TAD 2404 Build

[Dr.db]

The final tuning is spot on , more by luck than judgement . I have made a few changes .

What is your final port length in your enclosures?

[Doctor_Electron]

here are the answers from the seller GT-sound http://www.gt-sound.com/



HI Ari Oskarsson

Is it alright for a while, how are you?

Did you finish the Speaker box?

TD-4003

① DC-7, 5 Ω is normal value.
AC measurement will result in 12 to 13 Ω.

② I checked the sound at the time of shipping, but there was no
abnormality.

We opened the back chamber of DRIVER UNIT of TAD, GTS, and diaphragm
I will not remove it.

1. It does not have jigs that make precise height adjustment when
setting again. I have a TAD service.

2. The material of the diaphragm is beryllium and it seems there is a
danger to the human body.

Best regards
K.Goto


I am 100% sure he did not opened the back cap

Only if you breathe particles in the air, or get a splinter in the skin and not remove it.
Unlikely conditions when inspecting or replacing a driver diaphram.

[dn92]

If interest:

Exclusive DN-2404 LF crossover is a 36dB/oct, a bit (not so much) different from TAD TN-2 (to compensate a different delay from the compression driver that chould be lower than for TH-4001/TD-4001). HF crossover is of 12dB/oct, followed by an autotransformer, providing three levels positions from -1dB to +1dB. There is no EQ, which is quite logic from TH-4003/TD-4003 measurement graphic available somewhere on this forum, where the raw frequency response is already correct). A very simple HF network compared to TN-1/TN-2/TN-3.
This can be easily reproduced within an active crossover. If richluvsound or Ari send me impedance measurement files (.zma) I could simulate the frequency responses of the electric filters, the most difficult part to simulate being the autotransformer.

On DN-2404, the three cylinders on the right are coils of the LF filter, long rectangle contains all capacitors of the LF filter, on the left bottom rectangle box contains HF filter capacitor, the cylinder is the coil of HF flter, and remaining rectangle box the auto transformer. There are two resistor that are located elsewhere in the network plate.

[hlaari]

Bad news!

there look´s like on of the Td-4003 diaphragms is broken, there is a hole in the surround

I was going to sell the speakers and get some profit but it look´s like now I will get a big hit out of this
I have ask Speaker Exchange about the price for new Td-4003 dias and the price is 2200 USD for single and more than 3600 USD for single Td-4003 driver

this is very bad because Richard have made a great job in his work on the the enclosure

there is unlikely at I will sell them now, the most likely is that at I will get all the parts shipped back to me with the beautiful 2404 enclosures and the project will go on hold until I have got new diaphragms for the Td-4003 drivers

[hlaari]

I have send mail to the seller who sold me the driver parts
he said at all the parts he sold to me were 100% in good shape

the best way for him is to send me two new Td-4003 diaphragms

[Ian Mackenzie]

If you were my neighbour you could borrow mine (4003) so you could at least hear those beautiful loudspeakers go after all the work that has been done.

[hlaari]

If you were my neighbour you could borrow mine (4003) so you could at least hear those beautiful loudspeakers go after all the work that has been done.

thank you for good offer
we wait and see what the seller of drivers will do


are you using them in your system and what kind of speaker are you using them in?

[Ian Mackenzie]

thank you for good offer
we wait and see what the seller of drivers will do


are you using them in your system and what kind of speaker are you using them in?

I prefer not to publicise my lunicy too often ....LOL

Edit : Diy version of this
(Image C/- Oswald Mill Audio)

[hlaari]

I prefer not to publicise my lunicy....LOL

No problem

I think at the best way for me is to send my TAD Td-4003 to this company http://www.hornstudio.de/tad.htm in Germany for repair
I will not sell my TAD 2404 monitors they are going to cost me to much so I will not sell them

[Dr.db]

First of all, sorry for asking these things again, I hope I don´t misuse this thread!

In TSM2 (...), bass reflex port is tuned to 32Hz. 28Hz from formulas is a bit lower especially because the three inductances of the LF crossover ..... will have a resistance value that will modify a bit Qts of 1601c and you'll have to adapt port length to get what you want in terms of tuning frequency.

So the formula didn´t take the three inductances into account, right? So the 28hz tuning is without the crossover and in reality tuning frequency will raise from 28hz to 32hz because of the resistance of the inductors?
If I run the woofer without the passive crossover, I would have to shorten the ports a bit to reach a 32hz tuning, right?

