I think I will accept the challenge the sound I have now isn't very good and I would like to try to change it as cheap as possible. I was going to put Focal K2P in the front doors but I would like to know how good you can get the oem sound.

I'am going to deaden the doors in the one of the next weeks so this should be the ideal moment for a test.

Things said already could apply. What if I try a Butterworth 2 order filter ? The values are known already 8 µF cap and 0.26 mH inductance.

See drawing , we can use the same values for both tweeter as woofer.

What do you guys think, worth a try or am I wrong ?

Offcourse I'm assuming that the woofer is also 4 ohm impedance, and a cut off freq of 3500 Hz.

Hi guys - sorry for the delay in replying, havn't been on here for a couple of days.

OK: I didn't bother working out impedances, checking resonance F 2nd order filters or anything else. I just reckoned from the sound coming from the tweeter that it was cutting off(rolling over) at too low frequency for the unit. On tests away from the car with other speaker(hi fi units driven from separates) I quickly came to the same conclusion, checked (actually measured) the series HF pass capacitor value (circa 7-8uF - large for a tweeter / simple Hi pass) and decided to try a few smaller values to raise the cutoff (hopefully reducing the harsh upper mid racket).

First value 2uF -- too small - only extreme Hi frequencies. Second 3.3uF sounded good. Third 4.7uf sounded harsh --again too big. That simple --- try it , other values may suit other people but I reckon this is about right.

The unit does not have intrinsicly poor damping/ resonance as tweeters go - i have come across much worse bookshelf speakers. It is a cloth/doped unit so dosn't suprise me.....but like most tweets it ain'y no good at producing midrange (except the squawky harsh variety)

It may be possible to improve the X-over I have no doubt but try this first as I'm not convinced it's worth the bother.

I removed the original cap so this is just a replacement (electrically)

As a further comment a midrange unit separate to the tweeter would improve things if you want to hack doors around etc. X-over gets more complex & at the end of the day this is a car stereo in a not exactly Rolls Royce car(noise levels wise). If one does this I suggest buy a matched 3 way expensive component setup ....but this now suits me fine, wheas before it pi**ed me off.

I havn't done the rears yet as don't sit in front of them. Incidentally they strangely sound duller despite having the same tweets" but smaller basmid units. (Me thinks HU has some eq. on front channels)

Edited 1 October, 200817 yr by Penguin

Hi Penguin,

What I don't understand is If you replaced the original by 3,3 µF than you are allowing only frequencys over 12000 Hz to go to the tweeter.

All between 3500 and 12000 is going to the woofer. Did you get any harsh sounds from the woofer when testing?

Hi Penguin,

What I don't understand is If you replaced the original by 3,3 µF than you are allowing only frequencys over 12000 Hz to go to the tweeter.

All between 3500 and 12000 is going to the woofer. Did you get any harsh sounds from the woofer when testing?

Hi Bogey: No the sound from the woofer does not change in the slightest.

You have to rember the slope of this type of filter is very shallow - It probably is at full tilt at 12khz but still only 3-4 db down at 6Khz and 6-10 db down at 3khz so it not a brick wall job....but neither will the F. response of the tweeter be so add them together and its steeper than it would appear. Until one knows the slope of the tweeter (db/octave) etc. then the maths dosn't really work. If you increase the order of the filter then problems can arise with resonaces in the x-over/tweeter unless its very well designed. I just try it invariably & let my ears judge!

Hi Bogey: No the sound from the woofer does not change in the slightest.

You have to rember the slope of this type of filter is very shallow - It probably is at full tilt at 12khz but still only 3-4 db down at 6Khz and 6-10 db down at 3khz so it not a brick wall job....but neither will the F. response of the tweeter be so add them together and its steeper than it would appear. Until one knows the slope of the tweeter (db/octave) etc. then the maths dosn't really work. If you increase the order of the filter then problems can arise with resonaces in the x-over/tweeter unless its very well designed. I just try it invariably & let my ears judge!

You have a point there, so the tweeter isn't so good after all.

What about the remark from RDX, he left the tweeter disconnected and there was a harsh sound in the woofer.

Would an impedance for the woofer help ?

Don't forget as there's no x-over on the woofer it's probably 'filling in' some of the high freqs. Just not very well IMO!

RDX

Would an impedance for the woofer help ?

Do you mean 'crossover'? :confused:

RDX

Do you mean 'crossover'? :confused:

RDX

No, an impedance cuts off high frequencies so this will resolve the harshness problem in the woofer.

You could see it as a crossover but it is only a first order filter.

Don't forget as there's no x-over on the woofer it's probably 'filling in' some of the high freqs. Just not very well IMO!

