MLTL subwoofer any advantage over BR

[abn1701]

Hi!
Does a MLTL sub have more extended and tight bass over a bassreflex one?
and have that kind of sound of classic TL (I mean the folded type)?
Thanks

[GranteedEV]

Re: MLTL subwoofer any advantage over BR

My understanding of it is like this.

With your average bass reflex alignment you tune close to driver fs to get flat response down to that point.

With an extended bass shelf alignment, you tube around half an octave or so lower than that. Since it's tuned lower, the consequences of using the vent seem to be less audible. Your usual EBS has a drooping response towards the tuning point because it's lower tuned. You also ask for more excursion out of the driver above the tuning point so distortion can be higher with the wrong driver.

Now an ML-TL starts with the basic concept of an EBS, but uses internal box standing waves to increase extension, just like a TL. But since it's also a helmholtz resonance (mass loaded), you get two different resonances. So even though it looks like an EBS, it's actually a lot more flat down to that tuning point than your usual EBS. The TL aspect augments the vent output.... or something.

I hope my understanding is correct

Now as for whether it "sounds" like a classic TL or a sealed or a vented or an IB or whatever else, I don't know. I don't even know if we can genuinely hear these things in well designed speakers once equalized.

[Bob Brines]

Re: MLTL subwoofer any advantage over BR

You don't get the Helmholtz resonance if you did it right. All you get is the odd harmonic series. Mass loading basically is adding virtual length to the pipe. Are you old enough to remember CB radio? That big inductor at the bottom of a base-loaded quarter wave antenna is the electrical analog.

As far as EBS alignments, you are doing exactly the same thing with a MLTL as you are with a BR. Make the box extra large and tune low and you will get a droopy (low Q) roll-off. The secret is to make that roll-off match your room lift.

Bob

[GranteedEV]

Re: MLTL subwoofer any advantage over BR

Is there any advantage to an MLTL over an EBS, then?

I do think the modeling software is a bit more in-depth, but it's sounding like the performance is similar if not the same...

[Pete Schumacher]

Re: MLTL subwoofer any advantage over BR

Is there any advantage to an MLTL over an EBS, then?

I do think the modeling software is a bit more in-depth, but it's sounding like the performance is similar if not the same...

When you're talking subwoofer, MLTL and BR are purely equivalent, and both can be used to provide various alignments, including EBS.

In other words, no advantage, one over the other.

Where MLTL has advantages is when the driver is required to provide mids, as well as bass, or when the enclosure is tall/chambered, to create a longer path.

[Paul K.]

Re: MLTL subwoofer any advantage over BR

As much as I like to design and build TLs, both ML-TL and tapered, using a TL for a subwoofer doesn't really have any advantages IMO. But, then, I don't have any need or desires for a subwoofer, either.
Paul

When you're talking subwoofer, MLTL and BR are purely equivalent, and both can be used to provide various alignments, including EBS.

In other words, no advantage, one over the other.

Where MLTL has advantages is when the driver is required to provide mids, as well as bass, or when the enclosure is tall/chambered, to create a longer path.

[Bob Brines]

Re: MLTL subwoofer any advantage over BR

When you're talking subwoofer, MLTL and BR are purely equivalent, and both can be used to provide various alignments, including EBS.

In other words, no advantage, one over the other.

Where MLTL has advantages is when the driver is required to provide mids, as well as bass, or when the enclosure is tall/chambered, to create a longer path.

Right. Two points:

1. MLTL's are intentionally designed almost exclusivity for full-(wide) range drivers that are used from a bottom of something like 40Hz up to near 10kHz or better. The quarter-wave action allows a driver to go deeper than can be comfortably managed with a BR. Note that the deepest that is normally reasonable is F3=0.707*Fs.

2. MLTL's are unintentionally designed when the designer attempts a tower BR. Once the height of the box gets much beyond golden ration dimensions, strange peaks and valleys start to appear in the FR plot. These are, of course, quarter-wave resonances. All tall, thin vented boxes are MLTL's.

Bob