DIY Dayton Titanic MKIII 15"

[Jay481985]

diffy Q gah!!! that why i got out of engineering!!!

aim me and I think that was you on msn email??? lol

[Tom Adams]

For the record.....I too have enjoyed the discourse even though, at times, it's been over my head. However, I feel I've got a general idea of what you're talking about. So........

NO PM's BETWEEN YOU GUYS!! GOT IT??? []

Oh...and jay you said, "Just a tibit, honda spent over 200 million dollars on R&D on oval pistons for F1 or Indy or Cart I forgot but it really got nowhere (hence no oval pistons) but I bet they learned alot."

That's not entirely true. Honda did develop an oval piston engine for their motorcycle racing program. The bike (engine) was the NR500 and did quite well. Honda produced a street legal version called the NR750 (RC40) which was a V-4 design and made a solid 135Hp at the rear wheel which was A LOT in 1992. Not many were made, but were gorgeous bikes with a heafty price tag. Anyhow......

I wonder if an oval cone sub would work?? []

Tom

[Jay481985]

heh tom, were talked on aim for over 4 hours yesterday.

hmm oval pistons I need to read some more, thanks about that tibit

oval cones, heh what the 4X6 car speakers like ovals?

how about some kicker squares hahaha

[Dan1045]

I just recently built a dayton DIY subwoofer. Box came out to be about 2.75 (18.5" cube) cubic feet. Bought a used Dayton 1200 titanic driver on ebay for cheap, wanted flat response and this driver was known for that. High efficiency (90db/watt)and went down to 16hz and 14.5mm cone travel.

Used the Parts express 240 watt plate amp due to the 24db/octave slope. I think this sounds much better and keeps the sub from muddying up the midrange.

I do music and movies about 50-50 and have the sub adjusted where its great on music, you have deep bass if there is deep bass, but nothing added if there is none. Just what I wanted. Music barely challenges this setup. But on a movie with a deep bass soundtrack, turn it up and step back, it will nearly knock you down.

The cabinet is sealed and I used 3/4 mdf with one brace across the middle of the cabinet. I used elmers polyglue. Screwed and glued. I also countersunk the holes and filled with wood putty. Filled it using an old king size pillow poly fill that I wasgoing to throw away. I think all told, I had 290 bucks in it and a sub retail for at least $1200 would be needed to perform as well I think - at least this is what I think after listening to what the retial market has to offer. Still havent veneered it, but it impresses with performance. I will do that after I have my klipsch belle clones finished.

I used a free download program to design the cabinet.

Dan

[Zealot125]

Jay I saw your post about hurricane nuts, but I am still confused as to their use. Could you elaborate?

PS dont worry, I am installing trillian as we speak.

[DrWho]

I just recently built a dayton DIY

subwoofer. Box came out to be about 2.75 (18.5" cube) cubic

feet. Bought a used Dayton 1200 titanic driver on ebay for cheap,

wanted flat response and this driver was known for that. High

efficiency (90db/watt)and went down to 16hz and 14.5mm cone travel.

Is this the driver that you used?

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-404

I get -10dB @ 20Hz so perhaps you're talking about a different driver? Or you've got massive amounts of room gain.

Btw, WinISD is free...here's a link for anyone interested:

http://www.linearteam.dk/default.aspx?pageid=winisdpro

[Remotia]

I dont care how good that software is, you cant just plug in TS parameters to determine a fq response of a driver. You dont even know to what degree of uncertainty the TS parameters are! Futhermore, they dont tell the whole story. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

This whole thread is asinine, is anyone here even a freaking audio engineer, THOUGHT SO.

[DrWho]

I dont care how good that software is, you cant just plug in TS parameters to determine a fq response of a driver. You dont even know to what degree of uncertainty the TS parameters are! Futhermore, they dont tell the whole story.

This whole thread is asinine, is anyone here even a freaking audio engineer, THOUGHT SO.

So what better method do you propose for predicting the small signal behavior of a driver? And then how do you explain the real life correlation? You can't call something bunk unless you've got reasons for it....and you'd be up against hundreds of "engineers" dealing with this stuff every day. I think I'll rever to Thiele, Small, and Nousainne on this one....

And for what it's worth, I am an "audio engineer" (but the term really doesn't mean anything as it has way too many definitions).

[Remotia]

no, you didnt rever to Thiele, Small, and Nousainne , you reverd to winISD which sucks.

[Zealot125]

Wow, um, I didnt really understant where that came from... Are you angry because your enclosure is far less than ideal, or what is the problem. Dr. Whos point is 100% valid. T/S parameters can be measured to a very accurate degree, and are by far the most applicable variables by which to model subwoofer design. How do you presume that klipsch designs their subs, or how wilson designs theirs? - by starting with the cold hard numbers - thats how. There is a reason people use winISD over other programs- it is easy to use, covers all the bases, and does good math.

