How do you define "SQ" for a sub?

[BrianChia 10+ year member]

The bottom line is accurate musical reproduction. The parameters don't really mean shit as long as output is as close to the recorded input as possible.

 

[Electrodynamic 10+ year member]

Out of curiosity, would an underhung driver be better to go with for SQ or does it not matter? Are there any advantages of going with underhung subs?

Read Sundownz post again - underhung topologies are used to combat the non-linearities commonly associated with a typical overhung design. The non-linearities I'm talking about are BL, Cms, and Le - just like Sundownz posted.

Linear motor topologies (such as XBL^2) maintain BL better than conventional methods, so having a linear BL "curve" takes care of problem #1. It's important to note that it's not just the parameters (the parameters do matter - it's what speakers are designed towards) it's how stable the parameters are over stroke. A typical overhung motor can have significant BL non-linearity even within Xmax limitations. When BL isn't linear (read: BL distortion) your Q's shift (Qe and Qt). Ever stop to think about why your subwoofer sounds different when you turn it up (not just loudness - I'm talking about the overall sound of the driver)? That's because the driver is no longer operating within flat, stable, BL limits and it sounds different because the parameters have shifted.

Inductance is another beast that a lot of mfg's either a) ignore, or b) try to tame. Like Jake said, it's inductance variation and inductance itself that should remain constant (as little variation as possible) and low (read about inductance and how it affects woofer speed here).

 

[ramdaspadhye 10+ year member]

you seriosuly should never post anything again.
but atleast you know aq isnt an sq sub.

Thanks, dick //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[req 5,000+ posts]

thanks nick.

as stated, sq is about the fidelity of the input versus the output. nuff said.

and IB aura NSXX subs are awesome. like this install i did for a friend;

 

[spark plugs. 10+ year member]

most people that think they want sq usually just want a more accurate sounding spl driver //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Scoobydoo 5,000+ posts]

ok since i know nothing about this stuff. i am not sure what is considered a low FS or low BL, etc

would a sub with these specs be considered a SQ driver?

Fs: 22Hz

Qts: .46

Qms: 9

Qes: .48

Re: 2.9ohm

Bl: 16.75Tm

Z: 4ohm

Le: 3.3mH

Vas: 130L

Mms: 340g

Cms: .154mm/N

Sd: 771sqcm

Xmax: 23mm

Vd: 3.54L

 

[sundownz Pro Seller]

Well, it's not over-motored (BL^2 / Re figure is about the same as the "old" SI Mag) and would have a good sealed response.

The question would be how linear is it? At least fairly linear with 23mm of x-max, but what topology does it use? Does it address inductance vs. stroke? How about suspension curves?

 

[Scoobydoo 5,000+ posts]

Well, it's not over-motored (BL^2 / Re figure is about the same as the "old" SI Mag) and would have a good sealed response.
The question would be how linear is it? At least fairly linear with 23mm of x-max, but what topology does it use? Does it address inductance vs. stroke? How about suspension curves?

I understood none of that:crazy:

Right now it is in a 1.6cuft sealed box with some stuffing, it is the sub in my sig.

 

[req 5,000+ posts]

what sub is it?

lol.

 

[sundownz Pro Seller]

I understood none of that:crazy:
Right now it is in a 1.6cuft sealed box with some stuffing, it is the sub in my sig.

Thats a bit small for this driver - it's looking for over 3 cubes for a 0.707 alignment. You could probably get by with 2.25 - 2.5 with heavy stuffing.

It's probably a bit boomy in your box ?

 

[Scoobydoo 5,000+ posts]

Thats a bit small for this driver - it's looking for over 3 cubes for a 0.707 alignment. You could probably get by with 2.25 - 2.5 with heavy stuffing.
It's probably a bit boomy in your box ?

Unfortunately my rear hatch rattles too much to tell if it sounds good or not, gotta fix that problem.

It seems to like rap more than rock which sucks.

 

[BrianChia 10+ year member]

Unfortunately my rear hatch rattles too much to tell if it sounds good or not, gotta fix that problem.
It seems to like rap more than rock which sucks.

Rattling is a good indicator of sound quality.

 

[JohnEJanowitz 10+ year member]

There has been a lot of mention on motor designs so I figured I would throw this out there. I finally got a chance to somewhat format the information for the website. This goes through talking about one of the biggest distortion issues in woofers that is typically ignores. The issue with flux moving as the VC moves through the gap is one of the largest issues in creating distortion, and one of the most commonly ignored. If the coil was always in a stationary position, there would be no issue. However, the more power applied and the farther the coil moves, the more the flux moves and the greater the distortion. Most woofers nothing to correct this problem, or at the very most attempt to do something that is not ideal.

http://www.aespeakers.com/Lambda001-1.php

The page runs down the problems, methods for correcting it, the pros and cons of the 2 methods, and then talks about how we arrived at the motor design we provide.

John

 

[tcguy85 10+ year member]

that has nothing to do with SQ. a low FS and high xmax? negative. that is not what to look for in a subwoofer for sound quality.
sound quality, as defined by anyone with a brain, is the highest fidelity of the original recording as possible. fidelity is defined by the dictionary here;

http://www.merriam-webster.com/dictionary/fidelity

so, a sound quality speaker will sound natural, it will have good transient response, it will blend with the front stage so that the subwoofer can not be located in the system, of course build quality is a concern with all things purchased, power handeling is not a factor in sound quality subs, but is always good if a speaker can handle more than rated power. and - in most peoples eyes, sound quality is also about efficiency and space required. almost everyone in the sound quality scene looks for a speaker that does not need a million watts to function normally, and does not require a 5 cubic foot enclosure as well.

we are looking for a driver that operates well in small enclosures, that does not need a lot of power, that blends, transitions from upper frequency sub bass to low frequency with out lag or 'overhang', and that is not overpowering in the system.

so anything that is a power hog in a huge box will most likely NOT be a sound quality subwoofer, but more along the lines of a "street beat" subwoofer that is more loud than anything else. kids these days want SPL, and a SPL sub that is in the right enclosure will not sound bad persay, but it does not fall within the boundaries of sq.

some subwoofers that have been used in sound quality installations with success at world finals have been the following;

image dynamics IDW

image dyanmics IDmax

image dyanmics IDQ

oz audio ME

aura

arc audio

focal

jl w6

hertz

zapco

dls

morel

dynaudio

jbl

phoenix gold

steg

just take a look

http://www.caraudiomag.com/events/caep_0802_iasca_finals_2007/photo_02.html

but daily driving and SQ are totally different goals. you might want to reconsider what you are interested in before you go SQ, because its retarded. and im into sq //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

you should add the Dayton HO to that list.

anyway... this is how i describe an SQ sub:

-first off, like he said, not needing a huge box or a ton of power.

-i like a tight "quick" sounding sub(good transient response).

-it should still be able to drop low with authority, but not be bottom heavy.

-it should be able to reproduce ANY type of music accurately. if it sounds sloppy on metal then nope.

 

[sundownz Pro Seller]

Good read, John - I had seen that before on the old site //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif