TH folding like TH115

[rolandong]

Best TH Folding

Trying to design TH115 like using definimax 4015LF.
Any idea which folding provides min. box internal resonance.

Thanks in advance!

[weltersys]

I have not seen the inside of the TH115, but your “A” plan looks viable, “B” does not.
The corner radius pieces are not needed, either.

Do you happen to have a 4015LF?

I have been trying to get someone to measure the actual Xlim on that speaker, the 4015 I have clacks at only 16 MM peak to peak, about half of the rated XLim.

[FlipC]

rolandong
It will depend on what you are trying to achieve with your box.
Look at the LIVE SOUND Specific TH thread
LIVE SOUND Specific Tapped Horn thread...

Also a good thread over at Speakerplans.com
forum on the same subject.

Your A layout is the general
layout everyone comes up with.

[rolandong]

Hi weltersys,

thanks for posting.
I gues the discrepancy lies from how you actually did the measurement versus how Eminence did.
Specs. says:

Eminence response curves are measured under the following conditions: mounted 1m from wall/baffle | 2ft. X 2ft. baffle is built into the wall with the speaker mounted flush against a steel ring for minimum diffraction | Hafler P1500 Trans-Nova amplifier | 2700 cu.ft. chamber with
fiberglass on all six surfaces (three with custom-made wedges)

How was your way to skin the cat ?

[weltersys]

I simply measured the peak to peak cone movement with a ruler, using a dot on the cone and persistence of vision while running sine waves through the speaker.

Xlim and Xmax should be one way, my 4015LF measurements peak to peak are around what they should be one way, indicating either I have an improperly made unit that performs fine, or the specs are off.

I have 9) Lab 12 speakers, they all are within the Xmax and X lim specs.

[rolandong]

Can it be that standing waves and cancellation both sides affect this?
Meantime, I'll have 2 units soon so I'll check mine.

[weltersys]

No, standing waves and cancellation don't really have much to do with excursion.

Xmax is the amount of one way linear excursion, distortion increases above Xmax.
Xlim or Xmech is the amount of one way excursion that when exceeded will damage some part of the speaker, either by hammering the voice coil, tearing the cone, surround, or spider.

However, I just went out to the shop and re-tested the 4015LF, and it tests fine now, hit 30 mm peak to peak with no clacking, and 18 mm P to P before audible distortion.

I suspect there may have been a bit of debris, possibly a piece of glue in the gap that was causing the clacking noise and premature distortion before, and it was pulverized in use, the speaker performs fine now, right on spec.

In fact, I’m still feeling a little funny from the 10-15 HZ stuff...

[MarjanM]

Originally posted by FlipC
rolandong
It will depend on what you are trying to achieve with your box.
Look at the LIVE SOUND Specific TH thread
LIVE SOUND Specific Tapped Horn thread...

Also a good thread over at Speakerplans.com
forum on the same subject.

Your A layout is the general
layout everyone comes up with.

Your A layout is the general layout everyone comes up with.

Yes but it not even close to the TH-115 layout.

[rolandong]

Hi MarjanM,

Yes but it not even close to the TH-115 layout

Prove it.

What do you have for us to see?

[MarjanM]

I don't need to prove anything to anyone.

Sorry, i am a big fan of Tom's work and don't intend to publish anything that can harm him or his business.

My comment was made in order to the similarity with your sketches.

It can be done your way too, but it is not like the TH-115.

TH-115 has a horn length of almost 3 meters.

If i were you i would do it this way. TH mini way.

http://speakerplans.com/forum/th-min...409_page1.html

Be sure to carefully read entire thread.

Regards
Marjan