6.5 inch speakers in footwells..

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Mason

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Hi guys

A few people mentionend before they had considered this but though it was too tricky.

What you need is:

Jigsaw
Powerdrill
18mm MDF
Some fibreglass bridging compound or filler
Duct Tape/masking tape..

First of all make some baffles from 18mm MDF to attach your speakers to.

Remove the kickwell trim and attach the baffle to the lowest corner of the trim. You'll notice the baffle will be larger than the flat part of the trim, don't panic we'll get to that bit later.

Then depending on the speakers you've decided to use you'll have to cut a hole ouf of the back of the trim to let the magnet poke through and to let the speakers vent into the dash. Otherwise the speakers will be choked because of lack of airspace..

Next get your duct tape and use it to make an internal mould the hole where the baffle doesn't mount flat to the trim.

Then fill this with the filler of fibreglass compound and smooth and trim as appropriate.

I'll try and get some pics of mine when they are finished, but to get some operational 6.5's in kicks shouldn't take much more than an hour and a half or so..

If this reads badly LMk and I'll try and make it clearer...

Cheers

Dave

PS, if you are using 2 way speakers you may want to aim them a bit as well. This shouldn't be too tricky, you'll just need to use more tape and filler to secure the angle..
 
Thanks for that, Dave!

LMk? Not familiar with that abbreviation, I'm afraid...
(edit) just had a brainwave: let me know!(/edit)
But it does read a bit difficult, especially the crucial bit where you say (in just one line):
quote:
Next get your duct tape and use it to make an internal mould the hole where the baffle doesn't mount flat to the trim.
Click to expand...
I need a picture for that. Internal?

But, since this is the first time I actively thought about how to perform this, it seems to me that you are suggesting that you simply
- remove the original trim (sort of L-shaped),
- make a round hole for the magnet/basket, and then
- mount the speaker on a slightly oversized (for the speaker) piece of MDF,
- mount the MDF on the trim (without speaker)
- span the gaps around the edges of the mdf with tape, to make a smooth line to the trim
- fiberglass over the mdf and tape, thereby encapsulating the original trim
- finish the fiberglass anyway you like
- mount the speaker & grill
- replace the 'trim'.

Correct me on any of these steps, please.

And how about the 'enclosure' that you create for the speaker in this way? This is leaking in all directions! And it also doesn't seem too sturdy for me. Won't the mounts of the original trim vibrate to pieces, rattling as they go?

Edo


--
(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)
 
Edo,

You've described it much better than I did, thanks :)

To answer your questions.

The enclosure for the speaker becomes the area under the dash and under the trim. As the hole cut into the L shaped trim panel allows the air to vent to these locations.

So effectively I am running the speakers in "free air" or "infinite baffle". Thats normally how 6.5 inch speakers are designed. The most important thing is to keep the rear wave created by the speakers backward movement from coming in contact with the front wave. So there are no problems with mounting them in this way..

In terms of rattling the trim to pieces I seriously doubt I'll have any problems. The L shaped panel was very flimsly before the MDF was srewed to it. But once it's attached the build is very strong. The fibreglass bridging compound strengthens it further and I intend to fibreglass inside the L shaped panel as well inthe near future to make it even stronger.

However to put the strength issue into context, I currently have 250-300wrms per side available from my amps. I've not run it anywhere near this level, but I've run it pretty hard and the enclosure does not move and the trim is fine as well..
PS, if anyone thinks I'm lying about the amp figures I'm running 2 Sinfoni 45.2x amps, one bridged for the left side, and another bridged for the right..

Wait till you guys see the other speakers :)

I have the huge tweets and mids installed too...
 
All clear then. Thanks for the confirmation. I think this will definately be my next step in changing my current setup. I'll buy some additional Vifa drivers when I (ever) come round to building a proper center speaker for my own Home Theater. That one uses the same driver as my main speakers, Vifa P17 WJ-0008.

Last question, of which I'm hoping you have an answer. It's about the free-air principle and the enclosure:
What would happen if you'd put a free-air type driver in a relatively well sealed enclosure? Would it start to emphasize on the lows/mids?
Because I currently have that. And I feel like the A2's doors are the first doors I ever encountered that are quite well sealed in all directions. Before, my current drivers were in 'flimsy' Honda doors, which might explain the difference in frequency response...
If so, I'll start by 'venting' the door a bit more!

Cheers,

Edo

--
(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)
 
Vifa make very good drivers, nice choice :)

In terms of enclosure size you best bet is to download Winisd Pro from www.linearteam.org
Then put the TS parameters into in and you can work out how the speakers will respond in different sized enclosures.

The Vifa's will almost certainly not be designed for free air, the Morels I use aren't either really. The morels are designed for a 2.5cuft enclosure. That would yield the most SQ and let the cone move nice and freely.. I am running them free air with a crossover point at around 45-50hz, so the don't flap around when the bass hits..

I could have tried to build a 2.5 cuft enclosure of course, but it wouldn't be quite as easy to aim, so free air was the closest I could get.

I'd expect the vifas to be similar.

If you put a mid in a sealed enclosure it all depends on the size. If it were 30 litres or above I'd expect no real loss of SQ, and a nicely re-inforced midbass kick at around 80hz.

The smaller the pod gets the more the cone is controlled by the enclosure, so the sound gets less natural. But again the midbass kick will increase and the freqency of the kick will become higher.

So if you put a 6.5inch morel in a 2 litre pod the cone would find it harder to move, meaning you get considerably less low bass, a large peak in midbass (probably around 150-200hz) and the midrange freqencies would also suffer. Power handling would increase greatly as well.

So it's about finding a balance, Winisd will give you a good idea about whats ideal, then you have to work out what you can actually achieve.

If you'll be running a sub then small pods may be a good option if you don't mind a slight SQ loss. If you're not then I'd say a larger pod would be better, or vent them into the dash. Otherwise you'll lose so much low frequency information.

If you've got them in the doors then that should be fine. They are nicely sealed and must be at least 50 litres internal volume, most mids will be happy with that..

Hope this helps a bit..

Cheers

Dave
 
Yep, that helps. Partially in the wrong direction. Let me explain.
I currently have a three-way/coaxial Infinity speaker in my front door. It's a dedicated car-speaker (unlike the Vifa I mentioned) and I'm not sure if it is free-air or not.

If it is, then you suggest that the large sealed volume of a door would make it sound 'off', but only a little. Only (way) too small volume should have the effect that I experience: clarity suffers in the midrange and the midbass peaks (in my humbly opinianated ears, that is ;) ).
So either
- my current Infinity drivers are free-air and the door is effectively a smaller volume than I expect
- or the drivers are indeed meant for a certain volume, but that isn't present either
- or the door is still leaky as hell, causing the same.

I don't know. I'll research my speakers and the envisaged Vifa's and experiment with WinISD, before I do anything irreversible to my doors...

Thanks for thinking along!
-

--
(2003 Silver 1.4 Tdi Exclusive(SE), 95bhp/235Nm chiptuned by ABT, black interior, sport seats, heated mirrors, JVC KD-SH909RB cd-receiver, Infinity Kappa 63.1 + Vifa on-dash tweeters, 12" Subwoofer on 300w Amp)
 
The infinity should be fine in the doors though, most speakers would work very well in such a large sealed door pod..

You also have to consider that the infinity might not be a great speaker as well.. 3 way coax's are rarely any good when compared to a quality home speaker.

Plus you could start looking into on and off axis responce curves and working out exactly how to get the best from any speakers you choose. You could build dash pods and so on...

It all depends on how much you like your music ;)
 
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