Tangband W3-881 MLTL build

[GM]

?? Thanks, I thought the bipole was just dual Silver Flutes, so having done one back in Jan........

GM

 

[xrk971]

Ok, so the design is a dual driver bipole with silver flutes then. How far away from the back wall is the response shown for? It has huge effect from what I have seen.

 

[Scottmoose]

GM's looks to be a 1/2 space plot, and will be on the assumption that you'll adjust placement and Fb as you see fit for the practical in-room conditions encountered. Since the room dominates < ~300Hz this gives a solid baseline from which to work.

 

[ryani]

Hey guys, I appreciate all your work on this project, but don't worry about making this one work. I can always find a different driver. One better suited to this application. A 4 ohm full ranger of a different size. One on each side wired in series for an 8 ohm load to amp.

 

[ryani]

Here's a cheap experimental driver to try.

MCM Audio Select 5'' Aluminum Cone Woofer | 55-1870 (551870) | MCM Audio Select

I also used these in set for my basement in conventional enclosure. They sound good for their price point. I got the specs off the Monacor website for them.

5 Inch 50W 8 Ohm Full Range Dual Cone Speaker | SP-50X (SP50X) | Distributed By MCM

 

[xrk971]

OK, so you don't want to try the Silver Flutes anymore? I think the single driver option is actually very interesting in that it can reach 35 Hz with quite a high efficiency of mid 90 dB's - tough to find that kind of performance in any $30 class driver. Any bipole system will really like to be away from walls so keep that in mind. The 5 in aluminum cone Monacor SP-50X drivers you just suggested look like a neat low cost experiment to try. Does it sound like it reaches 17 kHz? If so that is enough for me. Same price point as a Vifa TC9FD.

 

[GM]

GM's looks to be a 1/2 space plot, and will be on the assumption that you'll adjust placement and Fb as you see fit for the practical in-room conditions encountered. Since the room dominates < ~300Hz this gives a solid baseline from which to work.

Right, I use MJK's early freeware to do the [ML]TL equivalent sims of what folks get using WinISD, etc. to get T/S sealed, vented alignments, i.e. a good enough design to allow a normally sufficient amount of in room tuning flexibility or to input into more powerful programs such as MJK's shareware, AkAbak, etc. to do further fine tuning before committing to wood/whatever.

GM

 

[xrk971]

GM,
Do you use AkAbak? I am wondering if it would be good to get a "Full Range Driver-Centric" AkAbak thread going to bring more folks into the very powerful modeling capabilities that it has. It was a real eye opener to see that once the basics of a MLTL script is there (maybe 30 lines of script) it was adding 6 or 7 more lines (copy and paste mostly) to make it a quad driver bipole with offset drivers. Need BSC? - add 2 more lines and modify a third. Very extensible and flexible but a bear to get past the initial learning curve. We are all very lucky to have Don Hills share his expertise and tips and tricks with AkAbak. There is another AkAbak thread but it is in multi-way forum and deals with ported BR type enclosures more than TL's and horns.

 

[GM]

I used it some for basic horn, tapped TL/horn alignments before Hornresp's Wizard, but nothing else since I've no current need for more design power for myself.

GM

 

[ryani]

It does sound like it gets there for sure. It's a great sounding little dirver for the money. I have them in a BR tuned to 55ish hz. There hooked up to an old HH scott amp.

Single driver MLTL. I can repurpose the ones I already have!

 

[ryani]

monacor spx50 specs

Here's the specs for the monacor 5 1/4

 

[xrk971]

Ryan,
Are the Monacor SP50x the ones you want to repurpose as a MLTL?

 

[ryani]

Yes please, I'll get some pics up of the enclosure of what I have them in now when i get home from work. They are almost in the MLTL catagory. 48" high 7.5" wide 5" deep outside dim. 3/4" stock.

Roughly .6 cuft. I'll have to check speaker height and rear facing port height. They sound very nice.

I have a isobaric 6.5 dual bandpass sub for the lower end. It was just a fun experiment too.

 

[xrk971]

Yes please, I'll get some pics up of the enclosure of what I have them in now when i get home from work. They are almost in the MLTL catagory. 48" high 7.5" wide 5" deep outside dim. 3/4" stock.

Roughly .6 cuft. I'll have to check speaker height and rear facing port height. They sound very nice.

I have a isobaric 6.5 dual bandpass sub for the lower end. It was just a fun experiment too.

It sounds like you want to use the existing cabinet but to calculate a new vent to make it MLTL? A lot will depend on driver placement and match between Qts, Vas for existing box. I will plug it in and see what comes up once you get me all the dimensions. Also, where is current vent and do you want to do a bottom firing vent with raised feet again? I kind of like those for how omnidirectional the bass is. But if you have a hole in the front near the bottom already, I would just stick with that.

 

[ryani]

X I'm ok with building completely new enclosures. Woodworking is the easy part for me. The calculations is what I'm slowly learning.

Here's my current setup in my basement. The driver is 12" down from the top and the vent is 16" up from the bottom. Vent is 3.5" long by 2" wide. I modeled the enclosure in winisd.

Aesthetics was the reason for the placement of both. Nothing more. Almost a truly AMLTL!

 

[xrk971]

I bet you built an AMLTL with this. If you were to do a measurement with a mic and Holmimpulse, I bet the low freq is about 5 to 10 Hz lower than the tuning predicted by WinISD. It would also show up in an impedance measurement. Placing the vent at 6 in will probably make it a truer MLTL. Do you have any stuffing inside?

 

[ryani]

Well I guess the old saying is true.....better to be lucky than good haha. I do have it lightly stuffed but it's the length of the enclosure not just the top third.

 

[xrk971]

SP50X MLTL Model

Ryan,
I ran a simulation of your as-built SP50-X tower speaker, and unfortunately, it doesn't look too good. The bass is what I would call kind of weak as it appears that the cabinet is too small in volume and the port is too high up. The bass starts rolling of at 80 Hz and there is a big dip at 175 Hz (see freq response of simulation). I think the default volume suggested by WinISD is just too small when stretched out to a long slender column.
I then proceeded to optimize it by increasing the volume, locating the port lower, and moving the driver location to 1/3. The optimized response is much flatter and reaches down to 40 Hz with a flat 'authoritative' bass shelf. You should notice a big improvement if you were to build the new cabinet. The calculated driver cone displacement also seems to be well controlled.

The new design is as follows: 6 in wide x 9 in deep x 46.5 in tall, vent 2 in dia x 3.25 in long located at 5 in from bottom, driver at 15.33 in from top, usual stuffing. These are all internal dimensions. To get the best response you should use a 0.8 mH inductor and 8 ohm resistor for a BSC circuit.

Sorry your as-built doesn't look so hot as a MLTL.

 

[ryani]

Haha, Well that's actually great to hear. I thought they sounded good before now I'm excited to see what they will sound like with a proper tuned enclosure!

Thanks again X. Hopefully I have some time this weekend to do some constructing. I have to get the boys dirt bike up and running first.

 

[xrk971]

You are welcome, hope it works out even better than your existing cabinet. You are pretty quick with the wood working as I recall so I have no doubt you will have something soon. I like the finish you have on your existing cabinets - is that pine board you used and you stained it grey and then varnished? Good luck with the dirt bike - 2 stroke or 4 stroke? I used to ride and rebuild 2 stroke engines on YZ's and CR's. Those were the good old days when we were invincible...