Large Ported Dayton HO18's - AVS Forum
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post #1 of 1058 Old 09-07-2013, 05:22 AM - Thread Starter
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Hey guys! I just purchased 2 of the Dayton HO18's, and I need some help on the enclosure design. I want to go with a large, ported enclosure that is tuned to either 16hz or 18hz, depending on which would be best.

I have no size, space, or WAF restrictions, so I can build as large of an enclosure as I want. I would prefer to use a traditional round port, as opposed to a slot port as my wood working skills are still in the novice category. I will be powering this with a Behringer iNuke 3000, using a MiniDsp 2 x 4 with advanced plug in for the HPF.

So with that being said, can someone please model the driver in a large ported enclosure tuned to either 16hz or 18hz? Which tuning do you guys think would be best? I am open to any suggestions on the tune. I need to figure out the hight, width, and depth of the enclosure, as well as the diameter and length of the port. Can someone help me out on this?
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post #2 of 1058 Old 09-07-2013, 05:40 AM
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hi marty, congratulations. i'll help you out.

EDIT: this is where it stands currently:

http://www.avsforum.com/t/1489541/large-ported-dayton-ho18s#post_23711347




.

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post #3 of 1058 Old 09-07-2013, 05:42 AM
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Quote:
Originally Posted by Martycool007 View Post

Hey guys! I just purchased 2 of the Dayton HO18's, and I need some help on the enclosure design. I want to go with a large, ported enclosure that is tuned to either 16hz or 18hz, depending on which would be best.

I have no size, space, or WAF restrictions, so I can build as large of an enclosure as I want. I would prefer to use a traditional round port, as opposed to a slot port as my wood working skills are still in the novice category. I will be powering this with a Behringer iNuke 3000, using a MiniDsp 2 x 4 with advanced plug in for the HPF.

So with that being said, can someone please model the driver in a large ported enclosure tuned to either 16hz or 18hz? Which tuning do you guys think would be best? I am open to any suggestions on the tune. I need to figure out the height, width, and depth of the enclosure, as well as the diameter and length of the port. Can someone help me out on this?

tuned to 18zh with a 16hz HPF you'd need about a 12 cu foot net box to max out the driver...it's about a 30x30x30 inch (roughly) estimated box including driver displacement and bracing. or you could use sonotube if you have the height for it. gives a smaller footprint... both would use an 8 inch port....29 inches long or 38 inches long depending on the 18 hz or 16 hz tune. although tuned at 16 hz vs. 18 hz isn't that big a difference. you only gain a 1db increase at the 16hz mark over an 18 hz tune.
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post #4 of 1058 Old 09-07-2013, 06:08 AM
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inuke 3000 outputs a maximum power of 820 watts into 4 ohms per channel.

as for tuning, that is a personal preference. there is no right or wrong answer.

your results may end up +/- 1hz or so anyways, so don't get all worried about it one way or another.

10 cubic feet tuned to 17hz would be a good one.

cone excursion only goes to 19mm with 820 watts in model. in practice, it probably won't even be that high.

as for vents, i'd actually suggest a slot port as being the easier build, but that is up to you.

for a round port, one 8" diameter port that is 41" long tunes 10 cubic feet to 17hz.

air velocity peaks around 21 m/s at 17hz, which is fine. use as large of a roundover as possible.

if that vent is too large, one 6" diameter port that is 22" long tunes 10 cubic feet to 17hz.

air velocity peaks around 39 m/s at 17hz, which suggests some chuffing at very high power. again, use as large of a roundover as possible.

if you want to go with a slot port, one 24" wide by 2" tall slot port that is 39" long.

or you could even go for two triangle corner slots that are 7" tall by 7" wide by 40" long.

the easiest build would probably be a rectangular box that is about 24" wide x 24" tall x about 44" long (so the port won't have to be bent), but you will have to work out exact dimensions depending on your bracing strategy and baffle thickness, etc.

good luck.

