Bose L1 type PA build

[Wakko59]

Hi there,
I'm a noob here and looking for advice. Had a look around and forgive me if this is covered elsewhere.

I was thinking of building a LA PA system in the Bose L1 fashion.This would be for my bands vocals and acoustic guitar /blues harp primarily and we play in small enough venues but I would like to have plenty of headroom. Maybe you guys could help with my thinking (or lack of). I figured looking around the posts here that the Faital 4" speaker would be a good unit to use. I thought a column of these each side (12)and a 15"Sub(maybe 18") and not sure what to use as hf drivers or how many. For a really good quality sound with plenty of power what ratio of power would I need between Bass Mid and Top assuming a 3way active system (I am leaning towards 2kW bass).Any help with choice of hf driver and any pointers would be appreciated. One of the main objectives here is a portable light weight system all things being relative

Thanks in advance
Ed

 

[djk]

I would probably use the 3FE25 Faital Pro driver, Art Welter here likes them for HF.

The guys at Speakerplans like them too, using them in lines of 8~16 drivers.

16 drivers would handle 640W on program material. I would cross them around 150hz to a dual 12 PPSL cabinet, about a 2' cube.

(cat is optional)

This is a quad 12 PPSL, a dual would probably all you need. This one goes to 27hz and can handle 2.2KW on program material. Each pair of 12s will have the same output as an expensive 18, but with much less distortion, and lower cost.

 

[Wakko59]

Hi djk

Thank you for your advice. Its very helpful. Is there a drawing for the PPSL 12". A 2' cube would be an ideal small size for us. Haven't seen that design before.
Does using the 3" woofer mean I dont need a crossover to a HF bullet/tweeter and could just use a 2 way system.
I was thinking of using a 4" waste (PVC) pipe (a new one ) to house the array in sections. The material should be easy enough to work with. Any reason why I shouldn't go that route.
Again thanks for your response..

PS my dog loves an optional cat..

 

[Wakko59]

Just found this link:
Speaker Project - Kuze3201 Line Array -- 8/18/2011
Darren Kuzma does mention issues with the high frequency :

Several people noted that the high-frequency reproduction lacked some "life" and "air".

He used the Tang Band W2-803SM. If I use the 3FE25 Faital Pro driver as djk suggests, would I need to go to a 3way active system and add HF bullets to avoid those issues.
The design approach looks good but I feel I need to trawl for more info before I crank up the tools. Any help greatly appreciated
Ed

 

[djk]

"Does using the 3" woofer mean I dont need a crossover to a HF bullet/tweeter and could just use a 2 way system. "

https://www.youtube.com/watch?v=630lO8iPJHk

Doesn't sound like it needs a tweeter to me, just cross it at 150hz (as in the video).

Multi-use Speaker? - Speakerplans.com Forums - Page 1

Seems to have more HF than the compression driver.

Shop Freedom 4" x 4" x 6' Vinyl Fence Post at Lowes.com

"Any reason why I shouldn't go that route.
Again thanks for your response.. "

I would use a plastic fence post, commonly available in 4" and 5" sizes. You could also add a metal face if desired. At Speakerplans some are using a laser-cut mounting plate.

"Is there a drawing for the PPSL 12". A 2' cube would be an ideal small size for us. Haven't seen that design before. "

I'll have to draw it up again. I did one about 30 years ago with some similar Eminence 12's. My friend's nephew used his as part of his DJ system with a 10" + HF horn top.

 

[djk]

Veranda White Vinyl Fence Post (Common: 5 in. x 5 in. x 8 ft; Actual: 5.0 in. x 5.0 in. x 96.0 in.)-73010700 - The Home Depot

Note that you could cut this in half and have two 48" cabinets. The shot with a gate attached to one of these posts suggests they are pretty solid.

