My Line Array Project

[setzer808]

Hey gang,

Decided I would post the results of my DIY Line Array towers I built..not a bad topic for my first PE forums post. This was just a summer project for the heck of it, and i'm very pleased at how they turned out. They use the JVC 3x5's that were recently on clearance at Parts Express. The housing is vinyl fencepost and caps. I'll let the pictures make things clearer. The sound is surprisingly good and produces a very lively/large soundstage on music. Currently I have them wired at 16ohm's each to fit the needs of an older amp for home use, but I did wire them at 4'ohm's each and ran them off a PA amp to test them in an auditorium vs a pair of Bose line arrays. Their throw is impressive. I like my results...especially considering the total cost for all the materials of the pair was under $50 or so.











Edit: Thought I'd add a few points I brought up on another forum that I didn't add to this post. Currently there is no crossover/filter being used...though I may add on in the future. The bass is good for what they are...but really...you need a sub with them. The highs surprise me...yes some tweets would add a bit of high end air...but they don't suffer as much sans tweeters as you might expect. Also, the cabs are dampened with shredded foam. ...oh...and yes thats a 1/4" jack for inputs...just made sense at the time for what I was powering them with...and I have 1/4" to bare/banana plug wires available anyway.

[D, Rose]

Re: My Line Array Project

Nice Work! I bet those are the loudest fence posts ever! Don't let my dog near them, though! These look seriously cool. I've been thinking about a line array since being given 40 2" (I think) speakers as a door prize at the May P.E. DIY show. Any suggestions about where to look for line array info?

[setzer808]

Re: My Line Array Project

Thanks. For line array info I ended up in all kinds of crazy places via google...the technical hows/why's etc are all over...its the details concerning actually getting started with some drivers and an enclosure that are tougher to find... I got lucky and found a few forums where people had used the 3x5's already.

I found sort of a whitepaper here http://www.audioroundtable.com/misc/nflawp.pdf that is full of very detailed explanations on arrays.

http://billfitzmaurice.info/forum/ --had a few projects using those drivers and a few threads concerning arrays that were very informative.

Probably the best read on the concept, and to some degree...evolution, of arrays in home stereo was http://www.roger-russell.com/columns/columns.htm -- kind of a journal of one of McIntosh's engineers and his decades long experiments with home arrays.

Hope some of this is helpful, or at least inspiring...go for it! :D

[bolland83]

Re: My Line Array Project

Good idea with the fencepost. What size is that stuff anyways, about 4" square? That's gotta be pretty high on the wife approval scale. What did you do the cutouts with, jigsaw? They look like they turned out pretty nice. I've been thinking about doing a line with these similar to the IDS-25. Not sure if I really believe everything that Roger Russel has to say about it, and for the price he's charging I think there are a lot better diy options out there.

[mikejennens]

Re: My Line Array Project

Setzer808,
Great idea!!! Do you have the T/S parameters for those 3x5 speakers? I picked up 12 of them and 2 TB woofers 264-850. So, I'm thinking of running 6 of the 3x5's and one of the TB woofers per side; 2 sets of 3 of the 3x5's in series (8 ohms x 3=24 ohms) and the 2 sets in parallel with each other for 12 ohms. If I can get the T/S parameters for the 3x5's, I'll figure a crossover point. This will be my first try at anything more than a single driver in box using WinISD, so I'll be doing and re-doing a bit, I figure. My hearing is pretty bad in the higher freqs (I can't hear the alarm on my watch in my left ear and the right's not too far behind), so I'm not sure if I'll need to augment the highs.
Anyway, thanks for the inspiration.
Mike

[setzer808]

Re: My Line Array Project

Thanks! Yeah I was actually considering PVC tubing when someone on some forum (I forget which) mentioned this being a possible alternative. They are normally 4" square (I think) but mine are actually 5". I did do the cutouts with a jigsaw...just treat the stuff like metal and you are good to go....metal blades...metal screws...very easy to work with.

Funny you mentioned the WAF of them...my wife does indeed like them. I've done the occasional birthday/wedding DJ gig and one of the first things she said when she saw these was "those look like wedding speakers". :p

[setzer808]

Re: My Line Array Project

@mikejennens: I only have the PE information on the JVC's (which I can send you if you need...you can still access it by checking your order history and clicking on the JVC's I found out). I think someone at Bills website (link above) might have done some testing for TS parameters....seems I saw a thread talking about that there.

I doubt even without some hearing loss you'll miss many high frequencies...these do quite well for such a cheap fullrange...at least as a project speaker. I can't wait to see you're results on your design. I tried to add a pair of Peerless woofers to my towers (in a separate enclosure..maybe as bases for the towers) to add bass (1 per cab) and the JVC's output was just too much for the woofers to keep up with. If you have any luck with your TB's I'm all ears, I would LOVE to get some more bass without having to use a sub as I currently am.

