Speaker building and designing thread.

[Jiggles]

errr thats whats all stated above!

[nigelwright7557]

errr thats whats all stated above!

I was just summing it up in general terms.

[Tom]

Just thought I would post this up.

This is a sim of 2x 12" drivers. The bad news is that they are 1000 watts rms each, so would need at least 3000 watts to get the spl out of this cab.

When I say 3000 watts rms, that means I can turn the amp down and not let it clip or produce distortion. This means I could run the driver as the max input of 1000 watts rms to get a max spl.

[Excalibur]

Dont know if it s possible but:
2 in series one in paraell. Comes to about 5.6666

IE

+ -
| |
| |
------/---------
| |
| |
--/------/-----

Unless my maths is wrong, I make it 16/5 =3.2 ohms.
1/(8+8) + 1/4 = 1/R
1/16 + 4/16 = 5/16

[Tom]

Well things are getting a lot better.

Just thought I would post up a new plot. This is a 6th order bandpass cab like the Mackie SWA1501 and the RCF Art 705-AS for example.

The mackies uses a 15" driver, needs 500 watts and gets 128db peak ranging from 36hz up to 120hz.

THe RCF Art 705-AS also uses a 15" driver which needs 800 watts and get 130db peak ranging from 40hz up to 120hz

My design uses two 12" drivers that only require 400 watts rms each, so that matches the input of the RCF being 800 watts. It peaks at 127.9db and ranges from 26hz up to 200hz. If you put in 1000 watts, it then peaks at 128.5db but can only run from 27hz up to 200hz. Much better than a reflex cab for the ultra notes in R'n'B, Bassline ect.

Here is the SPL plot for the cab using just 800 watts input.

[501damian501]

interesting tom...

[Tom]

Just did a few more tweaks and now it peaks at 131db. Lol.

I think this is quite impressive for a cab that is under 100 litres in size. Lol. My aim is to try and keep the size the same as the mackie, db tech and rcf 15 inch cabs. The only difference is that my design goes a lot lower. Lol.

If I can get the cab even smaller then the better really. The only con is that the cab will weigh quite a bit but still working on that.

I think this is the beast to build. The plots seem to be very good with the impedance spikes lower that 20ms I think. Xmax hits at 27hz so could run down to this with a strong limiter in place.

[Tom]

Well after some R&D I have now my final product. This is a single bandpass cab. It uses a single 12" driver which is in a small-ish cab. The cab can go as low as 18hz before hitting the xmax but we dont need that so, you can set the hp filter at 30hz. I would say the cab can go as high as 110hz before dropping off too much so it satill covers a good range.

The driver is only rated at 400 watts but is able to cope with 800 watts rms providing you are not playing music like dubstep. If you are playing dubstep I would say have a mix input of 600 watts, no more.

Below are a few charts.

[Daryll]

Looks good tom.

Is the cab a front radiator or a horn design ?.
If its a front mounted speaker , getting down to 18hz is excellent ( and I agree you never need to go that low )

Daryll

[Tom]

Looks good tom.

Is the cab a front radiator or a horn design ?.
If its a front mounted speaker , getting down to 18hz is excellent ( and I agree you never need to go that low )

Daryll

Thanks.

It's a bandpass design cab, like the RCF Art sub and the Mackie 1501 but with a twist. The port for the rear chamber goes into the front chamber. Don't know if you understand that. lol.

Inside of the cab will look like this


This is good because the cabs is quite small and goes down really low, but you get reduced SPL, hence only getting 117.9 db at 400 watts input.

18hz is 97.6db lol.

I was hoping to use this cab design for cinema and even car audio. Plus it also saves having to have large bulky cabs that are horn or reflex loaded. I use my car for djing, so I would rather have to move around more smaller speakers than a few larges one, as when packing a car, it is easier to pack smaller items, in my case anyway. lol.

4 of these cabs gives you just under 130db at 1600 watts rms and just under 133db at 3200 watts rms.


You might say well the DB Sub 15 has a max spl of 133db. Well I can tell you that it will only be at a certain frequency.

For example, on the Makie 1501 sub, it has a peak od 128db but if you look at the specs listed here, most of the power is only at 50hz to 70hz, what about the rest???

In my design, most of the power comes from 40hz right up to 80hz, before it starts to roll off. So, if you have two if these cabs, it wil be slightly under the 1501 in spl out, but will be louder when playing lower notes as well as the higher notes (up to 110hz).