mx5cartalk.com

No room under the seat.

I cant slide my hand under my seat, how on earth do you fit a sub under there?

Mazda used to install those bass shaker things inside the seat in some markets, but they are a lot thinner than a normal speaker.

I'm assuming you will be getting an NA because 8\" speakers fit quite nicely into the NB doors?

I refiited a set of 6.5\" splits into Agro's car and they seemed to pump out plenty of bass to me. I cant remember what brand they were, Alpine maybe? The original installation was woeful. They weren't sealed properly, the spacers were made from untreated MDF that had disolved from the water that enters the door and they produced vitually no bass. The crossovers were sitting in the bottom of the doors and were very corroded. The difference in sound quality after everything was intstalled properly was like night and day.

Taking out seats then building a custom box for a shallow sub sounds a lot like a fair bit of effort. You may as well do something simple in the boot, similar to the ones that sit in the sides that many people have posted about previously.

It'd be much easier than having to remove the seats just to take measurements before removing them again to actually install the box.

That and you don't have to run as much cabling back through to the cabin if you leave it in the boot.

http://www.jaycar.com.au/productView.as ... &SUBCATID=

slide passenger seat forward, place behind seat. plug in. slide passenger seat back

can't get much simpler than that.

nah mate sorry, i have no idea about it, other than i saw it in a jaycar store the other day and thought it was a cool idea .

Fatty wrote:http://www.jaycar.com.au/productView.asp?ID=CS2275&CATID=&keywords=subwoofer&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

slide passenger seat forward, place behind seat. plug in. slide passenger seat back

can't get much simpler than that.

I test fitted one in the boot, it works but really suffers at higher power levels

seems as though you are answering your own questions here m0b1liz3
but in reply to your original question the easiest I have seen would have to be either Marcuses's install (just dump a shallowish sub box + sub into centre of boot) or there was another one around here, I think it was Ajays really really old install

m0b1liz3 wrote:There are guys that have reported doing it with shallow 8" subs. How comfortable it would be to sit that seat is another question...

I wouldn't recommend it. Even if you can somehow be crafty enough to build a nice compact fibreglass enclosure to fit under the seat, you still wouldn't get enough enclosure volume to produce any form of useful bottom end out of it.

Moral? I'd explore other avenues.

m0b1liz3 wrote:I also heard it was possible to put in 8" 3 way speakers into the doors and seal around with a decent baffle to pick up the mids and lows.

It's possible, but a cheap set of 8" 3-ways won't give you the best bottom end (not good enough to replace a sub) and sure as hell won't give you good midrange.

Again, I'd consider other alternatives.

m0b1liz3 wrote:I have never listened to component 6.5" speakers but some guys are claiming they sound heaps better than 3 ways. Other guys have squeezed 8" 3 way speakers into their doors. It would be good if there was a 6.5 speaker that didn't sound too tinny and had some bass.

There are plenty. Name me a budget and I'll make you a list!

There are a lot of good 6.5" component sets that will provide decent midbass if properly installed - first ones that spring to mind are Focal 165K2P's - a bloody briliant speaker set but many would consider them out of budget ($849rrp).

If it helps, this is what I have in mind at the moment for mine:

how in the world can you fit a sub box under the seats

i see it as impossible

theres about 5cm at the max under the seat

AZNTieN wrote:theres about 5cm at the max under the seat

less, I would say 2-3 max

SM wrote:but in reply to your original question the easiest I have seen would have to be either Marcuses's install (just dump a shallowish sub box + sub into centre of boot)

It's cheap and nasty, but it works. I think the box cost me about $60 from Karatan Enclosures (they're on eBay, or you can google them) plus the cost of the sub & amp. The rest of the effort is just wiring.

muzzy66 wrote:

m0b1liz3 wrote:There are guys that have reported doing it with shallow 8" subs. How comfortable it would be to sit that seat is another question...

I wouldn't recommend it. Even if you can somehow be crafty enough to build a nice compact fibreglass enclosure to fit under the seat, you still wouldn't get enough enclosure volume to produce any form of useful bottom end out of it.

Moral? I'd explore other avenues.

m0b1liz3 wrote:I also heard it was possible to put in 8" 3 way speakers into the doors and seal around with a decent baffle to pick up the mids and lows.

It's possible, but a cheap set of 8" 3-ways won't give you the best bottom end (not good enough to replace a sub) and sure as hell won't give you good midrange.

Again, I'd consider other alternatives.

m0b1liz3 wrote:I have never listened to component 6.5" speakers but some guys are claiming they sound heaps better than 3 ways. Other guys have squeezed 8" 3 way speakers into their doors. It would be good if there was a 6.5 speaker that didn't sound too tinny and had some bass.