RDX

You can hear some HF from the bassmid but fo most purposes I reckon its essentially out by about 6KHz (listening guesstimate)....it dosn't "CUT off" but its response fades (as most speakers) & the tweeter "fades in" - hopefully overlapping a bit. I found the bassmid unit OK actually - not great but nothing really wrong and a low pass on it will probably leave a hole in the mid range. Most HF it produces is absorbed by the seat / my rear:D and is not noticeable in the prescence of the tweeter at ear level.

I think the tweeters are OK actually (compared them with some Audax dome Hi Fi units and TBH was a little surprised - little more "brittle sounding but not miles apart - prob bit more resonance)

You can hear some HF from the bassmid but fo most purposes I reckon its essentially out by about 6KHz (listening guesstimate)....it dosn't "CUT off" but its response fades (as most speakers) & the tweeter "fades in" - hopefully overlapping a bit. I found the bassmid unit OK actually - not great but nothing really wrong and a low pass on it will probably leave a hole in the mid range. Most HF it produces is absorbed by the seat / my rear:D and is not noticeable in the prescence of the tweeter at ear level.

I think the tweeters are OK actually (compared them with some Audax dome Hi Fi units and TBH was a little surprised - little more "brittle sounding but not miles apart - prob bit more resonance)

You have a point there ... again you are scoring tonight

On Friday I'am going to place a power lead from the battery to the trunk and place a little sub I just bought.

The wiring for the sub to the HU will be placed as well.

The pioneer TS-WX77A, a flat subwoofer , and I will also place an amp for the front speakers. I will try to place the cabling for the fronts as well.

If I will amplify these, the harshness may increase so I will try to use a 3,3 µF cap on the tweet and a 0,05 mH impedance on the woofer. The "cut off" freq is 12000 as said but it is not realy a cut off so I will hear if this is ok.

Are you sure the woofer doesn't have a crossover? The units look really similar to my old Leon speakers and they had a coil underneath the four terminals at the top.

Penguin what have you made of the imaging since you've done the change?

Are you sure the woofer doesn't have a crossover? The units look really similar to my old Leon speakers and they had a coil underneath the four terminals at the top.

Penguin what have you made of the imaging since you've done the change?

Hi A16: no I havn't checked by removing the bass unit & physically checking the wiring but others on here reckon there is no x-over. It certainly sounds like there is no low-pass as quite high frequencies are audible when listening to the bass unit alone - just at reduced level.... consistent with fading response of unit the higher the frequency~

Imaging :Not much different really as most midrange imaging is below the decent response of the tweeters anyway. The HF still pinpoints from the tweeters the same. As I noted before : ideally the system wants a pair of mid units probably placed just below the tweets to produce good imagery. There are cutouts in the panel apparently for the "12 way system that is/was available as an option but I'm not trying this. I just wanted to improve the irritating harsh sound of the tweeters & this simple mod achieves that ..for me...

Will probably do the rears soon - but havn't worked out yet - why the rears sound duller (check it out - sit in the back & then the front) when the same tweets are fitted & smallerBass/mid. I will connect an external speaker to first front & then back & compare sound . .....its almost like the HU amps are brighter on the front channels - weird:confused:

Edit: somebody please tell me I'm not hearing things on that one!

Do you mean 'crossover'? :confused:

RDX

As I was reading trough the posts today I saw what you meant and you where right. I made a translation error :eek: . It should read Inductance instead of impedance. I presume that inductance is ok in English for a coil.

sorry for the mix up.

No problem Bogey555, I knew what you meant!

A coil is usually called an inductor but inductance is OK.

BTW, your English is excellent! It's better than some English people I know. :eek:

Good luck tweaking the speakers. I've decided to replace mine with something better.

Cheers,

RDX

No problem Bogey555, I knew what you meant!

A coil is usually called an inductor but inductance is OK.

BTW, your English is excellent! It's better than some English people I know. :eek:

Good luck tweaking the speakers. I've decided to replace mine with something better.

Cheers,

RDX

Thanks for the compliment on my English, but technical terms tend to be more difficult.

Starting tomorrow I will start a small ICE instal. I will be placing cables from the front to the back and place an amplified sub and an amplifier in the trunk.

The amplifier is only because I will upgrade my front speakers as well but I would like to know how good you can tweak the OEM ones.

I was looking at Focal but Hertz seems very good to me as well and at a much better price.

The sub is a flat model (TS-WX77A)that I'am very curious about the results. Won't be as good as the bigger enclosures but doesn't take up much space either.

mr200sx has a very good article in the ICE section about installation of front speakers. I'm intrested in trying his solution for the mids in the side cup holders.

Anyway I will try to take a lot of pictures about the cable placements and will post an article in the ICE section about my "journey" :P

cheers bogey555

Hi all,

penguin and bogey555, your recipe seems interesting. AFAIK Dynaudio employes 1st order filters, so it must not be too bad I'll look for some 0,05mH coil

RDX, what speakers did you decide to go with?