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post #5 of 1058 Old 09-07-2013, 06:11 AM
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and the plots:

frequency response, 10 cubic feet, 17hz tune, no filters, 2pi space, 820 watts


air velocity, 8" port (or either the slot port or triangle ports; all these are about the same, roughly)


air velocity, 6" port


three back-of-the-envelope sketches for form factor roughly 24" x 24" x 40" or so

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post #6 of 1058 Old 09-07-2013, 06:23 AM
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NICE work LTD.. that’s a nice variety of suggestions. If a guy went with the sono option, none of them would present any problem whatsoever, although the OP never brought up sono.

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post #7 of 1058 Old 09-07-2013, 06:29 AM
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Quote:
Originally Posted by LTD02 View Post

inuke 3000 outputs a maximum power of 820 watts into 4 ohms per channel.

as for tuning, that is a personal preference. there is no right or wrong answer.

your results may end up +/- 1hz or so anyways, so don't get all worried about it one way or another.

10 cubic feet tuned to 17hz would be a good one.

cone excursion only goes to 19mm with 820 watts in model. in practice, it probably won't even be that high.

as for vents, i'd actually suggest a slot port as being the easier build, but that is up to you.

for a round port, one 8" diameter port that is 41" long tunes 10 cubic feet to 17hz.

air velocity peaks around 21 m/s at 17hz, which is fine. use as large of a roundover as possible.

if that vent is too large, one 6" diameter port that is 22" long tunes 10 cubic feet to 17hz.

air velocity peaks around 39 m/s at 17hz, which suggests some chuffing at very high power. again, use as large of a roundover as possible.

if you want to go with a slot port, one 24" wide by 2" tall slot port that is 39" long.

or you could even go for two triangle corner slots that are 7" tall by 7" wide by 40" long.

the easiest build would probably be a rectangular box that is about 24" wide x 24" tall x about 44" long (so the port won't have to be bent), but you will have to work out exact dimensions depending on your bracing strategy and baffle thickness, etc.

good luck.

is that 820 watts a channel actual real world specs on the Inuke 3000?? I thought that it only did like 650-700 watts real world output per channel like EP4000 does?
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post #8 of 1058 Old 09-07-2013, 06:30 AM
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it is what behringer calls max or peak power.

0.707 * 820 is about what you would call the rms number or about 600 watts or so.

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post #9 of 1058 Old 09-07-2013, 06:32 AM
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Quote:
Originally Posted by LTD02 View Post

it is what behringer calls max or peak power.

0.707 * 820 is about what you would call the rms number or about 600 watts or so.

ok, that makes more sense...
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post #10 of 1058 Old 09-07-2013, 08:26 AM
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Hey Marty.

Some time ago i modeled the Dayton as well. Its not exactly what you asked for as i modeled with 9 cft, 20Hz box tune and 700 watt input. Maybe you still can use it to get a little inspiration. If interested take at look here from post #8.

http://www.avsforum.com/t/1462099/need-help-for-diy-sub-dayton-audio-ho-reference-18
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post #11 of 1058 Old 09-07-2013, 10:56 AM
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I had another thought for marty. home depot sells "handy panels" which are pre-cut plywood and mdf. they tend to be available in several sizes including 3/4" x 2' x 2' and 3/4" x 2' x 4'.

the nice thing is that they are all cut identically (at least the last time I looked), so that would mean only one cut per board would have to be made and if you chose to make it 48" long, no cuts on any of those boards would be needed.

if you buy a bunch, ask for the same price as though it were a full sheet, and you may get it. :-)

green 4x2 panels would not have to be cut. yellow panel would require one cut off of a 2' x 2' handy panel. just an idea...

front


right side


the choice of a vertical slot port is for cooling. cool air enters at the bottom, while warm air circulates out the top. :-)

such a design would work out to about 11 cu ft or so net after internal bracing, driver, and port area...

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post #12 of 1058 Old 09-07-2013, 01:52 PM - Thread Starter
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Wow! Thanks the help guys! Being that I have a Lowes and a Home Depot locally, I believe they both have the pre-cut 2' by 4' and 2' by 2', I think that I will go with the last design that LTD02 suggested using the 2' by 4' panels that are available pre-cut.

If I do that, what would be the optimal slot port for either a 16hz tune, or a 17hz tune? I like the idea of using a side ways slot port, I just need to figure out the optimal hight width, and depth of the slot port, and the hight, width, and depth of the front baffle?