There are plenty. Name me a budget and I'll make you a list!

There are a lot of good 6.5" component sets that will provide decent midbass if properly installed - first ones that spring to mind are Focal 165K2P's - a bloody briliant speaker set but many would consider them out of budget ($849rrp).

If it helps, this is what I have in mind at the moment for mine:

Muz, it takes balls to get a sub into the front of a cabin, and good luck to you. Provided you get the size right, and given you are using an 8", you should be able to find 10-15l, it should be good. I'd suggest though that the tweeter goes down next to the mid-range driver. The vertical distance between the two frequency ranges of the mid and tweeter has more effect on the sound quality than the overall lowering of the 'set' by placing the tweeter down low. I had my tweeters in the kicks of my old Alfa Sprint and the sound stage was well up and in front of the dash. Sounded like a set of hifi speakers on the bonnet without any time correction.

The key...minimal path legth difference for all speakers.

Also, if you are going to the trouble of a sub in the kick, why not integrat a mid driver into the kicks on-axis? Being in the doors, and the way the MX5 is setup, you'll be almost 60deg off axis. I'm not sure of the off-axis performance of the Peerless, but such a large angle will kill tone and frequency response.

Again, I used 4" mids in the Alfa at 5khz-500hz, but I also had 6" woofers in the doors at 500ha-80hz. You might not have that luxury, and it made the passive crossovers quite complicated.

One more question though, how do you plan to deal with crossovers and amping?

Brad wrote:Muz, it takes balls to get a sub into the front of a cabin, and good luck to you. Provided you get the size right, and given you are using an 8", you should be able to find 10-15l, it should be good.

Measured up the 'usable' area the other day and threw it into bassbox - came up with an estimation of 13L internal volume. That works out a tad big for the ID8 (which looks happiest in around 9L) but with some modifications internally I'd be able to reduce the volume of the box without any major dramas.

I'd suggest though that the tweeter goes down next to the mid-range driver. The vertical distance between the two frequency ranges of the mid and tweeter has more effect on the sound quality than the overall lowering of the 'set' by placing the tweeter down low. I had my tweeters in the kicks of my old Alfa Sprint and the sound stage was well up and in front of the dash. Sounded like a set of hifi speakers on the bonnet without any time correction.

The key...minimal path legth difference for all speakers.

I've considered this, but the problem with tweeter down low have been the following:
* Lower sound stage
* Blocking of signal by panels, passenger legs, etc
* Increased probability of damage via being kicked etc

My general 'theory' is that IF I can keep actual path length distances close to the same (distance between pillar and door location is almost identical) and keep frequency response linear enough, the ears won't be able to percieve the vertical seperation between the two drivers and image shift will not be percievable.

I managed to come very close to completely achieving this with my previous system, but the decision to go two way limited me too much at the time - despite the quality of the components. I had to make the choice between midrange performance (in the kicks, 30 deg off axis) or midbass (in floor / door enclosures, heavilly off axis). In the end I decided midrange performance is more important and went with the kicks.

It sounded great, but in all honesty perfection would never have been achievable. You just can't (imo) get strong bottom end performance AND upper midrange performance from a two-way system - you always sacrifice one a little to optimise the other.

Also, if you are going to the trouble of a sub in the kick, why not integrat a mid driver into the kicks on-axis? Being in the doors, and the way the MX5 is setup, you'll be almost 60deg off axis. I'm not sure of the off-axis performance of the Peerless, but such a large angle will kill tone and frequency response.

Absolutely - this was one major consideration I looked into. For a while now I've been severely against door mounting of speakers (either midbass or midrange). The task or maximising midrange response and minimising reflections and resonances is too much of an effort and in general car doors are about the worst place you can possibly place a speaker.

Given the security weaknesses of the MX5 though, stealth is now a major consideration. I've been forced (for the first time in eyons) to let myself compromise on outright performance in order to achieve greater stealth.

I made the decision from the start that this would be my primary aim, and that has heavilly dictated how the system will be setup, and which components will be run.

As mentioned, no matter what I do the doors WILL be the weak point of the system. With the desire to keep the car physically unmodified, sound deadening is something I don't intend on using (perhaps Dynaxorb at the most) and that's gonna be a weakness.

Running in doors causes a number of major issues:
* Lack of structure regidity results in unwanted resonances
* Nature of metallic surfaces resuls in unwanted backwave reflections within the door cavity
* Physical limitations to driver diameter
* Uneven speaker angles in relation to driver leads to image shifting at upper midrange frequencies, as the off axis responses are picked up differently by your ears (your side will be 90deg off, other side about 60)
* High degree of off-axis angle means you get essentially no upper midrange performance, regardless of speaker choice

I took these factors into account when building the system.

