12v Eco project sound system

Silas Pradetto

Graduate Student
Re: 12v Eco project sound system

If you're talking about US dollars, $1000 for sound, considering speakers, cabling, amplification, processing, etc is very difficult to pull off. You could easily spend that on amps and DSP alone buying what many would consider to be quite entry-level items.

I also think that hoping to build a BF design for $150-200 is pretty unrealistic when you factor in all of the costs. Consider some of these: speakers, plywood, connector plates and jacks, wire, crossover components, construction adhesives, saw blades, sandpaper, filler, paint, handles, corners, grill, feet, etc. The little stuff really adds up, even if you use the cheapest drivers.

I really hate to be the harbinger of disappointment, but I was going to say the exact same thing. Home-building speakers is almost NEVER a cheaper option than going with something off-the-shelf, for a whole pile of reasons:
  • How are you going to design them? Without knowledge of horn and box physics, you're not going to just stumble upon a design that sounds good. That's why JBL, EAW, and all those other companies have people like Dave Gunness doing it- it truly does take a genius to design a good speaker. And of course, good designs and designers aren't cheap.
  • How are you going to build them? Without a dedicated woodshop and premium wood, the look, fit, and finish of anything you make in your backyard with a circular saw is going to suffer. The cabinets are going to look very 'homebuilt', and they will last nowhere near as long as a production, CNC cabinet.
  • What are you going to buy, did you actually budget this out? As Jeff mentioned, the little things really add up. Hardware could cost you hundreds of dollars for a couple speakers, when you factor in those wheels, handles, screws, washers, T-nuts, etc. Also, good sound usually requires good drivers, and good drivers cost hundreds of dollars.
  • How are you going to tune your custom speakers? Unless you're a Smaart measurement professional with a big outdoor space or a quasi-anechoic chamber, it's not going to happen. Especially if you intend to use a passive crossover, someone has to design that to work with the drivers and the box- again, not easy.
  • What do you do when you don't want them anymore? You really can't sell custom speakers, unless you're Clair. Even LAB subs have almost zero resale value.
  • On top of the lack of resale value, you also have no value to any potential customer that puts faith in a name brand. Virtually anyone with a clue wouldn't hire someone with custom speakers, because they know how lacking the homebuilt stuff usually is.
  • Are you considering your time cost? The above mentioned things take a LONG time to do, especially if you consider you're only making a small batch of speakers. There is no ROI to spending a hundred hours to build only four speakers.

Too many people think 'I can buy a bunch of speakers, throw them in a box, and save money and have good sound'. I hate to break it to those that think that; it's not going to happen.

Large companies like JBL benefit from economies of scale. Because they do things in huge batches, with custom drivers, and they already pay an engineering team, they can afford to design a decent speaker for those budget-conscious consumers and sell it for cheap. Think of the JRX line. They really aren't that bad, for costing only a couple hundred bucks. And I guarantee that no one could build their own speaker that beats a JRX for the same amount of money.
 
Last edited:
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

we have all the building materials and tools. cables we will need, other components etc. take the amps out of it for now, and we wanna focus at building the best cabs we can
not necessarily BF ones. just used as a reference point. i would love to find some more considered designs for are situation. ie out doors. if its gonna cost more than we have to try find the dosh. just now we need to get a suitable design and build up a list of components and cost. i hope with help from places like this we could perhaps come up with something adequiate that we can build on...
 

Jeff Babcock

Senior
Jan 11, 2011
1,007
18
38
Ontario, Canada
jeffbabcock.org
Re: 12v Eco project sound system

we have all the building materials and tools. cables we will need, other components etc. take the amps out of it for now, and we wanna focus at building the best cabs we can
not necessarily BF ones. just used as a reference point. i would love to find some more considered designs for are situation. ie out doors. if its gonna cost more than we have to try find the dosh. just now we need to get a suitable design and build up a list of components and cost. i hope with help from places like this we could perhaps come up with something adequiate that we can build on...


Sorry, I bet you're probably getting frustrated by all of the responses.

Part of the problem is that we still don't have a clear answer on some things, I think partly because you don't have a clear vision of what you really want, or at least if you do, it hasn't been made clear here.

