TAD 2402 clone

Hi,

I have always had a 'thing' for the classic TAD 2402 and now it is time to get started. However, the TD-4001 are either difficult or near impossible to source and even a pair of beat-up TD-4001's are pricey these days.

I have read a few comments about people that have had good results using the JBL 2450 with Truextent diaphragms - is this the way to go if I cannot find a pair of reasonably priced TD-4001's? It seems like it matching the horn pretty nicely in terms of exit angle etc.

Was the original fitted with a gasket between the enclosure and the horn to prevent air leaks and how was the horn held in place?

I will probably have Athos Audio do the horns and probably also the enclosures.

Thanks!

/Jeppe
 
Hi Diyaudio,

I did not get much reply on this topic. However, in the mean time I found a beautiful set of 2402 cabinets which is now residing in my living room and are waiting for drive units.

Any inputs on a proper compression driver to fit when the TAD TD-4001 is not in play? How about the JBL 2441 with Radian diaphragms?

Thanks! 🙂

IMG_0090.jpg
 
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If you want alternatives.
Try the 2450H/J as i assume theyre without a adapter -> 2450sl.
Also the reworked 2450s from meyersound will be good.
Throat angles should be similar from memory(if its not faulty)😅
Used prices are very fair.
And get SL diaphragms for them If you do.

The 4001 Is a descendant of the 375/2440/2441 drivers
 
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A couple of things: The JBL 2450SL compression driver has a 1.5" exit.

The 2450H/J is 2", same as a TAD horn entrance. The oral history is that this neodymium driver was designed for the TruExtent BE diaphragm. I've used it successfully with the JBL 4" aquaplas dusted (coated) titanium diaphragm originally used in the 2450SL. Under a slightly different model number it is used in later drivers and is still available. I would combine the 2450 with a 16 ohm dusted diaphragm and a super tweeter like the JBL 077/2402. If you do that you may be able to use one of the JBL treble/ UHF crossover topologies as a starting point for your crossover.

I have no experience with the Radian/TruExtent diaphragms.

The JBL 2441 is listed by Radian as suitable for its diaphragms, and it's a nice driver, but prices for 2450hH/J run much lower, and the 2441 should probably be remagnetized to boot. Also, buying used ones you must be wary of cracked or broken internal throats; I don't know if replacements are available; even if they are, that would be a professional repair.

Buying used TAD drivers is very risky because sourcing replacement diaphragms is iffy. At this time I believe the 4001 and 2002 are both available, but the difference between their price and the price if a new driver is not huge.

I doubt the TAD high pass for the TD4001 will work with any other driver because it incorporates compensation for known peakiness in that driver.

Every different combination of horn and driver requires its own crossover.

The TAD TN-2 low pass crossover is made for the 1601A. I believe Google will kick up a copy of the schematic in the 2402 manual.

That's a nice looking cabinet.
 
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Hi All,
Just trying to bring this 'old' thread back to life 🙂 I have been so fortunate to get my hands of a very nice set of TD-4002 with the original adaptor, so now I have the horns, cabinets and the compression driver. The woofers will hopefully show up soon.

So, now on to the crossovers. I have found the 2 schematics, but they are not quite identical. The "TAD TSM2 story" seems right, but it assumes a TD-4001 - I'm unsure about the effect.

Does anyone know what kind of load or autoformer was originally used? I haven't seen images that indicates that an lpad was adjustable from outside the cabinet.

Thanks!

/Jeppe
 

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Hi All,
Just trying to bring this 'old' thread back to life 🙂 I have been so fortunate to get my hands of a very nice set of TD-4002 with the original adaptor, so now I have the horns, cabinets and the compression driver. The woofers will hopefully show up soon.

So, now on to the crossovers. I have found the 2 schematics, but they are not quite identical. The "TAD TSM2 story" seems right, but it assumes a TD-4001 - I'm unsure about the effect.

