<No, not really.  That song's just running through my head, and so is this question.>

So's I'm looking at the specs for Dayton's Titanic MKIII....besides the price, why would it be an undersireable sub for a HW build?  Too much sag?  

How about using it for other decware plans?

Not sure how to measure the sag, or if there's a realtionship between (magnet) mass and sag.  (Or would that be voicecoil length and sag...hmmm).  

In your opinion, 2 dbs are "better" than 1 HW, but is part of that because you have 2x the number of speakers? (assume 2 per enclosure).  How would you rate  2 dbs  vs  2  HWs?

[quote author=Adrian D.  link=1156872872/0#3 date=1156874932]...one of steve's posts saying that 2 db-12s (1 woofer in each) would perform better than 1 hw with 2 woofers. [/quote]

Wow, that's a bold statement!  I'm very surprised.  I'd like to believe this, but can anybody else verify this claim?

From PE's website regarding Titantic MKIII 15's specs:

*Power handling: 800 watts RMS/1,100 watts max *VCdia: 2-1/2" *Le: 3.84 mH *Impedance: 4 ohms *Re: 3.68 ohms *Frequency range: 19-500 Hz *Magnet weight: 136oz. *Fs: 19.93 Hz *SPL: 91.7 dB 2.83V/1m *Vas: 7.79 cu. ft. *Qms: 5.89 *Qes: .41 *Qts: .38 *Xmax: 20.5 mm *Dimensions: Overall Diameter: 15-9/16", Cutout Diameter: 14-1/16", Mounting Depth: 8-3/8".

but my db12 had 1 x 12 inch driver and my hwk had 2?

60, you're experience of both is based on a car setup.
link to one of steve's posts in the old db forum.

I found it.  FYI for those who don't know.

http://www.partsexpress.com/resources/downfire.html

*edit*  Sorry to keep bumping my post, but according to PE's calculations, the 15" Dayton Series II (which is so popular here) has approximately 8.6% sag, while the 15" Titanic MKIII has approximately 3.05% sag.  

PE states "As a general rule of thumb, any time the sag exceeds 5% of the driver's Xmax, it's not recommended for a down-firing subwoofer application"

It looks like the Series II isn't such a good choice in a vertical HW... ???

Wreckin', I don't understand what you wrote.  Are you backing what Adrian (and Steve has) said about 2 db's being "better" than 1 dual-loaded HW?  How is a dual-loaded, magnet-to-magnet, HW not "utilizing the cone area of both speakers"?

[quote author=jkalet link=board=Housewrecker;num=1156872872;start=0#12 date=08/30/06 at 09:23:55]Wreckin', I don't understand what you wrote.  Are you backing what Adrian (and Steve has) said about 2 db's being "better" than 1 dual-loaded HW?  How is a dual-loaded, magnet-to-magnet, HW not "utilizing the cone area of both speakers"?[/qu                                        Think about it, the speakers are lined up back to back or front to front as the case may be. In this configuration you must wire the speakers out of phase with one another causing them to work as one. This configuration will without a boubt give you more control and tighter bass, but you will still be using the cone area of one driver 176.71 square inches. By using two single loaded cabinets you are utilizing more cone area 226.20 inches. The difference in cone area is approximately the equivalent of an 8" woofer. Pump one fist in the air you have your HW, pump 2 fists in the air you have your Db's. Get it?

I personally havn't heard the Db12's but in theory they should outperform the HW's, to a point. Remember when I said that you would have more control and tighter bass? that's where the fun starts. The db's should push more air to a certain power level and then the drivers will reach their X-max. With dual loaded HW's the opposing cones control each other. If you have the power the 2 Hw's will absolutly out perform the Db's side by side as would 2 single loaded Hw's. I use dual Peavey loaded Hw's to Dj with and they never fail to get the cops called regardless of room size. Power is the key here when comparing the output of these cabinets. I use a Peavey PV-2600 and I've got to chase these subs on the dance floor and pull them back to the stage about every 1/2 hour. The dual loaded HW is mountains away from the single loaded. The only time that I would recommend single loading a HW is for low power HT use.

Jude, (it is Jude right?  ???)
If you follow that thread, at the end, you'll find a nice HWK specifically for the LFs and below. I'm happy with what John and I have done, and will not go back. Remember this monster is for HT mainly. Slightly less musical than before but again, better to "blow things up" with.
No more 'klopping' now, even when I get stupid with it, but too boomy for music.
Somewhere in the last 5 pages or so, you'll find HZ/DB numbers after the mods.

Bob

Jude, I feel safe in saying that if you build one of Steves designs and use a recommended/proven driver, you won't be doing any mods.  

bob

[quote author=Adrian D.  link=1156872872/15#21 date=1157029038]if it's dj-ing you're after, go with the hwk. [/quote]
Fa Sho!!!

Interesting debate this has started.   ???  Although most of the posts have gone astray from my original question, I enjoy hearing/seeing the comparison between builds.

[quote author=jkalet  link=1156872872/15#24 date=1157078796]Interesting debate this has started.   ???  Although most of the posts have gone astray from my original question, I enjoy hearing/seeing the comparison between builds. [/quote]
JKALET, Do you have the sub already? If not, why dont you use the recommended driver which is a Peavey Black widow. The cost is about the same and if you blow it you can just change the motor instead of the whole speaker

Quote:


No not yet.  I'm not THAT lazy, but it would just be easier to get all the components from the same place (ie PE) and I don't see the Black Widow on their site.  I'm not opposed to the Widow, I was just wondering about the Titanic vs the "oh-so-popular" Series II because they have similar Fs, Qts, and Vas.  One thing about the recommended Widow, Steve says it's good to around 40Hz.  Just like limbo, I'd like to go lower.  :)


Quote:


Larger Vas...hmmm...good to know.  Correct me if I'm wrong but I thought I read somewhere on this board there was a misprint in the white papers.  Shouldn't it read "a maximum Vas of 10 cubic feet"?


