Dayton RS MTM TL?

[croat47]

Presently I have two projects underway, but am looking to plan the next venture.

Looking around, many of the intriguing designs (Cyburgs, BIB, and THOR) are a little bit beyond where I would like to go. Cyburgs Needle is a little limited on SPL. BIB's end up...well, big. THOR is just too expensive for my budget. But, I do have a pair of Dayton RS125S and a Peerless DX tweeter. Combined, it could make a nice low profile MTM setup at 8ohms.
Budget is a concern as well as size. Tall and slender would be the better move. My ultimate question:

Would someone be interested in helping me to design a TL with the MTM configuration above? Something like a THOR...but, on a fiscal and physical diet. I have read through much of the t-linespeakers "dummies" section. However I do not have MathCad or the CAD (and associated skills) to do design work. I am also open to a BIB based on the MTM idea.

Any help on the planning stages of this would be greatly appreciated.

According to Zaph's site, the RS125 measures:

Fs = 76 Hz
Vas = 2.15 l
Qts = 0.5211
Qms = 2.8941
Qes = 0.6355
Xmax = 2.8 mm
Sd = 51.53 cm^2

Regards,
Aaron

[nunayafb]

...I do not have MathCad or the CAD...

Just so you are aware, you can download a free mathcad viewer that will serve your purposes. You dont need any CAD software just some hand drawings and the numbers from MJK's TL program.

[croat47]

Thanks for the point. Still $25 for the sheets...he's right though, it's probably worth it.

Regards,
Aaron

[nunayafb]

Still $25 for the sheets...

That must be the new and improved sheets, based on the old ones that were free, I would say they are worth it. Are the old ones available?

[sreten]

Hi,

IMO Fs is simply too high to bother with a TL.

Specs indicate it would make a nice sealed MTM or 2.5 way TMM
for use with a subwoofer, or two for an active bass 3-way.

/sreten.

[croat47]

Sreten...back to the X.5 again? Seems a theme in your advice to me . The RS150 has an Fs of 48Hz...better option for the TL idea? I thought a properly built TL could get to ~1/2 octave lower than the Fs? That would put me in the mid 50's, yes?

As for the RS125's, I had also considered a bipole as Planet 10's WR/FR125 bipole. Based on Zaph's measurements, I could possibly cross at ~100 and use a side firing 10" sub for the lower register. In that case, would I fire in or out...or would that depend on the room?

I've read other threads preferring an MT or MMT over an MTM configuration due to various issues. Any thoughts there?

Regards,
Aaron

[sreten]

Originally posted by croat47
But, I do have a pair of Dayton RS125S and a Peerless DX tweeter.
Fs = 76 Hz
Vas = 2.15 l
Qts = 0.5211
Qms = 2.8941
Qes = 0.6355
Xmax = 2.8 mm
Sd = 51.53 cm^2

Regards,
Aaron

Hi,

You don't mention sensitivity which at 83dB/w is crippling for a MT.
A MTM or TMM after BSC is going to be around 83/84dB/W.

Which side for side firing ? no idea - but doesn't matter as you
can simply swap left and right speakers arounds in room.

Mid 50's for a 84db/W TL ?, pathetic.

/sreten.

[croat47]

Originally posted by sreten


Which side for side firing ? no idea - but doesn't matter as you
can simply swap left and right speakers arounds in room.

Mid 50's for a 84db/W TL ?, pathetic.

Fair enough! So, would an MT or MTM in a BIB be off your list then?

Regards,
Aaron

[croat47]

What abour a 2.5 system where the tweeter is sealed, the mid is sealed, and the 0.5 driver (same as the mid driver) is in a ported enclosure? The idea being to get the nice transients in the mids, but extend the bass an octave while also beating baffle step.

I seem to recall seeing similar, but I can not remember if it was two of the same drivers or two different drivers. Based on models, it looks like there would be a spike in group delay near F3 of the ported encolsure. Also, it seems about a 60deg phase shift would need to be corrected.

Regards,
Aaron

[GM]

Originally posted by croat47
But, I do have a pair of Dayton RS125S and a Peerless DX tweeter.

I am also open to a BIB based on the MTM idea.

Greets!

A 2.5 MTM BIB looks like a fun project based on PE's measured specs. Post a request on the BIB thread.

GM