The rear panel would just use a complete 2' by 2' sheet, right?
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post #13 of 1058 Old 09-07-2013, 02:26 PM
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the rear panel would actually work like the baffle and be one 2 x 2 panel that is cut down by a little bit (about 1.5" of an inch or so) to fit inside the side panels.

here is how the back would work using this method.

you can see that it is one handy panel size tall, but would need to be trimmed down to fit inside.


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post #14 of 1058 Old 09-07-2013, 02:32 PM
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or... [front / back]


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post #15 of 1058 Old 09-07-2013, 02:35 PM
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that gives roughly a 11 cubic footer, so for 16-17hz the horizontal slot port, it would be 21" x 2.5" x 39" long.

21" would be the 24" width of the handy panel minus 4 width of 0.75. as can be seen in the picture two widths for the side panels and two widths for the bracing panels inside the slot, so 24 - .75 - .75 - .75 - .75 = 21" wide net

the inside could just be braced with some 2 x 4 lumber in a + pattern or two. it doesn't really matter what bracing strategy is used so long as it is good. :-)

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post #16 of 1058 Old 09-07-2013, 02:40 PM
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and if you recess the front baffle (i.e. push it in by about 2-3", then there will be room to flush mount a grill.

i'm not sure how it could be made any more simple and look so good. maybe this could become a kit. :-)

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post #17 of 1058 Old 09-07-2013, 02:56 PM
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all done!






EDIT: BASED ON WHAT WE KNOW NOW, INCREASE THE LENGTH OF THE SLOT PORT TO 40". THIS WILL GIVE ABOUT A 17HZ TUNING POINT AND ABOUT 160HZ FIRST PORT RESONANCE. I CAN'T EDIT THE ORIGINAL POST ANYMORE BECAUSE OF THE NEW SOFTWARE IMAGE LIMITATION.
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Last edited by LTD02; 09-15-2014 at 08:35 AM.
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post #18 of 1058 Old 09-07-2013, 04:02 PM
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The Marty Sub Attacks!

what folks are say'n

"This sub is now playing loud & low! I am so impressed! ...I think that I will be ordering two more of these HO18's for use in 2 more Marty Subs, for a total of 4!" -Martycool007

"Yah, I,m lovin' having a capable sub in my system! I was shaking all sorts of things in my theater/office/storage room." -mhutchins

"...the 2 I have in my room are simply destructive beyond belief in the midbass..." -wormraper

"...now that i have had my marty sub broken in for a few days I can give my review. Lets start with WOW! ...bass is incredible. Chest thumping, pant ruffling, couch vibrating. Measured a couple of scenes and hit 115 db. Marty really puts my hsu vtf 15 to shame. It crushes it and is so effortless." -chalugagp

"...to be honest..I guess I wasn't really prepared for the brutal power of this sub. I don't want to sound like a newb, but Jesus H Christmas story! When Hulk is jumping around from building to building in Avengers, and you can feel the impact of his punches, and when he screams and your clothes start to vibrate...like he's yelling in YOUR face lol. I can't wipe the grin off my face! Uh...the Darla scene in finding Nemo.....my poor house. I have plaster walls in my living room...may need to switch to drywall. Anyway, long story short, un-freakin-believable!" -sooly1

"First listening impression... be careful with the gain knob. Made my eyes cross with some EDM..." -atredeis

"I just finished installing the driver and, of course, I had to give it a quick listen (just a couple of familiar songs). One point: this thing is freakin scary!! ...when I run my Marty variant by itself, it is a pure monster- - plain and simple. It has a lot more output than my dual PSAs combined and that’s easy to measure, hear and feel." -atabea



what it is
originally conceived as a simple subwoofer that could be built using 2'x4' "handy panels" from home depot or some other store and would have huge performance using either the 18" dayton 460ho driver or the stereo integrity 18ht subwoofer.

the purpose of using "handy panels" is that they come in approximately 2x4 foot length, so the top, bottom, left and right side would require no cuts and many of the other panels would only require one or two cuts. handy panels also tend to be pretty well square, which will help keep the whole project squared up.

tuning is targeted at around 16-17hz. net enclosure size is about 11 cubic feet internal. external dimensions are approximately 2x2x4...feet. :-)

drivers that work
there are a surprisingly large number of drivers that work well in the marty sub, but the exact cutout dimension for the driver are slightly different for each driver. just a heads up.

