Presenting the Trynergy - a full range tractrix synergy.

[BYRTT]

.....so it is quite interesting to play with damped gap's.....

Thanks nice research we could hope for pushing more in same direction would do as below : )

 

[kees52]

Thanks nice research we could hope for pushing more in same direction would do as below : )

Here are also some room effects, the dips are throat effects, but I go buy me some under carped to experiment with.

see picture after change the amound of damping and not change the gap, you did miss these in previous post..

regards

 

[xrk971]

Kees,
That's excellent performance for an all passive system. That throat foam damping seems to really work well. Nice job. I think the dip at 5k is not so bad at under 2.5dB. But the 5.5dB at 3.2k is audible and will need a notch filter. Try measuring with the frequency dependent window option in IR tab. Use 1/6th octave FDW. This will gate out external effects and show you what is in the horn itself and whether or not is correctable.

 

[kees52]

Did some measurements like you ask, mucho differents with distances.

 

[kees52]

This measurements are with some changes of correction filter, but looks like on 3.5 Khz there is a fase shift canceling some things out, get it not better.

picture two is a measurement without filter just a high pass on 250 Hz or so, as you see it extents to 3.5 Khz with ease, make it a nice K-tube candidate.

I go however test the titanium tangband, because these look well, maybe it do perform such that a K-tube is not needed anymore. Cone is titanium and so very strong an can use more compression without extra distortion.

regards

 

[xrk971]

Nice work, thanks for making the new measurements. I think the 20cm measurement is probably representative of the true native response of the horn as it will be unaffected by external room effects and there is enough distance for stuff to integrate. Did you happen to do a 50cm measurement?

So it looks like the horn is performing very nicely up to about 4-5kHz where there is about an 8dB falloff towards higher frequencies. This is expected and response looks very good. This is where EQ boost would work well as the cone doesn't move very much above 4kHz and you have room to EQ.

Overall, a very nice response for just using passive components. If you do use a 3.5kHz low pass filter here and combine with K tube tweeter above, you will have a very nice sounding system.

But in actual practice, if you can put a little more of a high pass filter to attenuate lower frequencies a bit, it will be quite flat. However that is at expense of sensitivity.

I imagine it sounds quite pleasant as it is now - the addition of a woofer to cover below 300Hz will make the sound complete and full. Have you added woofer injection holes yet?

 

[kees52]

Hi X

thanks

Fow what concerns the bass injecion ports, are the bassreflex ports before of behind the normal speaker injection ports?

I need some akabak tests to find the best spot, I need to divide the akabak total surface by how many ports to use?

I need bassreflex support, I do not now what happens if I port the back of the horn so it is in the corner, maybe I get then nice respons
I go use a tapped horn and then I need a from 80 Hz horn respons

Then I go experiment with it.

regards

kees

 

[xrk971]

The bass injection port is not that critical to locate exactly - it's more of a practical matter to make sure port lines up with driver cone placement. Typically two ports with about as much area as you can manage without disrupting horn wall too much. A good value to aim for is 20% to 25% of Sd of cone for the total are of ports. Placed about 10 to 15cm from the mouth exit is fine and gives them some horn reinforcement of directionally. You can make them bass reflex assist and if you are in a corner the BR can exit out the side or the back.

 

[kees52]

Some more tests with a gap and damping, a smal gap and 2 mm thick damping felt did work the best.

even without a filter it get very wide in my opinion, a K-tube wll be the best option to keeps efficienty oke

regards

 

[kees52]

And now started with the bass units.

 

[kees52]

X is this form of the ports oke, I get 27 cm2 on each side of the horn, for one speaker 8 inch for two ports. There is not much room, I need to stay in the cone area afcourse, and so maybe ports have to put deeper in horn, for now I did use 15 cm.

I do round off the port so it follow the tractrix corner.

regards

kees

 

[kees52]

HI X

This way I do it, I need to say that the wall where the port go through is 2 cm thick, I do not now if this area needs also be calulated into total area of port, for as far I see it is not.

I have done 25 % of cone surface for each side.

Did measure length from mouth to centre of speaker, or the middle of the ports.

regards

kees

 

[xrk971]

Looks good.

 

[kees52]

Horn test, one horn already go to 110 dB, but mic clips.

with two woofers 118 dB get possible, but have to measure distortion afcourse.

nice and interesting. The peak need a notch filter and I need a bessel delay.

It do go quite low, special because it has no back chamber yet, just open air, this way I possible need no basreflex port making things more easy and impuls is better with closed back.

 

[kees52]

Need to adjust ports for bass so it shift more to HF is this is possible because the woofer peak can then be fitered away with a low pass.

I put sound trough now, very nice, but need both woofers so tomorrow the rest..

regards

 

[xrk971]

To shift more HF you need to make a conformal volume plug to reduce front chamber volume of woofer. A lathe works well. Larger ports will also extend HF and reduce the peak. 55Hz extension is really good and your max SPL is quite high. Nice work.

 

[kees52]

I have high spl with just one woofer on one side.

I have now make the ports the right size with a mill machine, it is quite precise work and wood is unpredictable.

The higher extent of HF is just for more easy filtering, the ports also act as a nice low pass filter, I think 6 dB filtering and bessel delay lines I get oke.

X and all tractrix lovers, Here is a new program from volvotreter, we have change his calculator so you can copy and past right in akabak.

it have now 100 lines and the throat compression is present again.

Tools – Volvotreter Homepage

regards

kees

 

[kees52]

I have now made the ports on both sides and speakers are on, it will give extra 6 dB sensitivity.

later on testing.

regards

 

[xrk971]

That looks great! Are you going to run open back?

 

[kees52]

Hi X

No the back will be closed, maybe I do make a slit in the back as you did getting a kind of open baffle as de low end do very well allready, the woofers has high qts of 0,64.

I need a notch for the peak.

regards