Question about subs...

[VU-1]

Hey all -
New to this forum. I have to tell you that I know basically NOTHING when it comes to speaker design or workings.

That's why I'm bringing this question to you...

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Aside from the obvious listening test, how can I determine the performance of a sub by its specs - specifically by its RMS and magnet size?

IOW, it seems to me like a sub with a higher "Magnet-to-Power" ratio (if you could call it that) would be tighter than that of a lower value. For example: if Sub A is a 10"-115W sub and has a 6lb magnet and Sub B is a 10"-185W sub and has a 2.5lb magnet - wouldn't Sub A be the tighter sub?

What combination of things make one sub out-perform another?

Also, what things together make a sub go lower - other than just a larger driver?

Sorry for sounding "dumb"...

[knightfly]

Not the speaker expert here, but Barefoot's been even busier lately than I -

You can't compare ANY audio gear by looking at specs, even if you stick to manufacturers who don't intentionally "mis-test" in order to improve the "on paper" look. You must listen; specs will only help somewhat in deciding WHICH items to listen to.

In addition, it's nearly impossible to listen accurately in a showroom for the most part; placement in the room, sales people who "turn up the one they want to sell you" by a couple of dB, room construction, background noise, differences in any part of the compared CHAIN of equipment, more than about 2 seconds between tests, not having both compared units at EXACTLY the same volume/position in the room, etc, all make this an excercise in futility.

Things that affect performance - power of the amp, damping factor of the amp, wire size/type (small amount of effect usually) crossover type/slope/quality, porting dynamics of the box, cone stiffness, magnet efficiency/size, voice coil size/inductance/mounting method, coupling/non-coupling of the box to structure, structure stiffness itself, amount of acoustic treatment in the room, level calibration of sub vs. satellites, and probably a few dozen others I'm forgetting to mention.

Bottom line, you need to find a store that will let you either try before you buy, or has a return policy that will let you temporarily buy your top two choices and test them in YOUR place under carefully controlled and DOCUMENTED test... Steve

[Paul]

Personally i'd avoid subs completely.

If you are into dance or house then it's understandable.

I'd basically get some large cone speakers and some small cone ones to complement them, so frequencies can be heard and arn't cancelled out, but it depends what you are using them for.

In a dolby 2.1 or 5.1 environment ok of course the .1 means the sub i think so it's necessary for film or games production but for CD's subs will just confuse mixing.

That's just my opinion tho.

[knightfly]

Definitely subs can ruin a system if not done correctly; but if the time is taken to properly position the sub and BALANCE it so it's only an extension of the mains, it can work beautifully.

I've used a pair of KRK K-ROKs (7" woofer, 1" silk dome tweet, passive) with a Yamaha P2200 power amp and a Yamaha Y-120 sub with VERY good results, but it took a while to get the sub in the right place in the room for best coupling, and a while longer to get the balance right; once that was done, I've had people ask how the hell I got that much sound out of those little speakers (sub was behind the desk, offset from center to avoid that null) - you literally could NOT tell where the mains stopped and the sub started.

One problem with using NFM's to "do it all" is that woofers larger than about 6-7", when used in a 2-way enclosure, leave too much of a hole in the response between woof and tweet for a smooth response - so the midrange suffers usually. By properly setting up a sub and sticking with NFM's that don't try to get too wide a response with only two drivers, you get the mids/highs even and cover the bottom 2-3 octaves (non-directional anyway) with the sub.

Again, that takes more effort to get right; but since when was perfection free? Steve

[mixx]

i was in Masterfonic's 20hz room in Nashville...subs done correctly are great.correctly being the operating word..