[Zealot125]

This whole thread is asinine, is anyone here even a freaking audio engineer, THOUGHT SO.

Furthermore, this is a DIY thread about a project that I would personally enjoy. You are right I am nowhere NEAR to being an audio engineer, but I can sure as hell give it the best of my own humble efforts. If you arent going to be constructive, then what is your goal for these posts?

[Jay481985]

WinISD like every other modeling, cad or so forth type of simulating

program is limited by the parameters they are given by..... But like

life there are what we know and then there are the unknowns.

Engineering and science is here to find these unknowns and make them

predictable (everything from multiplication to algorithms of code

breakings etc) But because we cannot put real world parameters into a

simulation does not mean we should discredit the program. Should we not

simulate airplane wings/crafts before we make them? yeah, lets make

them first and see if they fly? oops I guess we built the wings too

small there goes 100 million dollars and the pilot's life? September 11

was an example of simluations that neglected real world threats. The

WTC was designed to withstand the impact at that time the biggest jet

plane, the 707 boeing. But they did not have the simulations and

computer power to calculate the fire and the needed firesuppression.

But their simulation was right, the building's outerskeleton transfered

the load up to the roof and transfered them to loadbearing metal plates

that were not damaged. Hence no immediate failure. Now we have the

capability to have simulations to predict fire. Now building codes are

safer than they were 50 years ago and stress mass evacuations. But you

have to put it into perspective. You cannot blame the engineers for

being a bit nearsighted. The world changes when governments fall etc

etc, 30 years ago we supplied the afganistan rebels stinger rocket

launchers to fight against the Russian. Now that was a major threat

when we invaded the country. Did anyone ever believe Osama Bin Laden in

Afganistan (he is Saudi Arabian) would plot such a evil plan?

Going round circle, we first dream or conspire with the idea, plan,

replicate on paper or computer (cad), simulate, and then build. Not

build then hope for the best. That is why most of the cost of anything

built is the planning and simulating stage. You can afford to make

mistake on paper but once the wheel is turning its hard to stop (when

assembly lines have problems)

[Jay481985]

BTW numbers do have their faults and quarks etc etc. Should we disregard math because of such mistakes?

Hell I been waiting for the Higgs Bosom for quite a bit to go tell my old Calculus teacher that everything he learned is wrong.

[DrWho]

no, you didnt rever to Thiele, Small, and Nousainne , you reverd to winISD which sucks.

Like I said...what is better that is also free? The guys over at

www.thielesmall.com wouldn't be working hard on converting their entire

database to also include the winISD data file if it was such a sucky

program. Also, I wouldn't expect real life results to come very close

to winISD either if the program sucked. And I wouldn't expect the

models to come very close to some of the expensive programs out there

either...

So instead of coming on here and ranting and raving about who knows

what, why don't you offer an alternative or at the very least

specifically point out key flaws? Do you really expect anyone to take

you seriously?

So how accurate are the T/S parameters? I put the same trust in the

posted specs as my decision to purchase the product from the company.

If I don't trust their specs, then I don't trust the company and I'll

go elsewhere. I also happen to talk with a few of the guys "building"

these drivers...even running design ideas by them....funny how the

models line up with their real measurements too.

Anyways, my reverting to T and S and all the other subwoofer gurus is

one of allowing them to defend the use of TS parameters for modelling

performance. They would all claim that winISD and boxcad and whatever

other free option you can think of all do a great job of modelling the

low signal performance of the driver. It's only with the cooler, but

rather expensive programs that you can start modelling driver

nonlinearities too and even taking measurements of the result.

And this is also a DIY endeavor....where the goal is to save money, not

spend more. Nobody here is running their own company and trying to turn

a profit. So nobody is going to go about building prototypes and

measuring actual performance to tweak the final design. Really, the

prototype is the final design. And the actual gear and equipment to do

real measurements would be insanely expensive - even to rent out a lab

for an evening (if you could even find someone willing to do that). And

even if you go through and play with all the cool toys, you're not

guaranteed to improve "much" upon the prototype...which is the whole

goal of good modelling. And lastly, even with the limitations of

winISD, it is certainly a great tool for learning the true nature of

the limitations of subwoofer design - which is what this thread or heck

entire forum is about. Learning.

[Tom Adams]

I dont care how good that software is, you cant just plug in TS parameters to determine a fq response of a driver. You dont even know to what degree of uncertainty the TS parameters are! Futhermore, they dont tell the whole story. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

This whole thread is asinine, is anyone here even a freaking audio engineer, THOUGHT SO.

Guys........me smells a troll.

Leave 'em alone.

