Wanted BIG BASS: Big room open to an even bigger room with lots of windows! - Page 2

That sounds like an Ideal sub system for your marvelous room. The sound quality of the Dayton subs are superb. Comparing the sound of them to a commercial sub I would say the sound like the Velodyne DD18 and JL Audio F113, if you've heard those. My Dayton subs are a great match with my Aerial Acoustics 7B's so you'll have no worries there with your 801's. Even good 300-500 watt plate amps will drive these units fine. Of course something can be said for kgvet's recommendation too.

With a limited budget, horns will get you more spl per $$ than anything else, IF you can spare the space, and don't mind the loss of extension. With $1500 in the budget, you can build approx four 15" loaded 20-22Hz basshorns (F20, THT, etc) and an amp to power all of them. For a slimmer profile, look at the THTLP or think of a group of tall tapped horns:

http://www.volvotreter.de/th.htm

Soemthing like what paulspencer described, 15" loaded, tuned to 20Hz. Tapped horns almost always need highpassing, unless designed very well.

How loud are you thinking of running? How low? Full reference? Less? Where do you listen now, dB-wise? Deciding that should narrow your choices.


JSS

the sealed cabinets tend to be the least sensitive and so require the most drivers and amps. they are great for small-medium sized rooms where the gain of the room is about 12db/octave and matches the natural 12db/octave rolloff of the enclosure.

the ported tend to employ larger cabinets, have increased sensitivity and max spl vs the sealed down near the tuning frequency.

horns tend to be relatively huge, but can take advantage of the driver loading to come very close to theoretical maximum efficiency, so they have the smallest amp requirements and produce the highest spl.

three w15gti drivers are presented for comparison. sealed and ported in winisd. the sealed cabs use about 12 cubic feet total, the ported ~24 cubic feet+, and the horns shown in hornresp use about 60 cubic feet total.

all are setup for 2000 watts total as the limitation on the amp (666 watts per each of the three drivers), and ~20mm xmax limitation on the drivers.

at 20hz, you get 114db with the sealed, 124db with the ported, and ~131db with the large horn.

Not if the design is halfway decent. I prefer the sound of either one of my horns over the sound of the IXL 18" build that came before them.


I wouldn't run any TH or even any horn in general without highpassing, to be honest. Problems with excursion below F3 aside (and that's a big problem on a TH design), you also run into issues with the harmonics being amplified by the horn over the fundamental.

Another horn built with the Dayton drivers. In various sizes including the above mentioned lopro. http://www.billfitzmaurice.com/THT.html

Here is an idea....I see you have vaulted ceilings. Why not fly a big ass bass horn, or two, from the ceiling and paint them the ceiling color to not be conspicious. No floor print, but not the fight with physics.

P.S. if they are truly flying, I'd opt for a PP horn (or tapped horn) to offset the kinetics.

like this....

http://redspade-audio.blogspot.ca/20...-horns_02.html

Fly it 2-3 feet below the apex of your vaulted ceiling but well above the beams, and paint it your ceiling colour to be inconspicuous.

here is a front loaded horn sketch with the w15gti. it is purpose built per your size requirements. unfortunately, the limited space (height and depth) limit the horn size so only gives about 3db or a little more vs. a ported design. each one of these will do about 120db+ at 20hz, so two should be around 125db+ or so.

there would also be plenty of space in between them for your center.'

another thing ch, you probably aren't going to lose a full 6db per doubling of distance with subs in a room. the models are all for 2pi space (aka sitting outdoors in a field). the walls and ceiling enclose some of the pressure. this is called boundary gain. theoretically is is 6db each time that you cut the the space in half. so a corner loaded sub will have 12db over model for the back wall and the side wall in theory, but it typically isn't that high. all that glass is going to vibrate and turn the sound into heat...hehe which in maine might not be a bad thing...but no its not enough that you will ever feel it like you do with the sun coming through. :-)

the hornresp numbers aren't precise to the physical model, but the small amount by which they diverge shouldn't materially affect anything, unless i have made a major calculation error somewhere.

