Very pleased with my ICE, but I have never been quite able to get consistently good imaging across the front sound stage.

I've often wondered about fitting a centre speaker to really nail the vocals to the front of the dash, and now I've got a centre pod full of gauges, it would be quite easy to stick a small speaker on the back of it, and bounce sound off the middle of the windscreen.

Is this a daft idea? Has anyone tried it or can give any guidance? What kind of speaker would be best? It's got to be quite small, obviously. A surface-mount jobbie would be perfect.

Thanks for any advice.

Richard.

BTW my system is an old Pioneer set up. Probably getting on for 10 years old now and in it's third car. Two big amps in the boot with CD changer, about 700w total I think - one four-way driving front and rear pairs of speakers, and the other pumping into two 10in boxed subs. All speakers are new Quartz summats - very good and very expensive! Fronts are big buggers fitted in custom pods in doors, with tweaters in footwell, carefully angled and I spent ages messing with cross-over frequencies etc to get the balance as good as possible.

 

Centre thing seems to work if you want a DSP.
If you don't how about a new head unit? I'd have thought that one of the newer ones should give a fair bit better soundstaging - I cetainly found this - and if that doesn't do the job, some of the Alpine ones have stuff on them that delays the sound going to different speakers - this is meant to improve the soundstaging as well, although I'd have thought that it's just as likely to screw it up with all the extra electronics... however, I've never actually heard one so I can't comment
Anyway, IMHO centre speaker wouldn't help!

 

Simple, just wire the front left tweeter out of phase.
If this doesn't help, wire the right out of phase and put the left back in phase. One or the other will help raise the front stage.

When first installing tweeters it's always a good idea to experiment with positioning to find the best position b4 fitting proper.
Good luck.

 

Or, if you're prepared to do some messing around with MDF, angle the front speakers (and tweeters, if they're not co-incident) to point at the centre of the sunroof (guestimate, if you haven't got one). The angle on the speakers improves the imaging HUGELY

R

 

Scooting off on a bit of a tangent here, I want to do pretty much the same thing (the playing with the MDF) but for a different reason - I'd prefer a sealed box to the door. Anyone got any ideas of great ways of doing this without destroying the door in the process

 

I'd agree with Audio G Man - try phasing first, then start playing with tweeter positioning.

I would not bounce anything off the windscreen as, in my experience, the sound is awful...

Centre speakers can work, but to be honest you're introducing more complexity into the system which is definitely a double edged sword. Try to get the most out of your components, and then (and only then) start to think about centre channel.

Re: processing - audiocontrol made an amp dedicated to driving a centre channel with the necessary DSP and processing built in. Citysounds on the tottenham court road still had one the last time I went in. if you really want do go down that route, it may be worth doing some web research and giving them a bell?

 

Thanks Chiark. As i'm sure you're aware, some speakers sound better off axis and some better on axis. After trying various locations i found that my tweets sound best sitting on top of the dash.

Hoppy. You should be able to get a good sound stage just using your Quart's. my personal opinion is that the factory tweeter locations are too close to the drivers ears. No offence to you but some of the problem may be the old equipment.

You could always install a set of USD compression horns and 8" midbass speakers with a crossover piont of lower than 1K. Fantastic sound with a price to match.

 

Oh God yes, definitely put some makes off-axis! The CD Technology stuff that I run needs to be off axis - (CD = controlled dispersion)...

 

Phasing is well worth playing around with (best to get someone else to make the changes while you listen).

I've never heard a centre speaker that really added much to the soundstage as you need processing to get it working properly.

Or you could add some sort of time alignment processing. I got great results with my alpine pxa unit. The difference with the delays on/off was awesome!

 

Again I would agree with above, no need for a central speaker unless you are intending to run dolby surround or some kind of serious wedge setup, for normal soundstage it would probably cause you too many problems to setup correctly.

 

Thanks for the replies, guys. So I am not mad

Hi Kryten - hope you're well Mart. Good to see you're still hanging around. Careful, or you'll be getting another Scooby soon

I have done all I can with speaker positioning and angles, which is why the tweaters ended up in the foot wells. It's usually pretty good, but with some tracks, and if I move my legs over a bit, the sound dives to the left! My missus has a good system in her 206 with A-pillar mounted tweaters. I tried everything to get some good imaging with them, and ended up shielding the tweaters with some stunningly attractive bits of cardboard from a cerial packet and sticky fixers. Much better, but amazingly she thinks they don't look very professional.

I'd not thought of the out-of-phase trick. I'll give it a go. Last time I did that was with a DIY surround-sound system at home. Called the Haffler Effect if memory serves, in the 70s.

If I do go for an upgraded head-unit, is there one with some kind of Pro-logic programme to drive a 5th centre channel? Sorry, I'm hoplessly out of touch with today's kit. Thinking about it, I guess this is more likely to be an amp function, as Nick (Chiark) suggests. I'll check it out.

Thanks again. Any other brainwaves welcome!

Richard.

PS I guess McLaren F1 drivers don't have this problem

 

A couple of Panasoinc's high end CD tuners have a small centre channel speaker attached to the unit itself, it fold out.
I have a mag. review somewhere around here so i'll have a look for it and scan it and post it or e-mail it. I seem to remember the review was very good and it wasn't in Max Power. It was in INCARS or Total Car Audio.
Not sure if they're still available though.

[Edited by audio g man - 3/26/2002 7:10:21 PM]