The Peerless mids are practically ruler flat up to 1.5khz, after which they begin to be effected by beaming and begin to roll off according to off axis mounting. By crossing the drivers at 1.5khz on a 24dB slope, I will essentially 'bypass' the roll-off caused by off axis response.

This led to my next dillema...there is MAYBE one tweeter I can think of on the earth that can play to 1.5khz with relatively low distortion - but it's a Scanspeak driver so it's size and cost lead it to not be suitable for this application. So realistically, I had to aim for a tweeter that has a flat frequency repsonse down to 2khz - and a decent response at 30 deg off-axis. The only compact dome I could find that matched these criteria was the the Morel MT-23. How it will handle distortion and power handling at those frequencies is another mystery I've yet to determine...but I'm going to have to give it a shot and see how it goes. If worse comes to worse it's only a cheap tweeter by my usual standards ($210/pair) so if I happend to blow them from crossing too low I'll simply go out and seek a more suitable replacement.

The big quesiton mark will be the capability of the mids to handle midbass. Those mids start to roll off softly from 160hz (as with most 6.5\" mids) so I'm going to need to run a high crossover point on the sub. Being in the passenger footwell soemwhat reduced the impacts of this, as it brings the sub closer to the mids and reducing the need for time alignment to optimise bass staging.

Again, I used 4\" mids in the Alfa at 5khz-500hz, but I also had 6\" woofers in the doors at 500ha-80hz. You might not have that luxury, and it made the passive crossovers quite complicated.

One more question though, how do you plan to deal with crossovers and amping?

Thanks to the desire to keep weight low and wiring simple, I'll be going with a single amp to run all of those drivers. I've pretty much decided on a DLS Reference RA50 5-channel. This will send 70w to each mid and tweeter, and approx 140w into the sub @ 8ohm - should be plenty.

Entire system will be run completely active - I'm not a fan of passive crossover networks and the negative impacts they have on sound quality, and I also like having the power to tune at my fingertips. That limits my choice of source units though. After crossing off Alpine 9887 (annoying interface), Clarion 776 (flawed build quality) and Eclipse CD7100 (I like T/A measurements in cm, not ms) I'm left with a toss-up betwen a Pioneer DEH-P80RS, Clarion HX-D2 (my previous unit before it was stolen) and a Pioneer P90 combo.

The P80's a well featured head unit for the money and does 90% of what I desire. It's not perfect - the 16 band graphic EQ doesn't offer the adjustability I like, and it doesn't support a four-way active system. It also doesn't use quite the same compoment quality or build quality as the two audiophille grade units. That said it's well priced, (compared to the others) simpler to install then the other models, has a removable face, and has MP3 support (rarely use it, bit it's nice to have).

The HX-D2 is an absolute dream unit. It's got the best build quality and sound quality of any head unit I've used, as well as increadible tunability. A rediculously flexible Parametric EQ, finely adjustable crossovers, a
0.5dB stepped volume adjustment, time alignment adjustable in 0.7cm steps as welll as mute and reverse phase options on every channel. On top of all of this it has an intruitive and simplistic interface (once you are used to it), a simple yet functionally brilliant display, and a stunning shadow-chrome finish that just oozes class. Downsides? It needs an external DC/DC converter to run (which compliates installation), the remote control has terrible range, they only allow up to 18dB/oct slopes, and they at $2,099rrp they are NOT cheap. It does however have 8ch RCA outputs, and full support for a 4-way active system.

Finally the P90 combo...advantages? Most of what the HX-D2 does, only it has a 31band Graphic EQ (rather then 5 band parametric) and offers up to 36dB slopes on all channels. Downsides? It's not quite as finetunable. The parametric EQ on the Clarion give you more control over the band you want ot adjust, it has qa 1dB (rather then 0.5dB) volume adjustment and T/A isn't as precisely variable. It's also the most complex to install because it's pretty much useless on it's own. It requires the P90 digital processor to be of any real use, and that means you need to find room (and install) two units instead of just one. It's also almost 50% more expensive then even the Clarion, at around $2,800rrp for the pair. Build quality is great, but IMO the Clarion JUST edges it out in that aspect.

The P90 is the only one that really gives solutions to all of my problems, but it really is a tad expensive for a system with 'budget' as one o the objectives.

So...there are the plans in a nutshell!



P.s.
MASSIVE apologies for the crazy-long three post response - never get me started on audio or I bloody never shut up!