Bandpass widest range


New member
Username: Soundfreak

Post Number: 1
Registered: Dec-11
What is the widest possible frequency range i can achieve with a bandpass box? regardless of efficiency or gain, BUT ,very few sacrifice to quality.
i just like the idea of a natural bandpass but i do not want a one-note wonder.
ultimately, i'd like to pass a clean bass from 24hz - 150hz with steep rolloff curves.(this effectively covers sub range and used by many producers, including myself, as reserved kick&bass space).. my door speakers will cover the rest of the spectrum. and i know u dont hear that low, but i love to feel it.
Is this even possible?
I don't think port-length would be a concern, i mean, i can coil a fat tube in that front chamber over a meter long.

would it be more feasible to just use a 'vented enclosure' and use the amps built-in filter to lowpass?

i lack a lot of conception so forgive my ignorance
would appreciate some insight from the gurus.

thx in advance

Silver Member
Username: Joe1234

Post Number: 980
Registered: May-09
Subwoofers are rarely used much above 80Hz, you pick up then with full range speakers or midbass drivers usually using an electronic crossover.

You can have better control over the bandwith going 6th order, but it always be a narrow band.

Bandpass is used for SPL not sound quality so I would recommend going ported, you can reach 24Hz without a problem with a low Fs subwoofer.

New member
Username: Soundfreak

Post Number: 3
Registered: Dec-11
well i'm glad you chipped in before i started a costly project.

like i said. the idea of a natural bandpass is appealing to my mind, if i'm not going to achieve clean bass then its not worth the bother.

It's definitely quality i'm after. i'm a hobbyist producer and compose music on my nearfield monitors but like to reference the sound on other systems now-and-again to check how it translates.
Good car audio is the most cost effective way of simulating a big rig system, or so i've been told. and a good way to pick up on flaws in the subsonic region and get more perspective. i mean, if you know what quality productions sound like in your car, you'd know what you are lacking.
the nearfields goes down to 38hz and its possible to have a accurate sub but although the 'studio' (more like a study room) is treated , i still have a infant and wife around so cant have the house booming all the time. i take my music pretty serious tho :-)
and i'm somewhat of a audiophile. quality takes priority in my work.

now after that long explanation. I'm starting my car sound project by doing research. usually i just leap before i look, but i want to do it as decent and cost effective as possible.
soooo, would like some info from you guys very much. i'd post some pics of the install and update as i go. "maybe start the 90s car sound fad all over again"

first things first. 'a plan' wwjd
the car is a 'toyota yaris rs 3(actually2)door hatchback'
This car has speakers in front and back panels and space for standard "doubel din" so i'll replace the stock stereo for sure. This is what i have in mind: ,because it can expand 6 channel output. (front, rear, sub) and i can get it for a low price.
i definitely want that deep in your chest bass. so recommendations on a sub and amp welcome. (quality and cost effective) OH, i've build a budget system for my old Fiat before and had a 10" sub in a sealed enclosure. NOT A FAN. tight accurate response but my ears disagree. i'll describe it as poppy-ear fatiguing bass. + its not just my car. all the sealed boxes i've heard had this characteristic. I actually recommended it to people because of what i've read. sorry folks, no good.
I can get a "JL 12w1" for $20cad or infinity reference for $80
joe mentioned the 80hz range for sub. so i'm thinking a ported box in the middle with space to each side for separate smaller mid-bass speaker sealed boxes. thinking maybe stuff those 2 boxes with dampening fiber to make it seem big + fiber cause i dont like that boxy sound. (your thoughts, +can u port them).
i don't know what range they cover but prefer them to cover 80hz - 500hz so the side panel speakers (which i will replace) can extend to 20khz.
can 1 amp power the sub and midbass. is that possible? would NOT like to wire 2 amps back there. (i would prefer mono below 80hz) but would like the midbass L + R.
would you have a separate amp for the 4 side panel speakers?
-doubt they will need it cause i'll cut all freqs below 500hz.

any input from you will not go overlooked. thx

New member
Username: Soundfreak

Post Number: 4
Registered: Dec-11
oh, one more thing.
i'll even consider a ported 15" sub if you think it'll work with space + both sides for smaller L R midbass boxes.
i'll post the dimentions a have to play with after i measured later.
i dont need that space.+can always unhook the box and carry inside if i do.

