Couple of Tritrix TL questions...

[Rob1119]

I am at the end of the Knock Down Tritrix build, which is ridiculously easy, and have a couple of questions.

I am wanting to place the XO on the rear most brace so I can easily access it if necessary at some point. Is this O.K. to do?

Stuffing, on the speaker build website it says 100% fill in the front section but here it says "light to medium fill on the front section and medium to heavy fill below the drivers to terminous." What has everyone found that works? After they are sealed up it will be difficult to change the stuffing amount.

Thanks

[Soundslike]

I'm guessing you're referring to the rearmost angled piece that's intended to deflect pressure waves upward. That's the recommended location on Curt Campbell's website, unless those directions have been superseded. I just recently completed a Tritrix build (in fact I'm listening to them now). I attached my crossover as shown in the attached drawing. I also included the fill and padding scheme I used, which I derived from reading everything I could find pertaining to the Tritrix. The drawing isn't to scale, by the way.

[Rob1119]

Thanks. I missed that bit about XO placement. Thats where I placed it. I put a little over half a bag of the stuffing behind the drivers, along the back wall, to the end on the sloped panel. They sound pretty good, a tad bright. The way I get decent bass is setting my avr to 50hz and turning up the bass adjustment around 3/4. Does more or less stuffing enhance the bass? I realize 5.25" drivers aren't really made for bass just trying to optimize the xo setting with my sub.

Thanks

[Soundslike]

I'm don't really feel qualified to comment much about the effects of stuffing. I think it's critical because it resists the movement of air which dampens the woofers. My speakers don't strike me as being bright, and I consider the bass to be substantial. I believe I read somewhere that the amount of fill can be varied according to personal preference -- I used all of the fill provided with the kit stuffing them loosely immediately behind the drivers and filling the transmission line pretty much completely.

Have you posed the question to Curt? He is very responsive to questions and as the designer, he's going to be your best source of information. An e-mail address is posted on his website at:
http://speakerdesignworks.com/

[Rob1119]

Thanks for the info. I have not contacted him but I may. I am going to try the same as you did which is also what is on the build site here at PE. They sound better and better the more I listen.

[john trials]

Regarding the lining/stuffing of the Tritrix:

When I completed my Tritrix TL build, I used both bags of the supplied Acoustastuff to fill the TLs (almost a full bag in each...using Curt's description for stuffing on his web page and the PE description on the projects page). It didn't sound as nice as my initial test when I just clamped the cabinet together and had no stuffing at all (but the 2 listenings happened a month apart, so I wasn't sure if my listening memory was correct). It sounded muffled when it was full of stuffing.

I e-mailed Curt, and he gave me this recommendation:
"As for stuffing I added lightly teased polyfill, (non stuffed) in the bottom of the line, and up the front of the line to just below the rear of the bottom woofer. The rear of the line is open. There is a piece of foam behind the woofers glued to the inside rear panel. Less is better than more, but try stuffing until you just hear the bass frequencies is starting to attenuate, and adjust from there to find what sounds best to you.

I believe I voiced the TriTrix with their front baffles about 1 meter into the room, but certainly you can trade off some soundstage depth for increased bass by moving them closer. Experiment with the stuffing and position to find the best combination for you."



I removed almost all of the Acoustastuff and positioned it as Curt mentioned. I used about 1/2 bag Acoustastuff for both speakers. The results were pleasing to me, so that's how I left it. Also, my Tritrix cabinets are lined with foam in the driver area. I cannot comment on how that affects the sound, and I'm not going to mess with it, because I'm very happy with the way my Tritrixes are sounding now.

[johnnail]

Thanks. I missed that bit about XO placement. Thats where I placed it. I put a little over half a bag of the stuffing behind the drivers, along the back wall, to the end on the sloped panel. They sound pretty good, a tad bright. The way I get decent bass is setting my avr to 50hz and turning up the bass adjustment around 3/4. Does more or less stuffing enhance the bass? I realize 5.25" drivers aren't really made for bass just trying to optimize the xo setting with my sub.

Thanks

How long have you had them running? I would wait for at least a week or more before passing judgement on the "brightness".....the midbass drivers have got to loosen up and then, once they do hit that "loosened up" stage, the bass will seemingly increase output....just how much is not known at this point...but it will happen. Most new drivers don't put out the bass that a simulation first predicts....the suspensions are a bit stiff, and so the bass output suffers a bit. But once the suspensions get loose where they can work better, the bass should improve.

John

[PWR RYD]

When I first built my Tritrix's I used one whole bag of stuffing for each speaker. They sounded way too damped. I posted here and Curt replied that I had about 2X too much stuffing. I restuffed them with half a bag per speaker and now they sound great!

[curt_c]

There are at least 3 factors at work here on finding the optimum stuffing the TriTrix, or any TL enclosure. An unstuffed line will exhibit strong enclosure resonance at multiple frequencies above the tuning frequency due to the standing waves and acoustic impedance of the line. Stuffing the line ameliorates these issues, and smoothes the response. However, too much of a good thing (stuffing) also has the effect of damping the output of the terminus. Fortunately for us, typical stuffing materials do not damp the lower frequencies as much as the higher ones, so to a certain extent we can have the best of both worlds. Hence axiom one for stuffing:

1) Stuff the line until the bass output of the terminus just starts to be attenuated. -Use this as a starting point and adjust your stuffing from there.

