Phoenix Gold Phorum

Subwoofer location - when you install a pair of subs do they both need to be together facing the same direction?

To cut it short, the install is in a VW camper, the only space left to fit subs is under the seat/bed that runs down one side of the camper, due to having to also fit the amps and other stuff under ther its not ideal. I can fit one of the subs on the end of the bed facing forward directly behind the drivers seat and the other, near the back of the camper facing across the van slightly angled towards the rear door.

No idea how this would effect the sound, anyone have any knowledge on this subject? Already started cutting the wood ....

I don't think the angle of the subs will be an issue necessarily, but where one is right behind you and the other is way back by the back door might cause a bit of muddiness in the bass from timing issues. It might be okay like that, but that would be what I would expect.

can you fire them both down?

they will almost certainly cause cancellation.

i would even go as far as to just use one and really optimize it.

Kirghiz wrote:I don't think the angle of the subs will be an issue necessarily, but where one is right behind you and the other is way back by the back door might cause a bit of muddiness in the bass from timing issues. It might be okay like that, but that would be what I would expect.

X2.... always make sure they play into fase with each other.....

Bugger, I was dreading that kind of advice .... but thanks. Muddied or cancelled out sounds very bad.

Guess I cannot bury my head in the sand, will have to drop to one sub but know I will not be happy with it, or what to do with the amps as the tray has been cut already. Really need help on this, shout if you need a diagram to help think...

Here's one idea....
ZX350 was to run stereo to Elite comps up front - now bridge into one sub
ZX450 was to run bridged mono into each sub - now bridge in stereo to Elite comps (is this even possible?)
ZX250 was to run stereo to unknown rear comps - same

Heres another idea....
The sub location near the rear facing backwards has no room for any changes, but the location facing forward has room behind it, is there a box that houses both subs in the one location so they work together? bearing in mind when wiring the subs the ZX350 does not like low loads. The subs are Titanium 12's 3.01 Ohms. Be a shame to loose the rear sub though as I was going to do a PG logo cut out to fire the sub through and was part of the design of the bed.

HELP

PhuckinGood wrote:Bugger, I was dreading that kind of advice .... but thanks. Muddied or cancelled out sounds very bad.

Guess I cannot bury my head in the sand, will have to drop to one sub but know I will not be happy with it, or what to do with the amps as the tray has been cut already. Really need help on this, shout if you need a diagram to help think...

Here's one idea....
ZX350 was to run stereo to Elite comps up front - now bridge into one sub
ZX450 was to run bridged mono into each sub - now bridge in stereo to Elite comps (is this even possible?)
ZX250 was to run stereo to unknown rear comps - same

Heres another idea....
The sub location near the rear facing backwards has no room for any changes, but the location facing forward has room behind it, is there a box that houses both subs in the one location so they work together? bearing in mind when wiring the subs the ZX350 does not like low loads. The subs are Titanium 12's 3.01 Ohms. Be a shame to loose the rear sub though as I was going to do a PG logo cut out to fire the sub through and was part of the design of the bed.

HELP

looking at the amps you have, put the zx350 on one elite12 sub....better one sub with the power it needs then two subs just getting

half the power they need.....

you can use the zx450 as 2 channel amp (front and rear brigded each on left and right) working passive, or

you can use the zx450 as 4 channel amp active on the compo set, so tweeters on front and mids on the rear.....

zx250 on the rear speakers


or.... life is too short to hesitate...........


http://www.ebay.com/itm/Phoenix-Gold-ZX ... 51aa643ca8

looking at the amps you have, put the zx350 on one elite12 sub....better one sub with the power it needs then two subs just getting

half the power they need.....

you can use the zx450 as 2 channel amp (front and rear brigded each on left and right) working passive, or

you can use the zx450 as 4 channel amp active on the compo set, so tweeters on front and mids on the rear.....

zx250 on the rear speakers

Hey, thanks for thinking about this, been banging my head all day at work thinking of a solution. This may surpise you but I have had the ZX450 bridged on the Titanium 12s to test for a couple of weeks and they run very well, surprisingly well in fact, the amps rated power has hiked do to a visit to the amp doctor. I know the ZX350 would run one better though but as for an Elite12 surley the ZX350 is not even close to enough power, is it?