Silver Member
Username: Alonzoub

Post Number: 315
Registered: Apr-10
If you are looking for sound quality as a way to reproduce a studio like sound, I highly doubt you should need ANYTHING over a 12", in-fact a 10" might even work well.

I think the MOST important thing for your build should be sound deadening the car as much as possible. This can get very expensive but without deadening, the outside noise will totally ruin your "studio" sound.

As far as the sub-stage goes, a nice low tuned 10 or 12 will do the trick, the only issue I forsee is developing a peak due to cabin gain in such a small car. You may end up needing to build more than one box to get the response you want.

Do you have a budget for this project?

New member
Username: Soundfreak

Post Number: 5
Registered: Dec-11
I'm not after studio sound at all.. my home studio is as FLAT is it gets..
I'd like to simulate big rig sound or something the majority of folks would like..
Having the car sound as studio (tho impossible) would rune the purpose. The purpose is to reference the music on sound the is appealing to the masses, u know, that big bass,, 'that classic disco-smile Equalization.. hyped bass and sizzle. we love that dont we.
also love that deep vibration that knocks your breath out..

My budget is minimal. I have to sacrifice the babies diaper money. kiddding. but
im not building this for competition, but i would very much like a system that even you guys would be proud to have.. i mean, if a better quality amp is $50 more expensive ill definitly consider it. quality takes priority
semi-decent.. not to impress the outside but impressive the people inside the cabin . as cost effective as possible. +/- $1000 'double din' inluded.. so $850 to play with. rather less than more.
that alpine stereo (mentioned above) is fine for $150 imo. i really dont care about the nice-to-have $500 gps,dvd systems. music is all i care about.
shopping list: amp, sub, 2xMidbass, 4 x 6" (door speakers) , box material.

i think a 12" is optimal choice. it should move enough air to feel in your chest. + the box can be smallest vented application that still sounds big.. so i can sculpt the 2 sealed midbass boxes to the you think the midbass is pratical with my budget?
i think they'll make a big difference.

i will build custom boxes. would probably save $$ on that. plus craft to the avaible space.. + it's fun hobby.

still have to go check the exact luggage dimentions i have to work with.

after all s done, i will record the a generated oscilation sweeping 0-20khz @ level db where my head is or center (between seats) and we can analize the spectrum. FLAT would be cool
hopfully we can achieve that disco-smile without much/any equalization.

again, any input you have is appreciated }

Silver Member
Username: Joe1234

Post Number: 985
Registered: May-09
Ok Christian, I loved the "boxy sound" term, I know what you are talking about, It's worst form occurs when you place an average to high Fs driver in a too small sealed box without damping.

Here is an example of a typical (non high end) SQ setup speaker spectrum division:

Subwoofer 20-60 @24 dB/octave, Midbass drivers: 60-180@12dB/Octave, full range speakers: 180 - 20KHz

The subwoofer(s) is(are) handled by a monoblock and the rest of the speakers are handled by a four channel amplifier and all in stereo mode.

Also if you want ixa-w404 I would recommend getting it with a PXA-H100 module which has time alignment and equalization capabilities or alternatively get a HU that supports that without additional hardware.

Finally yes, what is your budget and the level of effort you want to put in.

New member
Username: Soundfreak

Post Number: 6
Registered: Dec-11
yeah joe u know what im taking about..
Do manufaturers supply enclosure volume specs for midbass speakers?
I guess lining the inside walls of the box with thick carpet would contribute a lot towards dampening

your SQ list fits the bill to a exact T
now that you draw my attention (thx) to the PXA-H100 module. looks very impressive. a must have. BUT i will probably want to turn off the IMPRINT tecnology. having a cpu adjust acoustics is shady..

budget is $1000 give or take.. that ixa-w404 i can get for $150.
so $850 to play with. i'll scout for deals on that PXA-H100 module.

level of effort is infinite.. i love spending off-time with stuff like this.. but not commited enough to mold fiberglass enclosures..
im willing enough to try build all kinds of custom wood boxes..
For instance, i will go out of my way to build a box with a angle as not to create standing waves.. 'commited enough.

aslo, its fun learning. i'll install the entire sysem myself. its a fun process and i learn a lot.\ yeah im a techy geek. so what

New member
Username: Soundfreak

Post Number: 7
Registered: Dec-11
another thing.
should i be concerned about a/d convertors. Many stereos shows the 24bit spec.. im not recording.. im play-back data files d/a @ 1-bit. or do i understand wrong
marketing scam?

