FourTwenny

I ordered a MB Quart PWH 304 and it came today. Ordering the amp for it (MB Quart PAB 1200.1) either this friday or in 2 weeks from friday.

I need to figure out my box situation. I am thinking i will have to buy this box because i have no access to tools or a place to wood work at the moment. The sub came with a manual that has some specs but i am not sure if that is everything i need. Like it says how many cubic meters i need but it doesnt say how to space it. Like i don't know if it should it square or rectangle, if rectangle what are the LxWxH ratios, ect. It also has spec on frequencies, i have no idea what is up with that.

I don't expect anyone here to do my homework for me. But i was hoping someone could give me a shove in the right direction.

DeadlySones

iTrader: (4)

Does the manual show a recommended enclosure? If so, what does it say? ported this many cu.ft., sealed this many cu.ft.?

For the specs part, the Fs (free air resonance) gives you an idea as to around where you should port. Usually about 5hz over the Fs gives a decent flat response for a daily driver. If your after harder bass tune a it higher. You should never tune below the Fs.

FourTwenny

It also has the speakers dimensions but that is straight forward to me. I just have no clue what Qtc and F3 Hz mean. Here are the specs in manual.

DeadlySones

iTrader: (4)

Is it the DWH or PWH? Do you plan to go sealed? Is so, the bigger box will play lower. The F3 represents the rolloff. So basically the response will begin to "rolloff" around that frequence. I'd go with 1.4 cu.ft. 40hz if you have the room.

Do you have anything that lists the Fs? My understanding of an optimal Qtc is .707

FourTwenny

PWH 304. I plan on going with a sealed enclosure using the Optimal Sound Quality-Flat Response specs.
I would post each page from the manual but i don't want to clutter the forum. Here is a link to it though. MB Quart Info Archive (you have to click the manual for the PWH 302 at very bottom of premium catagorie)

DeadlySones

iTrader: (4)

1.3 cubes, 37hz F3 is pretty low for sealed .... Qtc .81 .... sounds like it should be a nice musical box. I haven't used any MB subs but the specs look good.

Let us know when your done how you liked it.

FourTwenny

Ok one thing i am not sure about is shape. Will it matter if the box is square or rectangle.

Also, is the F3 Rolloff frequency built into the box or is it something you tune a crossover too ? And what is the Qtc, is that something that is built into the shape/ design of the box ?

DeadlySones

iTrader: (4)

Shape not really as important as the proper internal volume. Sealed boxes are actually quite forgiving if your off by a little.

The F3 is combination of sub spec characteristics & enclosure internal volume +/- any fill material.

Qtc is also based on both sub spec characteristics & enclosure internal volume +/- any fill. My understanding is that Qtc is associated with the natural dampening of the enclosure and sub combination. As I said before I believe that a Qtc of .707 is suppose to be optimal for musical boxes, but not necessary.

Just build a box for it with the proper internal volume - 1.3 cu.ft and seal it very well. Your done. The F3 and Qtc are just FYI and they're not bad numbers at all.

HTH