How does a sub play 10 hz when..

[QuestionMan 0]

I see all these vids of people playing 10 or even 5 hz test tones, and i dont really understand how. If you have it tuned to 35, you set the SS at 30 give or take. Then how is it that the sub can play a 10hz tone. Doesn't the box constrict it, and wouldnt it be unable to control the sub below 30 hz or so if tuned to 35? This may sound noob as hell, i dont care lol.

Thanks for reading,

Mitch

Edited May 23, 2008 by QuestionMan

[///M5 2,833]

They shut off the subsonic and then play tones. Excursion greatly increases below box tuning potentially damaging a driver which is why you have a subsonic in the first place. Sort of a misnomer anyways since you can hear below the subsonic, but either way it is a cheating way to get lots of excursion with next to no power. One more reason why subwoofer videos are stupid.

[QuestionMan 0]

Thanks, i understand the concept of boxes, but dont really understand (just know) that they constrict the sub to certain frequencies. How does a sub play 10hz without getting screwed every single time? I guess i need to learn more about how a boxes role plays before i understand this haha.

[///M5 2,833]

Not sure what you mean by screwed. If it is damage, pretty simple since if you haven't either mechanically gone beyond the travel limits of the sub or thermally gotten it to hot it won't be damaged.

[QuestionMan 0]

Sorry, yeah i mean't damaged. Then what's the point in tuning if the sub will play well below that point. (I'm not contradicting, trust me i'm in no place to contradict people on this forum )

[///M5 2,833]

Tuning is meant to taper the frequency of the response to correspond to your desires. Generically speaking tuning higher will yield more output but it will be less smooth with a larger peak in the FR. Tuning lower will be a smoother frequency response. The tuning frequency is actually the -3dB point so it is sort of a misnomer. Either way it is dangerous to play your sub below tuning as you can easily go beyond its excursion limits.

[dustin420 0]

yep what M5 said. just adding when a sub goes below tuned hz its called unloading, its essentially the same as ruuning free air with all the power a sub can take thermally which useally allows the sub to have crazy excursion. also just because for ssf is set at 30hz doesn't mean your sub can't play lower then that, all the ssf does is have a negative DB slope beyond a certain point so depednign on the amp it could have a 12db slope or 36db slope just depend on the amp.

[QuestionMan 0]

yep what M5 said. just adding when a sub goes below tuned hz its called unloading, its essentially the same as ruuning free air with all the power a sub can take thermally which useally allows the sub to have crazy excursion. also just because for ssf is set at 30hz doesn't mean your sub can't play lower then that, all the ssf does is have a negative DB slope beyond a certain point so depednign on the amp it could have a 12db slope or 36db slope just depend on the amp.

So if the SS is set at 30 hz, the sub will still play below that, only with less power? Now that i know that, anyone know the ssf slope on a saz-1500?

[dustin420 0]

SPECIFICATIONS:

Type Mono Class-D

1500 watts x 1 1 ohm

800 watts x 1 2 ohms

400 watts x 1 4 ohms

3000 watts x 1 2 ohms (Dual 1500D's)

THD at 4 ohms <0.1%

S/N Ratio >90 dB

Input Sens. 200mV - 6v

Freq. Response 10 - 350 Hz

Fuse Rating 40 amps x 4

Dimensions 17" L x 9" W x 2" H

Warranty 2 years

Efficiency : 86% @ 4 ohm, at 100Hz

Double Sided Through Hole Epoxy PCB

Daisy-Chain Through Output RCA

24dB/Oct Variable Crossover

Multi-Way Protection Circuitry

(Thermal/Over Current/Speaker Short/Speaker DC Protection)

Variable Subsonic Filter

Variable Bass Boost

Variable Low Pass Filter

Variable Phase Shift

Zero(0) Gauge Power Supply Connectors

Tested Voltage & THD : 14.4V & Less than 1% THD

Operating Voltage : DC 10V~18V

Digital Class-D Linkable Mono Block Amplifier

1 Ohm Stability

RCA Line Input and Master Output

24dB Octave Crossover Slope

Wired Remote Controller

it has a 24db slope.

[QuestionMan 0]

lol thanks, i guess that could've been one thing i could find out for myself... haha thanks to the people that replied to this,

Mitch

[///M5 2,833]

it has a 24db slope.

It doesn't say that in the specs you just posted. I am not sure what Sundown is using on the SSF.

[dustin420 0]

it has a 24db slope.

It doesn't say that in the specs you just posted. I am not sure what Sundown is using on the SSF.

um ok then what does "24dB Octave Crossover Slope" mean? it says 2 lines above where i said it? and i got the specs right off this site?

[///M5 2,833]

it has a 24db slope.

It doesn't say that in the specs you just posted. I am not sure what Sundown is using on the SSF.

um ok then what does "24dB Octave Crossover Slope" mean? it says 2 lines above where i said it? and i got the specs right off this site?

That is for the crossover, not the SSF.

[dustin420 0]

it has a 24db slope.

