Fresh air vent speakers

Good luck but I doubt they'll fit. The 3" is the size of the moving cone (I'm pretty sure) so the speaker itself will be quite a bit bigger. I'll try and remember to measure my 3" speakers for you so you have an idea.

 

According to the data sheet the mounting diameter is 73mm which is 3mm too big. The outer diameter is 88mm which I 'think' will be on the flat portion of the dash.
But, fingers crossed.
I'll stick some pics up when I get the speakers and when I get my dash back. Obviously it would have been much more sensible to have decided to fit speakers BEFORE I sent the dash away for powdercoating.

 

I've used the Visaton FRS 8 (8 ohm version) in some small speakers I built. They sound good for what they are and are inexpensive. Size is about right. Grilles are available separately. Quite a few suppliers out there, you should get a pair for less than £20.

http://www.visaton.com/en/industrie/breitband/frs8_4.html

Actually I'm quite tempted to put a pair in my bus. Would I miss the vents though?

 

For blocking low frequency it's a capacitor, not a resistor you need.

 

Pardon

 

Absolutely correct - the resistor is for capping the higher end of the frequencies going into the speaker. A crossover being built from caps and resistors.
never the less the tweeter would still require a crossover.

 

The fitting dia is only 1mm too large so almost perfect, I've asked the seller about grills.

 

Hmm.

The frequency dividing part of a crossover is made out of capacitors and inductors (coils). In a simple (first order) crossover, capacitors filter out low frequencies, and inductors filter out high frequencies. Resistors are sometimes used for reducing the overall output level of one speaker, for example where a tweeter is more efficient than a woofer, but in themselves they shouldn't have any impact on frequency response.

 

Way above my head gentleman, I just spoke to a guy at car sound four masters about the speakers. He said the speakers would be ok but would be better with tweeters as well. He suggested a set with the crossover stuff already in them. All I'd need to do is wire them up to the same front speaker wires as the pair I'm buying.
So I've ordered the Audison Voce mid range speakers and I'll buy some tweeters later on to add to them.
Thanks for all the advice and help you've all given.

 

Apologies for geeking off. And here I go again...

I'm not convinced about the need for tweeters, but then I haven't heard the Audisons. Good full range drivers at this sort of size should have pretty decent treble response, particularly if they're pointing right at you. In terms of top end small speakers are usually better. There are some sound quality advantages to not using tweeters. The Visatons have plenty of top end to my ears.

It looks like the Audisons are designed purely as a midrange driver - so I'd expect the Visaton to sound better in the treble end. In order to get the quoted power handling (100 watts) you'd need to use a crossover on the mids as well as the tweeter, if not you might find that running a full frequency signal through them (i.e. straight from the head unit) results in limited volume before nasty distortion. Without the crossover, if your head unit has separate tone controls for front and rear speakers you could get more volume out of them by turning down the bass at the front.

If anything, with either speaker I'd expect a bit of a "hole" in the mid-bass. The specs indicate that the Visatons are better here again, but then specs aren't everything. The 6x9s in the back should fill in the bottom end OK though (bass tends to travel better than other frequencies) but I reckon you'll be missing out in the cello/bass guitar sort of frequency area. Depends what sort of music you listen to.

 

Ohh! Look, a pretty butterfly.

 

Actually I've bought the Audison ones and I'll wait and see how they sound before I decide about getting tweeters.

 

So do you think using a crossover would vastly improve the performance of a speaker above just using the head unit?

 

Yep without a doubt.

If you try and push mid bass and lower frequencies through a speaker not designed for them (ie a mid range) then they will distort quickly and in extreme cases wreck the speaker itself.
A high pass filter and the speakers natural roll off will be sufficient.

 

Yes and no...

...the problem is the Audison is a purely midrange driver, it's not designed to have bass signals put through it. You really want a speaker with a full (or at least wide) range.

It'll work much better as a midrange driver with a crossover, but then you'll get no bass from it, and you'll need another speaker for the bass end.

Without a crossover it'll sound all buzzy if you put too much bass through it. And eventually blow.

 

I can't remember if my head unit allows me to alter bass and treble differently for front and rear speakers. If it does I could turn down the bass for for the front and turn it up for the rear, and the treble down at the rear and up for the front.
In any event we don't usually have the volume blasting out so hopefully we don't blow up the speakers.

 

I don't think any head unit allows biased adjustment of bass and treble front to rear - the adjustment will be over all speakers..

As and when you receive the speakers, give either myself or Tommygoldy a shout with the specs and we'll advise of the best value capacitor for the mids so you don't blow them and still retain the bass via your rear speakers.

 

Mine will send bass only to the rears...

 

Is this via a sub out or hi pass filter in the head unit?

 

The one in my Golf does! It's not particularly high-end either, so you never know.

A 160uF capacitor gives the recommended 250hz roll-off .

This will work: http://www.falconacoustics.co.uk/al...capacitor-nonpolarised-reversible-series.html

This is a better quality component: http://www.ebay.co.uk/itm/Solen-160uF-250V-Polypropylene-Capacitor-027-626-/321558128961