12 inch subwoofer for my home system (first build ever) MINI-SCOOP (?)

Hello everyone,

I'm new to the forum and first I would like to thank all the members who contribute every day to share precious knowledge about diy sound system builds.
About my question:

I'm aiming to build a 4-way sound system inspired by typical systems used for dub/reggae music but in a smaller size. The system will be an home system, hopefully usable for small parties with max 20 guests.
I've already found a box design that I would want to use for mid-bass (kick) (already build but not loaded with the raccomended driver): the design

I've spoken to Jim Frize (the designer of the box mentioned above) a couple of days ago and he suggested me to pair it a whit a 2x12 inch scoop or a double 12 inch ported enclosure to hit the low-bass.
However, I'd like, just temporarily, to pair it with a single 12 inch mini scoop for economic and transport reasons. I know that, going this way, I probably can't hit low enough but it's ok for now on been my first build ever.

I've seen a lot of build plans for a 12 inch mini scoop just searching on Google "12 inch mini scoop" but all raccomended drivers are too expensive for me or not mentioned at all ( something like: "just use a 12 inch driver, no matter which u choose" but if i learned something in the last couple of months, scraping web pages for infos, is that this is not the way to handle DIY SS builds ).
I'm looking for a driver in the 80-120€ price range.
Here some drivers that I've seen but I didn't know exactly if they are good for what I'm trying to achive:
  1. Fane Sovereign 12-300
  2. the box Speaker 12-280/8-W
  3. Turbosound TS-12W350/8A
Many thanks to all the forum members who will want to help me. I'm a beginner and I'm here to learn from those who know more than me. I'm open to any advice you can give me.

From Italy :)

 

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Sir, my personal experience with scoops from my pro-sound days (a very long time ago) was that they were long throw devices and not well suited to domestic use. If you wish to have a speaker for use out-of-doors or in large spaces, then perhaps they ware worthy of consideration.
 
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Well, any light membrane, low excursion speaker would be bass-shy.
Personally my speaker journey was accompanied by some Little books, and I Remember myself playing with the idea of making that JBL style scoop .
Funny that when I discovered this site I was fascinated by the Karlson design.
But those are things from the past!
Nowadays I keep away from those designs and I prefer to concentrate on the sound coming from the speaker without any interference ( technical and also semanthical) from the error signal.
I Guess that a big WAW Is what's you're After, so Cyclotron guy wasn't offrail when thinking of a wideband.

Another hint : look for local or National ( postal service works...) ADS ...you'll find many drivers.
 
I'm a reggae/dubhead and like reggae soundsystems, but like said before, scoops are midthrow horns, not fit for small spaces. There are a few designs that work in small spaces (like the Staxx Miniscoop) but those are not open plans, only availeble build by the company. And scoops, when used as single, don't go very low in general. The trick of reggae sounds is using them in groeps of 4 so they couple and go about 10Hz lower than tuning of the single box. With scoops for home use, we say the bass is for the neighbours, not for you.

But it would be better to use tapped horns or TL speakers for sub at home. They use similar techniques as scoops (backloaded horns) and are fit for home use (short throw) and go low on their own. I'm building a retro "weight & Treble" reggae sound for domestic use and use the Beyma 12BR70 in an MLTL for that. The example i'm using as inspiration, King Tubby's Home Hifi also used (Jensen) scoops, but i don't.
 
Member Nigelwright always says that he's satisfied by Fane in a scoop, if I catched it right :giggle:
Not to mention member Indianajo with his Peavey obsession.
Not a pun! Simply those should not be headlines in speaker practice...
I mean, millions of pages spent for making an soundproof enclosure and..Boom! A plastic shell might suffice.
Ten million pages spent on analyzing wave sounds ...well, sound waves, and you end in hearing the tunnelized reflection-refraction of a tapped horn ?
 
Dave, the kind of scoops used in reggae sounds are tuned lower than in hifi, and are subwoofers. They are mostly in the 30-40Hz region, and when set in a stack of 4 more like 25-32hz. And they got a coloured sound that is very fit for reggae and dub. It's not a clean sub like a sealed one, but that is the goal.

I and the OP are talking about this kind of sounds that he wants to make in a smaller format:
1678905644389.png

(design and build by Stakx)

I know the guy behind these and heared them and they go very low and very loud. This is how a dub sound more or less is build (altough most do it diy, not a commercial build like this). And those scoops are tuned to 30Hz and get there.

But i agree that scoops are not the most easy or efficient or clean way to get that low. There are many better options, certainly for hifi use.
 
frugal-phile™
Joined 2001
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Been there done that, so yes.

The enclosures need to be stacked to getthe mouth area.

Here is a sketch of an evolution of the system we did in the early 80s. This one more for cinema than bands.

smallPA-sketch.png


Initial estimate of potential extention is in the low-mid 20s, it takes all 4 woofer bins.

dave
 
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I can see (hear) both Dave and WAXX's point.

Club sound can certainly be fun, albeit difficult to pull off in a domestic environment and generally the antithesis of what the hifi crowd is seeking for a home system.

Gigio9696, I don't believe you are going to get what you wish with a single scoop, Waxx is spot on, you are going to need to build more than one and set them in an array. A single scoop may give you the spectral balance but you are not going to get the impact of an array without having an array.

I went down your path a very long time ago and was disappointed in what I got in a 16' x 20' x 8' room with twin "super-scoops" loaded with 18" eminence woofers without a bunch of EQ.. I'm not sure if an array 2 wide and 2 high would have been up to the task.

Potentially easier to achieve the same in a conventional domestic space with an appropriately tuned box speaker array.
 
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Scoop = 1/4 wave resonator with expanding path to the mouth
Tapped-Horn = 1/4 wave resonator with expanding path to the mouth and driver offset to expand usable bandwidth (compared to scoop)
TL = 1/4 wave resonator typically with constant or contracting path to the mouth.

Basically they're all 1/4 wave resonator alignments, and the choice of which alignment would produce the best results for you depends on how low you want to go and which alignment would be best for the driver that you want to use.

My favorite at the moment out of all of them is the TL, or more correctly, an offset-driver TL, where the mouth is the same or larger than the driver's Sd. I have a hypothesis that how we perceive the quality and "effortlessness" of bass reproduction at low frequencies has a lot to do with the radiating area, which would explain why, even though the vented subwoofer I use in my HT system goes lower, I prefer the sound of my 40 Hz TH...
 
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Many thanks to all the forum members who will want to help me

Hello gigi9696,

There are two scooper models available for download in the website below. You can modify, resize and tune them according to the driver's T/S you intend to use. In the tutorial session you can find videos explaining how to use the model if needed.

https://freeloudspeakerplan.rf.gd
 
How do you measure distortion? Geddes has shown that as typically done gives us little info.

My objection to bandpass is the ugly phase response at either end of their limited bandwidth. A compromise i do not favour.

dave
I don't measure it. I can hear the difference between a direct radiator enclosure and a bandpass enclosure.

If a driver moves, it distorts.

A driver moves less in a bandpass enclosure per a given voltage.

Notice, I have 3 BP's and 1 BR. The 18" BR was a freebie from a church. I built the 2 BP4's and 1 BP6S (15" negative flare tapped horn).

The wooden coffee table on its side has a 2 x 12" BP4 enclosure bolted to it.

My car has a single 12" BP4.

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