Octavia II Poor Sounding Stereo Fix

[Mr Kite]

Octavia II Poor sounding stereo the Facts and the Fix (without taking the doors apart).

The original ICE sound of my Octavia II was positively horrible. The system fitted to my car was the Audience head unit working to the standard 2 way door speakers.

Having been s loudspeaker designer/builder both professionally in the past, and more recently as a hobby, it was easy to identify the problem.

If you tune the radio to BBC4 or another speech program, listen to the spoken word. It sounds “quacky” as if the commentator is pinching their nose as they speak. This I would call upper midband colouration of the sound and is a common fault on poorly designed speakers, not an amplifier problem. Listen particularly to the tweeter unit in the door, as this is the source of the problem.

With music, most vocal and horn instrument sounds will almost take your head off if the volume is up!

From the head unit, the full sound frequency range is output to the speakers via a dividing network or crossover. In the case of the Octavia this crossover is only a single capacitor wired in series with and attached to the tweeter.

This arrangement is very simple and cheap and in this case very inadequate. It forces the tweeter to operate down into the midband of the sound and as the unit is very poor, overworking it in this way causes the “quacky” tonal distortion that we can hear.

At this point I must say the bass mid unit in the lower door is of reasonably good quality so it can stay saving the door stripdown. Our argument is only with the tweeter end.

To sum up, a rubbish tweeter and high frequency crossover arrangement.

Now there are some fixes on Briskoda and Im sure many are very good. However most involve taking the doors apart.

My fix replaces the tweeter and inserts a suitable crossover in the door through the hole revealed by removing the tweeter/ window/mirror switch cover.

So then this is the fault what’s the fix?

I bought 2 Infinity 6010cs discreet speaker kits from ebay to make my upgrade. I only used the tweeters and crossovers but they are still good value. Other options may of course be used.

It goes like this:

The idea is to cut down the crossover to just the tweeter section with its protection circuit which will be small enough to fit into the door cavity.

Fit the tweeter to the outside of the plastic cover using the mounts supplied in the kit and wire through to the crossover. See photos.

First mask off the door card to protect it.

Next connect up as required by hooking the tweeter wires out of the door cavity cutting and reconnecting the new crossover. They are black/red.

Wrap the new crossover for protection and stuff the whole lot into the door carefully. Try to cable tie it so it cannot drop right down.

It is of course a good idea to test it all before fully fitting it in and adjusting if required by fitting 1 or 2 ohm resistors in series to trim the output level. Also try reversing the phase (neg and pos) it makes a subtle difference. The end result is a very tuneful sound with a sparkling treble quality unlike the original which sounded more like a bad 1970s music centre!

Im sorry this is just an outline but a full detailed description would be endless!

If you have a degree of mechanical and electrical ability this wont be a problem and is by far the easier way to go to get a great sounding system.

Please look at my photos to get the general idea and contact me for a few more details if needed.

Regards Mr Kite.

Edited 2 August, 2008 by Mr Kite
More Information

[Taxi 219]

The sound in mine is perfect.

[sebulbus]

They'd have to pay me to do that to my car. Why didn't you try some more discrete tweeters? I've seen some that you can mount on the A pillars, like the Golf has them installed.

Same here, my Octi sounds great, apart from some mid tones I miss from time to time in vocal performances.

[Yeti_Man]

The tweeters are certainly 'noticeable' like that. Im more of a stealth install man myself but if you are happy thats all that matters

[scoobynut]

I'm tone deaf and very happy with the standard set up, but good on you Mr Kite! I love to get the tools out ;-)

[Neo_VR]

Looks good mr kite

[Gillywibble]

A nice big sub sorted mine.

[Hedge]

I have something similar except mine are hidden in place of the originals.

[Shifty]

A nice big sub sorted mine.

I found it sorted both my Fabia and the Octy when I had it too

[blackspaven]

Hedge, what make/model did you use to keep the tweeters hidden then? Quite like the mod (i'll see if it needs it once I actually pick up the car!), just don't like the sticky out tweeters. Conveniently enough, I have a spare pair of Infinity passive crossovers sitting in my cupboard from a setup I bouht off a mate (needed the mids and he only wanted the tweeters so gave me the boxes as well). Didn't have a use for them... until now possibly!

[Hedge]

Fronts are DLS 6.5C's. They were fitted by a local company which had used a hot glue gun to hold them in place.

After the passenger side detached itself last year I have since araldited them in.

[sms]

even being slightly deaf i must admit the tweeters do give a high pitch ringing noise, thus why bass is turned up and treble turned down, might even pull the wires of the rear tweeters if i get a moment.

[Penguin]

Mr Kite : have you tried the new crossovers on the original tweeters - my thinking if they have a higher frequency x- over they might actually sound ok. I did think of doing something similar i.e. just replacing the existing capacitor (probably about 5uF as a guess) with a smaller value...but as most things ...havn't got around to it.

I agree incidentally : the problem is harsh - too much upper mid/trebble + resonance.

I notice another issue with the stream MP3 unit - FM sounds rather dull - like the de-emphasis is over done (lack of extreme top end ) I would like to look at a circuit diagram & make some mods - but getting a diagram from Visteon (makers) seems nigh on impossible!

[blackspaven]

Is this thread primarily about the Stream unit then? Just aware that different headunits can sound different so my Audience may well sound okay if it's the Stream that's getting a panning here? Also, how are the tweeters held behind the grills: screws or clips?

