Vented or TL


2001-09-12 3:01 pm

I'm planning to build a small tower design with a deep bass.

Why is it that i see a lot of vented designs and less Transmision Lines?
It seems that the tl goes much deeper than the same driver in a vented design...
Some advise please?

gr. Marcel
I have tried TL at several occasions but haven't liked the sound compared to a vented design.
TL have less distorsion in the lowest frequency but I have always found that the upper bass from 80-200 Hz lacks slam and resolution compared to a vented design, and the reason is the massive amounts of wool or damping material you need to put right behind the driver to make the TL work as intended. It makes the deepest bass too soft and blurred while the upper bass are thin and lacks impact.

I have always been more successful with vented designs, but the best I have done so far is with a drone cone instead of the vent. It doesn't go as deep as the vented type but have much less distortion and are the only type of bass where I have been able to hear wall reflections of the bass tones from a church organ.



2001-10-19 4:53 am
I certainly agree with Janne. Having build literally dozens of TLs over the decades; I find a good ported design has better balance throughout the spectrum. Also they're easier to build, and you don't need a source for long fiber wool(and yes it does 'sound' better) :). This is of course is just my jaded opinion.
The only TL design I've heard outperform a vented enclosure with the same drivers was the Ariel...

Pipo: What are your design goals for the tower? If you want to keep the design slim, you could go for an MTM design with a side firing 10 inch woofer. Its easy to build, and you need not worry about the "soft bass" of TL designs or the higher cutoff frequency of the ported enclosures.
I personally prefer the sound of a well damped TL. I find vented enclosures (the ones I have heard)lack detail and control as oposed to a TL which has far superior transient response. I agree with Janne that the upper bass is thinner than a vented enclosure but I prefer this to the exagerated hump of (most) vented enclosures. Like most other enclosures TL's can be tuned to give different results, this is achieved by changing the taper ratio and stuffing density. Just remember you should always aim for a nearly flat impedance curve with a slight broad hump at resonance.

Ariel is not a TL nor a vented enclosure in the traditional meaning, it's more of a suspended semi-open enclosure. In Ariel you don't use as much damping material as you do in a traditional TL so the upper bass is quite much better in Ariel than a TL. Compared to a vented it's very likely that Ariel sounds better but I say that for sure since I haven't tested Vifa P13 in a vented enclosure.

A TL always have two peaks in the bass like a vented enclosure. The only difference is that they are lower and flatter. If you only see one resonance peak the design isn't tuned correctly. Because of the lower peaks you get less phase-shifts and because of that less distortion which gives a cleaner but not deeper bass. What's makes the TL seems to go deeper is the lack of impact and support from the cabinet in the upper bass (>80 Hz).

Ariel is not an alternative if you want deep bass.
The driver is Vifa P13 which is a 5" bass and that driver won't produce bass whatever you do with it.
Look at some construction using Scan-speak 7" driver if you want the best combination of deep bass and good midrange in a 2-way design, or go with Supers suggestion and use a side mounted 10" bass in combination with a 5" midrange.

Janne :)


2001-09-12 3:01 pm
tnx, stick with vented, any ideas?

ok guys,tnx for replys. i'think i'll stick with a vented design, i really liked the design with a side firing woofer, but didn't yet find great designs, the only one i found was the "prodomo"from monacor; it's a german speaker,since i live in holland,but don't know if its good or bad.......
i posted the tread "Prodomo Monacor, anyone build or comment? " what you guys think of that?
or has anyone a better suggestion with for example vifa or audax drivers?????