Is that the guy that used to tune Graham Robins Tbird in 90/91 ??

 

Yes, towards the end of that competition year (1990). Graham Robins -- a name from the past. He was kind enough to let us stay overnight at his place in Arizona during the finals in Tempe. Like everybody else, I guess he quit competing.

 

JohnVroom,

I was, and still am using Linear X LMS 4.5. There are a few others, like Clio and MLSSA, that offer a few more features, but for what I'm doing the LMS is best. LMS offers a streamlined workflow for doing repetitive RTA testing that really speads up tuning. The other programs need you to navigate quite a few menus to label, test, and save RTA results. MLSSA for example takes a loooong time to compute results, whereas LMS is real time.

There is one BIG "but" with the above programs. MLSSA and Clio offer measurement in the time domain. LMS does not. In an environment where the first reflective surface is farther away from a driver than the test microphone, phase response testing is useful and accurate. In a car, forget about it! Measuring phase response in a car is the equivelant of measuring a coral sponge with a set of Vernier Calipers. There are just too many reflections...

DWVW, you aren't the only one puzzled by phase measurements. Seeing system phase response, and actually understanding it, are 2 separate things.

I don't think phase response is beyond most enthusiasts understanding, I just don't see people having the time to invest in learning about it in a car. In a house is easy....

Adam

 

Damn.... I want a Coustic RTA badly. What a concept! In dash RTA that can be pulled out...... dancing lights in the car - woohoo!!!!!

reverberation (echo), timing (arrival of various frequencies), phase shift, cancellation, etc. complicates matters, but being able to see the dips and peaks in the spectrum is so important.

In the case of cancellation, the more you boost, the worst it gets. The only way to fix a problem like that is to change the placement or alter the phase somehow. boosting and cutting some frequencies affect other frequencies - overtones. It's very complicated stuff, but if you have an RTA, it's like having a vacuum/boost gauge in a car - a tool used for both diagnostics and learning about the behaviour of an engine.

 

In a vehicle, reflections are the worst enemy of a good sounding system, to understand this you need to use a TEF.

A RTA is actually limiting when you are trying to work on timing, phase shifts and cancellation with respect to how they all interact in the vehicle. You can use them on individual speakers, but to get any useful information you need to use a TEF or other types of measuring equipment.

 

Not to mention off axis response of speakers, backwaves (maybe not right term, but waves not from source caused by interaction of other frequency mismatches), yada, yada, yada...... it's all so complicated and enough to drive you nuts. The RTA is only the beginning. That's why car audio is so much more interesting than home audio. <I'll probably get flak for that, but car is so hostile an environment - temperature, humidity, pressure, etc.>. On the other hand, there's nothing like listening to your favourite music in an abandoned parking lot - music craked right up. My wife and kids hate my music, so I escape to the nearest Safeway parking lot.

 

they also make pcrta as well as rtajr for pc
the only thing with there software is they use a dongle and when the dongle goes bad your screwed

 

i have one too still got the bag it come in too its a little worse for wear though