I was thinking back to box designs as the answer maybe but know nothing on the subject :- ideas?
1.The first sub sits at the front of the box facing out, second sub sits beind the first in an internal baffle - possible?
2. Keep the rear sub that angles towards the back corner, put the second in another box under the bed facing the same way and cut a vent in the bed facia to let it out?
3. See if I can fit the two together in a V shape to fir out the rear sub hole?
4 HELP!!!

I know it has been put to pasture as an obsolete method of doing things, but I installed a couple back in the day and I could tell a difference from adding the second driver.

What about an magnet to magnet isobaric enclosure behind the seat?

Kirghiz wrote:I know it has been put to pasture as an obsolete method of doing things, but I installed a couple back in the day and I could tell a difference from adding the second driver.

What about an magnet to magnet isobaric enclosure behind the seat?

Wish I knew what you meant by that, can you expand on it maybe, magnet to magnet?

I will try and sketch the layout with sizes so its easier to see the problem I face if I can find something on this computer to let me draw

PhuckinGood wrote:

Kirghiz wrote:I know it has been put to pasture as an obsolete method of doing things, but I installed a couple back in the day and I could tell a difference from adding the second driver.

What about an magnet to magnet isobaric enclosure behind the seat?

Wish I knew what you meant by that, can you expand on it maybe, magnet to magnet?

I will try and sketch the layout with sizes so its easier to see the problem I face if I can find something on this computer to let me draw

Basically it would be mounting the subs back to back like you are talking about, but use a shared chamber and wire the two subs out of phase so that one fires into the box and the other fires out, and essentially they are firing the same direction. Essentially what it does is make the two subs work together as one subwoofer, and you would get the SPL of one subwoofer, but it would be a subwoofer with twice the cone mass and twice the motor that can take twice the power. The two subs together like that also reduces the vas, which means you can get the two subs into half the space that is required for one. If you already own the two subwoofers you were planning to use it might be an idea rather than buy an Elite 12 that you don't have. Basically it would make a pair of Ti2 12" subs sound more or less like an Elite 12. All things being equal you'd be better off buying an Elite 12 if you don't own any of the subs yet.

It was a popular thing to do back in the '90's because subwoofers didn't have as strong of motors, had high sensitivities, and required bigger boxes to get low unlike now. When you needed 3 cubic feet for a 12" you could do a pair isobaric in 1.5 cu. and just double the power to get the same low end output in half the space. It does also sound better because isobaric loading reduces distortion from the motors of the subs. With modern subwoofers the box sizes needed to get low has shrunk to the point that it is something you seldom see anymore in car audio, because no one needs to do it anymore. The claim to fame of the Kicker Solobaric subwoofers when they came out was that one subwoofer would perform like an isobaric pair, which they did. They just had a more powerful motor, heavier cone, and reduced sensitivity, which is pretty much all modern subwoofers now.

The big downside to doing it is the need to buy twice as many subwoofers and twice as much amplifier power, but if you already own these things and want to fit them all, it's an option. If you don't own the subs yet though I would just buy an elite 12 and be done with it.

http://www.caraudiohelp.com/images/isobaric.gif

Okay, no giggling in the back at my drawing, not far of scale ... cough ...

So hope this makes sense, what your looking at is a birds eye view of the bed footprint in the camper showing my terrible subwoofer location choice, the amps & fuses are behind doors facing across the van. The outer footprint is built up using 18mm ply with door holes cut for the amp rack and fuses access and a spare for aesthetics, this is made. The sub facing to the front behind the drivers seat will have a hole cut in the wood, the sub facing backwards on a slight angle I was going to try to cut out a PG logo with the jigsaw for the sub to be behind.

