Getting the lowest extension from the W4-1337?

[mayhem13]

So the detail and clarity of the little TB titanium cone is one of the most resolving drivers I've heard in a Fullrange application, but it doesn't dig very deep in a typical BR. Any suggestions for a desktop monitor pair other than adding a subwoofer?

 

[xrk971]

How deep of bass extension do you need? This driver has a fairly low Qts so getting it to go below its fs using a MLTL is tough. Is a slender 5 in x 5.5 in footprint but 20 in tall box too big for your desktop? If not, this Karlsonator (scaled down) design could work - sim is for speaker placed 8 in away from the back wall (assuming desk is against the wall).

 

[IG81]

Looks like the W4-1337 is the Ti cousin of the W4-1320SIF. The specs are pretty close overall. FWIW, I really like the DCR enclosures I built for my W4-1320; I'm fairly confident the W4-1337 may be a good drop-in replacement or at least necessitate very few tweaks.

Have a look at the thread from earlier this year:

http://www.diyaudio.com/forums/full-range/236541-tb-w4-1320sif-double-bass-reflex.html

You'll find some dimensions, acoustic measurements and a link to an online calculator you can use to tweak the design. I don't think the DCR digs any deeper than a regular reflex of similar size, but you gain some cone control AFAICT and it may be slightly punchier. A 4" cone with Qt<0.4 is not really meant to go low in any case.

IG

 

[mayhem13]

Exactly.....desktop use where I don't really want 40hz content bouncing from the desktop and since we're talking nearfield, I doubt excursion limits will be a problem. My idea is for a tall enclosure to get the driver up at ear level......say 18" or so....but instead a wide baffle to remove the need for a BSC circuit. I want to keep the xo minimal with only having to deal with the rising response. But when I model it in a BR in Unibox, I'm kinda disappointed with the extension. I really don't have any practical experience with MLTLs and the like.

.....and don't have any knowledge of a Karlsonator either......every time a view a thread, the reviews of the design are great but the accompanying measurements show the top octave takes a big hit?

 

[xrk971]

The simulation is not accurate in the top octave for the Karlsonator with smaller 4 in full range driver. In reality, the highs will be there and very good - the simulation is a 1-d lumped element model, and as such, does not account for the fact that direct radiator has a very open access to the front through the larger part of the K-aperture. I run my Karlsonator with 3.5 in drivers and the highs (at least to 16 kHz - limit of my hearing) are very present and excellent sounding. Listen to the mp3 clips in the mini Karlsonator thread and judge for yourself. The drivers will be at table level (5 in or so up) and angled up - so they should work quite well for desktop use. They are tall though.

Give it a try!

Mini Karlsonator thread here: http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html

Sound clips here:

http://www.diyaudio.com/forums/attachments/full-range/360600d1374060687-mini-karlsonator-0-53x-dual-tc9fds-vocals-1-mp3.zip
http://www.diyaudio.com/forums/attachments/full-range/360601d1374060698-mini-karlsonator-0-53x-dual-tc9fds-vocals-2-mp3.zip
http://www.diyaudio.com/forums/attachments/full-range/360602d1374060731-mini-karlsonator-0-53x-dual-tc9fds-classic-rock-mp3.zip

 

[mayhem13]

Thanx for the detailed explanation of the Karlsonator. At some point, I'd like to give one a try, but I'm not sure i could put such a highly resolving driver like the 1337 and put it partially obstructed. My hearing too tops put around 17khz.

 

[Greebster]

Thanx for the detailed explanation of the Karlsonator. At some point, I'd like to give one a try, but I'm not sure i could put such a highly resolving driver like the 1337 and put it partially obstructed. My hearing too tops put around 17khz.

The 1337 is used in the Statements speaker utilizing it in a transmission line out the back. Having modeled this driver myself found the low end is restrained due to the Xmax, limiting it's use to 350Hz or higher.

 

[xrk971]

The 1337 is used as a sealed enclosure mid-range in the the Statements speaker - not as a main driver in a TL. I don't think the xmax is an issue in this sealed design with a x-over.

 

[Greebster]

Page two, first paragraph:

Jim: The cabinet had to be tall to accommodate the W-M/T/M-W format
and place the ribbon at ear level. The (2) RS225 woofers dictated a 100
liter ported enclosure to achieve the design goals for bass extension.
The actual cabinet worked out to be 55" tall with a 3" tall base and 2"
spikes to allow breathing room for the down firing port for an over all
height of 60". The cabinet measures 11 ½" wide x 16 ½" deep. The
ribbon is located at 38" from the floor. The ribbon height should match
the builders seated ear height and can be adjusted to what ever height
needed. An open back/transmission line design was chosen for the mid
range to eliminate the 'boxy' sound associated with closed cabinets and
to open the mid range sound stage for greater realism.

 

[xrk971]

It is talking about the cabinet for the two RS225 bass drivers. If you look at the plan, you can clearly see the tiny sealed cabinets for the two 1337's.

http://www.speakerdesignworks.com/Statementsautocadlayout.pdf

 

[Greebster]

Please reread the entire article. Both 1337's are open through the back. and is confirmed by the box plan. The RS225's are bass reflex floor loaded.

 

[xrk971]

My mistake, not sure why they call such a short duct an open back "TL" for the midrange - it's more like an open baffle with a 16.5 in long H frame on the back side. The 1/4 wave length freq of a duct this long is about 200 Hz, which I suppose can work if they use a crossover. You are saying that below 350 Hz, the driver will exceed excursion limit? Probably true. Not sure why this has anything to do with OP's request to get ultimate bass extension with the 1337 though.