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Project 4000 Speaker Renovation


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Thought I would post this as a way to inspire people who own the 4000’s

Consider the following…

Leave the big inductors, they are iron core but are good quality, not worth replacing with air core

Replace cheaper wire wound resistors with at least the ww vitreous enamel type or MOX type if you want too.

Replace the components that are in series with the tweeter and midrange drivers. (as these have the most effect on sound quality)

Upgrade wiring, the original wire is substandard.

Port the speaker, the woofer is actually designed for a ported enclosure (use at least 90mm diameter pipe). You will have determine length through trial and error.

Don’t dope the woofer; if you do you will need to redesign the woofer section of the crossover.

Separate the woofer section from the rest of the xo, so you can bi wire. (not difficult to do).

Only do these mods if your drivers are working fine.

Edited by linnit
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Philips AD12250/W8 woofer specs Fs (Hz) 25 Pe (W) 100 Qts .34 Re (Ohms) 7 Vas (l) 250 Qes .43 Sd (cm2) 530 Rg (Ohms) .5 Qms 1.6 Vd (cm3) 850 It would probably be debatable to go to the trou

I'm pretty sure I built those, in the mid 80s.    And I enjoyed listening to them   I changed the physical design by making them out of 30mm mdf, and giving them a triangular

Hi Linnit,

Sounds good I always thought about separating the x-over bits and placing them adjacent to each driver and hook it all up with descent speaker cable.

I am already onto replacing the inferior resistors and capacitors.

At the moment I need to have 2 x new boxes made, as both my 4 way and 3 way boxes have been damaged with water whilst in storage, and I have had 2 of my woofers damaged by pesky mice.

I thought to have at least the 4 way set of boxes made as per the originals, that why I was trying to get feedback from “speedorhaste” to see he/she got on.

I would also love to get my hands on 2 x of the original woofers if anyone has a pair that they no longer want and are willing to let go, id be prepared to take them for the right price.

As I mentioned before I had the ETI 4000/1 3 way system in a 100L vented box and the woofers sounded much better than the 4000 4 way system in the 80L sealed box.

Any way given that I am going to have to get 2 new boxes built please let me know if any one has any suggestion about new size for 4 way boxes.

And please if anyone has a pair of the original woofers I would rely like to get them, (almost kill for them) NO just kidding, or the woofer specs so I can attempt repair job with a local repairer.

Cheers Pablomez

Edited by Pablomez
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Philips AD12250/W8 woofer specs

Fs (Hz) 25

Pe (W) 100

Qts .34

Re (Ohms) 7

Vas (l) 250

Qes .43

Sd (cm2) 530

Rg (Ohms) .5

Qms 1.6

Vd (cm3) 850

It would probably be debatable to go to the trouble of having the boxes rebuilt as well as 2 woofers repaired. Unfortunately I can’t see you obtaining a pair of the Philips woofers. I think you would find that a lot of other woofers would surpass it. Like I said the best driver in the 4000 was the tweeter. The crossover is not really designed correctly, trying to get a 4-way sounding good isn’t easy and Tilbrook only used textbook crossover design. I would start saving for a better pair of speakers. With the mods I mentioned it should cost no more than $100, but that was only if everything was working fine to begin with.

Sounds good I always thought about separating the x-over bits and placing them adjacent to each driver and hook it all up with descent speaker cable.

I am already onto replacing the inferior resistors and capacitors.

No need to scrap the XO circuit board, it is fine for these speakers. I only suggest separating the woofer for bi-wiring, look at the board it is easy to do. Don’t worry about replacing the 47uf BP caps with Polypropylene as they wouldn’t be worth the cost to do so.

Edited by linnit
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  • 11 years later...

