Sealed vs Ported Vs Bandpass

[david_827]

I was just wondering what peoples thoughts were on each enclosure, myself i have always preferred sealed to ported. I've never had experience with bandpass so if someone could shed some light on that one.

Well anyways what are yall thoughts on the pros and cons of each enclosure, which do you prefer, and what are you currently using in your systems.

[_S7V7N_]

What type of music you listen too ?

What size subs ?

Specs on subs ? (Recommended air space )

[Alien Mantis]

I have tried all 3 types of enclosures over the years. It almost always ended up being some kind of compromise to what I really wanted. I either did not have enough space, or not enough money to buy better components.
I learned a few things with my "trial-and-error" process. Quick thoughts:

"Band-pass" is used to maximize SPL in a certain freq range. This type of box is only good for rap, hip-hop, and maybe some forms of "electronica".
It seems to maximize output in the lower range. ( Guessing 30-60hz, depending on the tuning ) Response is very bad with these boxes. Bass is boomy, muddy, and not very "defined". No subsonic roll-off. Does not handle the higher bass-range well at all.

Next is your "ported" box. Ported boxes can be "slot-ported", or "tube ported".
Ported boxes are a compromise of "better response" with higher SPL.
Ported boxes need to fit the subwoofer(s) you are using. Many variations required due to the many different subs on the market. What works with one sub, will not work with a different sub, and so on. You need to carefully follow the sub specs when building or choosing a ported box. You get a sub in the wrong ported box, and you will not be happy at all with the results.
The "shape" of the box does not seem to have as much effect on the results. It is more important to have the exact volume, port size and length, and port placement. Ported boxes are larger than sealed boxes, but smaller than band-pass boxes. It is possible to have tight accurate bass with a ported setup, but you will need to choose carefully. Ported boxes also do not control the sub as well as a sealed box, so you do not want to overpower a sub that is in a ported or "band-pass" box. Again, no subsonic roll-off. Helps to have an amplifier with a subsonic filter when running a ported box.

Last up is the SEALED BOX.
My personal favorite, and no doubt the personal favorite of audiophiles everywhere.
Sealed boxes have many advantages. The box can be smaller. The response is better. If you are looking for tight accurate bass, a sealed box is the way to go.
Sealed boxes control the sub better, so you can put a little more power to them if you happen to be running a slightly larger amp than what the sub calls for. Sealed boxes control subsonic freq's better than the other two boxes previously mentioned. Sealed boxes can allow your subs to play higher freq's more accurately, which allow your subs to blend with your mids if you have your crossover network adjusted for this.
Seems like the sealed box would be the clear choice, right? Why would they even make any other kind of enclosure if the sealed box does it ALL?


Here's the ONE DRAWBACK to a sealed enclosure:
SPL.
That's right, OUTPUT. You lose some DB's on the output with a sealed box, but the trade-off is totally worth it. If you need more DB out of your sealed setup, run: more subs. A bigger amp. Bigger subs. Whatever.

In the past, I would run a ported box because I had a smaller amp and wanted more output. Or I had only one sub and a small amp and wanted more output. This is just a total compromise. When I had to make a compromise, I was never satisfied with the results.

CAR AUDIO is one endeavor that you just can't make compromises or cut-corners with. You gotta DO IT, or not do it. All the compromises I ever made over the years only resulted in unsatisfactory performance.

I hope this helps.

[david_827]

Originally Posted by _S7V7N_

What type of music you listen too ?

What size subs ?

Specs on subs ? (Recommended air space )

i listen to almost everything rap, hip hop, r&b, reggae/dancehall, salsa, merengue, soca, country, pop, rock, and the occasional bollywood tune.

the sub is a 12 inch pioneer TS-W309D2, i want to say the recommended airspace is (if i remember correctly) is .85 cu feet to 1.75 cu feet.

[david_827]

AM,

Wow, thanks for the breakdown on the 3, as stated before i've never used/seen anyone with a band pass so i had no idea you can use it to maximize SPL in a certain range.

i was leaning towards ported as at the moment i only plan to use 1 sub (not looking to compete, just looking to have better sound), but as you said the ported boxes are a compromise, plus most of the better sounding systems i've heard used sealed boxes.

