I would think that you guys would find this to be a great challenge for yourselves. I would love to see you guys come up with a cool class A amp for the car like the one made by TRU audio.
http://www.trutechnology.com/main.htm
These guys are even working on a true tube amp for the car.
Is the reason that most of you don't design stuff for cars because it's so hard? I am not an engineer but I know that car amps take a lot work to sound good.
http://www.trutechnology.com/main.htm
These guys are even working on a true tube amp for the car.
Is the reason that most of you don't design stuff for cars because it's so hard? I am not an engineer but I know that car amps take a lot work to sound good.
it's to do with the PSU for a car amp...say if you were to build a Class A amp for a car, because of the SMPSU you have to invest a lot in filtering and stuff, and a SMPSU by itself is not an easy thing to build...add in the battery and alternator as another variable...you get the idea, basically in a car, you would want to have high effiicency, ok maybe in extreme cases you don't, so probably a class D amp for the subs, only class A or A/B amps for the mids and highs. As far as I know, with car subwoofers (that are themselves already inefficient) there's no real point into using Class A amps for them...
I'm not sure why anyone would bother. A car is a crap environment acoustically and most speakers and installations aren't anywhere near the resolution of home stuff, so it'd be much harder to tell the difference.DJNUBZ said:
As for putting vibration sensitive devices (tubes) in a vehicle when you don't have to, or class A (real class A, not just something with a sticker and a lot of dissipation) into a hot environment, my question is, why? If people want the challenge, sure, go ahead, don't let my opinion dissuade you.
Music in the car (for me) is something that keeps me sane in the traffic when I can't have the pulse of a twin (motorcycle) between my legs and in my ears. I just installed a new head and 6x9's in my car today; pretty basic Pioneer, but now I can hear what the late John Entwhistle and Booby Sheehan are playing. And it's good.
Well I can agree with you and disagree with you Brett. I car isn't the best environment for audio but it also has a lot of great points when it comes to audio. In fact I have heard many car audio systems that outclass a lot of highend home gear (yes I have heard quite a bit of high end home gear). I can agree with you on the bike thing though.
I am guessing though that you have no experience with SQ installs. You might want to check it out by stopping at a iasca compition and seeing if someone will let you listen to their system.
li_gangya Wouldn't those problems be what an audio engineer would find as a challenge? You would never use a class A amp on the subs but you would use an A/B or D. A lot of the high power sub amps out now are class D but there are still a few A/B around. You would use Class A (or A/B) on a nice set of componants or horns for the front stage.
If it is so hard how come there are so many companies making car amps? There are tons of cheap knockoff amps floating around that you can pick up for $50 and I am sure cost less then $5 to make.
I am guessing though that you have no experience with SQ installs. You might want to check it out by stopping at a iasca compition and seeing if someone will let you listen to their system.
li_gangya Wouldn't those problems be what an audio engineer would find as a challenge? You would never use a class A amp on the subs but you would use an A/B or D. A lot of the high power sub amps out now are class D but there are still a few A/B around. You would use Class A (or A/B) on a nice set of componants or horns for the front stage.
If it is so hard how come there are so many companies making car amps? There are tons of cheap knockoff amps floating around that you can pick up for $50 and I am sure cost less then $5 to make.
Could you tell me what experiences you have had with SQ car installs? I am just curious as to what types of setups you have heard and what you felt was missing which you have found in home audio. I do belive that there are a lot of bad sounding car audio setups and that a lot of people into car audio have not heard a good setup.
DJNUBZ said:
DJNUBZ said:
Hi,
I've had the priviledge of listening to the highest of quality car audio systems and I have to tell you, "Hi - Fi" is a term that does not apply!
They're nothing but show off bass /SPL generators. The reason there's so many is because there's alot of people with more money than brains and are willing to pay for what they mistake as being the best in an effort to elevate their social status, and so it's a big market.
It's OK to have a decent system in it that can overtake the road noise, and if you do it right you can have decent sound quality, with respect to other car systems, but it couldn't possibly compare to the quality one can get from even a cheap domestic system.
Class A or tubes in a car is a total waste.
When it comes to a car I'd rather build the power into it where the rubber meets the road, and listen to that, than to a thousand pound audio system. It's also alot more fun than the thousand pound audio system, which always seem to be coupled with chrome tipped tomato can tail pipes.
Seriously.... there's alot of people installing such foolishness as DVD players and plasma screens inside their cars too, there's a big market for that, but what's the point, do they pull over on their way home from work and watch movies? Nah, it's just to say "look what I got". I'll always tell em, "too bad you it's not a big screen".