We know this:
Budget around $1000
Want to DIY
Need tops and Subs with LOW extension
Outdoor use
As efficient as possible

Some important need to knows:
1) How loud and at what distance?
2) How important is loud vs sound quality?
3) With your budget, you're going to need to compromise somewhere. What are the most important wishes you have for this, and what are the least important factors?
4) Do you have plans to do anything with this after this research project ends? Does that affect your choices for the project?
5) Do you have any size/weight limitations?
6) What is considered a "victorious" outcome for your research project? Do you care more about the process and findings than the end result?
 
Last edited:

Robert Burns

Freshman
Jan 11, 2011
97
0
0
USA/WV
Re: 12v Eco project sound system

Dan:
This may be of interest
http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-45.html

Start looking around: I noticed on ebay UK a variety of drivers used professionally.

I've done work with non-profit organizations since 1988 and I'd suggest what all non-profits do: write a proposal, and submit grants for funding.

Realistically a DIYer is NOT going to build a Vertec; But not everything that bears a big name represents SOTA engineering. Many companies have made products for particular demographic markets to meet a price range; and many DIYers have replaced these products with their builds.
I've seen some examples of dreck that were just poor attempts to cash in on name status.
 
Last edited:
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

hi all

i understand and am not surprised by your responses.
we are confident of good build. we have access to CNC consonants out and recycle and find what ever we can.

"Some important need to knows:"
1) How loud and at what distance?
- interested to see what we can achieve. min distance is our enclosed canopy space with a diameter of 10meters.

2) How important is loud vs sound quality?
- sound quality over loudness. sustainability and efficiency over fast drain of power.

3) With your budget, you're going to need to compromise somewhere. What are the most important wishes you have for this, and what are the least important factors?
- a decent sound system we can use . elements in place we can build on and not just a means 2 an ends. and how to most effectively and efficiently turn all are volts to DB [which is how this all started]

4) Do you have plans to do anything with this after this research project ends? Does that affect your choices for the project?
- The larger project 'Treadle' is a creative canopy under which various activity's workshops and social events take place. te sound system would become part of the current infrastructures assets [not to sell but for our own use]

5) Do you have any size/weight limitations?
- not especially. liked the idea of big cabs as more efficient and to start with i thought would be the opposite. some thing 1m /1.5 is perfectly acceptable should it need to be the case. weight=as long as we can load it on and off the van/bus. no

6) What is considered a "victorious" outcome for your research project? Do you care more about the process and findings than the end result?
- an efficient sound system running at 12v DC. yes! most definitely and is why i am here, in it for the long run. and i hope the end result of this stage will power us on to the next whilst at the same time being useable.

-as for plans i was looking at the billfitzmaurice site and is how i ended up here waiting some balance to what ive been told there.
and to see if any other designer were available.

from what ive understood though out my conversations my mission is not impossible and i may achieve surprisingly good results in a home build and without huge investment from the off.
[and im not in my basement/or back yard with a jigsaw and circular saw] we have the facilities to put this together.
nor am i naive enough to think i can just put drivers in a box. ive seen it done. and in many found objects too. but the reason i am here is i want to do it right with the means i have available.

sorry if i am "vague" / Unclear"

i am just following a journey and exploring possibilities to see what is feasible.
processes and motivations are important. and this has all come from conceptual ideas brought up in discussions.

we do want to start piecing some things together now though as summer is fast approaching and we would like to trial are results.

incidentally i am really enjoying the discussions on here and am grateful to all of you for your input and opinions.

thx

dan
 

John Roberts

Graduate Student
Jan 12, 2011
2,309
3
38
MS
www.resotune.com
Re: 12v Eco project sound system

Not to repeat myself but to expand on some things already said.

12V supply will limit peak output power into conventional drivers, unless switching power supplies are used, but they will add cost/complexity.

One data point to consider... "old" speaker systems, decades old, before the modern generation of low cost high power amplifiers were often more efficient just to get the job done... Don't dismiss very old boxes and/or old designs.

Outdoors is generally much more difficult to generate high SPL. The sound has no walls to bounce off and build up, it just goes away and bothers your neighbors. Perhaps a 4 ch system firing into a listening area from all corners might work with the 12V limit to make more sound and all pointing at the middle has less places to go.

JR
 

Robert Burns

Freshman
Jan 11, 2011
97
0
0
USA/WV
Re: 12v Eco project sound system

In simpler days of low wattage - when bands hauled cabs like A-7 and EV Eliminators ( etc ) in the van: the tape deck had a jack to hook in - for the ride to and from the big gig :lol:.