 

[Wakko59]

djk,

Thanks again for your advice.
This should be enough to get me going for a while. I'm in Ireland, those posts are not widely available but it would be an easier build. I have downloaded Hornresp and will spend some time working out how it works etc. Lot of terminology. Do you know of a good reference for all the technical. I'll start with T/S.
I appreciate your help
Ed

 

[Wakko59]

Back again for another stab at this after parking it for a long while. I, in my head have settled on 2 x 24 x (3FE25) columns. I've been looking at the Cubo 12 and 15 as a bass bin (small size, lightish, and easy to construct) I cant seem to find a combination of cab/speaker ( 600-1000W per side) that will allow me to crossover at 150 Hz as they all seem lower (in the 100Hz range). Is it reasonable to assume I can crossover at 100Hz to a column of 24 x 3.5 " speakers (all 3FE25) as this would be ideal for my situation (DIY wise). Any help would be appreciated
Thank you and hope 2017 brings you all happiness and peace.

 

[turk 182]

other then the performance of the sub at higher frequency there no reason you can't cross higher(that would increase the power handling of your column) lower means you'll aproach the excursion limit of the 3FE25's sooner so it's a compromise as what gives the best result in your application

 

[djk]

A dual 12 PPSL will be useable to about 300hz (limit is the depth of the woofer plenum).

They lack the directional cues of a regular sub and can be used in a mono woofer system crossed much higher than you would think.

 

[Wakko59]

other then the performance of the sub at higher frequency there no reason you can't cross higher(that would increase the power handling of your column) lower means you'll aproach the excursion limit of the 3FE25's sooner so it's a compromise as what gives the best result in your application

Thanks turk and djk.

Thats helpful. I dont want to have any problems with the response curve around the crossover point so would a crossover at 300Hz be better and put less stress on the tower and its amp ?
I have seen a djk drawing of a PPSL design on another forum using 2 x Kappa Pro 15 LFs which he says will work up to 400Hz. Does this seem like a usable combination?. I would also ask if the ratio of powers is ok with my plan. I'm planning to use 24 x 20W per tower ( two towers) and 2 x 600W per PPSL in parallel. thats 480W above 300Hz and 1200W below per side. Is this a reasonable balance ?

 

[Wakko59]

A dual 12 PPSL will be useable to about 300hz (limit is the depth of the woofer plenum).

They lack the directional cues of a regular sub and can be used in a mono woofer system crossed much higher than you would think.

Thanks djk
I see there is a lot of faith out there for PPSL designs

I saw this on another forum:

High Efficiency Speaker Asylum
with this drawing:
http://i56.photobucket.com/albums/g196/dkleitsch/x-1.gif

basically a drawing of the PPSL panel cuts. I have asked turk182 already on my previous if this would suit my needs re crossover point but I feel should check with you also as this is your design.
Can this bin crossover at 300Hz to a column of 24 x 3FE25 Faital Pros as is and do you have any more build details of the PPSL cab (ie braciing and speaker mount details)? Dont want to get it wrong. This is a PA system build for a small (200 max people) venue. Again many thanks for your assistance.

 

[turk 182]

i don't know if the PPSL is becoming directional at 300 or if the phase response at that frequency would make for "easy" integration to the column. hopefully DJK can weigh in on that it's his design.
it would also depend what your using for a crossover.

 

[Wakko59]

Thanks turk.
The venues we play are small enough (100-250max). Would directional issues be a problem in small clubs?
I intend to use an active crossover Behringer DCX 2496 or similar.
I found sidicirichs post:
http://www.diyaudio.com/forums/subwoofers/259780-djk-ppsl-build.html
This is the cab I intended to build.
Do you think a 480W rms (24 x 3FE25)tower will match the two KappaPro 15LF-2 (1200W) PPSL?. I suppose I can always turn the bass down if it is too powerful. Is there a prescribed ratio of powers for the different ranges ?

 

[turk 182]

from the questions your asking i can tell your simply looking for someone to confirm your thinking so you can make conclusions, and base your descisions on gear choices without truly understanding.