The position of the stuffing and the density of the stuffing has a bearing on the damping level with respect to frequency. In general, the last 1/4th to 1/3rd of the line should be left open. Adding stuffing here will attenuate the terminus output, and ultimately turn it from a TL enclosure to an aperiodically damped sealed enclosure. In general, more dense stuffing from the driver end of the line down to the middle of the line, tapering to less dense from that point, will provide better damping and terminus output than a lighter, but linear stuffing density.
Axiom two:

2) Start with a light equal density stuffing, and if necessary add additional stuffing to the middle and closed end of the design. (Leaving room behind the drivers for them to breathe, of course.)

Room modes, and speaker position in the room will affect the perceived bass response at the listening position. If the speakers are required to be somewhat closer to the front wall than normal, extra stuffing can help attenuate the ‘excess’ bass from the additional room loading. In other words you can to a certain extent tune the bass response to your particular room requirements.

3) Do your listening evaluations with the speakers in their intended listening positions in the room.

Stuffing a TL is like putting chocolate syrup on your ice cream. It’s not rocket science, so don’t get carried away worrying about linear stuffing density or weighing each handful of stuffing. Start out with 2 equal piles of stuffing. Use the TLAR method to determine the initial amount to add to each enclosure. Listen to the result. If changes are necessary, add /remove/reposition a handful or two at a time in each enclosure to keep things relatively equal. You will be working through the driver holes, so some creativity may be required to obtain the stuffing placement you desire.

The bass response will come up as the drivers break in. A few hours playing music through them at reasonable levels should be close, but they may continue to loosen up a bit more with time. Hence, amiom four:

4) Allow time for the drivers to break in before making your final stuffing adjustments.

Listen to a variety of music. Like voicing, it has to sound good over many different genre, and certainly the bass output varies significantly from artist to artist.

C

[john trials]

Curt, you should put that on your website. Great info!

[Rob1119]

Thanks Curt and everyone else. I listened to them quite a bit last night and can already hear a small improvement bass wise. I run a sub so I don't need big bass from these. Overall they are sounding awesome. I got to get going on the center and surrounds to make some movie evals.

[curt_c]

Curt, you should put that on your website. Great info!

Good thinking John!

Based on the myriad of emails I've received on TriTrix construction, there was 2 things I didn't cover sufficiently in the write up:

Where to put the crossover, and how to stuff them.

I'll leave this here a bit to see if anyone has any questions, corrections, suggestions, or improvements, then I'll move it over to my site.

C

[Rob1119]

I listened again today and I really think they sound better than last night. I moved them 6" closer to the back wall and the bass really started hitting. For dual 5.25" drivers the bass is very impressive. It is enough for me for most music unless it has a heavy bass line. I left the stuffing as is. Each has about half bag of acousta stuff fluffed up and laying along the sloped panel. It stops around 4" from the end. I figured I like the sound so why mess with a good thing. Plus it sound about like Curt described above. Just have to finish the cabs and lay some paint.

[Rob1119]

Good thinking John!

Based on the myriad of emails I've received on TriTrix construction, there was 2 things I didn't cover sufficiently in the write up:

Where to put the crossover, and how to stuff them.

I'll leave this here a bit to see if anyone has any questions, corrections, suggestions, or improvements, then I'll move it over to my site.

C

Remember, dudes like pictures

[Rob1119]

And finally a completed speaker. Primed with Zinsser B-I-N then around 8 coats of Valspar flat black latex. I rolled it on to leave some texture. Looks pretty good although up close you can see some flaws. From a few feet away they are looking great
After reassembly I decided to try the AA battery test to check the speakers. Glad I did because I had one driver wired backwards this whole time. Now with the correct wiring, these things hit! The bass from these small drivers is pretty incredible. Even at loud volumes they hit hard and are distortion free. These are some fantastic sounding speakers, especially for the price. I am still likely going to build some bases to raise them up.


With the THT....

[Rob1119]

Some simple bases to elevate them 3" to better match up with the LP. 4 layers of .75 mdf. The speakers just sit on them. I used the gasketing tape from here on the bottoms. They don't move around and the bases add stability to the narrow towers on carpeting.

[joeybutts]

Very nice. I'll probably use something similar to raise up my Cyburg Needles....

How do these match with the THT?

[Rob1119]

I only have the fronts done so far but they match really well. Your center is coming out nice. Thats my next project when I get some clear weather.

[joeybutts]

Thanks Rob!

So the Tritrix keep up with the THT? I was thinking the THT may overpower them and was concerned in building THT's for my setup.....

[Rob1119]

O.K. the latest completed project. I swear this whole thing has taken over my life. It is a waaayyyy bigger project than I initially assumed. These sound really good. If they weren't surrounds I would have ported them. Running them at a 40hz and sub off on my avr they actually put out decent bass. Would be assuredly better ported. Overall they sound great when crossed at 80 and sub on, of course. My center is being finished now. I melted a cap so I ordered one today. I can get the xo through a speaker hole so I am moving along.