Newbie here, please help

[rca]

Greetings,

I am a newbie here so if my questions seem dumb, please excuse me as I am an audio lover and not much of a tech.

Anyhow, I've recently picked up a pair of empty cabinets that are in nice condition and want to make good use for them. Each cabinet has cut out holes for 2 12" woofers slots (bottom) and a slot on top that looks like for 18 sound XT1086 horn/wave guide. Dimension are about 40" tall by 20" wide and 14" deep.

What drivers would you recommend for me to put in the cabinets. I would need crossovers schematics as well as it would be a lot easier for me to copy/using existed proven design.

For horns and drivers, I am thinking of XT1086 and BMS 4540ND or 4550 or whichever you recommend. I am open to suggestions for the 12" drivers. I have a budget of $500~$600 max for all the parts altogether which include all horns/drivers, woofers and crossovers parts.

Please share your opinions/thought on what I should use. My main amp would be a 10 watt tube amp. I also have a 41hz class D 25wpc that I use from time to times. I can also use an old GAS amp that is 80wpc.

I forgot to mention that cabinets are sealed design and looks like they are about 7cubic in volume.

Thank you in advance and I am looking forward to hear from you all.

Nathan.

[1Michael]

I believe that most of us build boxes and crossovers to match the drivers not the other way around. There is a little bit more to designing speakers than slapping some drivers in a prefab box...

[engr_dave]

A two-way with 12" woofers (using a horn that only goes down to 1.5KHz) is a pro sound "make a lot of noise" solution, not a hi-fi solution. No 12" drivers that I know of are smooth into the kilohertz range and even if there were, they would beam like a flashlight.

If you decide to proceed, ignoring the ragged midrange and poor off-axis response... go ALL the way and bi-amp it like a true pro sound solution. Behringer and DBX/Driverack make some decent low-cost electronic crossovers.

Team 'em up with cheap Behringer or Nady pro amps and you can rent out for live or DJ gigs. :T

[JonMarsh]

With a high slope crossover, you might be able to squeeze an Aurasound NS12 up that high, as it's first cone break up mode is over 2 kHz. BUT, it is going to beam considerably, and you'll have to pad down the XT108t and driver that you choose- look at some of the BMS compatible parts. So, you'll probably be able to get on axis looking OK, but the power response will be uneven.

Also realize that a crossover for a horn is trickier than you might imagine, as waveguide and driver combinations tend to have bumpy impedance curves, which need to be EQ's out flat with a zobel network to get a passive crossover working correctly. As an example, the impedance curve for a DDS ENG1 waveguide and BMS4540 driver, with conjugate networks and resulting impedance.









That is just a zobel network, not a crossover.

Another problem is your budget- the driver and waveguide will be close to $200 each. That's close to $400 of your budget. High linearity 12's like the Aurasounds aren't inexpensive. Even cheap Pro sound drivers won't make your budget- typically $100 to $125 each.

The volume of your cabinet may be OK- for good bass extension into the 20's, about 75 literes is ideal for the NS-12's. A good two way crossover setup passive doesn't fit within this budget, either, considering driver cost.

[engr_dave]

Thanks Jon
I didn't know NS-12s would go that high.

"high-slope crossover"
"bumpy impedance curves"

...sounds like a ideal application for active. The Behringer DCX2496 with adjustable slopes (up to 48dB) & delays looks good. Would break rca's budget, though with the suggested drivers/waveguides. Could always cook up an easy analog 4th order LR with cascaded 2nd order Sallen-Key sections.

Requires some electronics knowledge of course...

[JonMarsh]

The NS-12 is remarkably linear in frequency response....



But that high there will be beaming and some energy storage issues.

Remarkably, harmonic distortion, 2nd and 3rd, are very, very low up to 1700-1800 Hz.

[rca]

How about using a single NS12 with a set of horn/driver. For the other 12 slot, slap in a subwoofer and drive it with a plate amp. Perhaps some suggestion for a driver that would work well for a simple first order crossover.. I can probably strech my budget to a $1000.

[Operandi]

How about using a single NS12 with a set of horn/driver. For the other 12 slot, slap in a subwoofer and drive it with a plate amp. Perhaps some suggestion for a driver that would work well for a simple first order crossover.. I can probably strech my budget to a $1000.

At $1k I think the question should be should this be done, not can it be done, as there are better & proven uses for $1,000 in DYI audio.

[rca]

You are right. Thnx. I just hate to see a nice pair of cabinets wasted...

[Operandi]

You are right. Thnx. I just hate to see a nice pair of cabinets wasted...

If you really want to save them perhaps you could just come up with a new baffle to accommodate a new set of drivers that would work well in the internal volume you are given to work with.

[rca]

Good idea. I want to throw in a 15" woofer and some horns/compression drivers. I am OK with crossing the woofer at 1600hz with a simple inductor.

Which horns/drivers would have nice natural sound from 1600hz and up with a simple cap and a LPAD (to match volume level of woofer.)

[Dennis H]

Which horns/drivers would have nice natural sound from 1600hz and up with a simple cap and a LPAD (to match volume level of woofer.)

Errrr, sorry, none. This forum might be better titled the crossover forum. Look at some of the completed designs for examples. The crossover is the heart and soul of a speaker and it takes a lot of blood, sweat and tears to get it right. (Sorry about the painful cliches. ) If you think 'oh, yeah, by the way, I need a crossover, maybe a cap and a coil,' you've come to the wrong place. Many of the designs here spend twice as much on crossover components as on the drivers. If you really want to learn about this stuff, I'd suggest starting with:

Speaker Building 201.

There's a lot more to designing a speaker than throwing some drivers in a box.

[rca]

No hard feeling. As I mentioned on my introduction post:

"I am a newbie here so if my questions seem dumb, please excuse me as I am an audio lover and not much of a tech."