# I.S.C.T – ‘Black Widow Maker’ High Velocity, Split & Heavily Shaped - Interactive (SEALED/VENTED) Sub Enclosure ….



## UpperCut (Feb 8, 2016)

I.S.C.T – ‘Black Widow Maker’ High Velocity, Split & Heavily Shaped - Interactive (SEALED/VENTED) Sub Enclosure ….


In my ongoing quest to find somehow something else maybe more or even different in improved sound reproduction in build or in more advantage shaped cabinets for 10”, 8”or 6.5” speaker chassis I have finish myself building a 2nd Interactive (SEALED/VENTED) enclosure as a Test Sub and that in a split module type with an internal Interactive EQ unit. As the Images show this unit is build with an 8” TB woofer, but the same shape of this cabinet could well accompany 10” chassis. Of course there has to be give & take as it all only will work in relations with speakers for smaller volumes to keep the cabinet size as small as and then for example it can also be used within configurations like (SP 8” & EQ 8”) – (SP8” & EQ 10” working on it now) or some approach I’m working on as well is like (SP10” & EQ 8”) – (SP10” & EQ 10”) Etc. By using any of these would have a quiet different outcome so correct relations like say 1 to 2.1 or 1.7 or 1.4 have to be established first for any of these volumes to be able to apply calculations to get somewhere to make it work.

This project now is simple with a SP 8” & a 8” internal Interactive EQ unit so with it must be in it’s volume relations correct yet I have to say I was a little out with this test build yet only by about 0.5 to 0.75 Liter but still out – still short for the tuned side. Well, can be fixed on this one but could become messy on a fully finished unit as the Horn you see is NOT what I would use to finish off a cabinet, but is ONLY for way easier of tuning. OK, now before going further into this I like to also say that this unit is not tuned in a way by say (port Diameter to Length) as in when you would make up a vented box, but as a high pressure (High Velocity Chamber) …. 


**** On my No.1 project I came across problems which I by now seem to have worked out so that I can start soon to complete that as well. This unit was build with a 10” Interactive EQ unit exchangeable with an 8” unit in a type East-West configuration, and my problems I had were of a kind I never came across before so I shelved it for a couple of month to investigate further & work out a fix and yes as mentioned I think that I did found that fix.

**** Anyway, now on my 2nd project I did everything very much the same, but with some further improvements of items I learned from the first project. This build is also for 8” or 10” Interactive EQ unit, but this time I started off with an 8” and as this was build in a type North-South configuration, split two piece module which came up this way much sleeker & more refined. 

**** I like also to state once again that these projects I’m working on over 18 month now (& mentioned in this thread & others before!) are presently (Interactive SEALED/VENTED) units, and NOT just single Sealed nor vented enclosures nor a Band pass in what ever order - NEITHER. The closes I ever could come in my long research was in PRINCIPLE a Strait 6th order Band pass, but again just in principle as it is NOT! & that out of many reason including that it has a pre tuned Interactive EQ unit installed as well as a if needed a tunable vented area - NO tubes. **** 
Well, all a little bit more complex if it comes to it, but this basics info should do for the moment!

OK, I’m actually quiet taken by the outcome of this project until now as it puts any of my own expectations to shame in my search for such a new type of project with a solid tonal foundation without Boom-y, Muddy bass reproduction (with speaker chassis 10” & below!) because this unit is able creating quiet accurate realistic bass reproduction characteristics with a real deep & powerful yet smooth, extended musical bass, clear & highly articulate with a precise action simple a bass I had not experienced before. By trying to describe any of it’s qualities I do have to say overall it is just in a way a completely different sound all around, and that is why I used the expression of a ‘Musical Bass’ which came to mind.
This project contains a (2 IN 1) and all the advantages of the sound reproduction of a SEALED as well as a VENTED enclosure are displayed. In case of this project it seems to be all so far on the right track for me to accomplish sooner or later my own idea of this type of an driven Interactive SEALED/VENTED EQ unit not only as a bass enclosure, but also incorporated within other configuration which was in general my first aim overall.

As you can see from the Images in this test enclosure I used presently two different ways of exhaust ports – (NO tubes), and which by the way are able as in this test cabinet in stages to be closed or at least been restricted for more sound performance evaluation values Etc. I have to say that this all is not as easy at all as there are hardly or better I say no information or even calculations available I could much go by …. I know already for certain that the lower port could have been larger in size to offset the size of the upper port, but again the upper is the most important one at the moment as I used that for a final tuning so rather then altering the lower port right now I prefer it this way as the unit it self is weighing around 37 Kg! Also the final placements of any ports differs completely from the present set up in shape & location, but for testing this way was much easier to use.

Following a short overall Info:
Decoupling of the driver & EQ unit was very important to me (as always) so I used inner & outer decoupling supports as well as dampening is a main issues for me, and with that an approach to mount / decouple the enclosure with rubber mounted Spikes or once again using an internal type Dampening off my own design which I call ‘Air Cushioning - Area Trapped Air Arresting Motion Suspension‘ on the walls as well as some normal Etc. Everything in the way of mounting was done with Threaded Rubber nuts and I used 12 gauge pro-audio wiring with a Neutric loudspeaker connection point. 

A lot of testing has been done on this unit; for example on the different behaviors of the very powerful & quiet high velocity sound energy volume deriving from the Interactive EQ unit which made this all worse while as in the end I had the pleasure to listen to a great lot of my music program material, but quiet in a different more enjoyable & less exhausting way!

I know this all is quiet complex and more or less all in a greatly unknown territory so simple nothing what can be taken from a web site or book as there is nothing …. But in any case I hope somebody can/will enjoy and can be a little bit more open minded for something quiet so different from the Norm!


rgs UpperCut


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## bmmoser (Mar 26, 2016)

Technically, to be a widow maker, the wood should come from a tree that was fatal to the man felling it ☺

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