this out

4. What are the benefits of one type of wood over another for the enclosures ??, I've looked into hardwoods like Cherry or Oak for the baffles but it seems that everyone uses MDF...is there a reason for this other than cost ???

Thanks in advance for the answers.......

 

[bpape]

I'm no pro with speaker building. I've done some of my own but no mult woofs and no MTM arrangements so I'll only answer the ones I'm familiar with.

2. Pad it in the xover - you may end up with 4-6 ohms - no big deal. Also, remember that unless you're going to bi-amp, the only thing that matters is the impedance of the whole system together. For example, running 2 8 ohm drivers in parallel to each other and in parallel with a 16 ohm resistor will get you in the ballpark.

4. MDF is used for stiffness and density as well as cost. Veneer with your choice of real wood for best look/performance

 

[sploo]

Some other info about MDF (having built tons of stuff with it, including speakers).

MDF is homogeneous - or to use the dictionary definition: Uniform in structure or composition throughout. In other words, no knots, splits, grain or gaps to deal with.

MDF is also very 'dead' in that a well constructed cabinet will be very rigid and 'dull'.

When you're cutting MDF - especially if you're routing rebates - wear dust protection!

MDF dust is very nasty stuff, and for less than 50 bucks (I'm converting from UK prices) you should be able to get a mask rated for particles and gases (I use a washable rubber mask with replaceable twin cans).

Looking like a camp version of Darth Vader is a small problem compared to the risk of lung cancer.