Having a home theatre system in your car is about as smart as having a car in your home theatre system.
Play Stations, DVDs and LCD screens are ideally suited for long trips carrying children and/or other people in the car for obvious reasons. Children and family stay quiet in the car as long as you keep them busy with their favorite picture or video-game 
LCD screens are also very useful as monitors for GPS travel systems [lots of traveling salesmen install these systems to make their life easier] and as 'active mirrors' to see the what's behing long cars through a small cammera when parking
However, other people installs these systems just to say 'look at what I got'
Finally, in order to produce Hi-Fi in a car : Conditioning the cabin against vibrations and characteristic resonances from its materials is mandatory, building rigid acoustic enclosures for all speakers is also mandatory. Placing the drivers in strategic locations in order to reduce undesired reflections and crossing then properly using digital-domain delays to compensate for driver/channel time offset and phase shifters to compensate for each driver+enclosusre phase response are also crucial tips
Anything other than this is wasting money, it's like adding in-car ornaments with audio-gear appearance, and amplifiers are the less critical thing here
However, car-audio competitions and manufacturers are almost entirely marketing oriented so it's not likely to see serious people or products, but just exotic stuff and fairy marketing tales. I strongly prefer to use standard hifi or PA components, particularly speakers [and I recommend lots of ply-wood and fiberglass for enclosures, custom-tuned crossovers and at least one DSP based adjustable delay line to compensate L-R time offset in order to get some imaging
]
LCD screens are also very useful as monitors for GPS travel systems [lots of traveling salesmen install these systems to make their life easier] and as 'active mirrors' to see the what's behing long cars through a small cammera when parking
However, other people installs these systems just to say 'look at what I got'
Finally, in order to produce Hi-Fi in a car : Conditioning the cabin against vibrations and characteristic resonances from its materials is mandatory, building rigid acoustic enclosures for all speakers is also mandatory. Placing the drivers in strategic locations in order to reduce undesired reflections and crossing then properly using digital-domain delays to compensate for driver/channel time offset and phase shifters to compensate for each driver+enclosusre phase response are also crucial tips
Anything other than this is wasting money, it's like adding in-car ornaments with audio-gear appearance
, and amplifiers are the less critical thing hereHowever, car-audio competitions and manufacturers are almost entirely marketing oriented so it's not likely to see serious people or products, but just exotic stuff and fairy marketing tales. I strongly prefer to use standard hifi or PA components, particularly speakers [and I recommend lots of ply-wood and fiberglass for enclosures, custom-tuned crossovers and at least one DSP based adjustable delay line to compensate L-R time offset in order to get some imaging
]Oooooh come on now, they'd still fight over what movie to watch or what game to play or who's turn it is
I see too many with dvd screens and no gps or kids either. I think it's safe to say the majority of the market is for the "lookee what I gots" But yeah they do have their uses... I always liked the back up camera but it's really not required unless it's a vehicle you just can't see behind otherwise.
I agree that's how the sound is done right.. but would you go so far as to call it Hi Fi?
Isn't MDF better than plywood, sealed with urethane bond?
I see too many with dvd screens and no gps or kids either. I think it's safe to say the majority of the market is for the "lookee what I gots" But yeah they do have their uses... I always liked the back up camera but it's really not required unless it's a vehicle you just can't see behind otherwise.
I agree that's how the sound is done right.. but would you go so far as to call it Hi Fi?
Isn't MDF better than plywood, sealed with urethane bond?
MDF and ply have its particular pros and its cons. I prefer ply since it's much lighter than MDF, it's moisture resistant and everything inside a car is subject to deformation, vibrations and big temperature changes
I would call Hi-Fi what I described with no dobuts, since by that procedure I've got far better in-car results than with Hi-Fi equipment inside any non-treated 2,5m x 3m x 4m typical room
For example, the room where I'm sitting now produces almost no imaging and cancels bass, no matter what audio equipment you use the effect is allways the same [the room is not treated, it has the previously mentioned dimensions and has asymetric furniture layout]. However, the same equipment produces nice imaging placed outdoors
Anyway, I'm very sceptical about what people calls 'Hi-Fi'
I would call Hi-Fi what I described with no dobuts, since by that procedure I've got far better in-car results than with Hi-Fi equipment inside any non-treated 2,5m x 3m x 4m typical room
For example, the room where I'm sitting now produces almost no imaging and cancels bass, no matter what audio equipment you use the effect is allways the same [the room is not treated, it has the previously mentioned dimensions and has asymetric furniture layout]. However, the same equipment produces nice imaging placed outdoors
Anyway, I'm very sceptical about what people calls 'Hi-Fi'
Yeah, I guess everyone has their own understanding of what Hi Fi actually is.
