What does this mean? I haven't learned it yet.jcmbowman wrote:Rune a sine wave test tone at a frequency within the passband for the sub, and measure using an RMS multi-meter -without- the speakers hooked up.
Thanks.
Hello! New guy here. (long read)
Re: Hello! New guy here. (long read)
Thanks.
TomS
Re: Hello! New guy here. (long read)
Put a RMS AC voltmeter across the outputs of the amp, with no speakers hooked to it. For subs, run a 40Hz test tone into the amp and read the voltage. Set your limiter to max at the voltage limit desired.
In a car, set the head close to max volume with the 40Hz test tone playing (you should not hear it through the other speakers) then set the amp gain to your desired limit. Don't use the max volume, as this will most likely distort. I set mine with the sub hooked up, so it doesn't get stupidly loud. I like the good bass, but I like what's left of my hearing more.
In a car, set the head close to max volume with the 40Hz test tone playing (you should not hear it through the other speakers) then set the amp gain to your desired limit. Don't use the max volume, as this will most likely distort. I set mine with the sub hooked up, so it doesn't get stupidly loud. I like the good bass, but I like what's left of my hearing more.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice
Re: Hello! New guy here. (long read)
Thanks.
Does "pass band" mean the frequency range that the sub works in?
Does "pass band" mean the frequency range that the sub works in?
TomS
Re: Hello! New guy here. (long read)
yes.tammojsmit wrote:Thanks.
Does "pass band" mean the frequency range that the sub works in?
Low End Junkie for over 20 years.
4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.
4 DR250s
4 Tuba36s @ 30" wide
2 ATs
...and a very serious addiction to the smell of BB sawdust and curing PL.
Re: Hello! New guy here. (long read)
I sure hope that the horn really does add impedance. If I do the math for 35 volts into 2 ohms, which is essentially what it'll be wired for, I get over 600 watts RMS! Don't think the speakers would last too long with that much juice.jcmbowman wrote:As far as the voltage... the MCM driver is rated for 120 watts RMS, so with a pair of those in an autotuba you'd want to be able to feed 240 watts into 6 ohms.
Following the formula: Watts x Ohms = Volts^2
You get the following: 240 x 6 = 1440 = volts^2
So Volts = SQRT(1440) = ~38 Volts.
Limit to 35 volts off your amp just to be safe, and you're all set.
Anyone have any links to some information about how/why a horn adds impedance? I assume it has to do with the mass and velocity of the air in the horn acting against the drivers cone which somehow produces added electrical resistance in the coil, but it'd be nice to read and learn about it from a more reliable source than my assumptions.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded
Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421
Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421
Re: Hello! New guy here. (long read)
Here is the educational materials area of the forum http://billfitzmaurice.net/phpBB3/viewforum.php?f=18
I would try searching on horn driver/cabinet impedance or similar. Good Luck!
I would try searching on horn driver/cabinet impedance or similar. Good Luck!
2-Jack 10
2-Wedgehorn 8
1-Auto Tuba
2-Wedgehorn 8
1-Auto Tuba