 

[Wakko59]

Thanks for that turk.
My focus is obvious I guess. I want to build a PA system for my band so I joined up as a member here. I certainly won't make decisions based on gear choices but rather the other way around. These decisions will be made hopefully based on information shared by knowledgeable sources like yourself and other members of diyaudio.The 3FE25 speaker and the PPSL fit the bill for lots of practical reasons for me (size, price, availability and ease of construction). This is information I have received from this and other forums. I don't have a lot of time spent with audio systems but I am an electronics engineer and I know I've come to the right place.
Thanks again for your help

 

[turk 182]

if it's for a band and open microphones are involved a ppsl design might not fit the bill properly (no offense to DJK's design) a ppsl can go deep for it's size and unless you have the ability to tailor the low frequency response properly you could end up in low frequency feedback territory.
as an old school PA dude i guess i'm more partial to a folded horn or direct radiator rather than a a 6th order box.
i'd look for a tapped horn that does well between 40 and 120.

 

[Wakko59]

Thanks turk.
OK. We play classic rock songs from the 50s up. two guitars bass and drums. Three vocals for the CSNY stuff etc. Our PA (1K but I doubt it) is used for the vocals and acoustic and tiny bit of kick drum and its not good. I had in mind to build a PA that allows me to run every thing through it and keep it all under control. For small venues this is maybe OTT but if we play in bigger halls (150-300 people) I want to control the sound in a better way than just turning the guitars and vocals up. A PA that does both? A PA I can construct myself? A PA that is small and lightweight? That's why I am attracted to the line array and bass bin. Has to be small size though. I'm 57, my back groans, Is there a small tapped horn you would recommend bearing this in mind? Is there also a Feedback Killer equipment for lo freq problem. Any help appreciated

 

[turk 182]

your not asking for much are you... the processing needed to create a successful line array is going to require a significant outlay of cash for hardware to control it (system processor/ controller, mutiple amps) or go with passive filtering to create a freq. shaded array.
when it comes to sub's there's no cheating physics, small, loud, or deep lows, pick any two but you can't have all three and getting the combination that works for you will be a compromise of choices to get there.
getting a good mix in a small space is sometimes tougher than in larger venue.
so i get a better idea of what your using now (and are not happy with) could you share a few more details of what you have now as a system? not to discourage your desire to build your system used gear is always an option. i'm wondering if there's other things like microphone choices or outboard gear like comp/limiters or even system equalization that will help now and still be applicable later as you head towards your final goal

 

[Wakko59]

Thanks again turk.

1)[ the processing needed to create a successful line array is going to require a significant outlay of cash for hardware to control it (system processor/ controller, mutiple amps)]
I am prepared to spend some money on this. My costings tell me its not cheap but I feel if I get what I want it will be worth it. Rack, iNukes maybe, DCX2496 maybe. Any advice on this would be great.

2)[ no cheating physics, small, loud, or deep lows]
Small is crucial, deep lows are not crucial but there is a great appeal to it. I had a look at the MTH 30 on freespeakerplans as one of the smallest units I can find. I need some advice here on a unit that will integrate well with the array as you mentioned previously. Ideally a 2foot cube or slightly bigger would be great.

3)[getting a good mix in a small space is sometimes tougher than in larger venue.]
I know this from experience and in smaller venues would not even try to mix everything and have been the victim of lo freq feedback as you mentioned already.
Ideally I'd like to be able to run all {2 guitar amps, Bass DI, 3 vocals and (drums maybe through a sub mixer to a stereo channel ?)} through the system but be able to just use it as a vocal PA for smaller size clubs....not asking for much...
The mixer is something I will need to investigate separately.

4[ share a few more details of what you have now as a system]
Just a Behringer powered mixer with two tops ( no name) on tripods. You can hear us sing but its poor and poor hi and lo presence. Like most PAs (around here) for small bands this has normalised a low expectation from audiences in my opinion.

5[ used gear is always an option]
Yes but I can't find a small powerful portable system plus the build challenge is appealing. I have access to a laser cutter which could help. I had in mind to split the towers in two for manageability.

6[ other things like microphone choices or outboard gear like comp/limiters or even system equalization]
We use 3 x SM58s and hopefully these will be good enough for now (as we've only just bought two recently). I would have no reservations about including outboard gear for a new system though and again any suggestions here would be appreciated

In summary

A line array and bass bin system capable of covering a 300 people venue but also usable as a vocal PA for smaller venues. Rack system to contain amps processors/crossover/controllers, EQ, power distribution etc.

Sincere thanks for your help here