New member
Username: Soundfreak

Post Number: 8
Registered: Dec-11
that should be enough

do i have to stay on manufacturer s recommended box volume. or can i experiment with winISD to tailor a curve?

Silver Member
Username: Alonzoub

Post Number: 317
Registered: Apr-10
Forgive me if I am understanding incorrectly but, you plan on putting the midbass boxes WITH the sub/box? Are they rear-fill or are you looking for a 3-way front-stage + sub-stage?

The reason I ask is because the main issue I see with the setup is picking an amplifier that will allow you to cross everything over where you need it.

EDIT: Just saw your previous post... Experiment with WinISD definitely but don't go crazy obviously. If they recommend 1-1.5 cuft, you probably don't want to give the sub 3 cuft. But then again each sub is different, you really can't know for sure until you try.

lol that warhorse should do the trick

Silver Member
Username: Joe1234

Post Number: 986
Registered: May-09
Ok Christian, I am still figuring out what to suggest, to answer some of your questions, A/D converters you use to record, D/A (DAC) to playback which is what all those HUs have, a 24-bit D/A is more than enough for any audio application (the "1-bit" is not actually 1 bit) and yes the first step can be to model the manufacturer suggestion to see what it delivers, I have some better modelling software that can factor "in-cabin" gain in but I guess it's too early to get into that. Finally midbass drivers for automotive use are designed to work in an infinite baffle setting so, like in the rear deck or the doors, not with enclosures.

New member
Username: Soundfreak

Post Number: 9
Registered: Dec-11
the plan is to build 2 completely separate boxes,, to fit in the sides. i dont know what "3-way front-stage" is,
but im NOT incoporating the boxes..
i'll draw a quick sketch of something that might work.. paint ha

stay close to recommendation with winISD. thx. i read you
what good to tune the port to ?32?

lol. that warhorse is insane. who in their right mind

New member
Username: Soundfreak

Post Number: 10
Registered: Dec-11

Bronze Member
Username: Soundfreak

Post Number: 11
Registered: Dec-11
mirror red on other side


Bronze Member
Username: Soundfreak

Post Number: 12
Registered: Dec-11
i see
"designed to work in an infinite baffle setting" ,interesting
all of them like this? is the box rendered useless..

maybe then i can fit them in the back door panel and use the front door panel for the full range..
i have a panel that lifts up with the hatchdoor. might be a good place to mount them (usaully a good place for 6x9s).. then i can use all the door speakers for surround.

i dont know. will think about it. might get to complicated having to split the front channels for 4 speakers. worth it?

Silver Member
Username: Joe1234

Post Number: 988
Registered: May-09
Yes usually the rear deck is ideal for placing them specially larger diameter midbass drivers like these:

Larger diameter midbass drivers provide the best results. For SQ is definitely worth it and is not as hard to do or as expensive as you may think.

Or there are 3 way component sets that have a passive 3 way crossovers. This is usually a very expensive solution.

Bronze Member
Username: Soundfreak

Post Number: 13
Registered: Dec-11
"The reason I ask is because the main issue I see with the setup is picking an amplifier that will allow you to cross everything over where you need it."

after some reseach i see what u mean.

adjustable crossover?

Bronze Member
Username: Soundfreak

Post Number: 14
Registered: Dec-11
tx. i'll seriouly consider those midbass speakers. will look around at prices. $58 x2. is not bad for what u get.
free-air! never would have thought
one review on that page:
"I mounted them in a 2.6 cuft box with a 2.75" x 5" port tube"

im checking out this sub
like the curve it makes with winISD. i can get for $80cad

if you can think of anything else sub wise. please tell

Silver Member
Username: Joe1234

Post Number: 989
Registered: May-09
Here is an example of an active crossover, you connect that before the amplifier, lets you set the frequency ranges for each set of speakers:

But the PXA-H100 has this device integrated to it in addition to the equalizer and time alignment.