- dayton rss460ho 18" (shown below)

- stereo integrity 18" ht (shown below)

- fi q 18": http://www.avsforum.com/t/1449579/4-18-fi-q-hts-project-spring-13#post_23753360

- ist/mach 5 audio uxl 18": http://www.avsforum.com/t/1489801/bought-four-sealed-18-cabinets-on-a-wild-hare-direct-me-to-a-driver-setup-at-least-competitive-or-superior-to-jtr-captivators/90#post_23756830

- ist/mach 5 18.2.2. 18": http://www.avsforum.com/t/1489541/large-ported-dayton-ho18s/600#post_23881394

- tc sounds lms ultra 18": http://www.avsforum.com/t/1489801/bought-four-sealed-18-cabinets-on-a-wild-hare-direct-me-to-a-driver-setup-at-least-competitive-or-superior-to-jtr-captivators/90#post_23756764

...will add more over time.

happy member chaluga with his driver for scale



drawings and architectural plan
member chalugadp put together a 3d drawing (nice work chalugadp!):



side view (with chalugadp's bracing strategy, other strategies are good too):


my drawings are no where near as slick :-)









inside (side view) (bracing not shown) (flush mount grill):


a couple of bracing concept designs:


mhutchin's bracing strategy as viewed from back and front (note the braces are cut just a hair short, this ensures that they will fit without having to perform exact measurements/cuts and simplifies the build).

rear view:


front view:


front view with baffle added (and grill panel dry fit):


front view with top added:


for the grill, small blocks of wood could be placed in each corner and the grill would mount to them with magnets or something.



that way the driver would have plenty of room to move and would not have to be flush mounted or anything fancy.



in wood finish:


in duratex:


bare naked :-) (unfinished mdf):



winsid model
here is the winisd model for 11 cubic feet, 17 hz tuning. green lines are the stereo integrity and dayton drivers. they have essentially the same performance. the blue line is for 3.5 cubic foot sealed subwoofer. all are at 1100 watts of power.

so why build a big ported sub? as can be seen, with the same driver and the same power, the larger ported cab produces around 10db more spl than its little brother in the lowest notes. doubling up a small sealed and doubling power into it will provide +6db, so it still won't quite be as powerful as the ported around the tuning frequency.



...since it needs a name...it shall be known as The Marty Sub! :-)

build instructions

forum member mhutchins provided an excellent detailed write-up of how he constructed his Marty Sub!

http://www.avsforum.com/t/1496365/another-ltd02-designed-sub-build/30#post_23876882

thanks mike!

additional tips

gluing panels and securing with braces while glue dries is ideal.

without braces, gluing and securing with brad nails or spax screws (which are designed to not split wood) is an alternative method. predrilling holes for screws will further reduce any risk of panel buldgeout and/or splitting.

wood glue is fine if the panels mate with no gaps. if there are gaps between the panels, pl premium can be used an an alternative adhesive. it expands as it dries to fill in gaps, but is more of a mess to work with.

this is a spax screw that was used with success by member wormraper. this is NOT for securing the driver. this is for joining the panels.



video instruction on how to wire a speakon connection if going that route:
http://www.youtube.com/watch?v=hCjpP0kYBAU

if you need an "extra hand" while gluing the boards together, corner cleats can really help keep things lined up. just pre-drill and don't use overly large screws or you could blow out the wood.



mhutchins did a nice write up with pictures on his grills:

http://www.avsforum.com/t/1489541/large-ported-dayton-ho18s/300#post_23781856





chaluga did a nice job finishing in cedar plank with black piping:







atredeis' helper offered encouragement during his build:






hopefully a couple folks will double check those dimensions. it assumes 3/4" wood is used, which might be right for MDF, but plywood may require slight measurement modifications depending on how many sixteenths they cheat. :-)

this sub is approximately 12 cubic feet prior to bracing and driver or roughly 11 cubic feet net.

the port will appear too short if modeled in winisd using k=0.732 for end correction. this is discussed in detail on the third page of this thread.

