BG20 Horn Project

[@Michael]

Hi all,

I have decide to make my first project. I choose full range speakers for easy connection purpose. No problem with crossovers etc. I have purchase two Visaton BG20 and waiting now for delivery. Two similar project I found online, both are horn/tube style.
I do not have accurate saw to cut board with necessary precision so need to buy with cut service, most probably from B&Q (I live in UK). Material will be plywood 18mm.

 

[gipetto]

If you don't have an accurate saw i suggest you hire a carpenter to build for you. I did so and have no regrets, apart from wishing i had done so sooner and not made costly compromises on inferior designs. i'll keep an eye on the thread all the same as i also own that driver so it is of interest, not too many builds out there, good bang for the buck though.

 

[nandappe]

Visaton BG20 has a weak engine, so it can't drive back-loaded horn.
Bass-reflex, ML-TL, and TQWT are recommended.
I use TQWT.

 

[@Michael]

I use TQWT.

How it sounds?

 

[nandappe]

BG20 + TQWT is a natural sound that feels good on my ears.

 

[@Michael]

I get some 18mm, hardwood plywood from B&Q, cut for size in the shop. Two boards (1220x2440mm) with cutting service, cost me less than £100. I gonna stored flat for a few days before gluing it together.

 

[@Michael]

Next day - next step. Holes for speakers are cutted. Should I use a gasket between the hole and the speaker? It`s gonna be a huge horn🙂

 

[Davor D]

Yes, gasket between driver and cabinet is highly recommended. You dont vant air pressure leaking there.

 

[nandappe]

To drive BH with BG20, it is good strengthen the magnet.

 

[@Michael]

Looks good, any idea where I can buy it?

https://www.ebay.co.uk/itm/141741874573?hash=item2100795d8d:g:JrUAAOSw7gxerH-C

Is that any good?

 

[nandappe]

The neodymium magnets I used are 8 pieces of 30mmφx2mm.
The magnetic flux density is 200 millistella.
110 yen (about $1.00) per piece in Japan.

I think that there is no problem if the size is close.

https://www.ebay.co.uk/itm/393408537433?hash=item5b98f9e359:g:FqgAAOSwCTNg0sgZ:PL_CLK|clp:2047675

 

[@Michael]

Gluing in progress. Plywood is not as strait as MDF. Have a problem with tension. Need few days to finish first box.

 

[@Michael]

First enclosure are done today, need only fill the gaps and holes with wood filler. Now I choosing paint colour. I did a sound test, not bad at all🙂

 

[nandappe]

Dear @michael,

Please crimp it tightly, the continuity will deteriorate.

 

[IG81]

Better yet, solder them.

 

[@Michael]

To be honest, I had some problems with crimping. I did my best, using the tool attached on photo. I know is not perfect, but I was doing it for the very first time, holds tight. Soldering sims to be even more difficult. Besides, I have no soldering gun.

 

[castlesteve]

To be honest, I had some problems with crimping. I did my best, using the tool attached on photo. I know is not perfect, but I was doing it for the very first time, holds tight. Soldering sims to be even more difficult. Besides, I have no soldering gun.

You should learn to solder. It’s really not that hard. Just experiment with a few pieces of wire. Just remember to heat the wire and let the wire melt the solder.

 

[GM]

Better yet, solder them.

......with Sta-Brite or similar spec/quality silver bearing solder for best performing joint. 😉 The downside is one needs at least a 45 W iron [ancient 60 W Ungar still soldering bras, steel rods, etc., just fine for me] or mini-blowtorch.

 

[GM]

holds tight

FYI/FWIW, 'tight' doesn't = a good electrical connection, i.e. done right with the right tools, crimps, for the app it's a cold weld joint [void free] and why soldering it also is a good plan for DIYers that can't justify the tool's/component's relatively high cost unless making a lot of something.

 

[GM]

let the wire melt the solder.

Ditto any soldering joint. 😉