I know it's a good 12 years since this thread has been replied to, however I am hoping to revive it as the new owner of these speakers. They have been ported to correct specifications and I'm very happy with them but I find the top end to be extremely lacking. They are certainly not forward or fatiguing, they are the total opposite, and I find myself needing to up the treble on the preamp to the 2'oclock position, something I've never needed to do on many sets of speakers. The speakers also have upgraded jantzen caps at decent expense. If anyone can please help me I'd be very appreciative. 

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Listen to the hf drivers up close, are they both working?

Check the crossover components the feed the hf drivers, are they of the correct value?

Are the components within spec?

Are the components installed with the correct orientation and properly soldered?

Are the hf drivers connected with the correct phase?

 

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On 25/03/2007 at 11:08 AM, Speedorhaste said:

 

Project 4000

For ease of reference, I'll refer to the speakers as "The 4000".  That was their project name at inception as explained later.

 

 

I'm pretty sure I built those, in the mid 80s.  :)  And I enjoyed listening to them

 

I changed the physical design by

  • making them out of 30mm mdf, and
  • giving them a triangular shape so the width of the cabinet at the tweeters was much less than the width at the woofers.

They may still be out there - I sold them when I moved house in 1989.

 

Andy

 

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1 minute ago, andyr said:

 

I'm pretty sure I built that kit, in the mid 80s.  :)  And I enjoyed listening to them.

 

I changed the physical design by

  • making them out of 30mm mdf, and
  • giving them a triangular shape so the width of the cabinet at the tweeters was much less than the width at the woofers.

They may still be out there - I sold them when I moved house in 1989.

 

Andy

 

 

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On 22/10/2020 at 5:31 AM, pwstereo said:

Listen to the hf drivers up close, are they both working?

Check the crossover components the feed the hf drivers, are they of the correct value?

Are the components within spec?

Are the components installed with the correct orientation and properly soldered?

Are the hf drivers connected with the correct phase?

 

I have certainly listened to the tweeters up close and they're working fine. I'll check all the other possibilities you mentioned. They sound beautiful but need some power for the soundstage to jump out of the speakers. Once I hit that sweet spot, I can close my eyes and point out where the band is. Pretty impressive considering theyre huge 4 ways. They've been ported correctly and go down to 26hz pretty well with a steep drop in db below that. Bass that can certainly be felt in the chest. I just find it strange that I'm increasing the treble on my preamp. Only from midday to 2 o'clock. Maybe I'm being picky. They certainly don't sound muddy, just need a slight nudge in the top end, almost as if the tweeters aren't sensitive enough. Maybe it's just the design, and I'm being a sook for having to adjust the treble on preamp.  Either way, thanks for the suggestions. I'll go through the list. 

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On 29/10/2020 at 2:40 AM, speakerhoarder said:

I'm increasing the treble on my preamp. Only from midday to 2 o'clock.

 

If the other suggestions have been attended to, and you don't have measuring equipment, you could try adjusting the attenuation of the tweeter.

 

Follow the input from the speaker terminals to the tweeter section, and the first series component there will probably be an attenuation resistor. Replacing this with one of about 1.5 to 0.5 Ohms less will give the tweeter a greater proportion of the available input signal. Eg - if it's 4.7 Ohms, try 3.3, and if that's too bright, go for something in-between. Jantzen have a large selection now - eg 3.6, 3.9 and 4.3.

 

Speakerbug in Brisbane is very handy (and helpful).

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On 31/10/2020 at 9:32 AM, BioBrian said:

 

If the other suggestions have been attended to, and you don't have measuring equipment, you could try adjusting the attenuation of the tweeter.

 

Follow the input from the speaker terminals to the tweeter section, and the first series component there will probably be an attenuation resistor. Replacing this with one of about 1.5 to 0.5 Ohms less will give the tweeter a greater proportion of the available input signal. Eg - if it's 4.7 Ohms, try 3.3, and if that's too bright, go for something in-between. Jantzen have a large selection now - eg 3.6, 3.9 and 4.3.

 

Speakerbug in Brisbane is very handy (and helpful).

That is exactly the sort of fix I was looking for. Thank you very much. 

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