.

Sorry if I might mix up on things, but the thread-starter used a volume of 171 liters in the formula rather than your 135 liters.
That´s why he gets 28hz tuning and you get 32hz tuning with the same port-length?
Or does the 2404 enclosure uses a different woofer-type?

.

I´ve looked at this page for the specs on the TAD woofers:
http://www.technicalaudiodevices.com/lf-units
QTS is 0,34 for TL-1601a and TL-1603, but is 0,31 for TL-1601b. FS and VAS is very similar on all of them.
That´s why I was thinking 1603 is closer to 1601a than to 1601b...

Btw; can I simply copy the value of the End correction factor or how do I determine this figure for the formula for the 1603 ?

.

Subtracting the panel thickness of 22mm from the outside dimension, I get 202,5 liters for the internal volume for the 2402 enclosure. Of course bracing, driver displacement and midrange-horn displacement has to be subtracted of that 202,5 liters, but my guess would´ve been this could result in 20-30 liters. To result in a netvolume of ~130 liters the insides must occupy nearly 70 liters! Is the 2402 braced that heavily?
Don´t get me wrong, I do not want to argue with you or doubt knowledge as you have build a copy yourself, I just want to understand.

[dn92]

First of all, sorry for asking these things again, I hope I don´t misuse this thread!



So the formula didn´t take the three inductances into account, right? So the 28hz tuning is without the crossover and in reality tuning frequency will raise from 28hz to 32hz because of the resistance of the inductors?
If I run the woofer without the passive crossover, I would have to shorten the ports a bit to reach a 32hz tuning, right?

.

Sorry if I might mix up on things, but the thread-starter used a volume of 171 liters in the formula rather than your 135 liters.
That´s why he gets 28hz tuning and you get 32hz tuning with the same port-length?
Or does the 2404 enclosure uses a different woofer-type?

.

I´ve looked at this page for the specs on the TAD woofers:
http://www.technicalaudiodevices.com/lf-units
QTS is 0,34 for TL-1601a and TL-1603, but is 0,31 for TL-1601b. FS and VAS is very similar on all of them.
That´s why I was thinking 1603 is closer to 1601a than to 1601b...

Btw; can I simply copy the value of the End correction factor or how do I determine this figure for the formula for the 1603 ?

.

Subtracting the panel thickness of 22mm from the outside dimension, I get 202,5 liters for the internal volume for the 2402 enclosure. Of course bracing, driver displacement and midrange-horn displacement has to be subtracted of that 202,5 liters, but my guess would´ve been this could result in 20-30 liters. To result in a netvolume of ~130 liters the insides must occupy nearly 70 liters! Is the 2402 braced that heavily?
Don´t get me wrong, I do not want to argue with you or doubt knowledge as you have build a copy yourself, I just want to understand.

You are right, I forgot the resistance of the coils (around 0.6 ohm in TN-2 network). This is lowering the Fb value repectively to the port length. This is meaning port has to be shorter than the computed value.

There should be something wrong as TS of 1603 are the same as the ones for 1601b (same cone, and magnetic field), while 1601c as used in Exclusive 2404 has similar TS as the 1601a

TL-1601a/b/c takes about 6L of volume. TH-4001/TD-4001 takes about 30L, Bracing parts are huge with 44x60mm sections

[Mr. Widget]

Congratulations!
They look great... always even better when they sound good too!


Widget

[richluvsound]

Finished

Good Enough .... the sound is just gorgeous . At any volume they are genuinely captivating

[Dr.db]

@ richluvsound:

It would be very kind of you if you could help me out with some informations on your build

Your bass enclosure has an internal net volume of 171 liters with two ports with 10cm diameter and 10cm of length, correct ?
Which woofer-modell have you mounted inside?

I own a pair of TAD TL-1603 and have a very similar enclosure size.
But my simulation-programm WinISD tells me I need a portlenght of 30cm!
Do our woofers differ that much or is my simulation-programm rubish?


Thanks a lot for your help,
Olaf

[dn92]

When trying to calculate the TAD 2402 port length by using WinISD I never succeeded to find the port length used by TAD 105mm for a 100mm diameter (fb 32Hz for 135L for a single TL-1601a).

Instead I did as it was in the plan, measured Fb, and it was working perfectly

The proposed formula written in a previous post, should be tried on my example to see if it allows to get the right port length.