So since 'thanks to the advice of members' finding out the two subs at different positions will ruin the sound I have been trying to work out how to install them both, the rear sub has limited room due to the rear wheel arch intrusion. Ideally I would try to fit both back there

So after racking my brains all day for the answer, I throw it out for ideas as to how to run both 12'' subs and still fit hope to hear plenty as I am stuck.

PhuckinGood wrote: 1.The first sub sits at the front of the box facing out, second sub sits beind the first in an internal baffle - possible?

Actually, this idea is a popular form of isobaric enclosure, and would behave exactly like I was talking about.

http://bluescaraudio.com/products/isoki ... isokit.jpg

Kirghiz wrote:

PhuckinGood wrote: 1.The first sub sits at the front of the box facing out, second sub sits beind the first in an internal baffle - possible?

Actually, this idea is a popular form of isobaric enclosure, and would behave exactly like I was talking about.

http://bluescaraudio.com/products/isoki ... isokit.jpg

Never seen that before! If it wasnt for the rear wheel arch intrusion I could see they would both fit at the back in small sealed enclosues in a V shape. Yea I already have the 2 Titanium 12s, buying an Elite 12 is not a problem but running it is, the ZX amps dont like 2ohms bridged to much if I remember and way way short on power, I would have to use a D class hiden amp to power it, then god knows how I would use the three ZX amps. The amp doctor made up new speck sheets on them so I am off to dig them out now. The isobaric enclosure you spoke of earlier I assume is a vented application? as I am after SQ I wanted sealed enclosures, but at the moment would take any way out. Can you see where it would fit at the rear?

you can run an isobaric sealed, vented, or bandpass. it's still a useful thing to cut down on the enclosure size of dual vented bandpass boxes that requires huge enclosures. the thing you'll run into with modern subs is that isobaric will cut the enclosure size in half. i'm not familiar with the the enclosure specs on the ti elite 12, but if a sealed enclosure is 1.5 cu for that sub, then you would need to use 0.75cu for the isobaric pair. good luck building a 0.75 cu sealed box that'll house both of those baskets/magnets. you'd almost have to go vented to get the enclosure size to something you can work with.

Kirghiz wrote:you can run an isobaric sealed, vented, or bandpass. it's still a useful thing to cut down on the enclosure size of dual vented bandpass boxes that requires huge enclosures. the thing you'll run into with modern subs is that isobaric will cut the enclosure size in half. i'm not familiar with the the enclosure specs on the ti elite 12, but if a sealed enclosure is 1.5 cu for that sub, then you would need to use 0.75cu for the isobaric pair. good luck building a 0.75 cu sealed box that'll house both of those baskets/magnets. you'd almost have to go vented to get the enclosure size to something you can work with.

They are not the Elite 12 subs I have, youre right no chance of getting them in! mine are the Titanium 12 single coil subs. Mounting depth is 16cm and will work in small sealed encolsures. 500wrs and 3.01 Ohms. Just got the test sheets out for the amps, the ZX350 does 2x129wrms stereo and 386wrms bridged. The ZX450 4x124wrms stereo and 2x346wrs bridged. So thats why the 450 works okay on the subs giving them somewhere around 400wrms I guess.

been for ever since I saw a clam-shell enclosure....

ttocs wrote:been for ever since I saw a clam-shell enclosure....

LOL me too, but it does seem like a viable option in this case, though the subs in question would probably be the most powerful subs ever used in one. LMAO

since I've been thinking about isobarics today I've been toying with the theory of using slim mount subs in one. I wonder if a pair of SL12's will work in a clamshell ported in about 0.75? The reason isobaric enclosures went the way of the dodo is because you have to contain the magnet and basket, and most subs will work in teeny tiny boxes anyway. If you had slim mount 12's with 4 Inch depth clamshelled, the subs would fit mounted vertically under a truck seat, and the isobaric would make them sound about like real subs. MB Quart makes one with a 2 Inch depth.

My mind wanders......

PhuckinGood wrote:Okay, no giggling in the back at my drawing, not far of scale ... cough ...

