cabinet build - from scratch

[fryer]

So a few years ago I bought an Eminence Delta 12A, 400 w at 8 ohm, and made a box for it, as shown. Never used it, so thought I would now build a proper cab for it.

I have some 20 mm ply, and the size I need it to be. It's gonna be vented, and I've asked Eminence for their recommendations on this.

I am seeking suggestions for covering, and grille material.

[SubsonicSimpleton]

Might be worth contacting Bill Fitzmaurice and asking whether that particular driver would be a good fit for any of his designs.

[fryer]

How ?

[TheGreek]

I bought an Apprentice Cabinet furniture piece to turn into a cab which will look like a piece of furniture.

I'll be following this thread for build guidance..

[SubsonicSimpleton]

Bill is a member here @Bill Fitzmaurice although I think he has messaging switched off, hopefully he will be notified that I've tagged him, look at the thread and contact you or post in the thread.

 

If that doesn't happen, you could try signing up to his forum and contacting him there

https://billfitzmaurice.info/forum/

[Mottlefeeder]

Eminence provide speaker design details for most of their speakers, but you have to go to that speaker page to get to them.

For your unit they offer this - http://www.eminence.com/pdf/Delta_12A_cab.pdf

In a large box, it goes deep, but has limited power handling (2.5 cu ft / 60Hz / 50W). In a smaller box, it handles more power, but does not go as deep (1.35 cu ft / 78Hz / 100W or 0.75 cu ft / 100Hz / 200W).

It might work in a monitor wedge, but not very well as a bass guitar speaker.

David

 

[fryer]

2 hours ago, SubsonicSimpleton said:

Bill is a member here @Bill Fitzmaurice although I think he has messaging switched off, hopefully he will be notified that I've tagged him, look at the thread and contact you or post in the thread.

 

If that doesn't happen, you could try signing up to his forum and contacting him there

https://billfitzmaurice.info/forum/

Thank you. I'll try him.

[fryer]

58 minutes ago, Mottlefeeder said:

Eminence provide speaker design details for most of their speakers, but you have to go to that speaker page to get to them.

For your unit they offer this - http://www.eminence.com/pdf/Delta_12A_cab.pdf

In a large box, it goes deep, but has limited power handling (2.5 cu ft / 60Hz / 50W). In a smaller box, it handles more power, but does not go as deep (1.35 cu ft / 78Hz / 100W or 0.75 cu ft / 100Hz / 200W).

It might work in a monitor wedge, but not very well as a bass guitar speaker.

David

 

thanks for finding that. I found the spec sheet, but couldn't find anything about a cab for it. But it's a 400 w speaker ? 

[Mottlefeeder]

400W @ 1KHz but at lower frequencies it runs out of cone movement well before that.

David

[fryer]

So I may not get the 400 w out of it, but I am going to proceed anyway. I have decided the size, and how to make it.

I have asked Mr Fleabag to add some comments, as I have just read his 15" speaker cab build.

I tried Bill F, but no reply. 

I will need help with sourcing 'tuff cab' & edge protection later.

Where can I get the ports ?

I can do a diary if that's normal ?

[fleabag]

You can get ports from screwfix.  100mm and then cut to length according to the cab design requirements

Its called Manrose Pipe   https://www.screwfix.com/p/manrose-round-pipe-white-100mm/15872

I sealed mine round the circumference with Silicone

The grill i already had from an old Peavey 1x15  Black Widow cab

The Tuff Cab paint can be bought from Blue Aran

Edited May 24, 2018 by fleabag

[fryer]

thanks. If I'm using 20 mm ply, I guess I won't need to brace it ? 

[stevie]

On 20/05/2018 at 21:11, Mottlefeeder said:

It might work in a monitor wedge, but not very well as a bass guitar speaker.

David

Much as I applaud any effort to DIY your gear, you really are wasting your time with that driver. Not to put too fine a point on it - it's rubbish for your particular purpose. Just trying to save you some grief.

[fryer]

 

In what way is it not suitable ? Sorry, I don't understand these things.

And what driver should I go for ? I am pairing it with an ATS    S 310x2, which has a 10" driver plus a passive speaker, rated at 500w at 8 ohm. 

[stevie]

The problem is the design of the driver: it's more like a guitar speaker than a bass guitar speaker. As Mottlefeeder said, you need to put it in a very large box to get any bass out of it, and when you do, it runs out of excursion very quickly. So it won't go very loud and is unlikely to keep up with your ATS cab.

You should be looking for a driver with a decent excursion and a power handling of about 300 watts. The Beyma SM212 works well as a bass guitar speaker for about £70. You're unlikely to find anything better at a lower cost unless you pick something up used on eBay (not a bad idea). You can get all your bits and pieces from Blue Aran, but the Beyma is a lot cheaper directly from the Beyma distributor, LMS.

[fryer]

thanks Stevie. I'll get one. I can't find LMS though ( but I've found lots of learning management systems ). Where can I get cab design for it ?

[stevie]

Sorry, fryer, it's LMC Audio: http://www.lmcaudio.co.uk/acatalog/LMC_Web_Catalogue_12__Drivers_53.html.

- although they're not much cheaper when you add VAT.

Plenty of cab designs on this very Basschat forum. In fact you're spoilt for choice. Start here:

 

[Phil Starr]

Good Luck with this, I'm sure you'll get plenty of help from people here. 

[Happy Jack]

Yes, I'm assuming that you already have enough scratch?

[fryer]

thanks for your help Stevie and Phil (whom I have messaged, and who has replied. ) I'll get started then. 

[fryer]

So I'm going to use Phil's cab design, but change the dims slightly to suit the size I want, being 348 wide x 440 high x 300 deep internal. This gives 46 litres, less a bit for the speaker itself ( as advised by Phil ).  I'll work that out tomorrow. 

[fryer]

The original box had ports. Maybe I'll try harder this time. 

Is there a formula for calculating the diameter and length ?

Also, wiring. I'm using a peavey minimega, with 2 speaker connections ( parallelled ? ), and pairing with an ATS cab which also has 2 connections. Do I just run one cable from each amp outlet to each speaker ? Does that then split the power between the 2 cabs so they only take half the amp output each ?

[Phil Starr]

The best thing you can do is to download Winisd. It does all the calculations for you and will calculate the best sized box to give you the deepest, flattest response the speaker can cope with. Then you can change the box size and see on the graphs what that does to the frequency response, It'll calculate the port sizes too and everything else you can imagine about the low frequency performance too and you'll learn loads about speaker design in the process. 

You'll have to put the technical specs of your speaker in manually though, once you've done that the rest is easy.

If that is too much for you one of us will calculate a suitable port size for you, probably using winisd.

[Phil Starr]

Couldn't resist it I've modelled your cab tuned to 55Hz and compared to my 30l cab It will give you just over 2dB more bass from 100hz down to 40hz (fundamental of bottom E). That extra box volume will give you noticeably more bass in other words, at the cost of a little power handling but power handling is still good, there's a dip to 300W at 90Hz and it handles 180w at bottom E which is pretty good, way better than the Eminence you started looking at. In practice you don't get a lot of fundamental from the pickups so unless you start using stupid power and an octaver you won't have problems at all in any normal use. There's still a bit of extra 'punch' at 120Hz but it's not a bad frequency response at all.

Use one port of 110mm (plastic waste pipe) 15.5cm long or two 64mm (guttering downpipe) vents at 11.2 cm long. (or 3 at 19.2cm) You'll get a little wind noise at full power but you probably won't notice it in practice.

Edited May 28, 2018 by Phil Starr

[fryer]

thank you so much Phil - I wasn't looking forward to doing that. Richard