Decisions decisions. Horn or reflex???

Ok, here's the situation.  I need to build some more bass bins for my system since things keep changing round, stuff gets stuck in installs etc etc.

I have 4x 18Sound 18LW1400 drivers.  My options are: Build two double 18" reflex boxes the same as I've designed for some other people recently.  All reports are they sound very good.

Or:  I've almost finished a design for a WSX style horn essentially the same size as the reflex boxes, optimised for the same driver.

Simulations say:  In singles, the reflex will be more efficient below about 70Hz, no surprise there.  Above that, the horn has it.  Crossover point in use will be 120-160Hz.

Once I get two or more horns per side the difference in low end becomes less significant.

Other issues:  The reflexes are easier to build and will be compatible with another local system.  Cons are needing more amps to run more than a pair.

With the horns I have enough drivers to build four and I could run up to six off one amp.  But the build is more complex and they might not be so good just one per side.

So.... what would you do?

System usage is mainly for live bands and other general PA useage, party DJ's etc.

Bandpass up to 120Hz???

I had considered sticking a pair of the drivers in some X1 style cabs and probably will at some point but they wouldn't be right for the system as-is.  Tops are twin 12" reflex + 1.4" and like to work from about 120Hz upwards.  My plan for ages was to use a 15" horn kick section and 18" bandpass but it's just not practical for the jobs I do at the moment and I still haven't got the designs right.  So I decided to shift to a compromise single bass section for the time being.

Just looking at the simulations again there is some discrepancy between Hornresp and WinISD for the reflex box.  I seem to remember this coming up before.  It's about 3dB difference!  If Hornresp is right then the above statements are true, however if WinISD is right (and it does look more sensible) then the horn is looking more promising.

Cheers. I think you've just come up with the answer regarding the simulation differences.  Will have to alter one of them so that they are both modelling the same voltage/power.  The two programs still give different response shapes though.  Hornresp seems to think you get a lot more output from the port than WinISD.

I know the double 18" reflex is the most sensible and if it was anyone else asking for the same advice that's what I would tell them....

But I have this terrible habit of wanting to do something different.  I think I'll probably end up building a pair of the horns, won't cost me too much. At least then I can try them against the reflex and see which I prefer.  I really want the transient response you just can't get from a reflex.

I built a pair of wsx style horns which were used just single a side and found they coped quite well with a minor eq boost at the low end (about +4db). I would say if the horn you've designed is similar width wise then 120hz is about the highest you would want to drive them due to the parallel walls causing the horn to boom a little higher than this. Must say though  I absolutely preferred the sound over reflex, really clean sound that sounds effortless even at high power. Since you're using dual 12" reflex for tops they'd probably be well matched too, ie the tops shouldn't run away from the subs output wise. What low cutoff did you design your horns for? Mine were solid  to 40hz which I found was plenty adequate for most types of music.

Mark, I guess it's a mixture of the above.  I looked at various ways of folding a horn into a sensible size/shaped cab and the WSX seemed to me the best way of doing it.  So, it's ended up very similar indeed but I will be doing things like the throat slightly differently, it'll be slightly different external dimensions etc.

I didn't set out to copy the WSX as such.....

And yes, with three per side the response flattens out very nicely.  40Hz easily, probably useable to 35Hz.

Re parallel walls.  I don't know if it'll work but I'm hoping to use the bracing to break up standing waves between the parallel walls so there aren't too many sections with the same dimensions.

I think the only way to settle this is just to try them.....  Now to find time to do the woodwork.

Thanks for reporting your own experiences guys.

Swap drivers? Ick. Go with the horns I say if you don't mind the extra work. 18" reflexes are very boring in Southampton these days, they're everywhere!