MM1040 and/or MM1040um

[pso9968]

I was looking at the specs for the MM1040 and the MM1040um (ultra marine), and they look exactly the same. Although the MM1040 says that the warranty will be voided if used in "free air", and the MM1040um was designed for free air. But there is a $50 price difference, is this a ploy to get more $$?

I know you attach the word "marine" to anything and it increases the price, does polk do this too? :p

I think I want to put this in a box from what I have read, it will sound much better. Can anyone attest to this? Even if the sub is designed for free air?

[rallyshark]

I can't speak for this speaker specificly, but there would most certainly be some differences. I wouldn't peg polk for a company to add the um to the end of the name just to charge more. I'm sure the designs of the speakers are quite similar, but certain materials the components are made from would likely be different. Some of the materials would be changed to resist the corrosion etc. that would be far more present in the marine enviroment. Free air speakers tend to have a stiffer motor structure since there is no "compressed air" to help maintain control of the diaphram. Also, the actual measurements would likely be different, i.e. qts,vas,fs, etc. So I would use free air (infinite baffle) for just that, and the others for enclosures. I apologize for my lack of specifics, but I'm not equipped with the propper knowledge/termanology to explain any better:D This is just my best guess, but I'm sure one of the gurus around here will do a better job. Good luck!

[pso9968]

I guess maybe I should have mentioned that this will be for a marine application. The specs I was referring to that are the same is the qts,vas,fs, etc, and all the MM line of Subs are "marine Certified" So I would assume they both have the corrosion resistance etc, required for use in a marine environment.

In general, do you get a much better/cleaner sound from a sealed box, or a free air woofer? Is it worth the extra to get the Ultra Marine free air, so I don't have to build a box?

[rallyshark]

Well, it really depends on where on the boat you want to put them. An enclosure would give you more flexibility on location most likely. Do you even have a "propper" place to mount the speakers in a free air configuration? Think the space of a car trunk. Free air would take up less space possibly, since you wouldn't have an enclosure. In most cases the speaker in the enclosure would sound better. Where specificly would the speakers be on your boat? I'm really surprised no one else has chimed in on this I know someone with more knowledge can give you some better ideas, but I'll keep trying if I need to:D

[pso9968]

Ok, I think I'm going to go with the MM1040, and build a proper enclosure for it. The next question is SVC or DVC? Are they basiclly the same, with more wiring options for DVC?

That is what I seem to be reading, since it can run at either 2ohms or 4ohms.

[rallyshark]

sounds like you got it figured out:)