I agree with everyone that horns would provide the best output, but how do you hide them along the front wall and still install base trim while only having 19" to work with (I assume base trim is 5" height). Mathematically to me the only thing that can work is multiple 12's spanning the length of the front wall. 4 Alpine ported 12's tuned to 21hz would provide 124db+ across the board. That's also in a relatively small 4cu ft enclosure. If there is a horn design with a mouth and box shorter than 15" I would vote that route or the above based solely with room design in mind.

i didn't even think about venting the horn out of the top. that could be an idea too.

Good call! That would allow you to accommodate a 15" sub, and you could stain match wood vents (ie IB floor installs) to conceal the mouth and keep debris out.

"LTD02!!! Love the Limey model! Thank you so much for putting the time into designing something like this. I really appreciate it!"

no problem. once you spend all the time to learn how to design and fold a horn, it doesn't take very long to cook something up. it can also become a little challenge to see what can be done/what is possible.

"What program/method do you use to fold the horn anyways?"

hornresp is the program that most everyone uses to design the horn in order to see how it will perform. if you know that you have 20 cubic feet per horn to work with, you design a 20 cubic foot horn as a start. from there, i use a little bit of intuition and mock up in microsoft word of all things and perform the calculations manually in excel. it's just geometry to translate the hornresp model into physical dimensions. my problem is that all my intuition is in inches and feet and hornresp is in cm and cm^2, so i spend half my time converting back and forth between units! it is a little bit of an iterative approach between the hornresp specs and the physical model until they are in harmony with the objectives and constraints of the plan.

others have spreadsheets that will calculate everything, but i haven't taken the time to learn them.

"Could you either touch on or point me somewhere that explains the pros/cons of Front Loaded vs. Tapped horns?"

i looked around quite a bit on that one and there isn't a strong consensus one way or another. there are people with both designs that report that they are better, cleaner, or whater, than the other. tapped horns are tricky because they tend to have more resonances and frequency suckouts to deal with. that said, they tend to do a little better on the low end for sensitivity. front loaded horns tend to have a much cleaner frequency response toward the top end. so there are advantages to each. it seems that tapped horns work a little better with stronger motored drivers, while front loaded horns seem to have a little more flexibility.

"Looking at the FLH and TH designs I wonder if it is easier to get a low tuned/little bit more gain on a single sheet of MDF with a TH because you're not sacrificing physical space to the sealed volume behind the FLH."

that is probably right in theory, but other aspects are more important.

"I've tried modeling several drivers with the TH, but have found nothing flat as the model you provided or that Volvo's design achieves with a no longer manufactured Eminence driver."

you have to be really careful when comparing horn designs for 'flatness' and sensitivity. if you model in something less than 2 pi space, the response will appear flatter than in 2 pi space. volvo's model is in 1 pi space. that also makes the spl higher than a 2pi space model.

then you have sensitivity. i always use 1w1m in model, while many others use 2.83v, which if your driver has something other than exactly 8 ohms resistance, will generate more power, so it is not a fair comparison. volvo used 2.83 volts and has a driver with an re of 5.27, so he is modelling 1.5 watts.

finding a flat response is a lot of trial and error with different drivers. i can sometimes get a sense for a driver that may work in a particular design, but sometimes i can be surprised, but that may just be me.

volvo has one mistake in that his s1->s2 length is 1cm. s2 is area in front of the center of the cone, so s1->s2 lenth can't be less than 1/2 the diameter of the driver. shortening up that length will make the response appear flatter. i'm not taking shots at volvo's design, just pointing some things out to look for in any design.

the flatness of the frequency response in what i posted was also "cheating" because i clipped off only up to 200hz and then scrunched it down to fit on the page. the peaks and dips appear much greater on my screen. in practice the peaks and dips won't be as bad as in the hornresp model. what the room does to your frequency response will almost always dominate.

some people suggest using "par" for the flaring, but in this case the difference is a db here and a db there. not practically significant.

i'm pretty sure a few folks put together a quick tutorial for what each s1 s2 s3 et al are in hornresp. if you search around, you can probably find it or ask lilmike.

bracing is also required. something like in this picture will work fine.
http://imageshack.us/photo/my-images...aklz7.gif/sr=1
one brace every 16 inches or so should help keep the cabinet from resonating too badly.

