TL SUB with 2x TIW 400 ??

[planezero]

Hello there,

My German is terrible so I am writing this in English...

I want to build a TL SUB and am wondering if it is possible to build one with 2x TIW 400 in the original construction design.

Is there lower (or the same) bass extension ??
Or is this a really bad idea


In this topic Mr.Woofa writes :

Die ca. 3,4m lange Line des TIW 400 bildet eine Reso bei 25Hz, angehoben werden natürlich auch doppelte, vierfache usw. Frequenzen, so daß sich ein sehr welliger Frequenzgang ergibt. Die ca. 2,3m lange Line des TIW 360 ist auf 37Hz abgestimmt und füllt so quasi die Lücken im Frequenzgang des TIW 400 auf. Durch die kleinere Membranfläche des TIW 360 kommt es zu keiner 'Überkompensation', als wenn jetzt noch ein 2. TIW 400 verwendet werden würde.

Can anyone make a frequency chart to see how bad the
'overcompensation' would be ?

Thanks very much for any help and ideas...

Planezero.

[monoton]

The line would have be of other length to compensate for the irregularities in the design with one line only if you take a second TIW400. So the smaller chassis is just perfect compensating the irregularities resulting if you use only one TIW400 in one line.

So if you'd take a second TIW400 in the second line, you'd compensate for some irregularities only, plus introducing new ones (resulting from the different line length) at another place, thus getting an even more irregular behaviour.

All the best,
monoton

[planezero]

Hello Monoton,

Thanks for your answer.

I was thinking along the same lines.
However in the latest installment of the TL SUB Visaton uses 2x TIW300 with exactly the same cabinet.
And the measured frequency curve is nice and flat.
This I don't really understand, just chance ???

That's why I am still curious if anyone had the TL SUB modelled in a program and could make frequency plot with 2x TIW 400 to see what it what look like.

Regards,
Planezero.

[doctrin]

I guess that no one ever have simulated the TL-Sub, because there is no Chance to simulate it completely. You could just simulate the first and then the second line...after this process you have to (approximately) "combine" the charts to see if there would be an overcompensation and how strong it would be!!!

Regards,
Norman

[bulla]

I made some simulations some month ago, Tiw400 + Tiw400 is not the best solution (i didnt make a screenshot of the simulation):

http://www.visaton.de/vb/showthread.php?s=&threadid=12955

[planezero]

Thanks Bulla,
I saw that thread and was impressed with the screenshots.
Its a shame you didn't save the simulation with the 400, but I'll take your word for it and forget about the 2x TIW400...


I want to build a sub for hifi, not for hometheater.
So I am interested in very low bass extension & flat response and not at all in high SPL.
(I play music at very low volume levels)

Is the TL sub with TIW400/TIW360 still the best solution or should I look at other designs ?

Perhaps an idea is to use TIW 360 X with the lower fs (21 HZ) and a smaller second unit to achieve better extension ?


Thanks for any suggestions ...

[doctrin]

@bulla: hast du das mit AJHorn simuliert und die Frequenzkurven übereinandergelegt, da ich nämlich kein Programm kenne das 2 Woofer in einer Line oder sogar Linekombos simulieren kann

MfG
Norman

[GabbaGandalf]

Hello planezero,
another subwofer design with very deep bass ist the dipole-subwoofer, but dipoles are only suitable if you are really listening at very low volumes. furthermore they do not have a very high spl so you will need a powerful subwoofer amplifier.
just check the forum search for "dipol subwoofer" to get more details.

[bulla]

Ok, here are the results for the TL-Sub-vote:

Setup (i changed some minor things in comparison to my previous simulations):

Measured in quarterspace.
Tiw400-Port:
Length: 380cm, 770cm^2
Tiw360-Port:
Length: 230cm, 446cm^2

Tiw400+360 as reference:


Tiw360+360 (similar to new TL):


Tiw400+400


Tiw400+360X


Tiw360X + Tiw 360X


I used LinearX Leap5 for this simulation. With it it is possible to simulate multiple-enclosure Subs as well as transmissionlines, however only with one driver per enclosure. The line also cannot be folded, so some resonances might occur. Horns cannot be simulated.

[bulla]

Here i changed the Postion of the ports:


And this is new resulting frequency response for the original TL:

[doctrin]

@ Bulla please, which app do you use to design and simulate the TL????
I think the Design is made with Hypercad or something similar, right?


Regards
Norman

[bulla]

I used LinearX Leap5 for this simulation. With it it is possible to simulate multiple-enclosure Subs as well as transmissionlines, however only with one driver per enclosure. The line also cannot be folded, so some resonances might occur. Horns cannot be simulated.

[doctrin]

Sorry kann ich da nur sagen, dass ich das überlesen habe. Du scheinst also mit teurer Software bestückt zu sein
Haben sich denn die >1000€ gelohnt?!?

MfG
Norman