So hope this makes sense, what your looking at is a birds eye view of the bed footprint in the camper showing my terrible subwoofer location choice, the amps & fuses are behind doors facing across the van. The outer footprint is built up using 18mm ply with door holes cut for the amp rack and fuses access and a spare for aesthetics, this is made. The sub facing to the front behind the drivers seat will have a hole cut in the wood, the sub facing backwards on a slight angle I was going to try to cut out a PG logo with the jigsaw for the sub to be behind.

So since 'thanks to the advice of members' finding out the two subs at different positions will ruin the sound I have been trying to work out how to install them both, the rear sub has limited room due to the rear wheel arch intrusion. Ideally I would try to fit both back there

So after racking my brains all day for the answer, I throw it out for ideas as to how to run both 12'' subs and still fit hope to hear plenty as I am stuck.

i would place both subs from the left side of the fuses to the right side of the zx450.... amps and fuses can be relocated then.....

this will be you're best solution....here you can install them next to eachother and use the ideal enclosure for them.......

Any more ideas how I can make this work?

Having already had the panels cut I am staring at a big loss. Even if I dropped to one sub the obvious solution is ZX350 bridged to it and use the ZX450 to drive the front and rear speakers, but I have cut the door opening to the amp rack to also take the ZX250 which was going to run the rear comps.

If I drop to one sub I have to loose the one facing the drivers seat as the sub grille on the one facing backwards was part of the bed base design and would look odd with nothing there.

Close to throwing in the towel ...

zeropoint0.5 wrote:
i would place both subs from the left side of the fuses to the right side of the zx450.... amps and fuses can be relocated then.....

this will be you're best solution....here you can install them next to eachother and use the ideal enclosure for them.......

Yes next to each other is ideal, the reason I didnt do that was the seat top flips out to become a bed, the angle with the rear sub starts just after the flip section. I took this back at an angle as thought if the sub fired directly accross the van is would cancel itself out, was I wrong there? I remember testing sub angles years back in a moveable box, the minute I angled it back the sound improved, the ideal was actually rear facing, this I cannot achieve with even one sub, so I made that angle on the bad base to at least point it at the back opposite corner.

I could remove the angle where the rear sub is shown to continue the straight line to the back with the two subs side by side, I thought subs poiting directly accross the van wouldnt work though?

Thank you for thinking on this so far

Is this what you mean? I thought the subwoofers facing accross wouldnt work? Thought they needed to be on angles or ideally facing the rear?

PhuckinGood wrote:Is this what you mean? I thought the subwoofers facing accross wouldnt work? Thought they needed to be on angles or ideally facing the rear?

this will not affect the sound, but i was meaning placing them from the left side of the fuses to the right side of the zx450, so you have more space

there aside of the wheel case to make a ideal enclosure....adjusting time alignment is another thing....sound dampening you're vehicle also......

have you maybe thought of a solution of a double 4th order bandpass ??

and letting the vents come out just behind the drivers seat ??

by the way,

there's a zx350 on ebay.uk....... take a look......

Yeah I understand where you meant the subs to go now, the reason I keep the amps there is to show off, they are opposite the side sliding door. If you think the subs will sound okay facing 90 degrees across then this set up seems okay, although thinking they should be on an angle I sketched another idea out like this ... what do you think?

Either of these ideas the wood I have cut is now junk I dont understand your last suggestion, but sounds good, do you have an example?

Thanks for the ZX350 tip, I have let a few go by now without bidding, as by the time they are fully restored its getting expensive ...

Both of those last two sketches seem like they`d work alright to me.

i think what zeropoint is saying is move the amps toward the back of the vehicle, and arrange them like you have them, but mount them in front of the wheel housing because you don't need much depth there. meanwhile, move the subs toward the front in between the fuses and amps. that would offer you more depth without having to work around the wheel well, offering more enclosure space, and being more forward would improve timing issues.

basically take the recent sketch where the subs are on the same angle and flip the subs and the amps locations.

the direction of the subs is really not so important....just make sure they play in fase with each other.......

hoping you have a sense of humor, unless you love to cook,

throw out the kitchen and build a big audiophile vented box for both subs there......


what do you prefer..?? dinner or bass ?????