My version would be the absolute purest, transparent, clean sound.
It seems to me all bass in a car has the same frequency, or tone, so it's not very transparent. Don't they often also try to optimise the bass at the car's natural resonant frequency to boost spl a bit more? I think SPL is their main concern, quality not being an issue at all.
If you try to dampen road noise and do everything you can to get decent imaging you've certainly gone the extra mile for the best possible sound, and I think it can be superb, but it's never a very pure reproduction of the source.
That said all the high end car audio systems I've gotten to listen to played nothing but special test cd's, and in the case of the very extreme (Rockford Fosgate demo van), which was impressive, no one got to listen to music in it, they played movies, I have to ask myself why?
While we could probably debate all the above until we're blue in the face, I have to say tubes in a car audio system is bordeline insanity, and class A is wasted.
My version would be the absolute purest, transparent, clean sound.
It seems to me all bass in a car has the same frequency, or tone, so it's not very transparent. Don't they often also try to optimise the bass at the car's natural resonant frequency to boost spl a bit more? I think SPL is their main concern, quality not being an issue at all.
If you try to dampen road noise and do everything you can to get decent imaging you've certainly gone the extra mile for the best possible sound, and I think it can be superb, but it's never a very pure reproduction of the source.
That said all the high end car audio systems I've gotten to listen to played nothing but special test cd's, and in the case of the very extreme (Rockford Fosgate demo van), which was impressive, no one got to listen to music in it, they played movies, I have to ask myself why?
While we could probably debate all the above until we're blue in the face, I have to say tubes in a car audio system is bordeline insanity, and class A is wasted.
Listening in car contest all aspect of realy good listening - noise of wheels, air, motor etc., small listenig space and small possible concentration of driver. But it is very good bussines for manufacturers, 'cos people like theirs metal babys and promotion says, that you can to evade physical laws 
.
and promotion says, that you can to evade physical laws .
You want specific vehicles and setups? Sorry, I don't remember. This is not stuff I'm into particularly, but a few of my previous students have been seriously into the competition side of it, both SPL drag racing (biggest WOFTAM ever) and some for performance in terms of SQ. Every single one of them that heard my home system was astonished at what it could do with all sorts of music. The best car systems I've ever heard, were orders of magnitude inferior in providing a realistic soundscape.DJNUBZ said:
Thanks for saving me a lot of typing. Couldn't have said it better.classd4sure said:
I am surrprised not to see more of you designing high end car amps.
Some thoughts;
1. How do you know nobody is?
2. The car audio amplifier market is flooded with good product
and many of the product carries a low price per watt ratio as is.
In some cases, 25 cents per watt. It's actually cheaper to
buy than DIY in many cases.
Class A in car
Some thoughts;
1. This type of amplifier design is not very efficient.
2. Sound quality of class A is subjective, many people will
claim to hear improvements in sound quality others will not,
factor in placebo too. For example, there are some class A car amplifiers
that are hybrid yet many people don't know. They claim that
the sound quality is better but unknown to them is the fact
that they are listening to opamps, tube predrivers and solid
state output stages -- > LOL
3. It's market driven. If the car audio market doesn't desire this, why build it ? Why don't they use class A power amplifiers
in proaudio considering they use higher than average efficient
loudspeakers, you would think there is a place for it.
Car audio vs. Home audio
I wasn't able to find a home audio system that could beat
the sound quality that my car audio system that I spend
2 years designing to satifisy my SQ needs. Keep in mind,
the phrase "To satisfy my SQ needs". Currently,
I'm working on a home system to satisfy my SQ needs because
I'm still unable to find commercial product that satisfies.
What does this mean?
1. If you haven't heard a car audio system outperform a
home audio system then that is no golden rule that it can't
be done and visa versa.
2. Designing a world class car audio system proves more difficult
but not impossible. I've heard more bad car audio systems than
good ones in my days, but on the same token, I've heard many
bad home audio systems too and very few I liked.
Some thoughts;
1. How do you know nobody is?
2. The car audio amplifier market is flooded with good product
and many of the product carries a low price per watt ratio as is.
In some cases, 25 cents per watt. It's actually cheaper to
buy than DIY in many cases.
