MLTL's, BVR's, QWP's, BIB's, BLH's, MJK's sheets, and everybody else

[pjanda1]

Why are we fullrange guys the only ones using these enclosures? Why are we (well, not me, the folks that can) the majority of folks using MJK's software to model enclosures? I know some things, like BIB's and some BLH's have downsides. But it seems to me that MLTL's and BVR's pose distinct technical advangates over standard BR enclosures. Why aren't the multiway folks putting their designs in them? I understand they are a bit bigger, but we DIY'ers usually aren't scared off by a little more size. I see a several commercial designs that look for all the world like MLTL's (tall, skinny, ported). Are those guys using software to optimize them, or just damping out the quarter wave action and hoping for the best?

I for one, would love to hear a good two way in a double mouth BVR. An MTM would look especially cool. Is it up to me to get 'er done?


pj

[MJK]

Originally posted by pjanda1
Why are we fullrange guys the only ones using these enclosures?

Actually, quite a few multi-way speaker designers and builders are using the MathCad worksheets. This includes both DIYers and commercial speaker manufacturers. If you look in my gallery you will see a number of multi-way systems. If you look at Jim Salk's website there are two TL based designs for sale. But I will agree that full range driver users represent the majority of my MathCad worksheet users.

Why are we (well, not me, the folks that can) the majority of folks using MJK's software to model enclosures?

I think full range speaker designers are already into the exotic out of the mainstream drivers so they select enclosures that are just as exotic and out of the mainstream. There are four software options, that I am aware of, that will model TLs and horns. In order of price they are Hornresp, my MathCad worksheets, Augspurger's TL software, and AJ Horn. I think if you look at the split of the population using these programs, it would probably be directly proportional to price. Price rules in software selection with free the biggest winner.

I know some things, like BIB's and some BLH's have downsides. But it seems to me that MLTL's and BVR's pose distinct technical advangates over standard BR enclosures. Why aren't the multiway folks putting their designs in them?

Some are already and more people recognize this everyday. In a recent Parts Express flyer there was a featured design that was based on simulations made using my MathCad software. A lot of multiway designers seem to be focused on the very small two way enclosures, floor standing designs don't seem to be popular in the home.

I understand they are a bit bigger, but we DIY'ers usually aren't scared off by a little more size. I see a several commercial designs that look for all the world like MLTL's (tall, skinny, ported). Are those guys using software to optimize them, or just damping out the quarter wave action and hoping for the best?

Most of these people stick to the claim that the design is really just a bass reflex box and therefore thay do not recognize that the standing wave even exists. They will argue for hours about the bass reflex theory over the ML TL theory. I have been in more than one exchange over this technical issue, I have since given up trying to argue this pint beyond pointing out the potential benefits, too much time is wasted on arguing. The discussions can take on the same fever as the tube vs SS amp discussions with inflexible positions quickly established. It is a tough question because I have not found one clear cut line of departure between bass reflex and ML TL behavior in an enclosure. There is a wide fuzzy grey area between the two behaviors.

I for one, would love to hear a good two way in a double mouth BVR. An MTM would look especially cool. Is it up to me to get 'er done?

Paul K, on the PE forum, has built a number of multi-way TL and ML TL speakers. You can see pictures of his efforts on my website in the gallery, they are very attractive speakers. I believe he is also the enclosure designer of Jim Salk's commercial Song Tower speakers.

[pjanda1]

Somehow it hadn't ocurred to me to check your gallery. There is certainly plenty of eye candy there. I remember seeing the PE flyer too. "The only ones" was too strong a term. It would be far more accurate to say that these enclosure designs, while common place in the fullrange community (thanks especially to the efforts of a few especially generous enthusiasts) still seem, to me, like fringe ideas in the larger community. I'm basing my opinion mainly on brief looks at a few forums, available kits, and the way enclosure designs are discussed. I find it odd that folks become so entrenched. It does seem like the tide is turning, and the thought of using the standing wave action to ones advantage is gaining traction.

Thanks for your insights and contributions,

pj

[planet10]

Us FR guys are pushing the current boundaries. We use all the time we save not having to do XOs to explore.

BTW: the 1st Chang -- Calhoun was designed initially to be a 2-way.

dave

[freddi]

hi Dave - at times you're saving quite a bit of money at times on passive components and HF driver besides all that fiddling.

I think theres some art, leeway & personal interpretation on speakers and also that real measurements may not look as good (or bad at times) as predictions and neither may pin down the impression of sound. Its great to see MJK's software - -none yet for Karlson but those may have been already developed properly as in building a balanced musical instrument - theres room with K for work.

[GM]

Originally posted by MJK

There are four software options, that I am aware of, that will model TLs and horns. In order of price they are Hornresp, my MathCad worksheets, Augspurger's TL software, and AJ Horn.

It is a tough question because I have not found one clear cut line of departure between bass reflex and ML TL behavior in an enclosure. There is a wide fuzzy grey area between the two behaviors.

Greets!

AkAbak is another and by far the most flexible/comprehensive of the bunch and free for non-commercial users, making it the price/performance leader by a considerable margin. The trade-off being a steep learning curve and fairly tedious/time consuming until you build up a library of default alignment models to modify.

Well, for me it's pretty clear cut, when the 1/4 WL loading is sufficient to require shortening the vent to maintain a given Fb, it's no longer a bass reflex. When most folks build a 'BR' tower design though, they tend to put the vent near the driver just as they would in a tiny box design and since the T/S calc'd vent size/length ~hits the target Fb, I can see why they believe the 1/4 WL loading scheme is nothing more than a 'pipe dream'.

GM

[pinkmouse]

Originally posted by planet10
Us FR guys are pushing the current boundaries. We use all the time we save not having to do XOs to explore.

Either that, or subliminally you recognise the flaws of a single driver system, and your subconscious drives you to change your system constantly to get what a decent multiway system already has to start with.

[GM]

Greets!

Yeah, that and typically low power amp topologies are preferred, so building in all the acoustic efficiency one's lifestyle can tolerate forces a person off the current 'beaten path' back to the original audio 'highway'.

GM