Vented or backseats?

[Dammed 12]

I want to have a system that hits the lows really good. (yeah you haven't heard that one before)

But that's pretty much the reason I went with two Fi Q 18" instead for 15s or even 12s.

So this is my option, I go for a sealed 10.24ft3 filled with PolyFiberfill giving me a theoretical volume of 11.5-12ft3 or I throw out the back seats and make one huge vented enclosure with subs and port firing towards the front seats.

I don't really want to throw out the back seats, but if the vented system would be a lot better at the lows then I'm going for it.

The questions is what system will hit the lows the best and give the best SQ? I'm also looking for some loudness, but it isn't the most important thing.

[thebiggmann12 14]

personally i would take the backseats out and tune the box really low...but thats just me.

[Dammed 12]

Yeah, but then my car becomes a car audio car, not a car with a good car audio. If you know what I mean. And I won't have any space to put stuff to carry with me, like grocery bags. But I will have a pretty cool car... And how low can you tube the Q's, is there a limit, what's the gains/loses to tune really low?

I was actually thinking about sending you a PM... Did you have the 18" Q in a sealed and vented enclosure or just vented? A bit curious regarding vented VS sealed and how they perform in those two types of enclosures.

[thebiggmann12 14]

i had mine ported tuned to like 28 hz or so...and the lower you tune the more u lack in the higher frequencies...but if u like low music i would tune around 28 hz.

[Don Ganso 13]

what kind of car do you have? I thought I read in another thread you have a celica, but if you have two 18s this must not be the same car...

[KU40 173]

Exactly what frequencies do you mean by low? If you want 30-40 hz like on most rap, personally I'd just use one of the 18s in a ported box since you don't have the room for both. That may well be louder over those frequencies than both in a sealed box.

[Dammed 12]

It is a Celica. And with the back seats out I could have 20-25ft3 box. People underestimate how much room you have in a celica.

The Q's are bought, so I'm using two 18" Q's, that's out of the question. And I was thinking about 28hz.

I have only had a 12" in a sealed box, so I have nothing to compare to. The question still stands, big vented box or a 10.24/12ft3 sealed box. How big difference would it be?

[Don Ganso 13]

If you have the room, my vote is definitely for the big ported box. 28Hz sounds good.

[///M5 2,833]

The questions is what system will hit the lows the best and give the best SQ? I'm also looking for some loudness, but it isn't the most important thing.

Some loudness? Saying that is specifically saying you DON'T want SQ. If you want your sub louder than your midbass you don't want SQ, I see no reference to your front stage here so I'd assume that it isn't your interest at all. You most likely should have bought the BL's and not the Q's. You will probably be frustrated by the lack of output in a sealed box, but by your description above that is what you should do. Whatever you do, don't put them in a ported box tuned to 28Hz that won't help you at all...

[Dammed 12]

Man this is such a stupid discussion, every time someone says they want SQ and a bit loudness you give almost the same speech. That it's impossible or that they really want loudness. There are many songs when the sub is louder then the mids, so I find that argument a bit strange. I want good sounding subs, I don't want a SQ setup. But I don't want a SPL setup. I want good sounding subs that can be louder then my front stage the times I want to be showing off or just crank them up a bit. But I want to have a sytem that can play with a nice sound at low volume. After all the gain remote to the sub amplifier is the thing that will be deciding if the sub are louder then the mids or not.

And what has my fronts to do anything with this this problem. It's like going to a shop asking for good shoes and the seller says, forget the shoes, you need a better jacket? I understand that the front stage, subs, HU, deadening, etc etc plays together to make the system, but the question is still about two 18" Q's in a vented or sealed enclosure? And what I should expect from each choice.

[KU40 173]

This is your decision to make. A ported box will give better results in the 30-45 hz range than a sealed box, but lag the sealed box below 25 hz most likely. So really it's up to you about if you want to use the back seat for a ported box or not, because you don't have room in the trunk for one for both subs. If you want to keep the subs in the trunk, sealed it will have to be.

[chrisommer 4]

He said he only had (1) 12 to compare them to. So I don't think he will be disappointed by the lack of output coming from (2) 18's sealed. Especially if he has not heard them ported. I would go sealed and keep the seats. (2) 18's sealed or ported would be more than enough bass for me. But that's me

go sealed, if thats not enough for you then go ported.

Edited February 1, 2010 by chrisommer

[Dammed 12]

This is your decision to make. A ported box will give better results in the 30-45 hz range than a sealed box, but lag the sealed box below 25 hz most likely. So really it's up to you about if you want to use the back seat for a ported box or not, because you don't have room in the trunk for one for both subs. If you want to keep the subs in the trunk, sealed it will have to be.

Yep, that's why the title is vented or backseats, like you said if I want to keep the backseats, I have to go with a sealed enclosure. So a vented enclosure plays better at 30-45hz, does music go much lower then 30hz?

M5, why shouldn't I put them in a vented box tuned to 28hz?

[kirill007 52]

Should make a vented/ported box, because you don't have enough room to make a good one.

Certainly if u want it tuned to 28hz, the port would be waay too big, and the sub will not sound good.

