Help designing ported cabinet for dayton rss315ho

saabracer23

Member
2006-05-12 11:17 pm
Hello,
I am needing help designing a pair of cabinets for the high output reference drivers from dayton. They are the 12 inch drivers. I called they tech guys at pe and all the guy said was "go sealed". All of their drivers are meant for seald cabinets he said. Hmmm I don't think thats the case.

I am going to be using 1 inch mdf and I was hoping for the driver on the front baffle along with a slot port. It be used 50/50 music and movies. What would be a good suggestion as a tuning frequency? I was thinking around 23 hz or so (I don't want to tune much lower than the fs of the driver right?). Any help would be great. I have done some searching only to find sono tubes with round ports.

Thanks
Dan
 
Greets!

Hmm, for some reason I have two different sets of specs, so one may be measured. Oh well, regardless, either specs 'scream' sealed, so apparently they know what their drivers were designed for. ;)

Assuming a bit of room gain, it's usually safe to tune a sub as low as ~0.707*Fs, so that's the practical limit IMO in most cases, but Fs or below, the vent will still be so long that probably a more practical alignment would be a TQWT, i.e. just make the whole thing one big vent. High SQ and nearly the extension of an IB, so a plus for movies.

GM
 

saabracer23

Member
2006-05-12 11:17 pm
Thank you for the input. For some reason I thought these were designed for ported cabinets. What does TQWT stand for? Would the cabinet be huge? Would you be able to help me design the cabinet? You are saying with TQWT I will have good SQ for music and it will still reach the lower frequencies? How low?

Thank you
Dan
 
Hi saabracer23,

FYI, The submitted picture shows a Ported ‘Fat-box’ simulation with your driver in mind; if you dare to follow this sub design.

FYI, The submitted picture shows a Ported ‘Fat-box’ simulation with your driver in mind, if you dare to follow this sub design.

Don’t pay too much attention to the ripple shown above > 140 Hz or the small dent at the Impulse plot that in reality will be blameless = minimal if you measure this speaker, due to the fact that this slot port should be stuffed and sectioned (i.e. or braced (reinforced)) to form at least 3 parallel, preferably irregular tubes that is so far too much for MJK: s program to handle correctly for the moment.

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saabracer23

Member
2006-05-12 11:17 pm
HAHAHA I am going to have to apologize but that is completly alien to me. Except for the graphs. Did that have the plans for the cabinet? If these are huge cabinets my problem will then be getting the wife's approval! I have decent wood working skills so I think I would be fine building them. If I went sealed what size cabinet should I go with to reach the lower 20s and still be fairly flat in response? How much better would the "fatbox" be than a sealed enclosure?

Thanks
Dan
 
Hi Dan,

…How much better would the "fat-box" be than a sealed enclosure?…

IMO a sealed box with this driver is only a very good Mid-bas.

…Also what size cabinet would be good sealed…

Between 17.5 to 59 L is ok

…If I went sealed what size cabinet should I go with to reach the lower 20s and still be fairly flat in response?…

If you design a flattest closed box (17.5 L) it will be at least 17 dB down at 20 Hz or at best a f-3 dB point at about 52 Hz, compare to the proposed slightly shelving ported box where f-3dB is at about 28 Hz. See picture 1(1). You could also try GM: s TQWT suggestion that might turn up as good as my.

…Are those internal dimensions?…

Yes.

…How do I know how big to make the pieces for the horn/port and at what angle to put them at…

All info is in the given data but if in doubt consult:

http://www.diyaudio.com/forums/attachment.php?postid=1441361&stamp=1204208215

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saabracer23

Member
2006-05-12 11:17 pm
Thank you bjorno. I think that I like your design. It will also have good sq right? Even with the new post you put up I am still lost. And on one of your first links it said the internal volume was only like 2.5 cubic feet which is perfect yet with the dimensions MJL21193 gave me it had an internal volume 5.75 cubic feet.I hate to ask but I think I would be better off if I was given the size of pieces I need to cut and maybe a little help with the angles otherwise I KNOW I am going to mess this up. At 50 dollars a sheet I can't afford to and I don't want to be stuck with good midbass.

Thanks
Dan
 

sbrtoy

Member
2003-04-04 11:40 pm
colorado
RS Woofers

I hate to say it but you may be better off selling the HO and getting the HF version. Stick it in a sealed box, add some EQ, and enjoy!

Parts Express even has their own version of this formula written up in their projects, using the parametric EQ on their sub plate amp.

Just an idea...
 
Was that sarcasm GM? I am supposed to be looking at the red right? So at 20 hz its down about 7 db from 80 hz meaning no good. You ealier mentioned a TQWT. Would you be able to help me with that, sound like you said it would be a good canidate for this woofer. Looks like the cutting is being held off til tomorrow.

Thanks
Dan
 
…I think I would be better off if I was given the size of pieces I need to cut and maybe a little help with the angles…

Make yourself an own drawing and post for angle calculation if necessary.
Even if you need to cut wood at angles don’t glue using an angle, instead aim for the right CSA and use wood filler to correct any misaligned joint.

Updated dimensions: picture 1(1)

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