Ciao,

Hi all,

penguin and bogey555, your recipe seems interesting. AFAIK Dynaudio employes 1st order filters, so it must not be too bad quote]

You are correct, in some cases 1st order filters are better because they are more lineair. They don't cut off so steep as a 2 nd order filter.

If you work with a 2way system you don't want a steep cut off because you will loose to much middle as Penguin already said in one of his previous posts.

Hi all,

penguin and bogey555, your recipe seems interesting. AFAIK Dynaudio employes 1st order filters, so it must not be too bad I'll look for some 0,05mH coil

RDX, what speakers did you decide to go with?

Ciao,

Ok, I could agree with this, but only if the tweeter can withstand the lower frequencies without overloading .

But this is not our case apparently :(.

I just have taken a closer look at the tweeter - there some type of accustical lense in front of membrane. It is too close to it .

Ok, I could agree with this, but only if the tweeter can withstand the lower frequencies without overloading .

But this is not our case apparently :(.

I just have taken a closer look at the tweeter - there some type of accustical lense in front of membrane. It is too close to it .

Yes but this all depends on were you decide to cut off. If the tweeter can't go very low, the cut off freq needs to be higher.

In the example of Penguin were he placed a 3,3 µF cap, the tweeter sounded very good according to him. He has a cut off freq of 12000 Hz

If we calculate the coil for this frequency, it is 0.05 mH. I'm hoping that the advantage of a 1st order filter will play in our favor here. The tweeter will go below 12000 and the woofer will move up to 12000. Lets see if there isn't to much loss in the middle.

I'm afraid, that position of the woofer is not suitable for such high frequencies.

In fact, it's position is not very adequate even for frequencies higher than 1-2 kHz.

I'm afraid, that position of the woofer is not suitable for such high frequencies.

In fact, it's position is not very adequate even for frequencies higher than 1-2 kHz.

That's possible and maybe even certain, but I just want to hear the result and if its not good enough I will try to change the coil and place a midrange in the door cupholders like mr200sx did.

It seems easy enough to do and I presume you will get a much better result. Anyway its only for fun and to see if I can improve the audio life of people who don't want to replace there speakers.

I'am thinking of placing the Hertz HSK 163 -3 way set in the front. I heard it play and it sounds beautifull. For me it sounds better than the Focal K2P and it costs 330€ in Belgium (Maybe even less in the Netherlands).

Ok, I could agree with this, but only if the tweeter can withstand the lower frequencies without overloading .

But this is not our case apparently :(.

I just have taken a closer look at the tweeter - there some type of accustical lense in front of membrane. It is too close to it .

First, if you use a lower cap, you let the tweeter "rest" more.

About the tweeter plastic acoustic lens, I just snipped it off (as per prevoius post), covered the tweeter with lacquer. Next step would be remove stiff plastic mount by using some blue/greytack, try to damp whole tweeter "case" and add weight to tweeter magnet.

I'am thinking of placing the Hertz HSK 163 -3 way set in the front. I heard it play and it sounds beautifull. For me it sounds better than the Focal K2P and it costs 330€ in Belgium (Maybe even less in the Netherlands).

Interesting, I'd like to keep mods at min, but... have you got a link to best offer for HSK??

TIA,

Dynaudio use 1. order filters because the expensive units can handle the power and because the lower the order of the filter, the less problems with the phase. Also you have less components in the signal line with a 1. order filter that ie. a 4. order filter. But it is impossible to make a general rule of which is the better filter.

It is also impossible to determine the cutoff frequence without knowing the "real life-impedance" of the tweater. It might be a 4-ohm unit, but such a thing doesn't exist. The impedance will go up and down according to the frequence and could be anything between 3 ohms and 40 ohms or higher.

Dynaudio use 1. order filters because the expensive units can handle the power and because the lower the order of the filter, the less problems with the phase. Also you have less components in the signal line with a 1. order filter that ie. a 4. order filter. But it is impossible to make a general rule of which is the better filter.

It is also impossible to determine the cutoff frequence without knowing the "real life-impedance" of the tweater. It might be a 4-ohm unit, but such a thing doesn't exist. The impedance will go up and down according to the frequence and could be anything between 3 ohms and 40 ohms or higher.

Of course, I was aware of Dynaudio idea and of the advantages in less phase rotation given by 1st order filters. Of course the impedance of the unit is a function of frequency, anyway the idea here (or so at least seems to me) is to help the standard setup perform better than "standard" .

If Skoda decided to use a el-cheapo electrolytic (!!!) cap in tw hpf and perhaps got completely rid of an inductor to prevent wf playing fullrange, with some cents we can certainly improve the sound!!! And of course, we're interested in tw (and woofer) impedance in the crossover frequencies, not in all his range...