Robb,

 

EDIT: this is an old post. I forgot I dug it up in the search feature

Damn, I didn't even read that whole thing. Looks like you didn't like that idea?
I have the setup for home theater subs and now I built a box for 2 clear coned POS's (brand name =???) and a passive radiator that I got from a friend. My PR is not the speaker w/o magnet, but just a flat panel on both sides with a foam surround.

Those 2 10's never sounded so damn loud and punchy.

EDIT: Passive radiators can either be speakers with the voice coil removed, or a flat diaphragm. http://hometheater.about.com/cs/loud...subwoofera.htm

Velodyne subs

A home theater sub w/ passive radiator. http://store.hometheater2u.com/n9subwoofer.html


A home theater sub w/ passive radiator. http://store.hometheater2u.com/n9subwoofer.html

EDITED IN:

Benefits and drawbacks of passive radiators:
The passive radiator system has many benefits here are a few important ones:
+ Low tuning in small cabinets possible.
+ The drive unit is more protected from large excursion at low frequency's because of suspension progressivity in the passive radiator.
+ Properly tuned results in high performance.
+ Low distortion and no port noise.

Some of the drawbacks of the passive radiator system are:
÷ Sometimes a little more expensive than vented systems with similar performance.
÷ Improper tuning may result in bad transient response.
÷ The passive radiator may run out of excursion at low frequencies.
Tuning the passive radiator system:
The passive radiator system works in a way similar to the vented system. The impedance curve will have two peaks like the vented system. A simulation package capable of simulation of passive radiator systems is needed to simulate the system.
http://www.d-s-t.com/main/tech/appxls2.htm

 

I would go with 1 12" but you can do what you like of course. For the music you are listening you might think about the new woofer alpine is comming up with.(Type X)

 

1 - 12" = Mono

2 - 10" = Stereo if ya hook it up in stereo

10"s should have more accurate/tight bass, and more bass than one 12" if you use the same brands as comparison.
Most companies use the same structure on 10", 12" & 15" antway.

 

How are 2 12"s? Do you think that is too loud?

 

There is s such thing as too loud?

10"s are usually more accurate than a 12" or 15" and up.

I'm going for SQ if/when I do my system, and will try to use two 10's if I can help it.

 

2 10s will hit HARDER, but the 1 12 will hit LOWER.
Too loud? NOTHING CAN BE TOO LOUD! hehe... Me and my 2x Kicker Solo-Baric 15L7s.

 

2 tens. louder and better sounding

 

As far as what ive heard 2 10's in a sealed box running tons of power will be just as loud as 2 12's sealed with a ported box..but tighter and faster recovering...i hate when bass misses a beat it ruins the feeling..i listen to a lot of rock and if i went with 12"s they would suck for me..


2-10" infinity kappa perfects for you


for me:2-10" alpine type r's both hooked up to 600watt rms amps..1200watts rms in sealed boxes should shake the old 89 pretty good.

If best buy sold infinity i would have them already

 

just thought id pipe in... i have 1 15", and it does a pretty good job, although sometimes the bass can be a bit relentless. for the music you are talking about, i too agree with 2 10"s. i went through the same delimma before deciding to "go big or go home" :-)

 

Old post batman!

BUT it's time to punch some holes in some very old, yet very famous fallacies... No offense to anyone quoted.


False. Technically speaking a ported box will ALWAYS be 3dB louder than the comparable sealed cabinet assuming it is compared in an open air environment. In car response usually sees a larger gain.


Ported boxes can be made to 'boom' or be 'punchy' as hell it is ONLY a function of designing the cabinet correctly.

If you want a sealed to 'boom,' increase its overal size. As a result you will loose upper end bass extension and power handling and you will gain sensitivity and low end extension. (Part of the HoffmanIron law) If you want a ported to 'boom' you increase box size, and drop the tuning through the floor. Conversly if you want it to be punchy.


That is the case with any box, and 99% of all prefabs too...

False. A sub's sd has nothing to do with how it will perform sonically. If you want to know which will drop 'lower' so to speak, take a look at the mms, fs, cms, as well as the motor topology. I've made my 2 8" rf HE2s drop lower than most people's 15s AND be louder off of 1/4 the power they were supplying. Also how 'hard' a sub hits DIRECTLY correlates to how well the box was constructed for that pourpose, not the sub's sd.

However stating that nothing can be too loud is CORRECT! 4L7 12s and 8800 watts rms here. (soon to be solo x 12s)

False. The two parameters, "louder" and "better sounding" are determined by the box the transducers are in. Secondarily that is a subjective comparison.

do what?? Ok if you are comparing 2 10s and 2 12s both in sealed boxes you cannot fairly asses which will be louder in a vehicle. Particularly if they are of different brands. If you mean to compare 2 sealed 10s to 2 ported 12s there will be absolutely no comparison in sheer volume if the boxes and subs are of comparable quality. The 12s win hands down.

Now if one is dead set on 10s and sealed, then one should apply as much power as is required to make the subs achieve full excursion as the amp is nearing is maximum output. Of course that is the case with any cabinet... However be aware that too much power will burn off the glue on the voice coils of a sub and blow it. Distortion does not kill subs, power does. (Provable fact.)