home depot and several other home stores have a saw like this and will make cuts for $0.50 or sometimes just do it for free. that makes things easy for a project like this! is it "kit simple"? no. but getting close. :-)






edit: this page is revised based on new information from this thread with the primary changes being a modified port and note that mdf handy panels are not exactly 24" x 48" since they may be cut from 49" x 97" mdf.

edit: more
when i originally threw together the martysub v0.1, we didn't know how significant a difference there is between actual tuning and theoretical tuning using winisd's calculator for port length. i designed the port height to be such that the port length would be in the ballyard of 3 feet long in order to keep the first port resonance out of the pass band.

it was pointed out by member nograveconcern that there is a calculator that considers this difference: http://www.carstereo.com/help/Articles.cfm?id=31

there is also a study of various ports and tuning frequencies for stuffed and unstuffed enclosures, here: http://www.troelsgravesen.dk/vent_tuning.htm

now, in light of the new information, i'd suggest changing the port height to 3.0" and going with a length of 36.0" for a "best guess" tuning of 17hz.

that is based on a multiplier "in my head" that i can't explain based on intuition from looking at all this information. it also happens to be consistent with the "best guess" in the calculator linked to at carstereo.com

the increase in port height will reduce port velocity by a hair and will not take much volume out of the sub overall.

so the new plan for the slot port, subject as always to revisions and updates, is 21.0" wide X 3.0" tall X 36.0" long. that targets a tuning of 17hz in a cabinet with a net volume of 11 cubic feet (a martysub).

member chaluga measured his marty which has a 2.75" tall slot port, 21" wide (effective) and 36" long, with light stuffing in the enclosure and gets 16hz, so this confirms 21.0" wide X 3.0" tall X 36.0" long will give about 17hz and 21.0" wide X 3.0" tall X 32.0" long will give about 18hz.

this works out to about a 25% reduction in slot port length vs. what winisd suggests. in other words, using the winisd length results in a port that is tuned too low. the port must be made shorter than what is shown in winisd to hit the target tune.

the addition of lots of bracing may bring the net enclosure volume down a bit, which pushes tuning back up a little high. that is no problem because the addition of stuffing can be used to bring the tuning frequency back down some.



edit: even more
ok, thanks to worm, we really went deep into understanding why winisd miscalculates actual vs. theoretical enclosure tuning.

several people have observed this error between theory and actual results and one great post is here:

http://www.troelsgravesen.dk/vent_tuning.htm

ports behave differently depending on how they are mated to the air at the end of the port. this is called "end correction" and is quantified by a mysterious variable called "k".

for ports that dump cleanly into free space, end correction is low, something like k=0.732 on a baffle and even a little lower if the port has no baffle.

for slot ports that are on the ground, the boundary in front of the port and behind the port have the effect of synthetically extending the length of the port.

as a result, these kinds of ports provide a lower tuning frequency than winisd estimates using k=0.732

this picture shows how end correction should increase as one moves more toward a slot type port:



source: http://www.diyaudio.com/forums/multi-way/97204-end-correction-formula-rectangular-port.html#post1148924

i do not speak german (if that is even the language used here), but i interpret it to be indicating whether there is 1, 2, or 3 boundaries reinforcing the port either in front of or behind the port.

there is also some averaging that occurs, so if it is k=1.5 to the front of the port and k=1.0 to the rear of the port, the average would be k=1.25.

here is the link to the calculator:

http://www.calculatoredge.com/new/ventlength.htm#factor

for k=0.732, the calculator gives the same results as winisd. however, the version of winisd that i have for windows 7 does not allow changing of the end correction to other value, hence the use of the calculator.

edit: even more

the original design intention was to make this as simple as possible, but as things go, it got more complicated. i decided to go back and redo it again from the ground up with the intention of a person being able to go to a home depot or other home store, grab some handy panels, have them trimmed down and come home with all the wood required for a marty sub.

the primary challenge is that the handy panels come in a nominal 24" x 48" size, which for plywood is about right, but since a full sheet of mdf is typically one inch larger to allow for the ends to get beat up, the handy panels that are called 24" x 48" are really a little larger. that is fine. so with that in mind, here goes...