I'll be the first to admit my horn knowledge is limited, but in my head my concern is the mouth of the horn would be the same width of the driver at least, and if you front fire using a 15" driver that would leave you with 4" clearance for casing and trim (which is likely not adequate for front firing without notching out the trim/casing). Again since my horn knowledge is fairly limited I could be missing something about driver/mouth size. From a design and output stance I think LTD is onto something by up firing the mouth and corner loading.

In that space volume and placement what I would do is...

Start with 6 Dayton 15 HF's in 3 dual-opposed boxes of 19x18.5 x22ish with 3 Behringer iNuke 3000DSP. Or even just two and then as your budget expands you could add as many as 10 boxes under the window because you have the space to grow. For a total of 17,600watts into 20 Dayton 15's @ 4ohm.

That really is the easy-button solution.

Finding enough power outlets will be your next challenge.

Obviously the LMS Ultra is going to be the best power handling wise, and it's
musicality is on par with the B&W 802 Diamond. It distorts less than just about any other subwoofer on the planet.

But as soon as you say the word 5400, you are instantly looking at $3000+ because you are probably going to need two for a room that size minimum.

You COULD fit it within those dimensions but you would have to mount it vertically like I do but 6 inches lower to the ground, with a box that is wider to compensate the decreased volume of the height and depth restrictions.

My room is just over half the size and volume yours is and my LMS does alright in it, I was able to crack the drywall as you can hear at the end of the video when it is vibrating against the joists.

See replies in bold


Ok decided to come up with something.

3 of these should fit:



Halfspace sim with 500w, Dayton RS15" driver, 15mm excursion:



http://redspade-audio.blogspot.com.a...rn-design.html

Simple to build.

The advantage of dual opposed is vibration reduction. Might help if you end up with pot plants or things on top that might rattle.

There is always a trade off. I tried a lower tuned version, allowing for two of them. Smoother response but 117 db max SPL for one, 123 db for two, -3 dB @ 17 Hz with 300w to each driver.

With the previous version, it can take more power (400w) and has slightly less extension (21 Hz) but 5 db more SPL at 25 Hz.

The little bit of extra extension is probably a lot less audible than twice as much oomph at 25 Hz, but the smoother curve of the bigger one looks better on paper. This is with the Dayton RS 15" driver.

The smaller one is much easier to lift and work on - it's a little bit smaller than my T20, which is light for a horn but certainly heavy enough! When it's heavy, it gets hard to lower things gently to the ground, they tend to land with a thunk! When installing my T20 it landed hard a few times, but I wasn't too concerned because it's an ugly beast under the floor that won't be seen. In your case, something prettier, so don't overlook this side of things.

I'll just warn you now - there's no known cure. It's best to just surrender to the addiction.

Just finished assembling two THT-LP with RSS390's. Cabinets were built to the maximum 36" recommended width. I'm still dialing them in.

My room is a similar size with a 9ft ceiling, but fewer windows. They are being fed by two Bash 300S amps.

This is one of them in a vertical position....



Here's their currrent orientation. Final finish to be determined...







Rattles my deck outside.

Assembled them out of the recommended 1/2" baltic birch plywood. I haven't seen a birch finish that I like so I have some rift-cut red oak veneer in waiting. Once I decide which orientation (horiz/vert) I'll give them a furniture-grade stain and topcoat. Probably black/brown dye stain mix, and satin polyurethane.

I'm still waiting on an OmniMic to mess around with response. The first one was amazing, but after adding the second...

My family room opens partially into the main level of the house, so effective volume is much larger. I'm glad I added the second THT.

THT and THTLP are both supposed to have the same performance. I went with LP's so I could max out on the dimensions and consequently, the low end extension, and still get them through the doorway. If you can get 36" cubes into your house, the THT's might be a better fit around your windows.

Think about how you will install the driver. Current design looks like it needs a hatch. You can use the mouth for that if you place it in the front.

Since the excursion climbs up just above 20 Hz, your only real way to get below 20 Hz is with room gain, if you have enough of it. This is where you think about the trade off between efficiency and extension.

I don't have anything constructive to add but I just wanted to say that your room is awesome. I wish I had a room that cool. Best of luck with your build.