TriTrix Enclosure Choices

[fshagan]

I'm going to build the TriTrix MTM speakers, and have a question about the enclosure choices (the article at Curt's Site details three choices, sealed, vented and transmission line).

The speakers will be incorporated into my eventual 5.1 set up that is now a 3.1 system with a Velodyne VX-10 subwoofer. I like the idea of getting lower sound out of the TriTrex, and favor the vented or transmission line enclosure. But there may be a potential problem.

Because of a small room and the ever-present WAF, I will have the speakers in the "entertainment center niche", a 30" deep recess in the wall that measures 81" wide X 63" tall starting at 32" from the floor. The planned TV is 50" wide, so there is room for speakers on either side of the TV. AV equipment will be set in a horizontal 'cabinet' under the TV that will be about 20" tall and can either go full width or something less to accommodate the speakers. I have two concerns about the TriTrix enclosure.

1) Bass response ... is it likely that with the vented or TL enclosure, with openings in the rear of the speakers, gets "boomy" or muddy because they are tucked into the niche in the wall? Would using the sealed enclosure be better (or perhaps another design entirely)? Or could I use the Triune vented enclosure design that has the vent on the front of the speaker to avoid this?

2) Height of the speakers ... the "floor" of the niche that the speakers will be on will be either 32" from the floor, or 52" if I build the horizontal cabinet full width. Is there a concern with the TL version of the enclosure, with the tweeter at either 58" or 78" from the floor? (I'm assuming the woofers are less important in this regard).

[ThomasW]

If you'll be using a sub just build the TriTrix as sealed boxes.

There's little point in worrying about a box design intended to boost output at frequencies the drivers won't be playing. Everything below ~80Hz is filtered out by the crossover in the receiver...

[fshagan]

Thanks, Thomas. That also solves my concern about the height of the tweeter since the sealed enclosure is so much smaller. I may even have my crossover set at 100Hz in the receiver with my existing bookshelf speakers, so I should have thought of this.

[zacjones]

Even if your front speakers are set to 'large'? When set to large my mains definitely play lower than 80hz.

[ThomasW]

Doubtful anyone would use the large setting with speakers containing only a pair of 5-1/4" drivers

[M.Roberts8]

Doubtful anyone would use the large setting with speakers containing only a pair of 5-1/4" drivers

It actually happens more than you would think, probably not so much with the people around here but those less in the know.
I agree though you shouldn't be running these full range or set to large let the sub do the heavy lifting. Especially with the low frequency content that the movie soundtracks have in all the channels.

[fshagan]

My current set up is with Polk R150s, a bookshelf speaker with a 5 1/4" woofer that sounds pretty good to me. I'm not enough of an audiophile to know what they are missing, but the system sounds much better with a subwoofer and the crossover set in the receiver to 100Hz.

The TriTrix looks like an economical pair of speakers to build to get my feet wet with speaker building. My expectations are that they will sound as good as the Polks, but we'll see.

[M.Roberts8]

I'm not enough of an audiophile to know what they are missing, but the system sounds much better with a subwoofer and the crossover set in the receiver to 100Hz.

IMHO That's how bookshelf or any small driver speakers should be set, crossed over to a sub. The point of the comments is its pretty unrealistic to expect much low freq content with small drivers.
Good luck and keep us updated on your build.

[fshagan]

As usual, I'm now considering another option, the Zaph Bargin Aluminum MTM, mainly because of the comments that the mid range is good and the tweeter looks to be much better. Looks like the same basic type of design.

I can't find the Dayton DA130BS-4 on the PE web site that the TriTrix uses, but do see a DC130BS-4. Is that comparable?

What attracts me to the Zaph BAMTM is my thinking that the Dayton DA175 7" aluminum cone woofer might do better on the mid-range. John also speaks highly of the Seas 27TBFC/G tweeter.

I'm still under $100 for the drivers on this one, so the cost difference is negligible. I listen to a fair amount of uncompressed music, mostly rock and pop but with a smattering of jazz and classical. They will be in sealed cabinets and have a subwoofer that I cross over as mentioned above.

Any opinions on the relative worth between these two? Or would they be about the same because the low end is being handled by the sub?

[ThomasW]

Given the choice I'd go with the BAMTM as long as the price difference isn't an issue.

BTW there is no 'uncompressed' rock/pop being released these days unless you're making your own recordings ...

[fshagan]

Given the choice I'd go with the BAMTM as long as the price difference isn't an issue.

BTW there is no 'uncompressed' rock/pop being released these days unless you're making your own recordings ...

thanks!

I did hear an audio guy lament that there are some pop recordings with less than 6db of range (or something like that). So I guess it is all compressed now.

MP3s sound awful on my system unless I rip and encode at a higher bit rate (I'm using EAC with the LAME encoder for a variable bit rate). Even then, they don't sound as good as the CD to me. There might be some bias involved, as I haven't done a blind test between the wireless streaming audio to my Roku and a CD of the same music. But I can definitely hear the difference between a MP3 at 128 kbps and higher bit rates on my home system (but not in my car ... too much road noise and rage going on).

[Dennis H]

'Compressed' has two different meanings. Thomas is talking about how they compress the dynamic range on the CD so it all sounds loud on the radio. MP3 is a different thing where you throw away info on the original recording to make the file size smaller. Technically, MP3 is lossy compression (loses info) and others like FLAC are lossless (you can convert back to the original without losing anything.)

[fshagan]

Thanks, everyone. I bought the parts today, and with shipping, the parts for the Zaph BAMTM was only about $50 more than the TriTrix design. I was able to source everything from Madisound and PartsExpress, although Madisound was out of the 10 uF Bennic Metallized Poly capacitor. I found an alternate Dayton model at PE (same mfd, voltage, etc.) so I think that will work.

I'll post pics as I start to build.

[keelay]

Did you complete them? So how did they sound? How about a comparison to the Polks?

Thanks,

Kyle

[fshagan]

Did you complete them? So how did they sound? How about a comparison to the Polks?

I did finish the two I set out to build, and they sound great. I'm not an audiophile, and I can't measure the performance but I like the way they sound. Compared to the Polks, they have a more "full" sound, which I think probably comes from the better mid-range performance, with a bit of brightness. I have the cross-over to the sub set at 80Hz, so I'm not using them for the low end. But I like the way the high end sounds on things like U2's music from the Joshua Tree album; very clear sounding. There's just a little bit of what I'll call brightness (maybe from the aluminum cones?)

I stuffed them with quite a bit of fiberglass, and I may try a little less to see if that changes the brightness. Even if it doesn't, I'll still be very happy with them.

I'll build the center next so I can have them permanently in the system, but I have to change my built-in entertainment center. They do OK with the Polk center I have on movies like The Dark Knight. I don't have any muddled sound with the CS1 center, and the dialog is fine, but I'm wondering what I'm missing!

I do have some pics I'll post later; my wife had cancer surgery on the 29th, so our lives have been on a roller coaster over the last few months. That's put our plans for a new entertainment center build on hold.