Introducing...The Marty Sub "One Cut" Version!

this version has all the performance of the original marty sub (same frequency response, same tuning frequency ~17hz, etc.), but with the added advantage that it requires **only** cross cuts to handy panels. by examining the cut sheet, the advantage of this approach will quickly be seen.

this version sits a little lower and is therefore a little "fatter" than the original marty sub, but this is so that all the internals can be the same panel width as the top and the bottom, even all the braces. since the width of the handy panels can be confirmed at the store before purchase, this makes this version virtually foolproof (at least with respect to cutting the panels).

front view in duratex:


front view grill off:


bracing:
at first it appears complicated, but it was designed to be easy to construct and doesn't require any further cutting of any of the braces.


cut sheet:
a total of 8 handy panels 24" x 48" nominal OR two full sheets of mdf or plywood.
four handy panels that are not cut down.
four handy panels that are cut down thusly:


the cutout for the driver will vary depending on the driver selected.

it is 16.7" diameter for the dayton driver for example.




if all that makes your head want to explode...




it's not that bad. really, it's not. :-)



.

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post #19 of 1058 Old 09-07-2013, 04:07 PM - Thread Starter
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Looks good! I will be starting on the enclosures on Monday. Two questions:

First, how do you figure the four .75" subtractions for the slot port width? From the looks of the model, it appears that the width only needs to be subtracted .75" twice as the right side and the left side are all that would take away from the slot ports width, or am I missing something?

Second, with regards to the baffle, should I just turn the drivers upside down, and draw a trace of the driver's diameter, then cut it out with a jig saw, or should I use a router? I have a pretty nice Craftsman plunge router, but I have never used it. It is my understanding that if I use the router, I would need a circle jig, and a straight cut bit, is that all? Would I just trace the drivers diameter and drill a hole in the line that I just traced, then set the depth of the router and slowly go around the circle trace lowering the depth of the bit a little with each pass?


Again, many thanks to you awesome guys!
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post #20 of 1058 Old 09-07-2013, 04:29 PM
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EDIT: BASED ON WHAT WE KNOW NOW, INCREASE THE LENGTH OF THE SLOT PORT TO 40". THIS WILL GIVE ABOUT A 17HZ TUNING POINT AND ABOUT 160HZ FIRST PORT RESONANCE. I CAN'T EDIT THE ORIGINAL POST ANYMORE BECAUSE OF THE NEW SOFTWARE IMAGE LIMITATION.








in the picture, it can be seen that the bottom panel is a full 24" across.

since the sides each subtract 0.75 from that, the port would be 22.5" across with NO bracing. with two braces each 0.75, that takes off another 1.5". so the end result is effectively a 21" wide slot port.

"Second, with regards to the baffle, should I just turn the drivers upside down, and draw a trace of the driver's diameter"

you wouldn't want to do that or your driver will fall right through the hole. the CUTOUT is 16.7" diameter for that driver. just lay a yardstick diagonal from corner to corner and draw a line. then draw a second from the other corners to create an X on the front baffle. the center of the X is the center of the baffle. from there draw a circle that is EXACTLY 16.7" diameter and cut that out. plop your driver in and you are good to go. :-)

"Again, many thanks to you awesome guys!"

no problem marty! good luck with it. they should be pretty darn good performers!

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Last edited by LTD02; 09-15-2014 at 08:34 AM.
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post #21 of 1058 Old 09-07-2013, 08:59 PM
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i tried to measure out the internal volume fairly accurately and before driver and bracing it comes out to 12 cubic feet on the button.

if the driver and bracing take up about 1 cubic foot (guesstimate), that leaves 11 cubic feet net, so everything seems right on a second look.

i just double checked the winisd model starting from scratch and the results are essentially the same as the 10 cubic footer back in post #5 (actually with 1/2 a db or so more output at 20hz and 16.9hz tune), so no need to repost them all. excursion is in check at just over 19mm and first port resonance is up around 176hz (which is well out of the passband).

home depot should have 1" x 3" lumber which will actually measure 3/4" x 2.5" so that works nicely for the port braces. only need to trim them to length.

the internal bracing is your call, just do it up pretty well in there.