On my 12v systems: After trying smaller wattage amps - there was not enough power to allow a clean crest factor, so a bigger car amp...
Many of the small cheap 12v Class D amps and modules have little or no documentation to do a proper assessment. In the doc. I've read: the output is severely reduced @ 12V power and the max power value is given @ 10% distortion.
In one design the input is restricted to only.8V.
 
Last edited:
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

yeah we are planing on applying 4 grants etc but wanted something in place to build on.
so i shall look into some old speakers to find drivers that need a good home and some love n care. we cld then use them in a bf design? i just worry bout the amp draw of car amps as i state but im always open to the best solution. we want a clean sound just not off the shelf cheep solutions.but u seem to have the idea what we are about. be great to use our cabs in our vehicle whilst driving around...
 

Robert Burns

Freshman
Jan 11, 2011
97
0
0
USA/WV
Re: 12v Eco project sound system

be great to use our cabs in our vehicle whilst driving around...

pages10-1005-full.jpg

Old horn ( no plans )

Some commercial plans:
http://www.parts-express.com//mfg/selenium/selenium-cabinet.cfm?CFID=3352292&CFTOKEN=81847562

Plans exist for this ( cost $8000 )
http://en.wikipedia.org/wiki/Horn_Massive


 
Last edited:

Marlow Wilson

Junior
Jan 11, 2011
305
0
16
Montreal/Ottawa
Re: 12v Eco project sound system

we want a clean sound just not off the shelf cheep solutions.but u seem to have the idea what we are about. be great to use our cabs in our vehicle whilst driving around...

+1 to older horn loaded cabs. I asked where you were located to try and suggest something available regionally. DIY is great for many things but I shudder at the thought of trying to build two horn-loaded speakers that will be super efficient and sound great in your price range. Any used products that have fallen out of favor are selling for pennies to the dollar so it's an uphill battle to compete with them. You might get away with something like TMS4's and no subs, and you could probably find some kicking around somewhere. I'd rather 'restore' an old Turbo speaker than build a BF or similar... and you might still get to use some power tools!
 

Ron Kreiger

Freshman
Jan 11, 2011
46
0
0
60
Pennsylvania
www.s-o-t.com
Re: 12v Eco project sound system

Bills boxes are designed around specific drivers as far as bass and mids are concerned.What you buy may or may not be usable afterwords in his designs.For the most part you have been given some pretty accurate advise.Buy used professional older horn loaded gear and be done with it.

Salis pretty much hit the finishing nail on the head with a sledge hammer when it comes to DIY boxes.It isn't something for the novice even if you have access to a furniture production facility.
If you can build go ahead and and get some plans but if it all doesn't work out when it's over you're pretty much stuck with what you have created.
If you buy used pro and you dont like the results you can always re-sell it for somewhat close to what you paid as long as your initial purchase price wasn't over the top.
If you can build and have the design and testing chops then DIY (design and development)might be for you depending on how advanced your skill set and knowledge of said systems is.

You might be in for quite a long wait if you think someone might design one for you. While there are plenty here with the knowledge, I highly doubt anyone would be jumping at the chance to work for free.I dont mean that to be arrogant in any sense. It's the truth and I wouldn't want to see someone head into a project only to be disappointed in the end because "we" didn't tell them the way it really is.There is no marketing BS here.
 

Silas Pradetto

Graduate Student
Re: 12v Eco project sound system

I just thought of something: my former truck stereo, from when I was 16 years old. Back in those days, I had no money, but all kinds of interesting ideas and old equipment. So I created somewhat of a 'system' from the junk I had:

I used a 700-watt 'Walmart' power inverter to get me 120V. There were two QSC Series 3 model 3500 amplifiers, one bridged into the sub, and one stereo on the mains. These amps are extremely inefficient; I think they were class AB. The sub was a single 18" W-bin in the bed of my truck, and the mains were a pair of JBL SF15s, which are 15" 2-ways. The whole system was crossed over with a Furman analog crossover, with an iPod or something providing the music.

All that gear cost significantly less than $1000.

This system went LOUD for only operating on a 700W inverter. People told me they could hear the sub a quarter mile away. The inverter would go into protect if I really got near clip. Remember, this is 1400+700 watts of amplifier on a 700 watt inverter.

My recommendation is this: Buy some used speakers, an amp or two, crossover, subwoofer, or whatever you can get to do the job for your $1000 budget, and get a pretty big inverter (2000 watts I'd say, or more) to power it. This way you can sell the gear if it doesn't work out.