As for a sub if you are going for deep bass, take a look at this:

Look at the Fs and the frequency range, best SQ subwoofer below $200 in the world (as far as I know). Infinity are SQ but I would go for JL Audio at that price point, anyhow I will model the Infinity to take a look and provide some feedback.

The amplifier set for those suggestions above could be:

1) 500W-800W monoblock.
2) 100W-150W per channel x 4 channels amplifier.

Bronze Member
Username: Soundfreak

Post Number: 15
Registered: Dec-11
oooo this tc fits the bill. Frequency range: 15 - 150 Hz, Fs 24.. perfect, wow, let me wipe the drool from my mouth
expensive but it'll certainly will make a great christmas present to some well behaved boy.

"1) 500W-800W monoblock.
2) 100W-150W per channel x 4 channels amplifier"

How about a more powerful bridgeable 4 channel. bridge 2 channels L&R for sub. and other 2 for L n R mid bass? only suggestion to save having to wire 2 amps.

are we then powering the door speaker of the hu alone?

yeah. im convinced the PXA-H100 is definite buy.

Bronze Member
Username: Soundfreak

Post Number: 16
Registered: Dec-11
yeah joe.

just forget the JL. that TC is the tits..
with 2 amps and the midbass speakers. the budget is almost reached..

i'll calculate tommorow where we are on budget after some bargain hunting.

i'll post then. cheers

Silver Member
Username: Alonzoub

Post Number: 319
Registered: Apr-10
damn joe, you beat me to the punch... that is literally the EXACT sub I was going to suggest...

Gold Member
Username: Joe1234

Post Number: 1002
Registered: May-09
99% of the advice you will ever give goes down the drain anyways!

Bronze Member
Username: Soundfreak

Post Number: 17
Registered: Dec-11
im getting the epic sub not cheap to ship north across the border but its better than anything else we have in the same price range.
also getting the midbass daytons for cheaper than parts express.

while i'm waiting delivery ,i'll construct the box..
and search for amps with the specs joe recommend.

will update

Silver Member
Username: Lord_huggington

Ontario Canada

Post Number: 530
Registered: Oct-10
Almost any subwoofer that's optimized for vented or sealed, with a low Fs, tuned to around 25 Hz, should sound "good enough", and have you covered to 20 Hz.

... but for ultimate sound quality, check out Morel. Mad expensive though. To feel the mustache blowing in the wind of some old blues musician, this is what you want.

... the Epic is great, but also check out the discontinued Eclipse SW8200 12"/670W RMS. It has an LMS-motor, meaning it has zero distortion at any volume, at any frequency, it retains its motor force during all of the cones movement while other motors retain 70% or less at full cone excursion and steadily decrease with more power, depending on the box. It has an Fs of 16 Hz and a one-way movement of 38 millimeters, and is recommended for sealed boxes only. I had 3 of them. I used one ported (it was fine), and 2 sealed (not 2 different types of boxes at the same time FYI). When sealed, they get into the low 20's like a boss, with sound quality, authority, and with mind blowing SPL that you wouldn't expect from a sealed box. That was with 1.25 cubic feet per sub. They needed a bigger box for a flat response, around 4.5 cubic feet NET for the 12" to have a modelled .707 QTS or QTC or whatever.

It's cheap at around $200 new. It was a bad move changing the motor to a more cost-effective, non-LMS ("Linear Motor Structure") motor, and then discontinuing them all together.

For pure reproduction, sound quality, and forcefull lows, it was my favourite.

Bronze Member
Username: Soundfreak

Post Number: 18
Registered: Dec-11
@lord huggington
i looked at the sw8200. u mean, it WAS cheap. I cant find any.
I know a guy who sells 2 eclipse 8812. it's not in the same class.
also, im not keen on the sealed box idea. i've heard it many times never liked that. i feel bass needs some air to breath.
these sw8200 might sound good sealed. curious.

@joe (or anyone) please
Can you recommend something more specific midbass amp wise?
how is this for the midbass daytons? AB-CAR-AUDIO-AMPLIFIER-/280773516784?pt=Car_Amplifiers&hash=item415f67ddf0

why did you suggest 4-channel?

will i be able to play all 4 door speakers of the hu alone while having the midbass and sub on separate amps?

for the sub im thinking this. ok-ish? will it suffice?

