T39 maintenance

[Tom Smit]

Awesome. A single t39 takes about 40volts (atleast with the KappaLITE 3012LF)?

My plans say that the 3012LF should be limited to 55v. (mine is a BP102 with a 35v limit).

[Bruce Weldy]

Awesome. A single t39 takes about 40volts (atleast with the KappaLITE 3012LF)?

My plans say that the 3012LF should be limited to 55v. (mine is a BP102 with a 35v limit).

Tom's correct....but, don't forget - It is also highpass dependent. Make sure that you are highpassing at 45hz at least.

[Joman116]

Awesome. A single t39 takes about 40volts (atleast with the KappaLITE 3012LF)?

My plans say that the 3012LF should be limited to 55v. (mine is a BP102 with a 35v limit).

Tom's correct....but, don't forget - It is also highpass dependent. Make sure that you are highpassing at 45hz at least.

Pardon my ignorance..but reading the SPL charts, the T39 excels in the 40hz-80hz range..so wouldn't I want to highpass more around 80hz (depending if my tops can reproduce the 80hz range)?

[Strange Kevin]

I think you are confusing high-pass and low-pass.
High-pass allows all frequencys higher than the specified frequency to pass onto the speaker. Low-pass only allows lower frequencies.
So for the T39s you will want to high-pass 45Hz or 40Hz if in groups of 4 or more. Then low-pass the T39s at around 80Hz to 120Hz depending on what tops you are using.

[Seth]

To add to what's been said, the 40/45Hz High Pass Bruce and Kevin are talking about (also covered in the plans) is to keep really low frequencies from damaging the driver in the T39 from over excursion.

[Bruce Weldy]

Pardon my ignorance..but reading the SPL charts, the T39 excels in the 40hz-80hz range..so wouldn't I want to highpass more around 80hz (depending if my tops can reproduce the 80hz range)?

Sorry I'm a little late to the party...broke a toe last week and haven't been in the office as much.

The other guys are correct - I was talking about high passing the T39. The voltage limits are based on excursion limits of the driver and excursion is also affected by frequency. The lower you go, the further it travels. So, both are extremely important to the health of the subs.

As far as setting your tops down to 80hz, that's fine - but by keeping it a bit higher, you also protect the drivers in the tops from over-excursion and farting out. The T39s can handle over 100hz just fine. I don't remember which tops you are using, but with most 12-15" tops, I'd keep it above a 100hz.

[Joman116]

I think you are confusing high-pass and low-pass.
High-pass allows all frequencys higher than the specified frequency to pass onto the speaker. Low-pass only allows lower frequencies.
So for the T39s you will want to high-pass 45Hz or 40Hz if in groups of 4 or more. Then low-pass the T39s at around 80Hz to 120Hz depending on what tops you are using.

Ahh whoops I had a brain fart. Yes I confused the terms guys...

[Bill Fitzmaurice]

Ideally you want to run subs up to where the tops reach their excursion limit at full power, if not a little higher. Knowing where that is can be a problem.

[Rich4349]

I found some gaps in the small braces so I applied adhesive on any brace that I could find, and the retested.

How did you retest, seeing as how the final side must make a complete and strong seal? Did you commit to PU adhesiving the final side back on and hope for the best? Weather stripping for a temp seal? Option C...?

[Tom Smit]

I used my phone and video-recorded the insides wherever I could to see how things looked and if anything needed attention. At the end of the "research", I committed to the PU adhesive on the final side since I couldn't find any other source.