Does anyone know what kind of load or autoformer was originally used? I haven't seen images that indicates that an lpad was adjustable from outside the cabinet.

Thanks!

/Jeppe
Double woofer = TN-1 = 2401
Single woofer = TN-2 = 2402

https://www.diyaudio.com/community/threads/tad-th4001-clone-project.80068/

https://www.diyaudio.com/community/threads/pioneer-2401-clone.212923/

https://www.diyaudio.com/community/...or-high-efficiency-loudspeaker-system.231594/

https://www.hifido.co.jp/sold/14-84862-31021-00.html?LNG=E

https://zozosir.blogspot.com/2013/09/tad-tn-2-crossover.html

The TD-40001 and 4002 are not identical so the HF section will need some adjustment most likely.



As for the Lpad you can see it in the Schematics and XO pictures.

White resistors, whirewound ceramic.

Core coils

The caps are potted in good, alle the black squares. Assume to limit microphonics /vibration effects, also makes it more difficult to reverse engineer.
 
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I did not get much reply on this topic. However, in the mean time I found a beautiful set of 2402 cabinets which is now residing in my living room and are waiting for drive units.

Hey, would you let me know where you found this beautiful set of 2402 cabinets?

I am actually engaged in a TSM-2 (2402) clone project too, but i intended to do the woodwork for myself. But if i could get cabinets in a quality like yours, i would have to think over...

Best regards from
Pioneer_Exclusive
 
Stunning - congrats on a job very well done!

What drivers and xover?
Thanks for the praise!

The drivers are the original TAD TL-1601a woofers and the TAD TD-4001 compression drivers.
The horns were made by Athos Audio in Hungary (TH-4001 clones).
I am currently operating the speakers with two separate amplifiers for the woofers and the horn-drivers ("bi-amping"). This requires an active crossover (Pioneer D-23).
The TN-3 network (1:1 replica) is used to protect the TD-4001 from frequencies that are too low and to correct the impedance and frequency response. It was developed by Pioneer specifically for this purpose.

I also plan to make replicas of the famous passive TN-2 crossovers soon. After that, I will hopefully be able to decide which concept sounds better...

Here are two photos of the TN-3 network

20241223_125451.jpg20240916_193813.jpg

😉 Greetings
Pioneer_Exclusive
 
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Ac
Which amplifier are you using?
D-23 Pioneer 4-way frequency divider?
Actually i use the following setup:

1. Preamp: Preamp-section of Pioneer SA-9500II (main volume set)
2. Electronic crossover: Pioneer D-23 (as 2-way frequency divider and for separate volume adjustment LOW/HIGH, using low-mid and mid-high sections, cutoff frequency 630Hz, slope 18db/oct.).
3. Poweramp LOW: low-mid-output of D-23 connected to poweramp-section input of SA-9500II
4. Poweramp HIGH: mid-high-output of D-23 connected to poweramp-section input of SA-8500II

This is the test setup at the moment.

In the near future an EXCLUSIVE C3 preamplifier, the D-23 xover followed by two EXCLUSIVE M3 power amplifiers will be used!
 
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This is my TN-2 clone, in this case used external. Some coils are adjusted by hand to get as close to the theoretical value as possible, since they are not standard values.
Great work! Perfect design in PCB format. An enormous effort if it was only intended for a single 2402 replica.

I think we communicated by email before, a few months ago...

As I said above, I'm actually using the TN-3 network and an active frequency divider and two separate amplifiers. Sounds great, no question. But to find out what is better, the bi-amping concept or the passive frequency divider network TN-2, I'm going to clone the TN-2 as well. I will build the networks point-to-point wired, just like the originals.

I have a copy of the original TN-2 service manual with parts lists and schematics. One question remains unanswered: the inductance of the L3 coil of the HF network - is it 0.8 mH or 1.1 mH? The service manual is contradictory on this.
I don't think it would make much difference at this point (notch filter), but could you please tell me which inductance you chose?
Best regards

Pioneer_Exclusive