Gold Member
Username: Joe1234

Post Number: 1027
Registered: May-09
Amp for the sub:

Amp for 2 speakers and 2 midbass drivers:

If you have midbass drivers you need nothing more for a rear fill but if you really want rear speakers then let me know, also which speakers do you have?

Regarding your questions, HUs put out low quality 14-16W RMS, the JBL amp is good but expensive, the amps I am recommending have proven to be of good SQ, do rated and also cost effective.

Only make sure to stay away from boss at any cost, also if your speakers are of lesser power I can find lesser power amps for less money.

Bronze Member
Username: Soundfreak

Post Number: 19
Registered: Dec-11
im going with your recommendation ,, tc epic and daytons midbass.

the rear speakers in the door is stock factory.. (still looking at replacement options)..
they will only cover 180hz-up.

the HU can expand 6 channels.. (front, rear, sub)
I want to use the rear channel RCAs as midbass L&R on the DECK(panel) and the sub on its own RCAs..-sub chan
the other 4 door speakers (rear2 & front2) i'd like the use as full range 180hz-20khz.. like maybe on front channel alone.. all the same

if this is not possible.. not use the speakers in the back door at all.

So why a '100rms x 4 chan' amp?.. i only want to power 2midbass drivers? not the door speakers..

perhaps a 3rd small amp to split the front channel to the 4doors.

the boss amp seemed a good deal because $130 include delivery to my door in canada.
your onyx is $250 to get to ship across the border to my door..

Im trusting you warning on the boss.. i'll avoid.

Silver Member
Username: Alonzoub

Orlando, Florida

Post Number: 335
Registered: Apr-10
My opinion:
-Skip out on the rear door speakers completely. As in remove the stock speakers and replace them with nothing.
-Pick up a decent 4 channel amp (like that MB Quart) that will let you lowpass the mids on the rear channels.
-Never buy BOSS. Since you considered BOSS, I will assume you don't know a whole lot about brands to avoid, so I will list as many as I can off the top of my head...
Power Acoustik

Gold Member
Username: Joe1234

Post Number: 1029
Registered: May-09
Ok Christian, those are just suggestions but yes keep me in check with your budget and your preferences, I'd like to share this thread, regarding boss amps:

Look and ask around and you will find many more like that one.

Ok, full range speakers on the back are not usually recommended for SQ purposes because they can damage your soundstaging, HU powering any speakers is also not recommended... obviously remains your call (and mine in my system) to follow or not those guidelines, if you ask me, after some tests of my own those claims are not completely baseless specially at higher volume.

What I would suggest is not buying all at once and upgrading where you feel necessary.

For example you could start not using midbass drivers, just using components with strong midbass and go with a typical configuration of sub 20-60 full range components 60-20k that would also would free yourself from implemeting crossovering. The HU can handle that. In that case I would suggest the Alpine CDE-123 because it has 3 band parametric equalization (or any other that has that).

By far the front stage components will give you SQ so I guess you should aim to get some good ones first. I would still get a 4 channel amp to power you 4 speakers for now and later the midbass drivers if you found that necessary.

Just thowing in ideas, in the end you have to make the calls..

Bronze Member
Username: Soundfreak

Post Number: 20
Registered: Dec-11
Well, 1st of all, I can't begin to tell you how grateful i am that you guys give your time to help me.
I just spunge of your knowlege. i realize you probably had to learn the hard way. trail & error and time(LOTS) and cash. so believe me your advice will not go down the drain, cause i realize.

thx for the heads-up on those brands. my father use to say, (in another language): "buying cheap is like buying even more expensive, in the long run."

i always make hasty decisions.. i itch to have that midbass drivers.
Waaaay more rational suggestion to consider a simpler system and listen where to upgrade.

i'll work on the front stage like you recommend.
I got to investigate cause i read on forums that the factory speakers is not standard size and modification is need to fit after market speakers. THEY say 5 1/2" can work

im still getting the epic.. no doubts
I will look at your amp suggestion and avoid those other brands.

will sleep on it and let u know what i decide
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