Exactly how important IS magnet weight in a sub?

[ThatChevyGuy 5,000+ posts]

Que?

 

[HeatSeeker 10+ year member]

If youre planning on smashing someones head in with it then its probably something to factor in, otherwise probably not

 

[newusername 10+ year member]

It does matter to a point.
Its really a lot more complex and you'll have to dive into some complex equations related to frequency response to understand the whole mess, but basically its the coupling between the fixed field B and the voice coil conductor cross section inside the flux field. This is defined as the force factor BL^2/Re.

You can pretty much straight up compare that from one sub to the next, but its not like horsepower. Too much can overdampen the driver and reduce SPL in the lower domain (outside of the port SPL). For SPL contests, too much BL is not gonna hurt at all, you really want as much as possible beacuse you're drawing all your SPL from the port only. In general too much BL is never bad because you can do a lot of other things with it if you have extra. (saturate t-yokes, make a linear-type driver, open up gaps and throw in shorting rings, etc etc this of course reduces the BL again back down to a noramal level but you can use it to implement many SQ features not found in many drivers)

For straight up SPL, I'll argue get as much BL as possible and it helps to use a large voice coil too so you can get even more BL from the motor without dancing around saturated t-yokes

I agree that the part I highlighted matters, but this has nothing to do with the weight of the magnets.

 

[Silverbane 10+ year member]

Those subs are made by Credence in the USA and are almost identical to the old kicker l5 series woofers before they went over to asia.

I have played with some protos from Cedence and their square unit was nice when I tested it.

 

[audioholic 5,000+ posts]

When looking at diff subs ive always thought magnet weight was a big factor becuase the magnet is what actually moves the cone. But how exactly does the magnet weight affect the performance of the sub?
Like these for example, YES i know theyre pyramids (shame on me) but these seem like theyd be a good choice for a cheap system build

http://www.thrillaudio.com/Car_Audio___Electronics/Subwoofers_Enclosures/15__Car_Subwoofers/Pyramid-2xPW1576-2xPW1576.html

Single voice coil...4 ohms, 4 of those would hook up nicely to a 1 ohm stable amp putting out about 2000w //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The signal/noise ratio looks good, but i notice the frequency response isnt listed, what is normally the main problem with the cheaper subs? Ive never tried any before and dont wanna find out first hand.

You seem to be implying those subs have a large magnet structure...? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[t00fatt 10+ year member]

Whatever you do don't buy those Pyramids! My stupid buddy bought a pair maybe a year ago. Blew the dust cap off the second day. The box was within recommended size, its just a horribly made sub.

 

[bikinpunk 10+ year member]

weight is a function of density and volume.

 

[Immacomputer 10+ year member]

So why do some companies put big *** magnets on their subs?? If it doesn't matter...

What they're saying is that it's not the size that matters but what you do with it.

 

[B_Rad_NC 10+ year member]

alright, guess those are out of the question. and no i wasnt saying they have a huge magnet structure, but most good subs ive seen do normally have quite a heavy magnet.