I once did a float in a parade on a 3000 watt inverter, with NO issues running full PA.
 
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

it was not my intention for a moment to suggest anyone would design us anything 4 free, remember i came here looking for an objective opinion on / alternative to the BF designs. my understanding from the discussions there were that it was feasible to build our own efficient cabs.i do not ever say i try to know better but listen and take on board what u lot say [which is incredibly useful, and i take as being good honest advice, and am thankful for]
from the start i hadn't wanted to go the inverter route [as detailed b4-it is not sustainable, we peddle our power and wanted to use it efficiantly not burn it off in loud burst of bass] or else i would have done just this. inverter in to a big old PA. i approached this from a conceptual idea. transference of energy. turning volts into DB most effective and efficiently. to see what we could achieve with this idea [if anything and move on from there]

i am coming round to the idea and would even like to 'restore' cabs if it is to do more effective than build then that's the way to go.

so new thinking based on ur imput

-mini DSP [active] crossover
-4x 20w class d/t amps [or even a efficient car amp with built in crossover?]
-some old school efficient cabs [ebay etc]

could u offer me any pointers on main things to look for?
ie. how do i judge sensitivity and efficiency when looking at these things.
size is good from what i can tell. bigger horns means more efficient amplification of the sound i produce.
ill take some of the names uve mentioned and see what comes up. anything else i should be looking for in an old pa?
ive a lot of reading to do with the links ive been sent so ill try and get though some of that now b4 looking.
i hope perhaps, at least in part can see my approach as an interesting conundrum.
of course there is going to be compromise but i am trying to acknowledge and be considerate of our specific circumstance [12v, outside, renewable energy source] and not mimic a 240v system with 12v.

if i can gain the knowledge to buy some old gems i still feel encouraged i can achieve my out come.
[i even like that old cabs our still more efficient than todays disposable market. we have a number of engineered components on our structure but sometimes there is nothing to beat an old fashioned lashing.
thx y'all
 

Robert Burns

Freshman
Jan 11, 2011
97
0
0
USA/WV
Re: 12v Eco project sound system

...ie. how do i judge sensitivity and efficiency when looking at these things...
From
http://www.qscaudio.com/support/education/
is
http://www.qscaudio.com/support/library/papers/3dB_or_6dB_white_paper.pdf

What you are looking for is SPL output measured in db ( qualified ) per watt in at a specified distance.

Use Google Book preview on: Electroacoustic Devices: Microphones and Loudspeakers By Glen Ballou
page 252 for a brief discussion
 
Last edited:
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

right then
we about there with our 1st test sub!
Having one or too problems in understanding the wiring for putting the amp in BTL mode.
can anyone help?
http://datasheets.maxim-ic.com/en/ds/MAX9709.pdf

i got the parallel output config i recon
just not sure about the dc input +-.
'logic high to mono'?
and the board has two v+ inputs... its confusing me

http://www.htm-audio.co.uk/HTM50S/HTM50S.htm


if anyone can shed some light on this for me i be very happy :) ive been trying to suss it for Days and my head hurts from schematics and learning [so much learning]

dwc
 

John Roberts

Graduate Student
Jan 12, 2011
2,309
3
38
MS
www.resotune.com
Re: 12v Eco project sound system

I'm confused too..

The part looks like it can't be bridged (H switch output is already driving both ends of the speaker), but PCB kit says it can be bridged so ask them how... .

JR
 
Last edited:
Feb 27, 2011
30
0
0
Re: 12v Eco project sound system

well... the amp says it is set to stereo by default and i wish to run it in mono mode [BTL] as it calls it but unsure how to wire this and the dc inputs?

it has a mono pin on the pcb on page 12 of the datasheet it states 'mono mode is enabled by applying logic high to mono'

the HTm people and site also says it can run in This[BTL] mode.

i just carnt figure out how to do tis or where to atach power?
 

Ron Kreiger

Freshman
Jan 11, 2011
46
0
0
60
Pennsylvania
www.s-o-t.com
Re: 12v Eco project sound system

Onboard logic supply rail

There is an onboard 5V 100mA regulator which can be used to power external logic circuits. The regulator also powers the logic rails of the module. All logic inputs should be 5V input max.
Simply put: Attach the 5V to the mono pin and it pulls that input "High". That would be the pin on the right 2nd one down marked 5v OP (OP means output). That would be used as a 5v logic signal for any logic needed to trigger functions on the board.

image4.jpg
 
Last edited: