I'm reasonably new to the realm of pure-SPL, but am learning quickly! In doing some testing with my new TermLab USB, I had two vehicles back to back. One a ford escort wagon that did a consistent 137.x (pair of Type S 12's a Directed 600D in a plain sealed box)

The next vehicle was an older s10 xcab with a pair of Pioneer SPL2000 12" drivers and a Kenwood 500wrms monoblock....subs in a large vented enclosure.

To my ears, the truck is sickeningly louder - there's no comparison in output. But on the mic the truck was able to only get to 138.9 vs 137.x!

Can someone explain to me where the installation is lacking in the truck? No sound dampening in either vehicle. I keep reading about the systems ability to pressurize the cabin - this is a case of yes, the truck is louder to our ears, but the car is much better at pressurizing?

I'm interested to learn how it all fits together...

bmoney

 

I bet you that the truck is tuned lower then the car. And with that it is harder to get loud on a mic with a lower note.

 

depends on the tuning ...just like NorthernSPL said... in the truck you might want to tune to aprox 52Hz -57hz box facing up..with a big *** port on the driver side... in the ford escort wagon you have better chances of hitting a good number because the vehicle is long and will play a larger range of frequencies LOUD..even the lower notes...but you propably with **** luck had a box that was better tuned in the escort..even tho it was sealed... I love station wagons for SPL...

[ February 24, 2005, 10:13 PM: Message edited by: MTA ]

 

my guess why both scores are low is b/c there really isnt much power behind both systems. and a 138.9 is actually not bad for a 500 watt kenwood amp.

also the tuning is probably way off in both

 

Both systems are just "put togethers" and not designed really for SPL...so ur prolly right in that the tuning isn't optimal for numbers on the mic.

Its just interesting that to the ear, the truck is vastly louder, yet on the mic its not even 2 db. My feeling is the truck is not tuned up right - with some setting adjustment and the right software, I'm thinking almost 140 is possible...

i agree - pretty good with $239 power!

bmoney