romycha1

Can this be done with any type of sub? I know the bass doesn't hit as hard when it is this way.
Also, if the sub is inverted, how does that affect the air space?

momo stereo

well.....first ......alot of people think that it can make your subs louder.....

but yes you can do this with any sub....

rotarygod

Air space is affected a little bit which is why this volume is usually stated with the thiele/small parameters. You need to take that into account when designing a box.

Theoretically they don't hit harder this way. However, there is one reason they might though. Many modern woofers have humongous magnets. When you mount these woofers in a box, it's not uncommon to have little room for air to get from the back of the cone, around the frame and magnet and into the box. The thicker the face of the box is, the worse this can get. You can radius the inside of the cutout to relieve this somewhat.

Yes you can do it but it isn't necessarily any louder. It's not impossible though. If a woofer is downfiring or upfiring other things come into play. You need to be sure the mass of the cone won't ultimately sag and affect performance. There is a calculator that allows you to figure out whether or not your woofer is a good candidate for either up or downfiring. I need to find it.

BTW: I worked as a custom car audio installer for 10 years. I've won both the IASCA and USAC WORLD finals and my final hoorah in the industry 6 years ago was building a show van for Rockford that went around the south for several years. I last saw it 3 years ago at Texas Heat Wave in Austin.

eviltwinkie

Isoplanar Bandpass is what you want...heh

romycha1

Thanks guys. I can build custom fiberglass enclosures all day... I just don't know much about speakers.... I do the box building thing as a side job, and when people ask what would be good, I almost never recommend anything or give my two cents on a product just in case in doesn't sound good. And if I do, it's only on what I've personally heard.

But the inverted sub question was for me. When I have time I am going to build an enclosure for the center console in the rear, and I would like to have an inverted sub.

romycha1

Oh, and Twink... what is that? Is that a brand name, or type?

WikkedOne

I think he's thinking of a box design - I couln't find exacly what he said but here is a collection of ridiculously complex boxes...
The12Volt.com - Boxes

as for inverting subs - I think for what you want it will be fine.. but i don't like the way they look and it seems to me that less surface area and stuff would hurt the sound too much.. but i have never done it so i don't know

but yeah it does help with airspace - you don't have to account for the mass of the magnets/coil and you even get a little extra space beyond the box because of the curve of the woofer itself. so if you have to build a super small box to fit in the center - inverted is the best (although tackiest IMO) way to do it.

eviltwinkie

Its a bandpass design that uses the subs in a push/pull configuration but mounting them inverted and firing into a common chamber.

Let me break it down for you...

###****####################################
#.....****..................................#..... ....................................#
#.....****..................................#..... ....................................#
#..................1..........................#....................... ..2..............#
#..............................................#.. .......................................#
#..............................................#.. .......................................#
##########################################
#..............................................3..........................................#
##########################################



Your subs are mounted so they BOTH fire into chamber #3.
Chamber #1 is ported and the port is tuned to your desired range.
Chamber #2 is sealed.
You invert the phase on the subs so that when sub in #2 is "pushing" the sub in #1 is "pulling".

ysoloud

Alot of good info here, but one more thing you should think about. Inverting a sub will cut down your power handling about 30%. Also make sure your surround does not hit the mounting surface in any way. Pending on the sub you are using you may see a increase in certain freq. and a decrease in others. Most manufactures have specs for inverted subs. If you are using a 4080 inclusure contact on of the Fukuda brothers, they are some of the best installers / builders in the world. I have a inverted sub you can see the post at https://www.rx8club.com/series-i-exterior-appearance-body-kits-27/audio-video-w-kick-133106/ .
Thanks

romycha1

I see.. That sounds pretty complex, I would definately give it a shot if I were using two subs. But since I'm going make something fit between the seats, I'm just going to go with one 10.

eviltwinkie

Get a JL 10W6 or something that uses a small enclosure...dont mount it inverted as there is no need...

rotarygod

Don't put a W6 in a bandpass box. It's not very efficient in one.

That push/pull bandpass box design has been done before. It's called isobaric. You need to make sure chamber 3 has enough depth that it doesn't smother the woofer as it moves. Just having enough clearance for the cone not to hit isn't going to be enough.

Your box will literally be half the volume of a bandpass designed for a single woofer. Efficiency will also be half as you have a woofer completely closed off from the outside world. I'm not a fan of the isobaric setup. It had it's day when subs needed large enclosures to play low. Back then they were more efficient on average too so a decrease in efficiency wasn't much of an issue. Today's woofers work well in very small enclosures but already do it at the expense of efficiency. Don't make it worse. Fortunately power is cheap.

romycha1

I'm not going bandpass..
Also, I don't really care about how hard the bass hits. I'm probably gonna get a really good sub, but just a mediocre amp. I just wanna make something for my car, so when people ask what kind of quality my work is, I can show them something. And the inverted sub, in my opinion, adds a little bling factor into it.

ysoloud

I agree with rotarygod, friends don't let friends build those enclosers. Small sealed is the way to go. With speakers now only taking .3 to .7 and even in those small boxes having deep, clean bass. Also brand name is not always a factor. JL makes great woofers, but with that being said, they are high in the price catagory. I like to take mid line equipment at half the price and watch others faces when they here it.
REF. Installation New , May 1995
CES Show Vegas I.J.I. Booth 1996,97
SEMA Show Video Concepts Booth 1996
IASCA Finals 5th Place Expert
2005 ZR1 Corvett

Car Audio Mag. , 2000
1998 CRX

romycha1

I'm probably going to go with a JL W3, but I kinda want something with a nicer basket. The W3 is really plain. I guess as far as the aesthetics go, I'm being kind of a ricer.... being that I'm more concerned with how it looks rather than sound.
.. not sure what kind of amp though.

But yes, the plan on the enclosure will be small and sealed.

ysoloud

You can have both looks and sound. Buy what you like, not what you friends tell you to! Your money your ears your eyes. Spend some time looking at both!

romycha1

What are you talking about? Look at both what?

serenitynow

The general question was can you invert any sub: make sure to test the sub first for mechanical noise when inverted. Not that important for the rx8 as the trunk will mask it but in a hatchback... flutter

romycha1

Yes, that was the general question... but you didn't answer it. And also, I'm not going to have the sub in the trunk. I stated earlier that it will be in between the rear seats.

serenitynow

Then I did answer your question... i.e. not every sub sounds good inverted... does it have mechanical noise? That is up to you to find out... if you can build fiberglass enclosures all day long then you should be experienced enough to know what mechanical noise is and how to test for it... good luck.

romycha1

The question is a simple yes or no. You said "make sure to test the sub for mechanical noise"... If you R E A D, the question was already answered in the second post. I appreciate your two cents though.

serenitynow

Then yes you can
do they all sound good, no they don't.
... ... ... ... ... time ... ... ... cause the "answer" in the second post was not entirely the correct answer. not trying to prove anything here, just trying to get through.... not trying to prove anyone wrong...just trying to get through... some subs do not sound good inverted....

ysoloud

Looks And Sound, You can have both! That is what I was talking about. I will answer the question . No, there are several woofers out there that do not have a spider as a recoil device. These woofer usually have what is called Air Suspension Excursion Control. They require the encloser on the back side of of the woofer for that control. So, no not all woofers can be Inverted.

romycha1

OH ok... when you said look at both I thought you meant look at both subs.. Yeah, I still don't know what I'm going to go with. Any suggestions? Again, I don't need killer bass... just some thump, but something good.

lurch519

8" Kicker L7