Crossover Points for Full Range Loudspeakers

[LR Audio]

Hi All,

Quick question to the wealth of knowledge here.

I am designing some PA style loudspeaker cabinets;

1 is a 15" driver (500w) + 3" (1.5" exit) compression driver (80w)

the other is a 12" (400w) + 1.75" (1" exit) (50w)

I have been looking around and cannot seem to find any solid answers, but what would be the best crossover points (approx) for these cabinets?

My inital instincts told me 1.2k for the 15" and 2.0k for the 12", any suggestions?

Thanks for your help.

Sam.

[Cal Weldon]

We aren't able to help without more info on the drivers.

[LR Audio]

Frequency Response:

15" = 39Hz - 2.3kHz
12" = 52Hz - 3.8kHz
3" = 600Hz - 18kHz
1.75" = 1kHz - 20kHz

All +/- 3dB

Anything else you need to know?

Sam.

[tinitus]

I would surely keep it below 1khz, be it 12" or 15"

In my world that would still be streching it
I have always considered 300hz as max xo point for such woofers
But this is a new world it seems

[Cal Weldon]

Originally Posted by LR Audio

Frequency Response:
Anything else you need to know?

Sam,

If this is a serious question then you are a long way from being ready to build speakers.

We need the T/S parameters.

[LR Audio]

Originally Posted by tinitus

I would surely keep it below 1khz, be it 12" or 15"

In my world that would still be streching it
I have always considered 300hz as max xo point for such woofers
But this is a new world it seems

Hi tinitus,

Well yes i can see where you are coming from, in an ideal world you would have a driver inbetween a 15" & 3" but this is for a live sound application. A 3 way speaker would not really be feasible because it would make the enclosure too big to cart around. I have some 12 + 1 cabinets at the minute which use around 2.4, but they've always been lacking a little mid range so this is why i thought possibly a little lower?

Thanks for your response though.

[LR Audio]

Originally Posted by Cal Weldon

Sam,

If this is a serious question then you are a long way from being ready to build speakers.

We need the T/S parameters.

Well maybe, but I wasn't after a mega accurate answer. I don't have access to the Thiele/Small values. They didn't get stated with the speakers so I don't know. I was just wondering whether anyone had any suggestions, (without getting too picky on the details) with whether these figures were around the right area's. Tinitus's response was kind of the response I had in mind he just misunderstood my application for the speakers...