[sqcomp]

A couple things to think about when talking a decision between sealed versus ported...

Going sealed means less output BUT it means more power handling. It's also a much easier enclosure to make versus any other type...even IB.

Going ported means 3 dB more output but less power handling due to increased sensitivity and unloading below the tuning frequency.

The sealed enclosure will give you a nice smooth response curve. The ported enclosure will give you that increase in frequency at the tuning point. Now, the "proper" thing to do would be to find the vehicle's resonant frequency and piggyback the tuning of the port to be just above the car's natural frquency (where it's the loudest in the car). If you decide to go ported, get amps that have a subsonic filter on them so you can protect your woofers.

[Alien Mantis]

I consider Infinite-Baffle, Isobaric, and T-line setups to be "exotic", and I don't even want to mess with those. ( The OP wasn't asking about them anyway )

Alot of people like to reverse-mount their sub, so the magnet/motor/basket sticks out of the box for "show". They basically front-load the cone, instead of mounting the basket assembly inside the box. You can play with polarity to see which direction yields the best results. ( push instead of pull )

About tuning:
"Natural resonant frequency" of the vehicle may be at a point where you actually do not want to amplify it. Different music requires different tuning frequencies. "What" you listen to plays a big role in trying to "tune" your system to your liking.
I've heard many systems that play a certain "style" of music really well, but other styles of music sound horrible. All systems, ( whether it is intentional or not ), play certain types of music better than other types.
One system sounds awesome with RAP. Another system plays JAZZ really well. Another system plays ROCK really well.
The mark of a true SQ top-line system is it's ability to play ALL styles very well.
I have been in a few cars that had that type of a system. And those setups were mega-expensive, and those cars were tuned and built by professionals.
You can throw alot of money on top-level gear, and do a bad install, and not get the results you expected out of the gear you bought. Happens all the time.

I like it when I don't spend alot of money, do a really good install, do some decent tuning, and get the results I was hoping for. That is what I call "success".

[Alien Mantis]

Originally Posted by david_827

i listen to almost everything rap, hip hop, r&b, reggae/dancehall, salsa, merengue, soca, country, pop, rock, and the occasional bollywood tune.

the sub is a 12 inch pioneer TS-W309D2, i want to say the recommended airspace is (if i remember correctly) is .85 cu feet to 1.75 cu feet.

Thanks for the model number. I looked up the specs for that sub.

From the styles of music you listen to, it seems like a ported box would be good for you. You did not tell us what AMP you intend to power the sub with, so I will just tell you what type of amp would be good for it.

Your sub has good sensitivity at 94db.
Your sub will handle 400 watts RMS.
It has dual voice coils at 2ohms each. ( gives you 2 choices for final resistance )
It has 11mm Xmax. ( not a long-throw sub, but enough to move some air )

The ported box recommended for it is: 1.5cf with a single 3" dia PORT that is 5.5" long. Port exits the same side as the sub is mounted on.

You can wire that sub for 1ohm, or 4ohm final resistance.
If you go 1ohm, you can run a smaller amp, but it better be a high-quality one. Not all amps are stable at 1ohm. Some will heat-up at that ohm load.
Every amp has specs. They will tell you what RMS power it makes at different ohm ratings.
I would wire your sub for 4ohms, and find a Class D monoblock amp that pushes 300-400watts RMS at 4ohms. Make sure the amp has a subsonic filter.
Once you find or build the correct box, do the install, set the gain correctly on the amp, set the subsonic filter, you can start playing around with crossover points and EQ. ( Find your "sweet spot" )

Good luck.

[sqcomp]

AM - Here's the thing, you don't tune the enclosure TO the resonant frequency of the car with a ported enclosure. That'd give you a nasty "bump" in response (unless that's what you're looking for). I meant to insinuate that one could "parallel" the response curves to acheive an even wider frequency "bump" without getting all nasty.

We also had 20 of the top SQ vehicles on the West coast in Redding, CA this last weekend. I'm sure most, if not all of them would have blown your socks off...The most expensive ones were in the ultimate and expert classes. The rest for the most part were very "affordable".

...Pennyracer said he came, but he sad at 3pm no one was there. Unfortunately for him he must have been at the wrong FRP Customs because the show was in full effect at that time. I know, I was there until 10pm.