Again it is not the transducer (sub) it's the cabinet it resides in.


Something else worthy of note: I have seen on multiple occasions people speaking of "TIGHT" sounding subs. This is actually how well the sub is capable of reproducing the upper bass frequencies and is dictated primarily by the inductance of the voice coil, particularly with high power handling subs. (the higher the inductance, the more limited the sub is on high bass extension) To a lesser degree it is determined by the mms, cms, and consequcntly Fs and this is where the generality of a big sub not playing high frequencies comes from.

But be aware there are some subs that break all such general lines of thinking. Aura sound's 1808 - an 18" sub with a neodynium magnet with a STUPID low inductance. How many other 18" subs do you konw of that will play without roll off to 800hz?

And on the flip side of that, the Kicker SoloX 10" - it has a stupid high inductance, with a very very high MMS, a high CMS, and a low Fs. This 10 will most likely be able to drop VERY low and have no usable output above about 150 hz if i had to guess. (this is, of course assuming that the motor was truely linear with no bl distortion which isnt the case...)

 

Coyote $x$

MASSIVE props!

One thing they left out as a general rule on passives - the passive(s) used should, in totality, be capable of displacing 3x the combined displacement of the drivers used. This prevents the problem of the passive(s) of running out of excursion on extremely low notes. (And it can be a total PITA too if you have large displacement speakers...lol)

 

get a Kicker 12inch solo baric the square sub.. i scored one of these $1400 setups for $600 from a friend brand new and that thing hits harder then two round kicker 10s and this guys american bass? 15s

 

This post is from 8/2004...

L7s and solo Xs are nice....btw im selling my 4 L7 12s for 125 each + shipping and they still have 2 yrs of warrenty.

2 10s and a 15, i pray that he was running the 10s as midbass, but something tells me no.... *shudder*

Primary rule number 1 - do not mix subwoofer sizes if they are to be playing the same frequencies.

 

Looks like Bumpin knows what he is talking about (Hard to find these days)

"Car Audio is like Greek mythology to most people.....
If they dont understand how or why they just make somthing up".

I want to get a Bumper sticker made

I try not to post on stereo related posts for this reason. Props to Bumping for trying to educate the masses.

 

Bumpin =


Looks like ganoid shares my enthusiasm for DOA

 

So are you saying passive radiators are no good?

When I built my box for some beat ass clear Pyramid 10"s, I used an old 12" that was blown as a passive minus the motor structure. I also played around with the flat passive that came with the Pyramids, but had the problem with the excursion of the radiator. I would "bottom out" and kill the bass or make it sound like crap.

I know from messing around that it is a good and cheap way to get more bass.

Is it safe to say that 95% of a speaker is the enclosure to make it sound right? Voice coils and cone material comes into play also.

Take the "best" sub on a planet and put it in a crap enclosure and it will sound like crap.

 

I think Bumpin is saying you need some big a$$ passives to handle the amount of displacement todays modern sub will move. To get you in the ball park just figure cone Surface area (Sd) x full linear excursion (usually Xmax times 2). Once you come up with a number you need to do the same to your passive radiator but you need the passive end number to be 3x the driven speakers number for effeciency and reliability.

I guess if you use run of the mill low excursion drivers then passives are fine. If you use any of the longer travel drivers then passives become difficult to implement properly. The Xmax value for the driver will give you a pretty good idea of what to expect for cone travel.

Your average kicker c10 of the mid to late 90's (Back in my day) was probably 10mm each way (Xmax is 1 way linear measurment) and I think thats generous for drivers back then.

Looking at speakers of today you can see that things have changed and passives are really lagging behind.
Take an MTX 7500 series 10" your slightly better than average speaker, Its running 16.5mm one way linear travel.
IF you start getting into just about anyones premium line of speakers and the numbers go up significantly

Here are some numbers for common higher end speakers...
MTX 8500 10"@21.5mm
MTX 9500 10"@25.6mm
ID MAX 10"@25mm
JL 10W7 @23mm
Fosgate TRF10@ ? (Fosgate is stingy with there numbers)

And if you start looking at really crazy speakers...
Adire Brhama 10"@28.5mm
Adire Tumult 15"@33mm one way!!!!! (This is pretty much the Holy Grail of home Theater sub's if you ask me)

Keep in mind Xmax is only 1 way so you need to figure xmax times 2 and we wont even talk about the suspension limits that are usually significantly more than linear limits.

Good high displacement passives can be had but your probably looking at $125+ just for the passive radiator and even at that you are gonne need 2 for the high end drivers.

I guess in the end if you are looking for $100 subs then passives will probably work for you. If you start into the $200+ name brand subs then thay are hard to impliment in an automobile.




Edit... Damn that came out long winded??

 

Speaking of Brahmas in HT... I had one 12" laying around and decided to make a HT cabinet for it... It hits so low and loud, i love it..






I would go with a nice 12" sub ported, tuned to 30hz over two tens sealed. I have a brand new in box Brahma 12 MkI that I might sell...

 

MMMMMMM! B&W mids and highs! MMMMM! The only thing that is in the same league are the Martin Logan electrostatics.