Stay dry east coast

[quote author=jkalet  link=1156872872/15#28 date=1157114913]

Larger Vas...hmmm...good to know.  Correct me if I'm wrong but I thought I read somewhere on this board there was a misprint in the white papers.  Shouldn't it read "a maximum Vas of 10 cubic feet"?

Stay dry east coast
[/quote]

don't quote me but I think the Titanic 3 is 1.84 which is well under that.

10 cubic feet is substantial.

Housewreaker says he backs off just a bit, you don't have to apply that to the DB, you pump a whole lot more before you have problems

This is my opinion only, not really keeping up as of late.

OK, I didnt say anything before, but you guys seem a little confused...

The DB is a 4th order enclosure, It makes one peak at its tuning frequency.  On either side of that frequency you get a natural first order (6db/octave) rolloff.  In free air, that graphs like a camels back with one hump.  making the DB have a much more restricted bandwidth than that of the HWK (before room gain is applied).  The cone will have excellent control between the driver's Fs, and the tuning of the box, but will easy fall on its face on either side of those two specs.

The HWK is a 6th order box, it makes two peaks (sometimes 3 if the Fs of the driver lies outside the tuning of either chamber)  These peaks are bounded by a first order rolloff, just like the DB, and also have a first order rolloff into the center between the two humps because of the phasing.  This results in a much wider bandwidth than the DB (before room gain)  

Now, with only 1 driver in the HWK, it will have a wider bandwidth than the DB, but with less cone control, as there is no sealed chamber, going bonkers very easily without a strict bandpass filter bounding the tunings of the cab.  

Two or more drivers changes this story a lot though.  First, the iso loading increases the apparent volume of the enclosure, lowering tuning, the iso load also vastly improves the cone's control, since as one cone loses control below the tuning of its adjacent chamber it is bolstered by the improved control of the other driver as it appraches the tuning of its adjacent chamber.  Add to this the weight of the air between the drivers in the sealed chamber (lowers Fs of the drivers) and now you have a much wider bandwidth with considerably less distortion and a MUCH higher power handling ability.  Set up like this, the HWK and DB are two completely different animals...

As far as whats louder, 2DBs will outperform the pair of single loaded HWK, and sound cleaner too without some strong filtering.  A single HWK with 2 drivers in it will be comparable volume to a pair of DB, provided that both drivers receive the same voltage as they did in the single loaded HWKs, in addition the HWK will have extended bandwidth.  This of course assumes that everything else remains the same, which it does not.  Since the iso load of the HWK reduces efficiency, but increases handling, a significantly larger voltage could be applied across the coils in the HWK, allowing for a higher output if you have the money for the amps.

A properly loaded HWK will be just as tight and punchy as a DB, but way less efficient.

Long story short...

2dbs, more efficient, allows for dipole setup, more tuneable and runs cooler, but restricted bandwidth

1 HWK iso-loaded (mags in the middle) LOUDER LOUDER LOUDER, wider bandwidth, and cleaner too, big downside though is a massive loss in efficiency

2 HWK, single loaded, allows dipole, more efficient, wider bandwidth than DBs and runs cooler, but it takes a LOT more space and is very easy to eat drivers with

A straight up comparison of all of the variables would likely show the two boxes to be completely different animals, each suited to a more specific purpose, just like everything else audio, it depends what you need.  A DB is likely best for the car, or maybe tuned very low for HT, this is because of its simplicity and efficiency which allows for extended compromises elswhere in the system (fewer, smaller amps, fewer, simpler XO's etc.)  The HWK is a real performer though, and would likely be better for large theaters, or DJ applications, or the back of ye olde minivan for some real eye-watering fun.  The fact that the power compromise happens in the box with the iso loading allows for different compromises in the rest of the system (allows more power, resulting in a LOT more sound, as well it has a wider bandwidth, meaning that one could, depending on the build, have both midbass and bass in the same cab reducing the number of components being lugged out of the van)

In the end it is like comparing a pair of Ford Crown Vics to a single Chevy Corvette, both go fast, one is faster, both turn corners, one does so faster, both have capacity for passengers, one has room for more etc. etc. etc. it all depends on what you need.

I just had to say something, I am by no means an expert, however if you look at the basic physics involved there are some definite advantages to either deisgn, but because of the many iterations of the systems that are available it is hard to say which is better.

JJ

While they are not physically bolted together, it serves the same purpose, only difference is that there is a small air chamber between them. The reason for this is that the HW can be set up in many configurations. Whether the cones are facing each other or opposing each other makes no difference. It is recommended that the magnets be in the center chamber for the simple reason that it sounds better because the magnet structures are using up a little volume in the middle. Perhaps with other drivers that it sounds better the other way, but with my drivers it works better for me. The important factor when iso loading is to make sure that the cones are out of phase and moving in the same direction.

remeber, the db and the hw aren't typical bandpasses. steve was talking in the db white papers about a varo-vent effect
something similar could happen in the hw because of the placement of the lower ports.
the whole bandwidth thing is tuning related. both cabinets offer lots of tuning options.

Wow!  I walk away for a few days, and BOOM a kick-a$$, informative discussion ensues.  Good stuff  :)

Wreckin', J, and jj thanks for that explanation, and thanks for coming down to my 'level'.

Bob

Low,... meaning, 'sub',.... you know,.... sub.
This is the Housewrecker forum after all. It's all about subs.  ;D

See, I knew I could turn a cheap shot into a positive.  

Bob