While I appreciate your responses, it's not your responsibility to defend yourself. He's the one with the issue - therefore it is HIS responsibility to solve HIS issue, not yours. Know what I mean Vern? []

Tom

[Jay481985]

he's not a troll. He's been on the promedia section a few times. I just think he is misguided... It's hard to change one's mind

[Dan1045]

No, the driver I have is the original dayton titanic, with different specs. fs=16hz. Yes, there is a lot of room gain. Didnt want the new dayton driver that you have the link too. I wanted something that would be good for music too, not just thump for movies. The original dayton titanic 12" was patterned after teh nht1259.

Parts express does not even have the info for that woofer online anymore. They started making the original titanic about 1995-1996. If you want to search on the web for it, its name is dayton titannic 1200.

here's a projects using that old driver:

http://webpages.charter.net/spatters/SpkrProjects/Subwoofer.html

nht 1259 project:

http://www.lungster.com/l/speakers/sub/sub.shtml

Dan

PS. I just read up on a lot of different projects. Really liked the idea of a flat response, musical sub. I have not been impressed by retail product, so I studied up for about a month then found the driver for a good price on ebay, ordered the plate amp from parts express, and put it together. Didnt use any software to determine response, knew from other peopls projects that it would turn out good. That is another reason I did a sealed box, it keeps things simple for placement.

I just recently built a dayton DIY subwoofer. Box came out to be about 2.75 (18.5" cube) cubic feet. Bought a used Dayton 1200 titanic driver on ebay for cheap, wanted flat response and this driver was known for that. High efficiency (90db/watt)and went down to 16hz and 14.5mm cone travel.

Is this the driver that you used?

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-404

I get -10dB @ 20Hz so perhaps you're talking about a different driver? Or you've got massive amounts of room gain.

Btw, WinISD is free...here's a link for anyone interested:

http://www.linearteam.dk/default.aspx?pageid=winisdpro

[Jay481985]

Jay I saw your post about hurricane nuts, but I

am still confused as to their use. Could you elaborate?

PS dont worry, I am installing trillian as we speak.

must have missed reading this sorry.

Hurricane nutes are like t-nuts they can be found on partsexpress.com

They essentially give the speaker screw (usually 8 on a sub) something

to bit into. Speaker screws are more or less machine screws that have

the threads (the twists) but not sharp point. Also the threads are much

too small to actually grip any wood. Sheet metal screws have a pierced

tip to bit into the well sheet metal. Wood screws also have that but

they have big thread (the threads are usually as wides as the inside

diameter) to grab onto the wood. But since screws have a tappered head

they need to be countersunk so they won't fit a flat speaker. Machine

screws have a non pierced head and very narrow threads which need

either a matching nut (not so great to hold) or a t nut (think a nut

with teeth that bite into the wood to hold in place but if

overtightened tear the mdf) or hurricane nuts (think nut with washer

that does not do as much damage overtightening)

[DrWho]

No, the driver I have is the original dayton

titanic, with different specs. fs=16hz. Yes, there is a lot

of room gain. Didnt want the new dayton driver that you have the

link too. I wanted something that would be good for music too,

not just thump for movies. The original dayton titanic 12" was

patterned after teh nht1259.

Parts express does not even have

the info for that woofer online anymore. They started making the

original titanic about 1995-1996. If you want to search on

the web for it, its name is dayton titannic 1200.

I thought you were talking about a different driver, just wanted to

make sure....it's a shame they went with the much higher tuning on the

newer models [] They must have felt more SPL was more important.

[DrWho]

Here's an example of T-Nuts:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-778

(I'm linking to the kit so that it makes sense how they're used).

I personally prefer T-Nuts because they are harder to accidentally pop

out when installing the driver (if you push down on the screw too hard

you lose the pressure fit and they fall out the back).

One trick when installing T-Nuts is to use the screw to seat it....so

instead of pounding the T-Nut into the hole with a hammer, what you

should do is pressure fit the nut with your finger and then put the

screw through a washer and then start screwing into the T-Nut.

Eventually it'll start getting tight and then bust out your screwdriver

and use it to really crank the T-Nut into the wood. I find this

approach really helps me line things up better.

And one last trick...when installing the woofer, lay the suboofer

cabinet on its back facing up. This way you've got gravity on your side

making it way easier to line the holes up. And then you don't have a

hand tied up trying to hold the woofer in place. I know it seems rather

intuitive and silly to point out, but there are times I'm in a rush and

I try to do it without flipping the speaker over (usually in a big PA

system where you've got hundreds of pounds of speakers to move....or

they're flown in the air). And everytime I do this the woofer never

fails to slip out on me and I about spear it with my screwdriver...It's

a very scary thing to have happen when you're 40 feet in the air too

(as that heavy speaker would surely leave dents in the floor too).

Anyways, whenever you can it's best to lay the speaker on its back.