BillFitzmaurice.info

Hi everyone, I'm new here. I'm Building currently building a mobile 12v soundsystem for small outdoor parties. I've already build my subs, they are a pair of Tham12s designed by Martinsson (it's seems sacrilegious to talk about other speaker designers, so I hope I won't be banished for that!) I've been looking at a few different designs for mid tops to go with them and I think that I'm pretty set on building a pair of SLA Pro 4x6. I have a few questions to put to you all about the SLAs before I go ahead, I hope that you can tell me what I need to know.

The SLA's seem like a great choice for a portable system because they are small and lightweight compared to most of the other PA tops on this site. The Line Array design also seems like a good choice for outdoor parties where there is no walls or ceiling to contain the sound. But because they use 4 drivers each I wonder if they will consume more power and run down my battery quicker? I know that they are small drivers, but when I compare the specs to DR-200 (one of the other tops I'm considering) that one only uses one 8" driver but produces more volume. Am I correct to assume that I would get more battery life out of the DR-200 than the SLA pro's if I were to play them at equivalent volumes? As you may have deduced I have a very basic understanding of electronics!

As I am a cabinet maker by trade having a go at building a pair of DR-200s doesn't seem like too much of a stretch for my wood working abilities. But I think that they might be a little oversized for the subs that I've already got. The SLA's on the other hand seem really neat and simple to build. Do any of you have an opinion about which design might be more appropriate to my situation?

Thanks!

micamica wrote: ↑Mon Jun 26, 2023 12:20 pm because they use 4 drivers each I wonder if they will consume more power and run down my battery quicker?

That's not how it works. What matters is sensitivity, the output per watt. DR200 sensitivity is higher, so at the same levels it will use less power.

I think that they might be a little oversized for the subs that I've already got.

If you have small subs the same answer applies. They won't have the sensitivity of a horn loaded sub. Where low power is an issue the fix is higher sensitivity, which means horns.

Looks like the sub doesn’t go super low but 100db at 1 watt at 60 hz seems decent. Dr200 might be cheaper than the sla….if the build doesn’t worry you I’d do that.

Joe

Ps the build worried me and I went otop 12 for my ridiculously overpowered garage setup. Two otop12’s and two tuba 45’s and I need like a single watt to annoy the neighbors. Depending on the music of course

Thanks very much for your messages. Okay I get it, so the higher the sensitivity the more efficient it will be and the better my battery life. In that case DR-200 or O-Top will be better suited to a 12v application.
The only other advantage I could see about SLA is size and portability. One of the other things that we need from this soundsystem is to be able to carry it on foot away from any roads. SLAs are just so compact. But on the other hand DR200 seems surprisingly light. The OTops on the other hand are getting a little on the heavy side.
I might just splash out on plans for both to see whats really involved. It might be a good idea to look over the DR200 plans properly before I commit, the more i read about the build the more daunting it seems. Although I'm confident I could do it I don't have masses of time and I'd quite like to get this thing up and running before the end of the summer!

I built the original in less than two weeks, working no more than three hours a day, and I didn't have plans telling me how to do it.

Consider getting all of the plans for $130, it’s a hell of a value and super fun to look them all over. I hope you post your project, I’d love to see how it comes together.

Joe

micamica wrote: ↑Mon Jun 26, 2023 12:20 pm As I am a cabinet maker by trade having a go at building a pair of DR-200s doesn't seem like too much of a stretch for my wood working abilities. But I think that they might be a little oversized for the subs that I've already got. The SLA's on the other hand seem really neat and simple to build. Do any of you have an opinion about which design might be more appropriate to my situation?

The DR200 would offer you roughly the same peak output potential with about ¼ the amount of 12V battery power it would take to power the SLA Pro's to the same volume. However, if DR200's are too large for your application, your decision is clear. If you can make room for them, DR200's would be the hands down right speaker to build.

Tweeter sections are comparable. Mids, where it takes more power, is where the DR200 clearly shines above the SLA Pro in sensitivity.



Either will max out at about the same peak output. It'll just take 4 times the power to get the SLA there, or any other particular SPL. Up to you which is more important, power savings or package size.

Decisions, decisions.

Thank you all for your input. I'll let you know how I get on

Hey, so in the end I’m building a pair of sla pro’s (against all of your good advice ha ha). Light and portable won over efficiency and volume. Time will tell if that was a good decision or not.

Progress is slow but I’m getting there, I’ll stick some pics at the end.



My question is about drivers. In the plans it says eminence alpha 6. When I came to buy them from blue Aran (uk) I had the option between 4ohm and 8ohm versions. I went for 8 ohm cause more is more right? Now I wonder if that was actually correct.

Which version should I have bought, and if I got the wrong ones is there a workaround? I’m post sure it’s too late to return them.

Thanks as allways for your help

Oops sorry that photo went in sideways!

8Ω drivers is what the plans are written for and the values of the crossover components are designed for. You made the right choice.

Build quality is looking good

Honestly, the SLA's may not require too much power to keep up with your subwoofer selection. You should be fairly happy with the results. If it turns out you require more bottom end, we can discuss options at that point.

Please keep us posted with results and/or feel free to check in for any EQ tuning recommendations.