Better to do a good sealed box for both 18's, if u went with 15's you maybe could fit both ported, but not 2 18's.

[Don Ganso 13]

Should make a vented/ported box, because you don't have enough room to make a good one.

Certainly if u want it tuned to 28hz, the port would be waay too big, and the sub will not sound good.

Better to do a good sealed box for both 18's, if u went with 15's you maybe could fit both ported, but not 2 18's.

Jeez, he's got 25 cubes if he tosses the back seats, how much room do you need?

M5, why not 28Hz? I understand that with an SQ oriented setup, the front stage is way more important, but why not that tuning if it is not an SQ only setup?

[Dammed 12]

It was a guess by eye that I have around 20-25ft3, I measured it now and I actually have room for a 30ft3 box (internal volume). Fi recommends 6-10ft3 per sub, so I should have more then enough room to build a 20ft3 box + port tuned to 28hz.

So I'm going for a big vented box, wish me good luck, first time building a wall. I'll be posting a building thread in the future, have to wait a bit before I begin becuase it's -17/-25C here right now.

thx for the replies.

P.S. still a bit curios why M5 thinks a vented box tuned to 28hz would be a bad choice...

[///M5 2,833]

Man this is such a stupid discussion, every time someone says they want SQ and a bit loudness you give almost the same speech. That it's impossible or that they really want loudness. There are many songs when the sub is louder then the mids, so I find that argument a bit strange. I want good sounding subs, I don't want a SQ setup. But I don't want a SPL setup. I want good sounding subs that can be louder then my front stage the times I want to be showing off or just crank them up a bit. But I want to have a sytem that can play with a nice sound at low volume. After all the gain remote to the sub amplifier is the thing that will be deciding if the sub are louder then the mids or not.

And what has my fronts to do anything with this this problem. It's like going to a shop asking for good shoes and the seller says, forget the shoes, you need a better jacket? I understand that the front stage, subs, HU, deadening, etc etc plays together to make the system, but the question is still about two 18" Q's in a vented or sealed enclosure? And what I should expect from each choice.

Read the NOOB posting guidelines and say everything you did above but make it match and you wouldn't get the same response. You are misusing terms and adding a subjective flair to them so NO ONE knows what you are trying to accomplish. If you take SPL to mean as loud as possible and SQ to mean the opposite, then you understand. If you'd follow what you agreed to and actually describe what you wanted without misusing terms there would be no issue.

As for why not the 28hz, I would throw that back on you as you. Why do you think 28Hz is logical in a car?

[KU40 173]

This is your decision to make. A ported box will give better results in the 30-45 hz range than a sealed box, but lag the sealed box below 25 hz most likely. So really it's up to you about if you want to use the back seat for a ported box or not, because you don't have room in the trunk for one for both subs. If you want to keep the subs in the trunk, sealed it will have to be.

Yep, that's why the title is vented or backseats, like you said if I want to keep the backseats, I have to go with a sealed enclosure. So a vented enclosure plays better at 30-45hz, does music go much lower then 30hz?

M5, why shouldn't I put them in a vented box tuned to 28hz?

I guess if you're asking our opinion on if we would do the ported or keep the box sealed in the trunk, I'd say keep it in the trunk. But I'm sure my goals are different than yours so my opinion doesn't really matter. Good luck on the wall. Make sure to secure it to the floor really well.

[Dammed 12]

I read them a long time ago. I think you should check out the newbie forum as well, becuase you have a hard time staying on topic. And I knew what SQ and SPL stands for before I joined this community. Sound quality and Sound pressure level. SQ doesn't necessary mean as low DB as possible. That's bullshit and you know it. While SPL does mean as loud as possible without any consideration to SQ.

Now, tell me this what's the problem with a system that sounds good and has a possibility to go loud, otherwise known as ""SQL"". Many HiFi brands have always been searching for ""SQL"", loudness without loosing sounds quality. You could argue that they are built for SQ and that they go loud. But many are trying to achieve just what I said loudness without loosing sound quality. And they state it in commercials and intros on their new catalogs.

I have listened to HiFI speakers where your ears starts to hurt, but the mids and tweeters were still giving a really good SQ. Do you mean that's SQ or ""SQL"", ore even SPL since they get fairly loud?

This discussion is fairly off topic, and has nothing to do with my thread. If you read the post here, less then 50% are on topic. The topic is even ridiculously easy, vented or sealed enclosure and how the subwoofers behave in each type of enclosure. Yet, many people including you are starting a stupid off topic discussion about my front stage and what SQ/""SQL""/SPL is, and some are even stating they know my car better then me and that I don't have room for a big enough ported enclosure.

To return to the topic:

I was gonna tune the enclosure to 28hz because:

1. Fi recommended it, and if someone knows the Fi products it should be them.

I can't give any other reason, becuase I can only relay information I have read, and since it's not my own experience I can't thrust that information to be 100% correct. I could google "enclosure tuning" and write it down here like any other person what I read on the links, but I have no reason to do so. I have no reason to prove anything.

This topic was created to seek information about this, and if you don't want to share information that's fine. But don't spam other questions instead of providing information.

