line array cabinets are finished

[chipco3434]

This is just a follow up to the line array questions I posed last week. Thought that you might care to see the cabinets... They are birch MDF with a birch corner stile. The cornert stile provides the strength for the glued splines. Base is 1-1/2" MDF with granite look laminate. Overall height is 81-1/2".

I'll drop in the drivers this week and start wiring. I am open for any sugestions on the type of caulk for sealing the speakers to the baffle. Suggestions?

[navin]

16 4" drivers? are you running them all fullrange? please let us know about interference and cancelations you experience.

[BrianGT]

Originally posted by chipco3434
This is just a follow up to the line array questions I posed last week. Thought that you might care to see the cabinets... They are birch MDF with a birch corner stile. The cornert stile provides the strength for the glued splines. Base is 1-1/2" MDF with granite look laminate. Overall height is 81-1/2".

I'll drop in the drivers this week and start wiring. I am open for any sugestions on the type of caulk for sealing the speakers to the baffle. Suggestions?

Looks good, but where are you going to put the tweeters? I thought you said that you were using the Pioneer 269-568 extended range 4" drivers along with tweeters.

You will get interference patterns if you run those drivers above if you run them higher than around 3khz. Read over Jim Griffin's Linus white paper for more info:
http://www.prism.gatech.edu/~gte929u/LinusWP.pdf
This also means that comb lines will occur at around 6khz.

image taken from the above document.

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Brian

[usekgb]

Hey! You stole my idea! I've got 40 of these drivers waiting to go in to cabinets. You will definately need tweeters with those drivers. I built a mini line with five of them, an the HF response was terrible. I added one of the Dayton PT2's, and the whole thing just opened right up. If Ravens or BG's are out of your price range, give the PT2's a look. They're not the best out there, but neither are the wide range Pioneers.

Keep us up to date on your project. It looks like you've really got something going there.

Cheers,
Zach

[BrianGT]

Originally posted by chipco3434
This is just a follow up to the line array questions I posed last week. Thought that you might care to see the cabinets... They are birch MDF with a birch corner stile. The cornert stile provides the strength for the glued splines. Base is 1-1/2" MDF with granite look laminate. Overall height is 81-1/2".

I'll drop in the drivers this week and start wiring. I am open for any sugestions on the type of caulk for sealing the speakers to the baffle. Suggestions?

How did you get such a nice looking cabinet done so quickly? Didn't you only start planning the project last week? Cabinet looks beautiful, with the various vaneer and laminate.

--
Brian

[Hybrid fourdoor]

Good luck with your project, looks like a load of fun. And if you encounter any of those problems that poeple mentioned, at least you have soom room off to the side for add ons.

I think most poeple on here talk about they would only build "Porsche's", but I like the few on here who actually admit they build "Miata's"...and like them.

Keep up the good work. And hopefully as always you'll learn something.


EDIT: nice workroom!

[chipco3434]

Here are the answers to your questions... Please take an opprotunity to review my questions at the end of this reply.

1. Yes, there will be tweeters. The holes aren't drilled yet because the tweeters have not arived from parts express. They come today??? There will be an array of ~ 24 to cover seated & standing height. Anyway, I can punch those holes after I decide what bits of plastic can be removed from those tweeters.

2. Yes, I understand about the interefence, but I don't understand how it will sound. With the 269-702 tweeters, the crossover has to be above 4000. So your suggestions are welcome.

3. Yes, it went together fast. About T + 10 days right now. Thankfully, I have a buddy (from the Scout troop, but he's thirty now) who works in a cabinet shop. In addtion to routers that already have tools mounted, and drills that are always mounted, and DA's with medium & fine, there's all the other "perfect" equipment. These should sound good, but they better look like they weren't made on a dirt floor. I'm still married for 28 years and I have some real bad habits. Got it?

>>>>>

Short term questions....???????????

Need some help. Nobody answered the caulk question. Silicone? latex? or 3M-5200 for that permanent solution?

I will initially test with a bi-amp arrangement. But I will install a crossover in the coming weeks. How about the active cross from Mr. Pomann out in cyberspace? Is that overkill?

I am thinking of wiring the driver series groups with 14, then weaving in 12 down to the posts. Two sets of posts per speaker... woofer side & tweeter side. I can bind them later if necessary.

The tweeters come with high pass filter caps installed. They are history, right?

The tweeters come with a phase shield? Garbage can, right?

Is there a relationship between impedence and sensitivity? Can I lower the tweeter array impedence slightly?

......

That's it for me. The moderator is keeping an eye on me... bas words & stuff. So all I will say now is that I have to go to W*RK.

thank you all!

[JeremyD]

Looks great so far!!!

I'm going to be keeping a close eye on this one. I have a whole load fo the same drivers you are using (both the 4" and the tweets!) As for the tweeters, you can remove the whole plastic piece with the phase sheild. I find the response actually improved without the phase shield. Off-axis response suffered slighty, but it was worth it for the improvement in on-axis response.

[chipco3434]

Tweeters are here.... Need some advice on foam/caulk mounting...

[Sherman]

I purchased 10 of these little drivers a few weeks ago and ended up building them into four driver cabinets with 6" c-t-c spacing. I used a single Goldwood tweeter in each cabinet at the top and offset to the outside.

Driven with my 8wpc pp tube amp they sound pretty good. I used a vented box with a rectangular port at the bottom and stuffed the area behind the drivers. I initially didn't put in the tweeters but decided after a few days they needed it. I decided to only put in a 2.2uF cap for the crossover, nothing else, and let the drivers receive the full signal. It seems to work OK.

Not quite a line array but I have to say they are the best $15 speakers I've heard. (My estimate of total cost of each box including drivers, wood, glue, screws, caulk, paint, stuffing, wire and binding posts.)

Experiment with these little guys, they're fun!

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Don't touch that, its hot!