so which tmww version is preferable

[peterS]

dennis' or curt's
ported or sealed.... this thread is a nightmare

https://www.htguide.com/forum/showthread.php?t=15323

[jonathanb3478]

Based on what I have read here, I am more of a fan of the Seas metal dome vs the Dayton RS metal dome. The only person with a TMWW Seas version is Dennis. Also, Dennis describes the sealed version as "smoother" (IIRC), and I figure 4 X 8" woofers will provide enough bass in my little room, even if they are sealed.

What you will notice about the above info is that it is based on my personal preferences and situation. You will need to determine your situation, then apply your preferences in order to know what works best for you.


Good luck!

[peterS]

both the 6" and 8" have low Qtc enclosures

thus the ported enclosure has worse transient response, but more output in lower regions
so that may explain his impressions that the bass may be more accentuated in tn the 50-100 hz range

besides, the port is WAY too small for it to behave linearly

i am concerned with standing waves and minimal bracing too...

[cjd]

Neither.

Oh... they're the only ones that have actually remembered to post a TMWW version. And either will be excellent I think.

C

[jonathanb3478]

i am concerned with standing waves and minimal bracing too...

Well, I can understand these concerns with the enclosure design posted. But I am putting them (ultimately) in an elliptical enclosure that is very well braced, so I am not concerned with this. Even the standard "Box" style enclosure I will be putting them in first (recent decision) will be a different design (my own) vs the one posted.

[oxcartdriver]

I was concerned with the bracing and port too. I changed the bracing to vertically oriented bracing and added additional braces. I kept the same interior volume as the original ported design. Increased the cabinet depth to keep the same volume. I also increased the port length, and used a flared port. Be careful as my cabinets came in at 135lbs complete with x-over and drivers. More bracing may be better, but 135lbs is all I want to move on a hand dolly.

I modified the schematic slightly using lower DCR inductors with very slight adjustments to the other drivers to keep response similar.

I am satisfied with the results. The towers sound very nice, I need to look at my center channel a bit more as the towers sound a better at the moment.

This is what puts the Y in DIY. I never would have attempted the project without the initial design by Dennis Murphy.

[ibilisi]

I was concerned with the bracing and port too. I changed the bracing to vertically oriented bracing and added additional braces.

Have any pics of the type of bracing you implemented? I'm going to build the towers and have the center box nearly built but if i want/need braces now would be the time to add them (top panel not on center yet/not started on towers).

[oxcartdriver]

Port Notes
rear port hole in MDF was tapered using 3/4 round over bit
rear port hole in MDF was min possible to allow flush mounting of port to cabinet rear MDF panel
This prevents putting the entire flared port assembly in from the rear
inner port flare was installed prior to driver installation
inner port flare held on with tape to port tube on inside of port (small piece of tape)
having the tape on the inside and a 4in port allows one to attach/unattach the inner flare without driver removal
allows port tuning if required
thought was to keep max mdf on rear panel
port length re-calculated
same freq tuning tgt as original design
slight change in internal cabinet volume accounted for
Brace Notes
Brace #1 was glued to the front facia prior to routing the driver holes
Brace #2 lowest hole was slightly larger to allow space around the port for the inner port flare
Facia
2.25in front facia requires long router bit, routed driver holes in 4-5 passes
rear of front facia was rounded over for mid and woofers using 3/4in round over bit
Tweet/mid subenclosure
volume compensated for the extra depth of the facia created by brace #1
Note #6
These pieces of MDF go from side panel to side panel
inner MDF braces on sides of tweet/mid box still used, trapped space between filled with foam.
Assembly Notes/sequence
Cabinet was assembled minus one side panel.
port constructed
mid/woofer cross overs installed between facia and brace#2 on side wall
utilizing entire height to maximize inductor spacing
tweet cross over placed in tweet/mid enclosure on side wall at top corner.
sizings verified such that port inner flared could be installed/removed through lower RS225 mounting hole
1 inch foam interanal to tweet/mid enclosure
1 inch foam on main box base and lower 12 inches of side walls
1 inch foam used between brace 1 and 2 on all sides
no foam on braces
1.5 inch foam on back wall, side walls (above 12in or so) and top of main enclosure
side panel attached
Drivers mounted/wired
binding posts mounted/wired.

Correction to attached photo
bottom of brace 1 starts at the same point as brace 2,3,4&5.
to much of a PIA to correct

[ibilisi]

Thanks for that visual and explanation! Your cabs must be rock solid! I personally was envisioning some combination of vertical and horizontal bracing, however I will now think about this approach.

[oxcartdriver]

Hello

My cabinets are not rock solid. One could do better, but again my speakers came it at 130lbs completed. Not light.

Results based on the qualitative knuckle rap test, YMMV:
If I rap on the sides of my TMWW cabinets and it gives a bit.
If I rap on a veritcal piece of 0.75in stand alone MDF it gives more.
If I rap on the stack (15-20 sheets) of 0.75in MDF at home depot it doesn't give much
If I rap on my 3cm granite counters it gives very little.