TLAH PRO Build

[gzc_stageTech]

Yes, I agree with Leland. Your filter looks correct. And you driver scheMatic is correct as well. That should do it.

One note tho, make sure you mount your filter circuit securely. As the cabinet gets moved around (and I'm sure it will) you don't want stress to fracture your solder joints. I used zip-ties drilled through a block of 1/4" plywood as a filter board. All the elements are solid and won't bounce around. I'm sure you have a small scrap of wood around there somewhere.

Hooo haaaa! You're almost done.

Chris

[gzc_stageTech]

ok.... have any recommendations regarding a crossover/filter for the midbass speaks....

I asked about this too, since the plans didn't address the driver filter if piezos were used for the tweets. Bill responded that the mid bass driver rolloff should be adequate for the low pass cutoff.

I didn't see a ohm / frequency chart for your drivers, but with a frquency range up to 3.5k, the resistance of each driver increases as the frequency increases and the driver itself attenuates. With a series of drivers the combined output will rolloff.

In some mid bass (woofer) drivers ther may be a frequency where the resistance falls again with increasing frequency. If it falls significantly, then the the driver could be unstable at that range and you'd need a low pass filter to avoid that instability.

But again, the multiple drivers (series) helps to avoid that condition. I didn't need a low pass and I don't think you will either.

Chris

[mattaudio]

I can't wait to hear how you like the drivers. <$10 compared to a $45 Alpha 6a sounds appealing, so long as it's "close enough."

[gzc_stageTech]

chenry,

Are you up & running? Did you get the electronics sorted out OK?

I'm curious about those buyout drivers. How Dow they sound? What amp are you driving the boxes with?

I tried a CE1000 (275W-275W) and the 9 drivers were OK, but could use a little more headroom. So I connected a CE2000 (400W-400W) and it helped a lot. With my drivers (the Goldwood 525-8s), the RMS capacity is over 600W. So the extra voltage swing helped to liven the cabinets up.

What are you thinking?

Chris

[chenry78]

chenry,

Are you up & running? Did you get the electronics sorted out OK?

I'm curious about those buyout drivers. How Dow they sound? What amp are you driving the boxes with?

I tried a CE1000 (275W-275W) and the 9 drivers were OK, but could use a little more headroom. So I connected a CE2000 (400W-400W) and it helped a lot. With my drivers (the Goldwood 525-8s), the RMS capacity is over 600W. So the extra voltage swing helped to liven the cabinets up.

What are you thinking?

Chris

electronics sorted out and everythings on the "up and up".

I should have them ready to test today...should. Ive gotta run some nuetriks and mount the baffles...dont and done. Ill worry about the covers next wk. Also, im gonna fashion a tophat mounting system on the back and hang them from standard speaker poles..I att a really crappy drawing just to give you an idea of where im going with it

Ill post a vid this week of the audio, but I can really test them till next week cause all my equipment is two hours south! But I do have some power amps and preamps to get some sound out of them. I will be drivin them with a crown slx 602 amp (http://crownaudio.com/amp_htm/xls.htm) so roughly 450 watts or so. Right about where I need to be with them RMS...roughly that is. Ill be setting up some limiters on the Driverack.

Just messing around with my test amp I can tell your that they sound decent, they will need a lot of EQ help (expected) but well see. Im looking to give you guys a sample this week but it will be straight outta the box, basement style!

[mattaudio]

Why not just put a tophat in the bottom and lower the stand?

[gzc_stageTech]

chenry,

I don't know about your cabinets, but mine are relatively heavy and top heavy. Since they're tall and slender the cg is high.

Mounting the tophat in the bottom of the box would likely not provide enough upper cg support to keep it from tipping. Locating it at the midpoint (like you're planning) would help this somewhat.

If you could get the support point even higher, the gravity would help to keep things solid and less likely to tip (think...suspended vs. projected). I don't know if your poles will extend up 6 to 7 feet like you'd need. But if they will then that might be the best approach.

The Crown XLS-602 is 600W (4 ohm) / 370W (8 ohm). You'll be running around 6 ohms with the 8 x 40W RMS drivers, so the XLS should be a good match (with good headroom).

I'm curious if the low frequency extension is deep enough to run without a subwoofer. Your drivers are 8" with a Fs of 41 Hz, lower than my 5 1/4" Goldwoods with a Fs of 81 Hz. With the power margin, you may not need the sub at normal listening levels (90 dB, or so).

Also on my TLAHs, I needed to drop the 3k Hz by 2-3 dB and the 4.5k Hz by 3-6 dB to quench the sharpness of the piezos. Other than that, it isn't too bad.

Chris

[chenry78]

Yeah these boxes aren't heavy but they are too tall and heavey to mounjt hats on the bottom, they wouldn't be secure. Plus I wanna get thee up un the air a little. Chris, reagrding the piezo responce, that filter in the plans works great. It really cleaned the piezos up.they aren't overwhelming and are crisp..I can't tell they are piezos!

[wallywally]

Somewhere in this thread you can see my mount. I did end up making it deeper so I could angle the box more. I built it this way so the mount would be removable.

[gzc_stageTech]

Somewhere in this thread you can see my mount. I did end up making it deeper so I could angle the box more. I built it this way so the mount would be removable.

Yuuup!

Great build thread. I reviewed that many times before starting my build. I like the stand mount & the pivot bolt setup you have. Plus, the way your arrays transport. Very slick. You have a dozen woofs and at least 16 tweets in each box. Did you have some EQ needed to soften the piezos?

Great job Wally.

Chris

[chenry78]

well here are sum pics of todays work. Should be stuffed and sealed tomorrow.

[AntonZ]

well here are sum pics of todays work. Should be stuffed and sealed tomorrow.

If the coil in your second pic (24.jpg) is for the woofer low pass, it looks a bit smallish to me for a TLAH PRO (although I should add that I have never build one). If it's rather the piezo HP, you can completely ignore this.

[mattaudio]

In that wallywally build thread, the Aurasound NS525-255-8A was used ($3.60 ea) which is tempting... 1/10 the price of Alpha 6a. For a TLAH with 12 drivers each, I'm considering their "case" deal for 30 at $2 each, to have some spares.

[chenry78]

well here are sum pics of todays work. Should be stuffed and sealed tomorrow.

If the coil in your second pic (24.jpg) is for the woofer low pass, it looks a bit smallish to me for a TLAH PRO (although I should add that I have never build one). If it's rather the piezo HP, you can completely ignore this.

Its the highpass filter for the piezos..build to spec.

[chenry78]

finishing up, sealed the boxes up today, gonna slap some corners on in the morning and fire them up. My good audio recording device is with the rest of my equipment so I wont have access to it until next week. Otherwise Im gonna try and run some pink noise through them this weekend and rta them...as mentioned earlier in the thread, i will be rta'in them with my droid but I would like to get a more official (accurate) reading. I have an rta mic that came with my drivrackPA and I have a personus audiobox deal so that I can run that into my laptop..but from there I get lost on what to do. Are there any decent free programs or otherwise that I can use to get a respectable reading?

again i have an rta mic (http://www.dbxpro.com/RTA%20Mic/index.php), a personus audio box plus software (http://www.presonus.com/products/Detail ... oductId=60) and obviously a laptop. That should get the sound into the computer and my computer may also act as the sound generator. The question is, what software to use

Thanks guys!