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Re: TLAH Pro for a church sanctuary
Posted: Tue Mar 12, 2013 6:00 pm
by mattsk8
Tom Smit wrote:I meant that the tweeter filter had to be installed in addition to just wiring up the drivers...but you know that.
Yes, the woofer and tweeter wiring should be done as you described.
If you were to set a limiter on the amp so that you limit by db rather than volts (but keep an eye on the volts), you'll find that you won't come near the wattage that your amp provides.
Thanks for the reassurance!!!
Jon Barnhardt wrote:It doesn't make any more power. It's actually less efficient at 4 ohms.
500 watts at 8 ohms is 63.25 volts. That same voltage at 4 ohms is 1000 watts. So if the amp is putting out 800 watts at 4 ohms, it's only delivering 56.57 volts. It's more watts because watts is dependent on voltage and resistance (ohms).
Your speaker don't care about watts. It only knows voltage. The more voltage, the louder it goes (until too much and then black smoke.)
Ohms is nothing more than the amount of resistance the speaker creates for the amp.
Thank you for clarifying! I was able to call and change the order from the 8ohm version to the 4ohm version on the woofers. So, I'll end up at 8ohms now!
One more question... Is there a preferred connector used for the inputs on the cabinet? Banana plug style, RCA, speakon? I plan on using the banana plug style but figured I'd ask before I did that.
Re: TLAH Pro for a church sanctuary
Posted: Tue Mar 12, 2013 6:21 pm
by Ryan A
It can't all be chalked up to volts alone...even though volts is a good way of measuring and limiting output, it doesn't tell the entire story.
The speakers will be louder wired at 4 ohms than 8 ohms for instance (at the same voltage). And it will draw more power. Not more voltage, but more power. Power = output.
This is not to say that you should always wire to "max out" your amps capabilities. But you are missing out on some output capabilities by wiring 8 or 16 ohm speakers to a 2 ohm capable amp, for instance.
Re: TLAH Pro for a church sanctuary
Posted: Tue Mar 12, 2013 6:37 pm
by Bill Fitzmaurice
Ryan A wrote:
The speakers will be louder wired at 4 ohms than 8 ohms for instance (at the same voltage).
By 2dB at full power, which isn't much, and unless you really need that 2dB not worth what you're giving up.
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 12:43 pm
by mattsk8
The Alpha 8a (the driver that's recommended in the plans) is only available in 8ohms. Suggestions???
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 12:54 pm
by Bill Fitzmaurice
mattsk8 wrote:The Alpha 8a (the driver that's recommended in the plans) is only available in 8ohms. Suggestions???
Use nine wired as triplets and you have an 8 ohm load. IITP.
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 1:39 pm
by mattsk8
Bill Fitzmaurice wrote:mattsk8 wrote:The Alpha 8a (the driver that's recommended in the plans) is only available in 8ohms. Suggestions???
Use nine wired as triplets and you have an 8 ohm load. IITP.
Would I still have a respectable amount of pattern control (if I'm understanding that term correctly) if I went down to 7 drivers as opposed to going up to 9? Using 8 drivers was the maximum cabinet size that would still allow good view of the projector for the entire audience.
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 1:53 pm
by Bill Fitzmaurice
mattsk8 wrote:
Would I still have a respectable amount of pattern control (if I'm understanding that term correctly) if I went down to 7 drivers as opposed to going up to 9? Using 8 drivers was the maximum cabinet size that would still allow good view of the projector for the entire audience.
You can't use seven drivers with equal voltage distribution.
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 2:55 pm
by mattsk8
Bill Fitzmaurice wrote:mattsk8 wrote:
Would I still have a respectable amount of pattern control (if I'm understanding that term correctly) if I went down to 7 drivers as opposed to going up to 9? Using 8 drivers was the maximum cabinet size that would still allow good view of the projector for the entire audience.
You can't use seven drivers with equal voltage distribution.
IMO, the simple solution is to drop back to using 8 per cabinet of the 8 ohm speakers and stick w/ the 4 ohm cabinets. Short of "waisting amplifier usage", is there any reason why this shouldn't be done??
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 3:17 pm
by Bill Fitzmaurice
mattsk8 wrote:
IMO, the simple solution is to drop back to using 8 per cabinet of the 8 ohm speakers and stick w/ the 4 ohm cabinets. Short of "waisting amplifier usage", is there any reason why this shouldn't be done??
It's not a problem so long as it doesn't restrict potential system expansion.
Re: TLAH Pro for a church sanctuary
Posted: Wed Mar 13, 2013 4:16 pm
by mattsk8
Bill Fitzmaurice wrote:It's not a problem so long as it doesn't restrict potential system expansion.
Thanks. Woofers and tweeters are finally ordered. Once they show up, I'll get the wood and start making some sawdust.
Re: TLAH Pro for a church sanctuary
Posted: Thu Mar 14, 2013 12:40 pm
by subharmonic
Jon Barnhardt wrote: The more voltage, the louder it goes (until too much and then black smoke.)
The technical term is..."Magic". Magic Smoke appears
Re: TLAH Pro for a church sanctuary
Posted: Sat Apr 06, 2013 10:21 pm
by mattsk8
I basically have all the pieces cut and I'm about ready for the glue up, I hope to do this tomorrow. I still have to cut the driver holes in the front baffle but I have a question about the tweeters.
The plans say I'll gain a flatter response by eliminating the frames on the piezo tweeters. Once this is done, the tweeter array ends up being 24 7/8" long, as opposed to the sketchup drawing's array of tweeters (that aren't cut) at 49 1/4" long. Do I still mount the cut array of tweeters 6" up from the bottom of the front baffle??
Re: TLAH Pro for a church sanctuary
Posted: Sat Apr 06, 2013 10:34 pm
by Tom Smit
mattsk8 wrote: Do I still mount the cut array of tweeters 6" up from the bottom of the front baffle??
Yes.
Re: TLAH Pro for a church sanctuary
Posted: Sat Apr 06, 2013 10:36 pm
by mattsk8
Tom Smit wrote:mattsk8 wrote: Do I still mount the cut array of tweeters 6" up from the bottom of the front baffle??
Yes.
Thanks! I hope to have a pic of the unfinished cabinet tomorrow w/ drivers mounted, waiting for a test drive!
Re: TLAH Pro for a church sanctuary
Posted: Sun Apr 07, 2013 10:44 pm
by mattsk8
Got some work done this weekend. Tomorrow I'll glue and wire the tweeters, then mount them and the woofers.
I braced the cabinets well. Here's a pic of the inside.
I have about as much faith in those glued up tweeters not leaking as I do in politicians, so I made an air tight cavity for them.
Clamped up.
Waiting for drivers to get mounted.
