12 replies to this topic

[Starry Blue SP20]

Does anybody know where I can borrow or hire an RTA from in the Sydney area.

I am installing a system in my car with a pair of Audio Control EQT's and would like to use an RTA to fine tune it.

Any other suggestions or advise would be appreciated.

Cheers
Brad

[JohnA]

RTA is good to see if there are any major peaks or dips in the freaquency responce other than that they are useless for tuning..
Back in the days of iasca they judged cars using an RTA...you had to have as smooth a freaquency as possible...ever heard a car setup like that? sound like total crap!!!!!!

These days they don't seem to be used anymore for sq comps so just tune it by ear and have it sound the way you like it and not what a machine tells you is best whilst playing pink noise

[roughcactus]

An RTA is a guide that is helpfull to achieve a smooth band to band transition.....especially if you are using 30 bands of eq or more.....John is right on the money, never ever tune your car for flat response as it sounds terrible....might score a perfect 40 in RTA at an IASCA comp but really does sound like **** ..... although an RTA can help you tune your car, they are a tool and can never replace a good set of ears and a competant tuner......that being said i would'nt try to tune a car with 30 band mono eq's without using one to at least get a good baseline to start from.....

Just ring around the specialists in your area and see if they will allow you to pay a few dollars to use theirs, on their premesis of course....as an RTA's woth about 3g for a good one, so they probably don't wanna lend one out

[T-Bro]

yes: a flat response sounds like sh1te
NO: tuning an EQ by ear is NOT the way to go.

tuning a total of 60 bands 'by ear' is like trying to tie your shoes with chopsticks - it aint gonna happen! i agree, that tuning needs to be done with a pair of ears as that is why you tune and what you aim to please, but you need a graph of the systems response curve, before you know even where to start. the curve will show you which peaks to attentuate, and those dips (if really necessary) that you need to boost. once you identify these points, only then are you able to use your ears to start tuning.

at least this is how i do it, and i find it works well with both graphic and parametric EQ's.

as an alternative for you, think about buying a handheld SPL meter from jaycar or d1ck smith, i have a digital one that cost about $150. all you do is play all 30 frequencies from a test disc (ie the same freqnecies on the EQ), and measure the dB of each frequency. write it down, until you have dB readings for all 30 freq's. then go to your computer, enter it all into a spreadsheet, then create a line graph - VIOLA! you have your systems actual response curve

sure it can be a little slower than using an RTA but its all you need to do the job and you can take your time because the equipment is yours - and it is patience that helps produce the result you want when it comes to tuning.

[NowHearThis]

Hey Starry, if you find one let me know. Thanks.

[Konrad]

Have you guys ever stopped and considered that when a system has a flat response, it is reproducing the music exactly how the artist intended it to be heard?

[Marc ♫]

Not Quite Konrad.

I can assure you it was not recorded with the intention of it being played back at a perfect RTA flat response.

[T-Bro]

audio is one of those things where theory doesnt often equal reality. in theory, a perfectly flat response means the system is playing exactly what the disc is telling it to, ie accurate reproduction. but if you listen to it, its terrible, and sounds bad enough that you know the artist never wanted it like this.

for various reasons, what a meter hears as 'flat', is not what your ears hear as flat.

for example, the sensitivity of human hearing 'rolls off' or attenuates at higher frequencies (treble) hence the reason why most high end speakers have response curves that lean upwards.

as others have said, there is a 'black magic' to audio, you just gotta try and see

[rolli]

Quote

Originally posted by T-Bro:
for example, the sensitivity of human hearing 'rolls off' or attenuates at higher frequencies (treble) hence the reason why most high end speakers have response curves that lean upwards  

This is exactly right, and if you can plot the natural response of your ear, this is what you would ideally want to tune your system to. There is a weighting scale that doctors use when testing hearing, but I have never seen anything in the domestic market which has it incorparated.

[Konrad]

Quote

Originally posted by Marc Rushton:
Not Quite Konrad.

I can assure you it was not recorded with the intention of it being played back at a perfect RTA flat response.

Are we talking flat A weighted or C weighted? I'll admit I'm not sure how SQ comps are judged.

[Bassaholic]

The issue in cars is the reflected sound. The RTA can't tell the difference between the reflected sound and the sound from the speakers.

But an RTA can still be useful, particularly in the bass region.

Of course the aim still is to reproduce the music exactly as the artist/producer intended it to be hear, this means you want your speakers to have the same frequency response what the artist/producer used. They use speakers with flat responses and we should too!

[Bassaholic]

Quote

Originally posted by Marc Rushton:
Not Quite Konrad.

I can assure you it was not recorded with the intention of it being played back at a perfect RTA flat response.

@ Konrad

[Cyberpunky]

RTAs take a 2 dimensional picture of 3 dimensional reality, and so wont make things sound perfect, if ruler flat response shows on RTA display. As stated they are a help with 1/3 octave eqs to highlight peaks.

As a peak may be standing wave related, an EQ may not be able to fix it and an RTA is helpful to see if this is the case.

Anyway only use the EQ to cut, and the RTA to highlight what areas are problem areas, and then trust your ears, as ppl have already pointed out a flat RTA response will sound very bad, which kinda defeats the purpose of a SQ system IMO
peace
Cyberpunky