DIY sub for Klipschorn based HT (and music) - Tuba HT - build done (except for finish)!

[psg]

I don't have a woofer gasket. Weather-stripping tape from a hardware store? Bicycle inner tube?

[CECAA850]

How much do you need? Do you have any for the driver access covers?

[psg]

No, I don't.

Would this work?

http://www.rona.ca/shop/~weather-strip-r.c.r.-clima-2000-360311_!weather-strip_shop

Weather strip. 10 ft. x 3/8 in. Made of foam rubber. Black.

And I still haven't decided how I will screw down the access door. I have a bunch of small T-nuts but would need to get matching bolts from the hardware store; maybe something with a nice hex. Or I could use plain drywall screws (like I'm being using for assembly).

[CECAA850]

3/8" is pretty thick for an access door. I have some left over from my build that I'd be happy to send you. I think it was 3/16 but I'd need to check.

[psg]

I think 3/8 would be the width and not the thickness.

Someone on AVS recommended duct seal compound for the woofer seal as it's easy to manipulate into a circle. Could also work for the access door I suppose.

http://www.idealindustries.com/products/wire_installation/accessories/duct_seal.jsp

http://www.rona.ca/shop/~compound-iberville-63578_specialized-electricity-tools_electrical-material_iberville_lighting-electricity_shop

Thanks for the kind offer but I'm sure I'll find something locally. I'll keep your offer in mind if I don't!

[CECAA850]

LOL, the pic made it look thick, my bad. I've got plenty if you get in a bind. I ordered a 50' roll, 1/2" wide by 1/8" thick. Sticky on one side. I doubt I used 5 or 6 feet of it. The whole roll was only $6.50 or so from parts express.

[psg]

Back at the beginning...

A couple of questions... What sort of gear is needed for the EQ? I hear some version of Audyssey may be sufficient?

If you already have a receiver with Audyssey, it may suffice. Try it before you buy something else. If you don't, look into getting a BFD. It takes a little time to get the hang of it, but it's worth it. you're basically getting a 12 band PEQ for around a hundred dollars.

In a sticky thread here:

http://www.hometheatershack.com/forums/bfd-electronic-equalization-devices/

there's talk of the dreaded BFD hum. Is this an issue for you? Should I worry about this or buy one anyway?

[CECAA850]

I've never heard of a BFD hum, nor has mine ever made any noise. Let me start over. I had a ground loop hum when I first fired up the IB. I assumed that it was because my sub amp was on one circuit and my receiver/BFD was on another. I put a cheater plug on the sub amp and never gave it another thought. I honestly don't know what the root cause was.

[gnatnoop]

Your build is look great! Have been following this thread and can't wait until we, err you finish it!! []

[psg]

I've never heard of a BFD hum, nor has mine ever made any noise.

Yeah, I think I'll just pull the trigger and not look back.

And thanks to the newcomer to the thread too! Yeah, these things do feel like a community is involved, don' t they?!

[psg]

I looked at the Behringer 1124p manual

http://www.behringer.com/EN/Products/DSP1124P.aspx

So it looks like 12 programmable frequencies per channel from 20Hz up. Is the 20 Hz lower limit a problem? Can't really do a high-pass filter with it, but I don't suppose I'd need one anyway. I guess I can expect to EQ the THT down to 20 Hz and let the response drop off from there. It isn't a 15 Hz sub anyway, so can't expect magic to heppen anyway, right?

[CECAA850]

The 20 Hz limit is not a problem. Most subs roll off so fast below 20Hz,that there's no need to EQ. You'll be using the BFD to tame peaks, not raise nulls or drop offs.

[psg]

So no need for a little boost below 20 Hz to get that extra low end?

[CECAA850]

So no need for a little boost below 20 Hz to get that extra low end?

No! Let the sub roll off naturally. Trying to boost below 20Hz taxes the amp and really taxes the driver. You're going to get some boundary gain if you're close to a wall (or corner) which will help with extension.

[psg]

Gotcha.

[ClaudeJ1]

As I said earlier since I have the 2 x 12" Eminence LAB speakers I might as well build some TUBA's or tapped horns with them, that way if I decide to dive into the world of IB I can sell a working set of subs!

If you build either of those, you won't need to sell them.

[Vicoaster]

As I said earlier since I have the 2 x 12" Eminence LAB speakers I might as well build some TUBA's or tapped horns with them, that way if I decide to dive into the world of IB I can sell a working set of subs!

If you build either of those, you won't need to sell them.

Your reply made me laugh, not because it was funny but because I am taking it to be a masterful understatement... []

[ClaudeJ1]

Your reply made me laugh, not because it was funny but because I am taking it to be a masterful understatement...

Precisely how it was meant. The Tuba is more efficient but the TH goes lower......takes a lot to do 16 Hz. but there is content we never feel otherwise. Transformers Movie (first one) contains tons of 18 Hz. stuff to Klipsch commercial engineers use it to set up theaters, like Malco.

[CECAA850]

As I said earlier since I have the 2 x 12" Eminence LAB speakers I might as well build some TUBA's or tapped horns with them, that way if I decide to dive into the world of IB I can sell a working set of subs!

If you build either of those, you won't need to sell them.

Claude, have you ever heard an IB or either horn sub in question?

[Vicoaster]

I understand that the TH is supposed to go lower, it still might be a possiblilty for my project however the plan recently posted in this thread is very basic in it details, I little disconcerting when deciding over the Tuba HT... Also based on this information posted on Bill's Tuba HT site, the Tuba might get to the necessary frequencies anyway?

Your reply made me laugh, not because it was funny but because I am taking it to be a masterful understatement...

Precisely how it was meant. The Tuba is more efficient but the TH goes lower......takes a lot to do 16 Hz. but there is content we never feel otherwise. Transformers Movie (first one) contains tons of 18 Hz. stuff to Klipsch commercial engineers use it to set up theaters, like Malco.

Not impressed yet? Add in the cabin gain of an average room (12dB per octave below 30 Hz) and you can end up with flat response to 10Hz with 110dB sensitivity. Not even the most expensive theatrical subs made can make that claim. Here's what builder 'Tweedpower'has to say about his THT:

Built a Tuba HT, my third Tuba. This is a different animal. I built a 30" wide version. This was the widest size that would fit through my door. The low end output is unreal. It is the greatest for the LF channel in my HT. I have been experimenting with different crossover points and I think that I like crossing it over lower at 60 or 80 hz. The power in the sub 50 hz region is impressive. It lets you know what the sound engineers had in mind. I get great output down to 15 hz and basically flat to 18 hz when using minimal EQ.

The sensitivity advantage of the Tuba HT means bass more solid than you've ever heard before. The folded horn geometry reduces distortion to levels that no direct radiator sub can even approach. Here's what builder MaxMercy measured from his THT:

20Hz: 114dB at 4.5% THD. I did not push any further, as the panes in my windows were moving about 1/16" at the time. I think they would have broken if I went further. Above 20Hz, you can get damned near as much as you want dB-wise, all clean. Basically, from 16 or so Hz on up, you have strong bass, from 20Hz on up, INSANE bass. I designed the system to give me great sound at -10dB from reference (with Dynamic EQ frequency correction to account for equal loudness curves), which it does with flying colors flat down to around 16Hz before dropping off. Useful output down to 12Hz. All at less than 5% THD. In a sweep and distortion test of a $9950 sub, the Genelec HTS6... the Genelec runs over 10% THD at 115dB. This is significant, in that a sub almost 20 times less expensive to build can seriously compare with one of the best subs available.