BillFitzmaurice.info

Bill Fitzmaurice wrote:

miked wrote: the spec'd drivers have a natural rolloff near the tweets' crossover freq and therefore don't need to be crossed over.

+1. You could put a low pass in, but it wouldn't benefit that much. If they were hi-fi cabs where EQ would probably not be used and maximally flat response was a goal that would be another story, but these are pro-sound cabs, and in pro-sound a good EQ isn't optional, it's a necessity.

Thanks for the input Bill! We did get a DBX Driverack, plus we have the eq in our soundboard. I'm also excited to figure out how to dial all that in! I'll have help w/ that from a good friend that owns a local recording studio here in Grand Rapids.

I do know the acoustics will change completely once these are flown in the huge sanctuary, compared to how they sound standing on my concrete floor upside down in my shop

miked wrote:I know the feeling; I've been planning/building my OTops for two years already and should be firing up at least one tonight!

That's awesome!! I can't wait to get your impressions on their sound! Another build I'm considering for the church is the wedghorn 8. Considering this for replacing the studio monitors we currently use.

The tweeter crossover made a HUGE difference!! They went from mid heavy to hot!!!

My goal was Motorhead loud, I'm there w/ just one playing in my garage!!! When I got home I skipped the Dire Straits and went right for Motley Crue Livewire and the TLAH's took it well and loved it, I think I might have heard them begging for more! After I hammered them w/ that I ran the gammut w/ music, everything from Natalie Merchant to Clutch to Rob Bass. I'm very happy w/ these!!! Thanks everyone for the help w/ these; I know it was frustrating at times answering all my questions.

The next step is to take one of them to Meniscus so they can measure them and help me figure out an ideal position to mount them. I've decided on satin black paint for the finish, but that could still change as I'm worse than a woman when it comes to decisions like that. I would like to add some kind of flare to them somewhere that spells out that I built them.

Thanks again! It was fun punishing these tonight!!

mattsk8 wrote: I would like to add some kind of flare to them somewhere that spells out that I built them.

Humility, my son.....it's for the church.

Whenever I build something, especially if it's not for me/staying in my house, I always either sign it or put my initials either inside or in a very inconspicuous place. Made a shoe cubby for my buddy's wife; I signed it underneath the bottom shelf, facing the floor. He found it.

Very happy to hear that the TLAHs sound great! There's nothing like hearing your creation come to life for the first time and saying "Wow, that sounds AWESOME!" I will fire up at least one OTop tomorrow night. I ran out of wire AND time tonight.

Bruce Weldy wrote:Humility, my son.....it's for the church.

Not thinking red racing stripes or anything like that , was thinking more along the lines of trying to figure out how to put my favorite bible verse (Isaiah 40:31) somewhere on them w/out it looking ridiculous, or maybe Psalm 95:1.

miked wrote:Whenever I build something, especially if it's not for me/staying in my house, I always either sign it or put my initials either inside or in a very inconspicuous place. Made a shoe cubby for my buddy's wife; I signed it underneath the bottom shelf, facing the floor. He found it.

Very happy to hear that the TLAHs sound great! There's nothing like hearing your creation come to life for the first time and saying "Wow, that sounds AWESOME!" I will fire up at least one OTop tomorrow night. I ran out of wire AND time tonight.

It was fun!! I still have to assemble the other cabinet, I imagine I might have long term hearing loss after I fire them both up in the shop! I did play TSO's Carmina Burana and I'm surprised the cops didn't show up, and that I still have windows in my shop! The truly insane thing is that my shop stereo is a circa 1990 Kenwood receiver that puts out around 120 watts/ch at 4 ohms; I'm afraid to take these inside and hook them to my 350 watt/ch Adcom because I lack self control when it comes to stereos and I'm afraid I might do structural damage to my house!

SUPER excited to get these flown, I can't imagine these w/ the right subs (which, once these are done, will be my next build)!!

Those TLAHs with a pair of 24" Tubas or Titans would be a sure-fire recipie for some serious SPL. I say go for it!

mattsk8 wrote:

Bruce Weldy wrote:Humility, my son.....it's for the church.

Not thinking red racing stripes or anything like that , was thinking more along the lines of trying to figure out how to put my favorite bible verse (Isaiah 40:31) somewhere on them w/out it looking ridiculous, or maybe Psalm 95:1.

