Upturned sub baskets

[hydeyho]

How does this work? If you upturn them will the boot space act as an encosure? Would the sound be greatly affected if my setup had one in an enclosure and another upturned?

 

[Roamer]

When you say "upturn them" what do you mean? fit them in the parcel shelf? or have them face into the sub box?

 

[hydeyho]

Facing into the sub box

 

[Djw John]

No thesub box is still the enclousre. All that means is that the box is effectively bigger as the sub isnt taking up any space in it.

 

[Irfan]

if you need to build the box slightly smaller, then you can mount the sub with the magnet facing outwards as you dont have to take into account the magnet displacement in the box. however, the surface area of the face of the sub is normally greater than the underneath of it, so it may not be as efficient compared to mounting it in the traditional way.

after all, speakers work by moving air. the bigger the surface area of the speaer, the better it will work.

 

[Rorrie]

one thing to bear in mind, is you may need to reverse the polarity, as the sub will be moving the opposite way to what it sould when it is arse out

 

[hydeyho]

Is rorrie correct as I wouldnt have thought that it would make any difference to the polarity?

 

[Mole]

Shouldnt matter, our ears cant hear phase shift, well not at 180 degrees anyway, as thats all your doing by basically changing polarity

 

[Djw John]

You would be best to, so that it moves in the same direction as the other speakers.

 

[Mole]

i spose, but would only be benificial if your running rear speakers that use the same air space as the other speakers.

I dont have to worry coz i dont run any rear speakers, and have no intention of running rears as i sit in the front, sod what people hear in the back lol

 

[hydeyho]

Never thought about the other sub moving in the opposite direction, good call eviljohn. Should be running two 12 jls off this Ive just bought off ebay > http://www.caraudiodirect.co.uk/images/mrdm301.jpg

Anybody had any experience with this amp? Is it any good? Should be pretty much perfect for the subs as it gives out 350rms @ 2ohms

 

[Djw John]

Whats the ratings for the JLs?

I personally like Alpine amps, run a 4 channel for my comps and coaxs. What model is it?

 

[hydeyho]

The one pictured is the mrd301, Im getting a 300 (same model just a little bit older). JLs are 125w rms iirc, only got one atm and its running off a crappy amp (450w continuous) and sounds good so the alpine should hopefully make it sound even better

 

[Djw John]

I assume they are 4 ohms each then. Wired in parallel thatll be fine. Are you redesigning the build then? What ideas have you got for it?

 

[hydeyho]

Yea they are 4 ohms each. Not sure what to do with the install really yu got any ideas? Was of booting both subs in the middle of the boot, amp above the rear arch but would then need to put something up the other side to balance it out.

 

[Djw John]

A power cap? Even it up, functional and if you get one with a display will work well with the amp.

 

[clio_massive]

whats the difference with the speakers facing inwards or outwards

 

[Djw John]

If its a sub then no big differnece, but coaxs would sound muffled!

[Edited by EvilJohn on 22 August 2004 at 12:04am]

 

[hydeyho]

Power cap is a good idea but Ive heard that they are quite bad for your battery or am i just talking rubbish?

clio_massive - its only for a visual difference, depends what the cone and magnet look like

 

[Djw John]

No they dont damage the battery, dont help it as much as some people think but itll mean that the amp can run the subs better when your pushing them.

 

[Irfan]

if you run the sub with the arse out, its mainly for looks. remember, subs work on the principle of moving air, you have more surface area on the front of the sub than the rear.

you will need to reverse the polarity of the subs, so that it still uses the box for the airspace, as this is what makes subs work. it will also keep it in phase with the front speakers.

 

[Rorrie]

with subs inverted, it can make a difference, as if you have any overlap of freqs then you can get bass cancelation issuses, even in the front, but not to such an extent as the sub will be slighlty out of phase with the fronts unless adjusted already.



a quote from thes the most publicised installer in the US, which pretty much makes it the world, (Matt Bogart) listen to the sub, If the sub seems to anchor in the back of the car flip the phase on the subs



it certainly makes a difference in my car, and i have no rear either

 

[16vneil]

u wont need a power cap , total waste of money

 

[Djw John]

Yeah wont need but may even up the looks of the build. Trying to think of something else, other than an amp to run the front speakers.

 

[hydeyho]

I know I wont need one but would stick one in the install if I could get one cheap / second hand. 16vneil what would you recommend to even up the boot? What size fuse should I have by the battery on the feed to the amp as I hooked up my new amp and it worked fine, but when I sorted out the wiring (rather than the bodge that it was earlier) and stuck my neons on the remote and ground off the amp I got sparks off the positive on the amp (when I connected the wiring to the +ve) and it blew the fuse by the battery. Why would this happen?

 

[Djw John]

Cos you should have the amp connected then connect the fuse. Just use the same rating as before and it should be fine.

 

[hydeyho]

Ok, never thought about that, will do tomorrow when I get my hands on some new fuses. Might be getting another alpine amp now to power my front speakers, an mrv t320, looks exactly the same but is 2x140w. Is it worth getting a 4 channel amp and powering the rear speakers too?

 

[16vneil]

seems alot of money thats all to even things out , if u wanted a voltage display brax 1s are very good and can be found cheaply.

maybe mount an EQ there or your crossovers , some thing more functional than a cap