I’ve been modeling drivers and talking to various people for awhile now, designing a very high sensitivity 3 way for parties and the occasional DJ gig.
I’ll be using an SEOS waveguide for my CD (probably Beyma CD10ND) and a waveguide from limmerhorn for the 8NSM64, that’s specifically designed for that driver.
limmerhorn produces a waveguide for a 15” woofer as well. The woofer Im leaning towards is the Faital Pro 15FH520-4. It’ll be in a ported cab around 4cuft tuned around 45+ hz. They will NOT be full range, I will have dedicated subs 100% of the time. My question is, would I get any benefit from loading the 15 in that horn as far as directivity and SPL go? I’ve never heard of anyone doing this, but in theory it seems that horn loading this driver as well would make the directivity match much better, and I think if it works out audibly, that it will look incredible aesthetically as well. Thanks guys!
Also feel free to comment on any other of my choices and give suggestions if you’d like.
I’ll be using an SEOS waveguide for my CD (probably Beyma CD10ND) and a waveguide from limmerhorn for the 8NSM64, that’s specifically designed for that driver.
limmerhorn produces a waveguide for a 15” woofer as well. The woofer Im leaning towards is the Faital Pro 15FH520-4. It’ll be in a ported cab around 4cuft tuned around 45+ hz. They will NOT be full range, I will have dedicated subs 100% of the time. My question is, would I get any benefit from loading the 15 in that horn as far as directivity and SPL go? I’ve never heard of anyone doing this, but in theory it seems that horn loading this driver as well would make the directivity match much better, and I think if it works out audibly, that it will look incredible aesthetically as well. Thanks guys!
Also feel free to comment on any other of my choices and give suggestions if you’d like.
I guess you wanted to build something like this: https://www.prodance.cz/nd374-lak.html (please use Google translate to read the description) or this https://soundgear.co.uk/orbit4.html (but that is with 12" bass).
The Megaton thing is using a "planar waveguide" which looks like it is only a simple frame around the woofer.
By hornloading, you would need some really large horn to be really useful - at least JBL 4560-sized IMHO.
The Megaton thing is using a "planar waveguide" which looks like it is only a simple frame around the woofer.
By hornloading, you would need some really large horn to be really useful - at least JBL 4560-sized IMHO.
There is not enough information on that site to really know what's happening. Maybe you could guess that it will make the 15" act like it's just a little larger.
Yes. There will be a slight improvement in the directivity at slightly lower frequencies using that "cowling" for a 15" woofer, but so much on the horn gain. There are always at least two benefits of horn loading that occur:
1) a dramatic increase in SPL gain on-axis (~15 dB), usually requiring at least a 1/4 wavelength of the horn path length itself at the lowest frequency desired, and...
2) there is an extension of the lowest frequency downward at which loss of directivity control occurs. Loss of directivity control occurs at the frequency where the horn mouth is half a wavelength at the lowest frequency point desired--in the vertical and horizontal directions separately if the horn uses a non-circular or non-square mouth. This is usually called "directivity gain".
So what is the effect of slightly lower directivity control frequency? You can do the math to see the frequency where it reaches 1/4-wave axial path length (point #1 above), and it loses directivity control (point #2 above).
There are more benefits of horn loading once you use the effect with placing that horn mouth within a 1/4 wavelength of a room boundary, which extends the effective path length of the horn to room dimensions (with only ~3 dB loss in horn-loaded SPL), with notably 25 dB lower distortion at lower frequencies--modulation distortion. (This can be a larger distance than anticipated.) A bit more on that subject here. This enables much higher SPL operation in the lowest frequency region, needed because of the human hearing system's need for much higher average SPL at lower frequencies due to equal loudness effects--otherwise called "Fletcher-Munson" effects.
Chris
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I'm massively dubious that it does anything of real benefit. LF horns are large for a reason.
If they’re going to be that massive for any benefit, I may just horn load the CD/Mid and front load the woofer. I’m going to have to move these every now and then so I want to keep them under 100 pounds or so for 2 people. I’ll also have a hypex FA503 in each cab as well.
1/4 wavelength of 80hertz is around 3 feet or so, so i suppose i wouldn’t see any real benifit until around 200 or so.
I know you have quite a bit of experience, do you have any advice on that 15” woofer?
Thanks!
Thank you so much for the input! When I get a chance I’ll send you a better message back but I’m at work right now.
Not on that specific driver beyond that my experience with the FPs has been good with those I've used and I'm packing for a house move so I'm on my laptop which doesn't have excel to model the box for you.
My suggestion is to front load the NF and HF and use 15s as direct radiators. If you need multiple drivers to get the SPL and LF extension you desire, my advice would be to mount them singly in enclosures even if that makes them a bit larger in internal volume to say half a dual, to make load in/out easier. A 1x15 ported box is much nicer to move on your own than a 2x15; I used 2x15 PPSLs at the end of my PA owning time, and I wouldn't do it again. After my move, I'm going to build a small PA again for my Church and other small functions and they will be multiple 1x15 enclosures (JBL2226 because I already own them).
Well the 15’s in the 3 way are only going to go down to around 50hz, and up to 500-700hz. I’m not designing them to play full range, I’ll have 4 sql 15’s from stereo Integrity for those frequencies. I’ve already got my first box built at 4cuft tuned to 28hz and waiting on Nick to ship the first one. Based on what I’ve calculated my mid will be 103db 1w/m in its horn, the tweeter is around 111 1w/m, and the woofer is 98. The Hypex FA503 I’ll be using has individual gain controls, as well as DSP so that I can adjust my gains and filtering accordingly. The 4 15’s will be in individual boxes and ran by either an NX-6000 2 channel or NX4-6000 4 channel. I also have a minidsp 2x4hd on the way as well. Should be here tomorrow.
Thank you, me too. Also, if you could find time to model that driver at some point could you? I’ve already modeled it in WinIsd but I’m not super savvy, I’ll post my results when I get home to my computer so you all can see. Thanks!
I'm busy for the next day or so, but I will if I get the chance: I don't have it on this machine.
Also, I was going to use an SEOS waveguide for the CD, but it appears that it wouldn’t match the directivity of the 8” mid well at all. At +_ 500hz from 2,000, the SEOS 10 is around 70 degrees, while the 8” mid loaded in the limmerhorn 870, at the same frequency, would be around 45-50 degrees. Does anyone have experience with a horn that would work well with the Beyma CD10ND and offer similar dispersion around the crossover point I’m planning on?
Also, I’m curious on what width the baffle needs to be for the 15”. I’m not certain on how the baffle will affect the dispersion or directivity of the woofer, if any.
Also, I’m curious on what width the baffle needs to be for the 15”. I’m not certain on how the baffle will affect the dispersion or directivity of the woofer, if any.
I just modeled it in WinIsd, in a C4/SC4 box. It put it at 5.11 cuft @ 38.8 hz. The SPL graph makes sense but not so much on the others. I’ve used WinIsd to get the proper box size for subs, but I’m not certain on what I should be looking for in terms of a Lf driver in my 3 way. Not sure which curves need to be observed and for what, to compare which is best. I also uploaded a dispersion plot of the 8NSM64 in the limmerhorn 870, as well as the SPL graph.
Also worth noting, they have a comparison of a B&C woofer in the 15” flare on the site that i overlooked. It shows roughly 5 more db output from around 150-500 hz with the flare, than direct radiating. That benefit alone seems like it’s worth the time if it’s reasonably priced. May be a bad question but I’ve never tried horn loading in a bass reflex cab before. Do you run into any other issues with this? Thank you!