Good recovery!



Along those lines.....last week, my neighbor across the street returned one of the two stepstools that I built for his grandkids as they have outgrown 'em. Inside, we had written the date and that he and I built 'em. Kinda' cool seeing that. And now I have one for my grandsons.

They were built totally from scraps in the garage.....
So, yeah....I do understand wanting to put a signature on your work.

[quote="mattsk8"]

Not thinking red racing stripes or anything like that , was thinking more along the lines of trying to figure out how to put my favorite bible verse (Isaiah 40:31) somewhere on them w/out it looking ridiculous, or maybe Psalm 95:1.
Either one is very appropriate.

Bruce Weldy wrote:Along those lines.....last week, my neighbor across the street returned one of the two stepstools that I built for his grandkids as they have outgrown 'em. Inside, we had written the date and that he and I built 'em. Kinda' cool seeing that. And now I have one for my grandsons.

They were built totally from scraps in the garage.....

Stools 2 - Feb 2006 small.JPG

So, yeah....I do understand wanting to put a signature on your work.

Bruce, that's fun! Nice job BTW!

Question about the speakers, does anyone know if they would benefit from any kind of fill?

mattsk8 wrote: Question about the speakers, does anyone know if they would benefit from any kind of fill?

The Pro needs to be filled just the same as the home version is.

Been a long time since I've updated this, slowly but surely I have been working on them!! I took them over to the boys at Meniscus (meniscusaudio.com, also where I purchased the drivers) for some measurements to figure out placement, angles, etc, and also to see if they could do something about the tweeters being so obnoxious. Due to a huge peak at about 2k hz, we decided to go a different route on the tweeters. The new ones are Eminence tweeters and we went w/ a single tweeter, as opposed to the original array. What a HUGE, positive difference in the way these sound!! There's still a small peak in the midrange at about 200 hz, but I think this will EQ out.

One of the original tweeters vs the new Eminence. Sorry for the blurry cel pics, I'll take better pics once they're in the church...



Tweeter crossover (mids are still full range)...



Grill frames I made. I'm using 3/8" spacers and screwing the frames to the cabinets w/ 10/24 machine screws, I already put the threaded inserts in the cabinets for the grill frames.





For the final finish I took them to a friend of mine that owns a truck accessories shop and he sprayed them w/ spray on bedliner. The texture is a little rougher than I originally anticipated, but I think they still turned out well. Almost done w/ these. My wife said the grill material showed up today, so I hope to have these done and delivered by this Wednesday!!

No offense, but major faux pas. With only one tweeter you have no vertical pattern control in the highs, and pattern control was the reason for using a line array in the first place. The response with a line of piezos would have EQ'd just as flat as with a single compression driver. Not that you can't use compression drivers, but to get the desired result you needed to use at least four of them. A cab with a line of midbasses and only one tweeter is the poster child for how it should not be done.

Bill Fitzmaurice wrote:No offense, but major faux pas. With only one tweeter you have no vertical pattern control in the highs, and pattern control was the reason for using a line array in the first place. The response with a line of piezos would have EQ'd just as flat as with a single compression driver. Not that you can't use compression drivers, but to get the desired result you needed to use at least four of them. A cab with a line of midbasses and only one tweeter is the poster child for how it should not be done.

No matter what in this situation it was going to be a bit of a trade off. Isn't using a flat array of tweeters (the original design) considered "faux pas" as well because it makes the beam too narrow? So in this instance I used what sounded decent. These actually measured well and I no longer listen to that finger nails in the chalkboard peak that used to be there in these speakers that are going in a room that already struggles in the 2k hz arena.

Where are you saying this new tweeter will be an issue? Because of where these will be placed and based on the measurements that were taken, the only area I can see a potential issue would maybe be the front couple rows. But, I think the original tweeter design was worse.

mattIsnsk8 wrote: Isn't using a flat array of tweeters (the original design) considered "faux pas" as well because it makes the beam too narrow?

No more narrow than that of the midbasses. If you're going to have a line source then it should be a line source across the entire spectrum. If you're going to have a point source it should be a point source across the entire spectrum. As for the piezo response at 2kHz, there should not have been any. The piezo high pass filter in the plans has a 3.5kHz knee.