Door speaker builds

[Bazil]

So i've given up with the idea of putting speakers in the tiny holes in the dash. As i actually want some decent sound quality up front.
I wondered if any one on here had done a decent door build I could have a picture of? I'm probably going to run a set of components with crossovers.
Thanks, Baz

[Guest]

Re: Door speaker builds

Didn't TonyK do something nifty based on the front door pockets. I think he was offering them for sale at one time.

[Bazil]

Re: Door speaker builds

I'm unaware of this fella. Nifty sounds good though

[Guest]

Re: Door speaker builds

I see Tony still visits this site though he no longer has a Vauxhall even, so it may be worth dropping him a message!
Or seeing if Danny is still in contact with him.

[Bazil]

Re: Door speaker builds

Do you know their usernames because I dont know them outside of this forum. Thanks for the help.

[Guest]

Re: Door speaker builds

Well Danny is the one who wrote the Astra mk2 Total Vauxhall article about 4yr ago and was a full member until a few months ago.
Tony is still in the user list as Tony K!
They both live in the Peterborough area.

[Vinci]

Re: Door speaker builds

I am an audio engineer actually and have created superb sound in my MK2 by using speakers that are attached to the bottom of the dash. Even in the doors it'll never really sound great, they leak all over the place and are barely steady enough to form a good baffle. And apart from that I just hate cutting in the door panels.

Don't really have very good pics of the speaker set, could make some new ones soon, but here you can see the grille on the left:


The basic design is a 90 degree bend of 125mm PVC pipe, then another 90 degree bend to go sideways, then a straight piece with an end cap. They are basically tied up under the dash with very large tie-wraps, so only the 90 degree bend comes from under the dash. A tweeter is placed on the side on an L-piece of aluminium.

Here are some other speakers I made with a fairly similar construction:


When built right these can sound really great, especially with a sub added. And they don't really cost much either.

The speaker drivers I used are Monacor SP60/4 and Monacor DT-284

[Belmont turbo]

Re: Door speaker builds

this is the thread tony k did all the pictures are gone now tho
http://www.astra-mk2.com/forum/showt...t=speaker+pods

[Vinci]

Re: Door speaker builds

Here's another pic I have found:


It may not look like much, and the trim panel that should cover the ECU is not fitted there because I was working on it... But they sound nothing short of amazing! There is no underestimating a good speaker enclosure! Car speakers are usually designed to work in the poorest of places, but that basically means their performance is downscaled by quite some margin. Basically that makes most car speakers totally unsuitable for a good enclosure, they would sound just really bad. If you take a good 4 ohm hifi speaker in a good enclosure it sounds a million times better....

[Bazil]

Re: Door speaker builds

Thanks Belmont turbo, For finding that thread. Also I was trying to remember whos car it was that I saw at billing last year with the 6x9s in the door. It was yours.

[Vinci]

Re: Door speaker builds

Beware with 6x9"s, 99 out of a 100 are not that great quality. Most specific car speakers are actually. They are designed in the first place to look good and in the second place to be cheap. Then specs are almost always twisted to look good.

Example:

Look at the sensitivity of a car speaker. Most specify for example 93db/2.83v/m Which means they give 93 decibels of fun at one metre at a certain amount of power.

2.83v looks familiar to many, because that gives exactly one watt of power into an 8 ohm load. With a car speaker the load is 4 ohms though, which means they give 93db at 2 watt. Which in fact makes them only 90db/w/m. The latter being the REAL sensitivity because it SHOULD be specified at one watt/one metre away.

Then the resonance frequency is usually quite high, which makes them tremendously efficient and play well in an 'enclosure as leak as a basket. Though they won't produce any real bass.

Then the specs. If you do a simulation with the average car speaker with something like AJdesigner (if you can get hold of any Thiele&Small parameters, which is usually only reserved for 'real' speakers) the result is usually a several hundred litre enclosure for a 6x9" Which means it is a really really bad speaker basically....

And people always wonder why it always sounds so bad in a car.....

[BenH]

Re: Door speaker builds

Yeah there are some good freeware speaker design programs as well, was fun with a 6th order bandpass box I built for friend for his sub. Very loud (too much for me) and a pleasent soft sound, not to harsh. I also boxed out his doors inside to make a sealed box,it involved cutting out the bottom of the door out and all sorts. I dont think I have any pics anymore, was a bit pre common digital camera. But was worth it in the end.

[BlackBox]

Re: Door speaker builds

For door pods many years ago I built a 2 speaker pod for each door in fiberglass.

It consisted of two MDF rings that the speakers mounted to spaced and angled as I wanted them with bits of MDF to hold them in their relative positions.
An old sweatshirt was stretched over which gave nice curves. This was then soaked in fiberglass resin and left to set. When cured I glued on some matching cloth. The result was great and factory looking.

Had them for many years but sadly threw them out just before I got my old GTE back ... always the way !!

Sadly no pictures but hopefully you get the idea.

[Bazil]

Re: Door speaker builds

Thanks everyone for all the advice.

Vinci, you clearly know what you're on about, being an audio engineer. I understand quite a lot of the things you are talking about as well. I'm fairly sure of what i want to do though, so i'm going to go with the idea in my head.

Blackbox and BenH can you have a scan over this link, and tell me if it is like something the pair of you did on your various projects.
>>> http://uk-mkivs.net/forums/t/303714.aspx?PageIndex=1
The bit that interests me most in it is the use of the expanding foam around the speaker. Surely all speakers have a required volume of enclosure to work at their best and the expanding foam is just reducing this?

Replys and advice welcome as always

[BenH]

Re: Door speaker builds

Looks ok to me, you could have the perfect size box but if it rattles then you will hear that and not the music.