Car Audio systems... according to Tonkins...
I was bored one day, so, I emailed Tonikns audio (A local copmapy specializing in car audio)
Heres what I said..
> I am looking for a system to accuratly reproduce all types of music,
> covering the whole audiable audio spectrum if possible. Probably from
> 20-20000Hz if possible... I am looking for a full package including
> headunit, subs, 6X9s and whatever else I would need.. What can you
> reccomend? Thanx
for us to provide you with an audio system to recreate the entire audio
spectrum we will need to get some more information from you. ie:
What can be modified
I replied.... (something along the lines of...)
I don't really want to buy a system, all your gear is too expensive, I know its quality, but whats the difference between your Eclipse 4 X 85watt RMS amp for $800, and the 4 X 100watt RMS Response amp for $450...
Also, It isn't physically possible to correctly reproduce all the way down to 20Hz in a car...
the reason that you would buy an eclipse product over a response is the same
reason why you would buy a Ferrari over an excell. Sure they'll both do the
job, but you can guarantee that one is going to do it a hell of a lot better
than the other. At the end of the day you only get what you pay for.
As far as 20Hz is concerned, we have an expensive piece of testing equipment
called an 'RTA' or 'Real Time Analyser' that's specific use in life is to
test a system for frequency response from 20 to 20000Hz. I can assure you
that it is very much an achievable objective with quality audio systems. The
quality brands that I refer to are Alpine and Eclipse (and some others),
however not being all that familiar with the response brand this may not be
I hope that this has cleared up some of your issues.
The difference between a Ferrari and an Excel is that at the end of the day, the Ferarri salesman is much richer. Besides, I think he went a little overboard with his analogy. It's more like a Ferrari vs. a Corvette. Since when does an Excel have better performance stats than a Ferrari? (85x4 vs 100x4???)
Actually, you make a good point.. its more like comparing a FORD and a HOLDEN..... Both are similarly priced cars with similar performance... 50% of people like one, 50% of people like the other.. Plus, the guy had never even heard a Re/Sponse amplifier.. :S
It is definitely possible to reproduce 20-20k in an automobile. Doing it accurately on a limited budget is usually the problem.
Got a link for Response? I'm not familiar with them.
Re/Sponse is sold my www.jaycar.com.au
Thats all I know.. :rolleyes: lol
My forays (and still is) into car audio has taught me a few things, amongst them is to take amplifier ratings with a grain (or two) of salt. I have seen the Re/sponse loudspeakers and amps, but have yet the honour to hear them. But a 4 x 100W (400W total) continuous RMS rating is no joke, it is far TOO high for $400+. A realistic rating for a 4 channel car amp may be: 4 x 50W into 4 ohms, 0.1% THD at 20Hz-20kHz, plus minus 3dB...... I have never seen a car 4 channel amp rated (realisticly) more than 4 x 50W. This may be due to the thermal dissipation limitation of the package.
The acid test is to ask the dealer to open up the bowels of the amp to you. That way, you can check the number and type of output devices, SMPS etc. I have done this at a local dealer and you'll be surprised what you'll find. I guess the saying "Good things don't come cheap" is true, at least 90% of the time.:cool:
Perhaps I will buy a Re/Sponse amplifier and test it? :)
I believe them anyway.. :p lol
What I remember from my car-fi days was this-
Halving the impedence should double the output while keeping low distortion. That philosophy may have changed, but it's how we used to judge an amps true output capabilities. At the time (early/mid '90's) Pheonix Gold, Fosgate and a handful of others were great at this sort of thing. I've no idea how they stack up now. I seem to recall Orion having amps that could run at 1/8 ohms all day without getting hot. Try that with an over-rated inexpensive amp and it'll fry in seconds.
I've done A/B comparisons with products like old Fosgate Punch amps rated at 25X2 rms vs Profile 300X2 rms. The results speak for themselves. Better control over the cone, better sound quality, lower audible distortion from the old Fosgate.
All watts are not created equal (in brochures)
I have to agree with everything tonkins says. It is actually easier to achieve 20hz-20khz in a car than in a room if your budget is limited. Admittedly, damping is a huge factor and it is MUCH easier to achieve this if windows are open fully. This is not allowable in autosound competitions. For a total of $650 I purchased a jvc deck, an esx amplifier, a soundstream amp, 2 jbl gt1200's, and a full set of polk db midranges. I built an extended bass shelf ported box set with the rolloff accordingly to match the cabin gain characteristics of the car (I was lucky enough to be able to use an MKII (?) subwoofer that my dad has. it's 2 10's in an 11in^3 box that is equalized and has a 2700 watt amp.
Now I haven't had this thing tested with an RTA but As far as I can tell it sounds almost exactly like my dad's NHT 2.3's, which are + or - 2db from 20hz-20khz. These are 2000 dollar speakers, and just about the best one's you can get for that price!
The car will play this accurately and evenly at 135db (guestimate on the volume, but it sure hurt my ears). My father's speakers only do this to 110db, measured on a db meter that goes up to 130 db. The db meter was maxxed in the car. Subsonic frequencies clicked the meter to the max as well, and can be heard because of the distortion they cause in the ambient noise (sounds like everything gets quiet.) I synthed a 5hz tone and played it, and smoke shakes ~1.5 inches at the loudest volume, measured with a ruler in the drivers and passenger's seats. Accidentaly played it in the garage once and almost all the pictures in the house fell off the walls.
Windows rolled up = different story entirely. subsonic frequencies can barely be felt, cabin resonances in many different flavors, Shrilly reflections off the glass.
Designing a car audio system has more to do with "building around the car". Placement of speakers is a tough thing to do if you have the wrong car. Also, van's and many suv's are much too boxy and contain many panels of poor resonance.
The car audio market is dominated by people that want something for their car soon. They don't know anything about audio and look at the watt's only and not distortion, signal to noise ratio, frequency response, etc. I've seen amps rated at .5% and more THD. Signal to noise ratio's of 50-80 are all too common on some of the cheapo brands.
That double power/half resistance thing still holds true for the most part, except some amps now have quality voltage regulators that can keep high output at high risistance. Another type of regulator in use guarantees a low output at 4 ohms, but allows huge output at lower resistance. This is for competition purposes (they only take the power of your amps at 4 ohms rms). The most extreme I've heard of is a 1x10 watts at 4 ohm and 16000watts rms at 1 ohm (not a typo). Most extreme I've seen is 15x2 watts at 4 ohm and something like 1400-1800 watts at 1 ohm.
That orion amp does 50x2 at 4 ohms, 800x2 at 1/4 ohm. It does get hot if you turn the volume up, but will play all day. Fosgate amps are usually stable at 1 ohm stereo, as are the sony mobile es line of amps. The better amps are stable to lower resistance in general on the car audio market (is this just true for amps in general?) I know my home reciever is stable at 1 ohm or less, but is intended for 4-8 ohm speakers (used it to test some car speakers.) and I run it at 2 ohms with no discernable loss in quality at low volumes and a large increase in output power.
By stability I mean that it will distort when volume is turned way (to the point of complete ugliness) up rather than cut out
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