DIY Limiter

[Steve H]

Hi everyone

I have put this question in my thread is the subwoofer page but its probably not the correct place so we will try here.
For horn loaded subs we need a limiter to protect the driver. Most people have suggested a driverack or similar but they are to expensive for me, and as much as i would like one the budget does not allow one. So I was wondering if anybody has made a limiter for this application?

I found this http://sound.westhost.com/project67.htm, would that do what were asking of it? Im not totally sure what i'm actually after.

Thanks
Steve

[Rune Bivrin]

I have built some of Rod's projects, and they tend to work as advertised. The main problem with this design is the lack of adjustable limiting voltage.

[Bill Fitzmaurice]

You need a crossover, you need an EQ, you need a limiter. It's only logical to get all of them in one package. Yes, you can make a rudimentary limiter. But it needs a case, a power supply, jacks, etc., and by the time you're done it will cost more than buying one. Buying one as part of a loudspeaker management system will be less expensive than buying a limiter, EQ and crossover separately.

[MissileCrisis]

Buy a DCX 2496, you can find one for 150 used most of the time. Its well worth it.
*Apologies, didn't know it was so hard to obtain/operate in NZ

[Grant Bunter]

Buy a DCX 2496, you can find one for 150 used most of the time. Its well worth it.

-1
You're not taking into account where the OP lives, the domestic power supply voltage, or the fact that if that could be bought at that price locally, the OP wouldn't be considering building a DIY limiter...

[byacey]

Any reasonable comp limiter with 2 channels or more that has a peak stop limiter function can be bought very cheaply nowadays. I still believe that Bill's recommendation to use a complete processor is the best route to follow.

By the time you build a power supply, design, etch and stuff a circuit board, buy and fit up an enclosure, you'll have paid for a used DBX 166 or 266.

[CoronaOperator]

This idea might be cheaper and more effective as a limiter

[Grant Bunter]

CoronaOperator

Steve:
I've been searching for alternatives and circuitry to try to assist.

In my searching, I came across the Behringer CX3400 crossover with limiter(s). It's not a DSP unit per se, but does have limiting and retails for about half the retail of the DCX2496.

Here's the rub.
In the manual it says the limiter is not a "hard" limiter (which is best for Bill's sub designs to protect the drivers and your investment), and that you may expect around 6dB over the threshold once set.
I was reluctant to put this info up, but I guess if you know it can go up to 6dB over, that lets you work it to a point.

As already pointed out, to build your limiter is going to run to it's own cost, and the most difficult part will be finding a design to ensure it is a brick wall type limiter with as steep a slope as possible, not less than 24dB slope being preferred.

When I first got here, one of your fellow countrymen told me I would have to "suck it up" that you need brick wall limiter. It's not what any of us want to hear, ie go spend more money.
It is the right tool for the job though...

[Steve H]

Thanks everyone

Just to clarify, i'm not against having a driverack or buying limiters, I would love these, but the fact is i just cannot afford it. I guess ill keep saving and see how we go.
Thanks for all the advice. Just out of curiosity, how does one work with a auto tuba, do i still need limiters and EQ in a car?

Thanks
Steve

[Grant Bunter]

Steve,
it's the pro audio cabs that require brick wall limiting. It protects the driver, and that ensures the show goes on!
In the Auto and Home Theatre designs, the cabs just get too loud to listen too (for most people anyway) before the voltage limit is reached.
Though with the advent of mini DSP etc, some folk hear have in deed worked out voltage limits for those cabs dependant upon driver of course.
In the end though, while not desirable, blow a driver in the end of either of those environments, and it's not the end of the show...

[DJ Higgumz]

I've looked at that too, but for an autotuba. I never built it as I found with the autotuba you can tell when you overpower it. and when you are overpowering it you are already too loud to listen for more than 10 minutes