It doesn't say that in the specs you just posted. I am not sure what Sundown is using on the SSF.

um ok then what does "24dB Octave Crossover Slope" mean? it says 2 lines above where i said it? and i got the specs right off this site?

That is for the crossover, not the SSF.

hmm i allwasy thought they were the same for both? i know on my 12.1 its that way.

[Thumpper 266]

all of my systems go right down to 10hz but I design my enclosures

with the right amount of internal cf3 and port velosity wich is very

important if you like the LOW LOW"S

personally I like it when my system can produce sub sonic waves

that are felt 3 or 4 cars ahead..feels like the floor of the car rolls

like when you flick out a towel

here is a pic from my last system....this pic was taken at 15hz

take a look at the surround...it is full of dimples and wrinkles

a little HEXCURSION

[JimJ 11]

personally I like it when my system can produce sub sonic waves

that are felt 3 or 4 cars ahead..feels like the floor of the car rolls

like when you flick out a towel

Personally, I always think to myself how annoying those people are.

In a vehicle, isn't it just easier to go sealed or IB? There's already a massive amount of cabin gain that isn't there in a room...heck, even in a room I'd rather have IB and a lot of swept area over a very low tuned enclosure...

[dem beats 1,223]

I think sealed or IB is always the way to go unless you have some ungodly sized room, or you are looking to get more boom in the room from less equipment.

In car, you go ported to chace spl numbers and scare old ladies and cats.

[helotaxi 46]

Playing below tuning can actually yeild MORE excursion for a given amount of power than running the sub free-air. The inertia of the air in port gets out of phase with the cone movement and works to decrease the effective moving mass of the driver. Lower mass means more excursion. The problem is that because the port is out of phase with the cone, the potr output cancels the cone output. This is what gives a ported enclosure its steep rolloff below tuning.

[sqguy 0]

Port is a trade off. Say you have limited power and want low bass, so you tune for 30-40Hz or low as you can get something out of the subs in question (before they really roll off). You get a nice boost there for the same power, and a boost there to counter the roll off you get with sealed or IB. But below that it unloads and makes little sound while the sub can damage itself flying all over. It takes more room than sealed box, makes more db where it is tuned to. I have IB subs and set to 15Hz SS on my crossover, I only have it on because some CDs would make the subs move at 5hz or whatever. It does not do that now but I can get 20hz pretty good. IMO ported is good for limited power or SPL needs, and those who like ported of course. If you are pushing good power you better have a SS filter.

Roll off is where the lower you go, the less sound you get. Sealed box has the most as it damps the cone more as the cone wants to move more to make lower tones. Any sub will play 10Hz, but you may not hear/feel it if the db is really low. An 8" sub for example just can't push enough air to do the job. That is why I put four 12" IB in my car to get down there better.

(btw ///M5, finally sprung for an 880 Pioneer )

[helotaxi 46]

Roll off is where the lower you go, the less sound you get. Sealed box has the most as it damps the cone more as the cone wants to move more to make lower tones. Any sub will play 10Hz, but you may not hear/feel it if the db is really low. An 8" sub for example just can't push enough air to do the job. That is why I put four 12" IB in my car to get down there better.

Sealed doesn't have more roll off than ported, it just typically begins to roll off at a high freq but a shallower slope. Get down into the really low stuff and the sealed will have more and better output than the ported setup which falls off quite steeply when it begins to roll off.

[///M5 2,833]

Indeed and neither does IB.

[sqguy 0]

Roll off is where the lower you go, the less sound you get. Sealed box has the most as it damps the cone more as the cone wants to move more to make lower tones. Any sub will play 10Hz, but you may not hear/feel it if the db is really low. An 8" sub for example just can't push enough air to do the job. That is why I put four 12" IB in my car to get down there better.

Sealed doesn't have more roll off than ported, it just typically begins to roll off at a high freq but a shallower slope. Get down into the really low stuff and the sealed will have more and better output than the ported setup which falls off quite steeply when it begins to roll off.

Don't want to nitpick but depends on your definition of low, mine is say plays down to 30Hz which a ported can do better than sealed for the same (or limited) power right? If you have the extra room, and yes under tuning it will unload and may be harder to get right SQ from it. Seems to me a lot of people think 50Hz is low (maybe not you guys or so much on this site), sometimes figure I am one of the oddballs wanting 30Hz by the stuff I've read on boards?

I was looking at the IDMAX, it sure seems to get low sealed in the chart I saw but they are not free. A flat box for that sub would have to be built bulletproof and the sub is deep as well so maybe inverted mount. I don't need louder so can't see any benefit. I generally dislike sealed but I've never run a low Q quite like that thing.

[///M5 2,833]

Umm, you were talking about roll off and lows and 30Hz isn't low, it is right in the middle of a range where a sub should play. 50hz is midbass not subbass.

[sqguy 0]

"Should play," but I see piles of subs that can't gut under 30 in their recommended sealed. I've had piles of them. You end up forcing them and don't get much sound out of them.

[///M5 2,833]

Obviously operator error on your part then.