[Alien Mantis]

Originally Posted by sqcomp

AM - Here's the thing, you don't tune the enclosure TO the resonant frequency of the car with a ported enclosure. That'd give you a nasty "bump" in response (unless that's what you're looking for). I meant to insinuate that one could "parallel" the response curves to acheive an even wider frequency "bump" without getting all nasty.

You sir, are 100% correct.
I was referring to tuning it "TO" the resonant freq, which would result in the nasty bump at a freq that might not be optimal.
I was not disagreeing with you at all. You have way more knowledge and experience than I ever will. This is your "thing". This is what you do.
( This is just a hobby for me. )

Originally Posted by sqcomp

We also had 20 of the top SQ vehicles on the West coast in Redding, CA this last weekend. I'm sure most, if not all of them would have blown your socks off...The most expensive ones were in the ultimate and expert classes. The rest for the most part were very "affordable".

Oh man, I'm sure I would have been blown-away by all of them.


The old saying goes: "the best you know, is the best you have experienced".
I got to experience a few very high-end systems in the past, and I know what a great system is supposed to sound like!
It kinda ruins you though, because you know what can be done, and you won't be truly impressed with anything that is a huge step down.



But alas... I am sensible and realistic, and I do set limits and goals for myself.
I really enjoy the modest setup I have in my Yaris right now. It's not the best system I ever had, but it's really nice for what it is, and it gets the job done. Nice clean full-range music "IN" my car. That's what I like.
I'm not trying to impress anyone else. I'm too old, those days are long behind me.

[_S7V7N_]

Do you plan on adding another sub ?

Here's an idea. Get a 4 channel amp.
Upgrade your front speakers. Possibly with a component set.
Use channels 1 and 2 for your component set.
Use channel 3 and 4 for the subwoofer.
If you don't plan on adding a sub later on go with a custom ported box. You can probably get a plan (blue print) for about 5 bucks. They'll be able to plug the specs into a program. Then get somebody locally to build the box.

If you go sealed go with a bigger box and polyfil it. ( stuff used in pillows)

[david_827]

AM,
i have an alpine mrp-m500 amp at the moment that i got as a gift, it is only rated at 300Watts RMS at 4ohms and has a subsonic filter. and i believe 500Watts at 2 ohms. i believe it is a Class D amp and it should be sufficient to power this sub correct?

[david_827]

Originally Posted by _S7V7N_

Do you plan on adding another sub ?

Here's an idea. Get a 4 channel amp.
Upgrade your front speakers. Possibly with a component set.
Use channels 1 and 2 for your component set.
Use channel 3 and 4 for the subwoofer.
If you don't plan on adding a sub later on go with a custom ported box. You can probably get a plan (blue print) for about 5 bucks. They'll be able to plug the specs into a program. Then get somebody locally to build the box.

If you go sealed go with a bigger box and polyfil it. ( stuff used in pillows)

Though i havent ruled it out, i don't plan on adding another sub yet, i want to see what it sounds like first and then decide if i need another sub.

i do plan on getting another amp though, as i plan to use one amp to power the sub(s) and one for the speakers.

[Alien Mantis]

Originally Posted by david_827

AM,
i have an alpine mrp-m500 amp at the moment that i got as a gift, it is only rated at 300Watts RMS at 4ohms and has a subsonic filter. and i believe 500Watts at 2 ohms. i believe it is a Class D amp and it should be sufficient to power this sub correct?

In a ported box, YEP!

Those are decent little amps. ( Alpine's lower line, but still good. )

[Alien Mantis]

Originally Posted by david_827

Though i havent ruled it out, i don't plan on adding another sub yet, i want to see what it sounds like first and then decide if i need another sub.

You will probably be happy with that single sub, and your Alpine amp.

Let us know.

[_S7V7N_]

If you go ported do you have the tools to build ? Or are you gonna have to pay to have one made ?

[sqcomp]

Be wary of the prefabs!

[david_827]

Originally Posted by _S7V7N_

If you go ported do you have the tools to build ? Or are you gonna have to pay to have one made ?

if i dont pay to have one built, i can ask my carpenter friend to assist me in building one.