What Would You Build with 4 LF21N451's

[Brian Steele]

These are for your personal use, like in your living room??

If I was in that position, I'd be considering an open-baffle solution, two H baffles, two 21" drivers each. And use something like an iNuke 6000DSP to drive them and flatten their response down to 20 Hz.

 

[Fidstang]

These are for your personal use, like in your living room??

If I was in that position, I'd be considering an open-baffle solution, two H baffles, two 21" drivers each. And use something like an iNuke 6000DSP to drive them and flatten their response down to 20 Hz.

Well, I'll be doing a HT room downstairs, so these will be there, but occasionally, they will be brought outside for parties on some property.

I'm currently playing around in HR with 105L sealed boxes for 4 of these. I might do some quick sealed boxes, just to play around with.

 

[globalplayer]

Nice vid.
I would put them in 30 hz frontloaded horns.

 

[chris661]

For domestic use, 4x 21" sealed will be plenty IMO. Make sure you've got DSP to even things out in-room and you'll be fine.

I'd only be looking at THs or ported designs if you want to cause structural damage to your home, and I'm not kidding.

Chris

 

[Fidstang]

For domestic use, 4x 21" sealed will be plenty IMO. Make sure you've got DSP to even things out in-room and you'll be fine.

I'd only be looking at THs or ported designs if you want to cause structural damage to your home, and I'm not kidding.

Chris

No doubt, the whole floor shook from the motor force with these. I think long term, I'll be going bandpass, but for spring these will go sealed. Who knows, maybe sealed will be enough for me. I have a NU12000DSP, that should run 4 of these fairly well. I've tested that amp and it puts out around 94volts RMS for a few minutes on a 7.89ohm load. Should give me close to 1000watts RMS to each driver, per channel driven at 4ohm and keeping it clean.

 

[Fidstang]

Nice vid.
I would put them in 30 hz frontloaded horns.

I'd love to do a huge front loaded horn, but I don't have the space or a way to transport them, when needed. I need to limit the size to a max of 360L per enclosure. I can do that with BR, BP and Sealed. Maybe in the coming years, I'll have the space and transport capabilities, but I have to work with what I got now. For the price I paid for these, I just couldn't pass them up.

 

[MemX]

For domestic use, 4x 21" sealed will be plenty IMO. Make sure you've got DSP to even things out in-room and you'll be fine.

I'd only be looking at THs or ported designs if you want to cause structural damage to your home, and I'm not kidding.

Chris

+1 to this.

I can attest that four 18s in sealed PPSLs run off a CV5000 @ 2ohms in an 500sqft apartment are enough to make the neighbours very unhappy and that was with them running at about -9 from Reference when watching movies, so not even that loud compared to what they could have done...

 

[Fidstang]

I'd be considering an open-baffle solution, two H baffles, two 21" drivers each.

This has me interested and made me think about the ability to easily swap them to other enclosure designs for their intended use. Maybe open baffle for the HT room, then be able to quickly release the entire baffle and swap it onto the other enclosure with industrial quick release locks or similar.

What is the best method for designing an open baffle arrangement in Hornresp? I'm assuming it would be an offset driver with the front side being S1 and S2, then using Ap and Lpt to for the rear of the driver. Is that correct? How would you compensate the simulation for distance away from the walls?