i must admit that i kind of like this one. :-)

take lots of pics as you build them if you wouldn't mind.
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post #22 of 1058 Old 09-07-2013, 09:27 PM
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as for the protective highpass, a simple 2nd order butterworth at 17hz and one parametric eq at 16hz, q = 2.0, gain = 3.0db will put you in good.

here is the response with and without the high pass and eq filter engaged:


and excursion with and without the high pass and eq filter engaged:

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post #23 of 1058 Old 09-08-2013, 12:12 AM
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with LTD02,s dimensions the box would be 10.55 cu ft net with bracking (estimated using simple 1.5 x 1.5 rods criss crossed every 7 inches....10 cu ft flat if you recess the front baffle by a couple inches for the speaker grill.

http://img208.imageshack.us/img208/9728/jdig.png

only thing "wrong" in the calcs from his dimensions was the slot port calculating .75x 22.5 x 39 as the ports volume.. it should be 3.25x22.5x39 since you're supposed to calculate the whole volume of the slot port including the air passage when calculating into internal volume

edit: I take that back. it WOULD be 11 cu ft... I miscalculate the height as 24 inches instead of 25.5 (24 inches for the panel plus 1.5 inches of mdf for the top and bottom)
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post #24 of 1058 Old 09-08-2013, 01:12 AM
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Quote:
Originally Posted by Martycool007 View Post

Looks good! I will be starting on the enclosures on Monday.

Don't forget to post pictures !
:-)
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post #25 of 1058 Old 09-08-2013, 01:36 AM
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What do you guys think of incorporating much lighter 3/4 ply of some sort instead of MDF? Of course VF BB would be best. If weight is no problem then just discard, but if it is a concern, the ply would come in so much lighter. The last two 4 cf sealed I built out of two layers of mdf must come in at close to 150 lbs apiece.

Looking forward to your project Marty.

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post #26 of 1058 Old 09-08-2013, 03:48 AM
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LTD

I wonder why you model with 820 watt. As far as i know 880 watt is the peak value for inuke, corresponding to ~620 watt RMS. Most (all?) speaker simulators calculate -peak- cone excursion based on the RMS value. I think you would get a more "correct" simulation of cone excursion and max SPL if you input the RMS value in the sim? As I understand it you are overstating the power of the amplifier by sqrt(2) by inputting the peak value. Any thoughts on that?
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post #27 of 1058 Old 09-08-2013, 03:52 AM
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Not if he's running the amp bridged. U can get more than 820 watts out of an inuke 3000
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post #28 of 1058 Old 09-08-2013, 04:08 AM
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Well, that is true. As far as i know it will give approx 2000w RMS bridged in to 4 ohm, but in that case 820w seems kind of arbitrary? Also I think OP is planning on running two subs? I'm not second guessing LTD. I'm Just asking :-)
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post #29 of 1058 Old 09-08-2013, 06:00 AM - Thread Starter
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Quote:
Originally Posted by splotten View Post

Well, that is true. As far as i know it will give approx 2000w RMS bridged in to 4 ohm, but in that case 820w seems kind of arbitrary? Also I think OP is planning on running two subs? I'm not second guessing LTD. I'm Just asking :-)

Yes, I will be running two of these Dayton HO18's off the iNuke 3000. I am unsure, at this point, if I should run one sub on each channel, or run the iNuke bridged for both subs.
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post #30 of 1058 Old 09-08-2013, 06:07 AM - Thread Starter
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Quote:
Originally Posted by steve nn View Post

What do you guys think of incorporating much lighter 3/4 ply of some sort instead of MDF? Of course VF BB would be best. If weight is no problem then just discard, but if it is a concern, the ply would come in so much lighter. The last two 4 cf sealed I built out of two layers of mdf must come in at close to 150 lbs apiece.

Looking forward to your project Marty.

I would really like to make these two giant enclosures look as nice as possible. I would prefer to use some 3/4" plywood just for the fact that I can stain it a very nice dark color, as opposed to MDF which would not look as good with stain.

My local Home Depot & Lowes both have 3/4 birch and 3/4" pine in the precut 2' by 4' and 2' by 2' panels, although I am not sure if the birch is Baltic Birch because it just says "Birch" on the sign. Also, how do you guys think Pine would work? I really wish I knew where to get some nice veneer because that way I could use MDF and still get a nice finish.
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