[JJJ66]

Is this thread primarily about the Stream unit then? Just aware that different headunits can sound different so my Audience may well sound okay if it's the Stream that's getting a panning here?

From the original post:

"The original ICE sound of my Octavia II was positively horrible. The system fitted to my car was the Audience head unit working to the standard 2 way door speakers."

[Mr Kite]

I know some folks have no issues with their Octy sound.

I can only guess that some may have parts from a different supplier, if so you are lucky!

Both my car and a mates were horrid so hence the mod.

My head unit is the Audience and I tested it to a known good Hi Fi speaker to prove the problem to the door speakers.

Mr K

Edited 3 August, 2008 by Mr Kite

[Mr Kite]

Ok folks the sticking out tweeters are not for everyone.

But if you want to mount them, prise out the grills with an old credit card.

Drill one hole in the centre of the circluar see thru bit of the grill and one near its edge for the wires.

Fit the tweeter mounting supplied by infinity (the silver bit) with an M4 bolt nut and washer. A touch of glue can help. The tweeter fits with a push/turn motion.

I did try using the original tweeter but its not up to the job at all.

Replacing the original behind the grill would need a door strip to do it right.

Also the sound would have to pass through two mesh grills so I wasnt keen.

Mr K

Edited 3 August, 2008 by Mr Kite

[Penguin]

Ok folks the sticking out tweeters are not for everyone.

But if you want to mount them, prise out the grills with an old credit card.

Drill one hole in the centre of the circluar see thru bit of the grill and one near its edge for the wires.

Fit the tweeter mounting supplied by infinity (the silver bit) with an M4 bolt nut and washer. A touch of glue can help. The tweeter fits with a push/turn motion.

I did try using the original tweeter but its not up to the job at all.

Replacing the original behind the grill would need a door strip to do it right.

Also the sound would have to pass through two mesh grills so I wasnt keen.

Mr K

Thanks Mr kite. As an aside has anyone tried comparing the front speakers to the rear ones by turning the fade to first front only & then rear only.

I'm sure mine sound quite different - the fronts being over-bright/harsh & the rears relatively dull. ( yes I did actually move to the back of the car to check as trebble can be quite directional & dampened quickly by soft furnishings etc.)

When first noticed this I thought my ears were decieving me as the front & rear tweeters are the same (look the same ) - only the bass/mid units being slightly smaller in rear doors - which I expected to produce the opposite result i.e. rears sounding more trebble/brighter!

Has or can anyone else confirm this? The rear tweets are definitely working & the HU is the stream MP3 (2007 MY Elegance HB)

I put this down to the Stream rear channels being duller (possibly deliberately to maintain the Audience's premium as manufacturing costs of both units will be virtually the same) but find it a little hard to believe though I haven't checked with a separate "reference" speaker hooked in.

Edited 4 August, 2008 by Penguin

[Mr Kite]

Penguin Hi,

Interesting question. The reason that the rear speakers sound dull is most likely due to the 5.5 inch drivers being a bit more efficient relative to the tweeter (xxdb/watt/metre) than the 7 inch ones in the front.

The same effect as fitting a trimming resistor to the front tweeters.

The only way to bring the rears up a touch would be to connect a high value shunting resistor across the 5 inch bass/mid unit. To find the correct value, shunt with a 100 ohm variable pot and adjust it to get the desired sound. Disconnect and measure the resistance then fit a fixed resistor of that value. fanny is then your auntie!

Mr K

[Nick P]

I run Diamond D6 tweaters (in the original tweater positions, under the grilles) in the front and Diamond D6 woofers. In the rear doors I have Alpine co-axials and factory tweaters disconnected. Dynamat in all doors and 10" Kenwood sub in the boot, does the job.

I've got to say, apart from the rear tweaters, I didn't think the orignal Stream stereo set-up sounded that bad for a standard factory set up.

[Mr Kite]

wega3k,

Were the diamond tweeters a good fit in the doors? The infinity ones are larger and hence the external fixing.

Some say their standard kit is ok perhaps it is different. I couldnt get on with the sound of mine at all.

Mr K

[Nick P]

wega3k,

Were the diamond tweeters a good fit in the doors? The infinity ones are larger and hence the external fixing.

Some say their standard kit is ok perhaps it is different. I couldnt get on with the sound of mine at all.

Mr K

Yes, they fitted perfectly behind the grilles. Sound lovely.

[RDX]

Hi Folks,

Just to revive this post, can you tell me if it's possible to replace the tweeters without removing the door cards?

I like the idea but want to put the new tweeters in the original position, behind the grills.

Also, can someone recommend some tweeters which fit without to much hassle?

Thanks for any info.

Cheers,

RDX

[Mr Kite]

RDX Hi,

No is the short answer. You have to remove he door cards to remove/replace the original tweeters. Because Im lazy my fix places new tweeters on the removable covers and the crossover behind them. If you do remove the panels Im sure the kit I used would work well. The infinity tweeter is about the same size as the original so may well be an option.

Also as a foot note to my mod I also fitted an additional 3.3 microfarad cap in series with the tweeters to smooth out a touch of tizz in the treble.

Mr Kite

[RDX]

Hi Mr Kite,

Thanks for the reply, however looking at this thread:

http://briskoda.net/octavia-ii/add-illumination-internal-door-handle-l-k-vrs/93651/?highlight=handles

it looks as if it is possible to remove the door handle, complete with tweeter, without removing the door card. Am I seeing that right?

Thanks again,

RDX