Class A in car
Some thoughts;
1. This type of amplifier design is not very efficient.
2. Sound quality of class A is subjective, many people will
claim to hear improvements in sound quality others will not,
factor in placebo too. For example, there are some class A car amplifiers
that are hybrid yet many people don't know. They claim that
the sound quality is better but unknown to them is the fact
that they are listening to opamps, tube predrivers and solid
state output stages -- > LOL
3. It's market driven. If the car audio market doesn't desire this, why build it ? Why don't they use class A power amplifiers
in proaudio considering they use higher than average efficient
loudspeakers, you would think there is a place for it.
Car audio vs. Home audio
I wasn't able to find a home audio system that could beat
the sound quality that my car audio system that I spend
2 years designing to satifisy my SQ needs. Keep in mind,
the phrase "To satisfy my SQ needs". Currently,
I'm working on a home system to satisfy my SQ needs because
I'm still unable to find commercial product that satisfies.
What does this mean?
1. If you haven't heard a car audio system outperform a
home audio system then that is no golden rule that it can't
be done and visa versa.
2. Designing a world class car audio system proves more difficult
but not impossible. I've heard more bad car audio systems than
good ones in my days, but on the same token, I've heard many
bad home audio systems too and very few I liked.
Actually Rockford is one of these marketing-fairy-tales manufacturers. They just sell exotic-looking SMD ultra-low-production-cost amplifiers and massive-looking bass drivers intended to resonate strongly around a single frequency [High Qts] that show very poor efficiency outside this range [typ 84dB/W]. Most american manufacturers are of this kind. Audiobahn is another example : They buy the best looking stuff thay can find in China and sell it as 'High-End' [they perform no electronics or acoustics research and development at all]
To listen for music actually you need to know the behavior of the cabin gain [about 12dB/oct boost below 50-65Hz] and design enclosures providing premature bass rolloff to compensate for it. Bandpass enclosures are ideally suited for this since they can provide upper bass boost [80Hz-150Hz] and smooth rolloff below that. Fine compensation is achieved through equalisation
But this is no bussiness for manufacturers since each enclosure has to be custom-designed for each car-speaker combination and the speaker ends hidden inside a black-box so nobody can see it. That's why some people place speakers inside-out showing their fancy motor assemblies to the world : Stupid marketing issues
To listen for music actually you need to know the behavior of the cabin gain [about 12dB/oct boost below 50-65Hz] and design enclosures providing premature bass rolloff to compensate for it. Bandpass enclosures are ideally suited for this since they can provide upper bass boost [80Hz-150Hz] and smooth rolloff below that. Fine compensation is achieved through equalisation
But this is no bussiness for manufacturers since each enclosure has to be custom-designed for each car-speaker combination and the speaker ends hidden inside a black-box so nobody can see it. That's why some people place speakers inside-out showing their fancy motor assemblies to the world : Stupid marketing issues
A truly outstanding car system could be very simple, and best of all. not annoying to other motorists. How about a pair of headphones, the kind with foam cups that seal out road noise, and a mechanical bass shaker bolted under the seat of the driver?!!!! One could easily use a small SET, class-A tube amp to drive the headphones since a watt per channel would be plenty.
Here is someone's nice tube car amp I found on the net.
Here is someone's nice tube car amp I found on the net.
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Re: Re: I am surrprised not to see more of you designing high end car amps.
But it has just 25W/4Ohm in Class A than it turns to class AB...
Being editor of croatian HiFi magazine I conducted several tests of car audio amplifiers. The way we did it was to hook them up to a powerfull 13,8V DC supply and listen to them in home audio envirement of magazine's listening room. We used to compare them to home audio amplifiers in their price class. Some of them were suprisingly good sounding. I remember that some small Poweramper and RF blew Rotel's top integrated amplifier away. Mainstream car amps (like Alpine, Clarion, Kenwood, Pioneer etc.) usually sounded awfull.
Anyway, car audio can be lot of fun! At home, Doobie Brothers or Missy Elliot never sounded as good as in
Nelson Pass said:
But it has just 25W/4Ohm in Class A than it turns to class AB...
Being editor of croatian HiFi magazine I conducted several tests of car audio amplifiers. The way we did it was to hook them up to a powerfull 13,8V DC supply and listen to them in home audio envirement of magazine's listening room. We used to compare them to home audio amplifiers in their price class. Some of them were suprisingly good sounding. I remember that some small Poweramper and RF blew Rotel's top integrated amplifier away. Mainstream car amps (like Alpine, Clarion, Kenwood, Pioneer etc.) usually sounded awfull.
Anyway, car audio can be lot of fun! At home, Doobie Brothers or Missy Elliot never sounded as good as in
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