[mikejennens]

Re: My Line Array Project

@mikejennens: I only have the PE information on the JVC's (which I can send you if you need...you can still access it by checking your order history and clicking on the JVC's I found out). I think someone at Bills website (link above) might have done some testing for TS parameters....seems I saw a thread talking about that there.

I doubt even without some hearing loss you'll miss many high frequencies...these do quite well for such a cheap fullrange...at least as a project speaker. I can't wait to see you're results on your design. I tried to add a pair of Peerless woofers to my towers (in a separate enclosure..maybe as bases for the towers) to add bass (1 per cab) and the JVC's output was just too much for the woofers to keep up with. If you have any luck with your TB's I'm all ears, I would LOVE to get some more bass without having to use a sub as I currently am.

Thanks for the reply and suggestion, but... I picked them up at the showroom in Ohio. I was driving through on business and made it 20 minutes before they closed. So... no order history on them. But, I felt like a kid in a candy store, but in a hurry. I wish I could have gotten there with more time, but at least I got there with some time.
Didn't have any luck on Bill's site, but I'll keep looking. If you don't mind sending me the PE info on the 3x5's, that would be great. I have a WT3, so I'll check them and see if the results look like what I should be getting, too.
I'm finishing a pair of the 8 inch Pioneer FR's in a half-chang now, so these 3x5's will be my next project.
Thanks again,
Mike

[setzer808]

Re: My Line Array Project

No problem (would love to see your WT3 results!). Here's the info for the JVC's from the PE description:

Extended range oval speaker with bright, extended frequency response. Paper cone, stamped steel frame, and front and rear mounting gaskets. Flat spider and treated cloth half-roll cone edge. 3/4" voice coil helps extend HF response to 16,000 Hz. Great for TV speaker replacement or custom projects. Mfg. #QAS0437. Manufacturer buyout, limited quantities. Specifications: *Power handling: 15 watts RMS/30 watts max *VCdia: 3/4" *Le: 0.75 mH *Impedance: 8 ohms *Re: 7.5 ohms *Frequency response: 90-16,000 Hz *Fs: 90 Hz *SPL: 85.5 dB 1W/1m *Vas: 0.13 cu. ft. *Qms: 2.88 *Qes: 1.33 *Qts: 0.89 *Xmax: 1.5 mm *Dimensions: A: 3-3/8" x 4-7/8", B: 3-1/16" x 4-1/2", C: 2"

[mikejennens]

Re: My Line Array Project

Thanks. When I get around to running them on the WT3, I'll post the results.
Thanks again,
Mike

[john trials]

Re: My Line Array Project

Very nice. Great idea using the fence post...I like it when everyday materials can be used innovatively like this. My brother has fencing like this around his pool. It'd be so cool to have a weatherproof version!

[Randy L]

Re: My Line Array Project

I did wire them at 4'ohm's each and ran them off a PA amp to test them in an auditorium vs a pair of Bose line arrays. Their throw is impressive. I like my results...especially considering the total cost for all the materials of the pair was under $50 or so.

SO how DID they sound versus the Bose? Which Bose model was it?
Sounds like it was a fun project. I might need to look for some fence posts! :p

[setzer808]

Re: My Line Array Project

SO how DID they sound versus the Bose? Which Bose model was it?
Sounds like it was a fun project. I might need to look for some fence posts! :p

I believe (would have to double check) that it was a set of MA12's mounted about 50-60 ft apart on either side of an auditorium stage. I can't say i'm impartial, but my co-workers agreed that my speakers had a richer sound... particularly in the lower-mids and bass region as well as an overall more natural sound with voice and music that was less tinny.

In my earliest test when using just one of the JVC arrays running off a 100 watt power mixer I was able to fill the auditorium...even with a janitor vaccumming in front of the stage, the sound cut right through the noise I had no trouble talking to people entering the auditorium (roughly 75ft+ I would estimate). That was at 1/4 volume on the mixer...a lot has to be said about the efficiency of an array I feel.

I say go for it to anyone that wants to try using the fencepost as a building material for speakers...I can't claim its an acoustically ideal material...but its fun....I literally just cut an 8ft section in half to make my two 4ft towers. You could use a few cheap tweets/mids or a few cheap fullrangers and one 8ft post cut into several pieces and have an entire surround setup easy and cheap...I've been considering it.

[Erich H]

Re: My Line Array Project

This reminded me of my JVC array project I started last winter. I need to get that done.

I also used the fencepost, but went with the composite material. I should try to finish mine up within the next few days.

I have the measured parameters for them somewhere, I'll try to dig that up.

Here's where I left off:

[setzer808]

Re: My Line Array Project

@Eric: Wow, those composite posts look great! I would imagine they are a much more inert material...the vinyl one's are a bit on the thin side I feel. I'd try composite in a heartbeat if I could find it local.