Newbie Time Alignment Question
 

I am new to car audio but work as an audio engineer in another field. I have seen where some head units have delay for time alignment to the listeners ear. That seems to be good solution for point source single speaker or coax speaker systems. How is the problem of different arrival times between the HF and LF and the related phase problem in the crossover region handled in component systems handled? Any insight is appreciated.

JP

It is best to run a full active system so you can TA the tweet independent of the mid. Most car processors don't have fully adjustable phase per channel but by playing with polarity, slope, and frequency gapping one has a fair amount of control in the crossover region..

Dukk,
Thanks for the reply. That makes sense. I was unaware of the full active systems when I asked the question. It looks like those are mostly high end systems. Most of what I've been looking at are component systems with external passive crossovers. In my world, sometimes the manufacturers passive crossovers are pretty good and going fully active doesn't always yield a benefit.
FWIW, My preliminary research is leading me to go with a Pioneer DEH-80PRS head unit with a set of front stage speakers like the Morel Hybrid 602's or similar. I haven't started to research amplifiers yet. And, I am open to suggestions. Thanks again.

JP

Yes, in car audio generally passives are frowned upon as power wasters. With the cost of a watt so little these days though it seems like hardly an issue any more. Too many people do not appreciate that many passives do more than just divide the frequency range and it can be a challenge for a neophyte to surpass their performance.

The DEH-80PRS is a nice choice if running a 2way front end plus sub.

if i had unlimited space, money, and time (to install) i would have a full active system, with motorized speaker pods, and laser alignment of the speakers (done years ago...for those who are old school, pauls 5 series).

what you have to consider are the limitations in the auto environment. you can use time delay to maximize the listening experience for you (the driver) but it will make the sound that much worse for all passengers. there is no way to make it perfect for everyone, so if you tend to have a front seat passenger and care how it sounds for them, then i would find a good median. you can be more strategic in your speaker placement and negate the need for time delay (alignment).

passive x-overs can be junk, but on higher end components they are not too bad. you still have some adjustability.

Good components and their passives can be much better than an all active system in the wrong hands! This i know from experience. Many friends of mine that had little experience with active systems put aside their passives and actively tuned themselves to terrible results. In a few cases I switched to the passives and imediately their systems sounded 10x better...to their surprise. That said...after I finished tuning their systems (i have a lot more experience), they were very happy! Active rules in the hands of a good tuner...passive works well for simpler systems or inexperienced installers.

Not to be arguementitive, but two seat cars need time alignment as much as one seat cars do. It's also possible to have both seats image quite well, but not many do due to difficulty.

Time alignment and phase are related. Adjusting one can effect the other. You can use this to your advantage if you think about what you're doing. Use your ears and leave the measuring tape at home when adjusting TA!

There are also very affordable and good quality DSP units out there. minidsp is the first that comes to mind.

^ I hear they may have improved lately but, from what I understand, MiniDSP seemed to often have noise issues in a car. I was interested in their product for a while.

I am somewhat anti-TA and believe firmly that you have to do what you can physically to get any decent results. Just dropping speakers in at a whim and thinking they can be digitally fixed is foolish.

Absolutely, install first. But having a few digital band aids at your side can come in handy.

The minidsp originally had noise issues, but there is a DC to DC that eliminates the noise. The 8x unit has a different design and is supposed to have no noise (I haven't played with it).

Nice. Other than the potential noise issues, it looks like a really nice piece.