My questions still stands, why do you think that a 28hz tuning would be a bad choice?

[Dammed 12]

I guess if you're asking our opinion on if we would do the ported or keep the box sealed in the trunk, I'd say keep it in the trunk. But I'm sure my goals are different than yours so my opinion doesn't really matter. Good luck on the wall. Make sure to secure it to the floor really well.

Will do. I'm thinking about making some sort of frame around it and then bolt it to my car, but I'll check around to see what other people have done as well.

My questions was actually how big difference it is between sealed and vented if you want to subs to hit hard at low frequencies. Because if a sealed enclosure could make the subs hit hard at 25-30hz, I would of course built it then a vented one. Cause I'm not looking to have a lot of sound pressure, my goal is a good sounding system with the ability to hit hard at low frequencies. Since I'm gonna use a 3200W rms amplifier I'll get some sound pressure either way. So I wasn't having that as a primary goal.

I started this topic becuase I was afraid that if I made a sealed enclosure that it wouldn't play well on low frequencies.

[///M5 2,833]

You don't understand and you didn't read. It isn't bullshit and you agreed to it. Change your tune or don't post.

[thebiggmann12 14]

I guess if you're asking our opinion on if we would do the ported or keep the box sealed in the trunk, I'd say keep it in the trunk. But I'm sure my goals are different than yours so my opinion doesn't really matter. Good luck on the wall. Make sure to secure it to the floor really well.

Will do. I'm thinking about making some sort of frame around it and then bolt it to my car, but I'll check around to see what other people have done as well.

My questions was actually how big difference it is between sealed and vented if you want to subs to hit hard at low frequencies. Because if a sealed enclosure could make the subs hit hard at 25-30hz, I would of course built it then a vented one. Cause I'm not looking to have a lot of sound pressure, my goal is a good sounding system with the ability to hit hard at low frequencies. Since I'm gonna use a 3200W rms amplifier I'll get some sound pressure either way. So I wasn't having that as a primary goal.

I started this topic becuase I was afraid that if I made a sealed enclosure that it wouldn't play well on low frequencies.

u should probably keep ur gains down, especially if going 10 cubes per sub...1600 watts is 600 more watts than what the subs are rated for...ur just asking to blow them to peices in that big of a box.

[Dammed 12]

You don't understand and you didn't read. It isn't bullshit and you agreed to it. Change your tune or don't post.

I have read it, and yes I have agreed to it. And yes I was misusing your definition of the terms. Which I find retarded, but yeah, not my forum. Everywhere else in the world SQ stand for Sound quality and SPL for sound pressure level, but apparently not here. You will not see me using those terms since they apparently are meant to be only used by people building SQ and SPL car audio systems for competition.

If you want a better explanation without using the term SQ, """"SQL"""" or SPL here it is:

I want my subwoofer to reproduce the bass in music correctly without any distortion or inaccuracy. I want them to sound good, not loud. As I said earlier my focus is sound quality. I want my system to sound good. Not to compete in SQ contests, but just plain and simple sound good.

But I want to be able to turn the gain button all the way up so that my system can play loud. This is as I said not my primary goal. I like lots of bass at times, but I find myself more often turning the gain down and drive to school listening to music on a "normal volume". Meaning so low that you could talk to the person sitting next to you without any problems. And this would be SQ as you define it, to reproduce music as it was recorded as exactly as possible.

Like I said earlier, still curious why I shouldn't use a tuning of 28hz?

u should probably keep ur gains down, especially if going 10 cubes per sub...1600 watts is 600 more watts than what the subs are rated for...ur just asking to blow them to peices in that big of a box.

That was the idea, I was going to buy a amplifier that was much more powerful, and then I'll turn the gain down so that I can keep it cool, have enough headroom and be a bit future oriented so that if I find that I want it to be louder, which I really doubt, then I will be able to purchase some other subs and still use this amplifier to power them.

Edited February 2, 2010 by Dammed

[KU40 173]

I guess if you're asking our opinion on if we would do the ported or keep the box sealed in the trunk, I'd say keep it in the trunk. But I'm sure my goals are different than yours so my opinion doesn't really matter. Good luck on the wall. Make sure to secure it to the floor really well.

Will do. I'm thinking about making some sort of frame around it and then bolt it to my car, but I'll check around to see what other people have done as well.

My questions was actually how big difference it is between sealed and vented if you want to subs to hit hard at low frequencies. Because if a sealed enclosure could make the subs hit hard at 25-30hz, I would of course built it then a vented one. Cause I'm not looking to have a lot of sound pressure, my goal is a good sounding system with the ability to hit hard at low frequencies. Since I'm gonna use a 3200W rms amplifier I'll get some sound pressure either way. So I wasn't having that as a primary goal.

I started this topic becuase I was afraid that if I made a sealed enclosure that it wouldn't play well on low frequencies.

Quite a large one. Probably 6-10 more dbs over the 30-40 hz region with a ported box.

[Duran 387]

Quite a large one. Probably 6-10 more dbs over the 30-40 hz region with a ported box.

Which is there all your rap music is FYI