12" Cab Diary Continued

[RichardH]

What @Chienmortbb and @Phil Starr said!

[Pea Turgh]

The only reason I can see for building two is so you can also use them as an absolutely banging pair of hifi speakers.

 

Unfortunately, Mrs Turgh does not share my vision.

[Chienmortbb]

16 minutes ago, Pea Turgh said:

The only reason I can see for building two is so you can also use them as an absolutely banging pair of hifi speakers.

 

Unfortunately, Mrs Turgh does not share my vision.

True, try playing some Sade through it/them. Mmmmm!

[LukeFRC]

I have one. I have the ply all cut up ready to make another (sub version. With no horn) … but I feel no need to

[Phil Starr]

1 hour ago, Chienmortbb said:

True, try playing some Sade through it/them. Mmmmm!

True, in the development we listened to a lot of female vocals to check the midrange was honest. Sade did sound good. As did Dolores Keane

[Bassybert]

Thanks for the replies everyone, to be honest I was thinking about building 2 because I was looking at the cutting plan and you can get 2 boxes from a standard 15mm sheet of ply. (and let's be honest who doesn't love a bit of real oomph sat a few feet behind 😂)

 

I can see that it's going to be a powerful cab and that one would probably be enough for almost any situation. I could still make 2 from one sheet and sell it at cost on here if anyone's interested and wants to supply their own drivers, crossover etc.

 

 

Edited September 29, 2022 by Bassybert

[Phil Starr]

@LukeFRC you are a hero. 
 

im so pleased you got there with this project @glambass

[GlamBass74]

So am I! All thanks to Luke! 

 

It's an impressive piece of kit.

 

First fire up, I was all ready to say "yeah not bad, not bad", but I could feel my ears smiling as I played a few favourite songs through it.

 

The long suffering missus really liked it too and she's been subjected to many an A/B test.

 

Already considering selling my very recently purchased, expensive, highly regarded cabinet 😁

 

Next up is a gig. I need to make a grille first though as that speaker needs protecting! 

 

Roll on the next project! 😁

 

 

[chyc]

@GlamBass74If you could report back how you get on with the grille I'd be very interested. The instructions say you contact an eBay seller, to get something relisted on eBay if it's missing (which it is). Blue Aran lists grilles but they're out of stock. In the end for my current build of the BC110T I went with a circular disc grille. Hella ugly (IMO) but cheap and easy to buy.

 

Saying all that, if you know somewhere where I can get a proper BC112T grille.......

[LukeFRC]

2 minutes ago, chyc said:

@GlamBass74If you could report back how you get on with the grille I'd be very interested. The instructions say you contact an eBay seller, to get something relisted on eBay if it's missing (which it is). Blue Aran lists grilles but they're out of stock. In the end for my current build of the BC110T I went with a circular disc grille. Hella ugly (IMO) but cheap and easy to buy.

 

Saying all that, if you know somewhere where I can get a proper BC112T grille.......

I made my own…

[stevie]

If you intend to use the cab on its side, @Bassybert (I take it you're using a full-size amp), you'll need to alter the horn cutout on the baffle to enable you to turn the horn round 90-degrees. Otherwise, your plan should work. However, like the others, I think one cab is plenty for most people.

[stevie]

That's a really nice build, @GlamBass74. Well done.

 

The grille is always a sticking point with DIY cabs. The round ones never look right. Luke's looks the business though - and neatly finished with piping.

[Stub Mandrel]

22 minutes ago, stevie said:

If you intend to use the cab on its side, @Bassybert (I take it you're using a full-size amp), you'll need to alter the horn cutout on the baffle to enable you to turn the horn round 90-degrees. Otherwise, your plan should work. However, like the others, I think one cab is plenty for most people.

 

Could also mirror image the baffle for one cab, so that the two tweeters are vertically aligned.

[stevie]

Good idea, @Stub Mandrel.

[Bassybert]

2 hours ago, Stub Mandrel said:

 

Could also mirror image the baffle for one cab, so that the two tweeters are vertically aligned.

Hypothetically, if I did that presumably there would be a negative effect when using one cab vertically on it’s own?

[stevie]

Mirror imaging the baffles won't make any difference to the performance of one cab on its own, but turning the horn round will reduce the vertical dispersion at high frequencies.  The dispersion will still be good for the player standing in front of the cab  and it won't affect the sound out front.

[Stub Mandrel]

5 hours ago, Bassybert said:

Hypothetically, if I did that presumably there would be a negative effect when using one cab vertically on it’s own?

 

Not as long as the tweeter is still at the top.

[chyc]

Can someone please explain this to me like I'm 5: why do identical (not mirrored) baffles have not vertically aligned tweeters when on their side?

[Chienmortbb]

11 minutes ago, chyc said:

Can someone please explain this to me like I'm 5: why do identical (not mirrored) baffles have not vertically aligned tweeters when on their side?

The horn/compression driver in the BC112 MK3 is offset to one side of the cabinet, the port is in the other side. If you mirror the baffles, providing you stack the two cabs the right way, the two “tweeters” will be as close as possible and tend to act as one. The further apart they are, more frequencies will be subject to what is called “comb filtering” where some frequencies are amplified and some attenuated. 
 

In the real world, it may not be a big deal but it’s certainly good practice. 
 

The irony is that when I built mine, I fitted the baffle the wrong way round. Of course with a single cabinet  it does not matter. 

[chyc]

5 minutes ago, Chienmortbb said:

The horn/compression driver in the BC112 MK3 is offset to one side of the cabinet, the port is in the other side. If you mirror the baffles, providing you stack the two cabs the right way, the two “tweeters” will be as close as possible and tend to act as one. The further apart they are, more frequencies will be subject to what is called “comb filtering” where some frequencies are amplified and some attenuated.

I think the fog is clearing. So it's that the tweeters, with the cabs on their side, will be vertically stacked in either configuration, but if mirrored they're closer together for better vertical dispersion?

 

Thanks

[Chienmortbb]

15 hours ago, Bassybert said:

Hypothetically, if I did that presumably there would be a negative effect when using one cab vertically on it’s own?

Having used the cab with the horn in both directions I would say that that there Is a difference but if you had the horn optimised for the can lying on its side, the loss of dispersion would be counteracted by the increased height of the horn.  It is possible to enlarge the horn cutout to enable the horn to be mounted either way. You then only have to unscrew four screws, rotate the horn,  and replace the screws.

 

In that case I would suggest using threaded inserts and machine screws to hold the Horn/Compression driver in place. 

[funkydoug]

Would adding a switch for the 2nd cab's tweeter help?  In my experience one tweeter , if allowed to, can keep up with two woofers. You just switch off the tweeter in the bottom cab.

... I am no expert.

 

[Phil Starr]

21 hours ago, GlamBass74 said:

Already considering selling my very recently purchased, expensive, highly regarded cabinet 😁

Expect a rash of people searching your posts to see what that was

 

[chyc]

6 minutes ago, Phil Starr said:

Expect a rash of people searching your posts to see what that was

 

Done and done. And I mean done.

 

[LukeFRC]

55 minutes ago, funkydoug said:

Would adding a switch for the 2nd cab's tweeter help?  In my experience one tweeter , if allowed to, can keep up with two woofers. You just switch off the tweeter in the bottom cab.

... I am no expert.

 

Or just building one as a sub without the horn …