Dumb Tech Questions

[SEAWOLF97]

I see the car audio ads with the amps that procalim they produce " 800 or 1000 or 1600" watts or somesuch. These are relativly small boxes.

Normal audio gear , rather large amps are rated at 100 or 150 ...etc.

do you see my question ?? Arent all watts the same size ? Why are these little boxes producing so much ? and is it really so much - in terms of home audio terms ?? If this was true, why not use a 12v converter and run in the home ?

[kingjames]

the audio sector is not rated by a government agency and manufactures can proclaim any wattage they want and not be called on it. I had this very same discussion with a teacher of mine in the past and as a result when I sold a few amps of mine through the newspapers I use to state "true wattage"

Your name brand stuff usually sticks to the true meaning of wattage when they advertise their stuff.

Buying an amplifier rated at 500 watts per channel only running a 10amp fuse should tell you that it's:bs:

[coherent_guy]

Why do you always ask "dumb" questions? You've said that about so many things you've asked about on this forum, like using a tape out as a pre out. Don't 'cha know there's no such thing as a dumb question?? You have no reason to apologize for your inquiry by classifying it as dumb. Now, having an Ohm F as your avatar on the Lansing Heritage site, well that is . . . different. ;) (Have you fantasized about a JBL built Walsh driver? Could be pretty cool!)

I've wanted to ask you about your Ohm F, is it really a full-range speaker using only the Walsh driver, and what is the bass response like? But I'm afraid that this question might be. . . you know :blink:

Regarding the mobile, 12 volt powered amps, I have thought the same thing myself, bringing them into the home with a big 12 volt power supply. I'm not 100% about the reasons why those amps are the way that they are, but . . .

Realize that those power ratings are into 2 ohm and even 1 ohm loads! The speakers for mobile applications are mostly very low impedance drivers, which is related to the 12 volt power supply limitation. Given a theoretical perfect amp and power supply, it's power doubles with each halving of the load impedance. So a 100 watt into 8 ohm amp would produce 200 watts into 4 ohms, 400 watts into 2 ohms, and 800 watts into 1 ohm.

You are right about your observation that with the 12 volt power supply in a car, how do these amps produce more voltage than that. I believe the answer is that there are multiple amp circuits within each single amp case that are bridged together, just like some home and pro stereo amps are bridge-able into higher powered mono amps. I think bridging a stereo amp results in a mono amp with four times the power of the individual channels, which helps explain the high power figures you mentioned.

These amps also may be using the so-called switching power supplies used in PC's and now in some home and pro audio equipment. They might be able to put out more than 12 volts, I'm not sure.

How these amps survive into the low impedances of mobile speakers is something I cannot explain. May I join you with a "dumb" question regarding that? :o:

[edgewound]

the audio sector is not rated by a government agency and manufactures can proclaim any wattage they want and not be called on it. I had this very same discussion with a teacher of mine in the past and as a result when I sold a few amps of mine through the newspapers I use to state "true wattage"

Your name brand stuff usually sticks to the true meaning of wattage when they advertise their stuff.

Buying an amplifier rated at 500 watts per channel only running a 10amp fuse should tell you that it's:bs:

Well...that really not the case. This isn't the wild west so much anymore, and I believe the mfgr have to answer to the FTC if asked to do so...and the pro audio community is less concerned with hype and more with accurate, conservative numbers. The Car audio community runs it's numbers on the verge of destruction.

Yes...watts is watts....but "Ohm's Law" dictates how you get there.

In a simplified example...because that's all I'm able to do...

Take the 500 watts divided by 120volts and you get current draw of 4.166 amps.

Take the 500 watts divided by 12volts and you get current draw of 41.666 amps.

Power=Watts; V=volts;
P/V=I

That's why mega car audio systems have huge multihundred amp alternators, more batteries and huge stiffening capacitors to augment the cars electrical system.

[kingjames]

Well...that really not the case. This isn't the wild west so much anymore, and I believe the mfgr have to answer to the FTC if asked to do so...and the pro audio community is less concerned with hype and more with accurate, conservative numbers. The Car audio community runs it's numbers on the verge of destruction.

The problem is their not asked to do so.

Here in Chicago where sounds are not so much a hobby but more of a lifestyle I see all those junk amps all over the place.Mostly from China,Taiwan,S.Korea etc;. They sell these amps on assumpions of producing in excess to 500 watts per channel and,then you look at the fuses supplying these amps and they are 5 watt fuses.

I have a few teenage friends who are children of my friends who marvel at my system and the power it produces. I always tell them that this is true wattage. I also show them what I think is about 30 to 40 watts of power and they can't believe the volume even at that low wattage.

Yet all of them have thousands of dollars in sounds in their vehicle and though the music is loud you can't tell a horn from a drum.

I remember years ago I bought a Pioneer amp rated at only 25 watts per channel, it was still quite expensive at that time and I was skeptical at the time because I believed like everyone else. I also remember the salesman telling me that this is true wattage. I was thinking 25 watts ain't shit.This is when I really learned about true wattage. I put that in my car with a set of 12" JBL's in a box and could not believe the power of that liitle amp.

I would like to think that wattage (power) is not so much for volume but rather for clarity.

I still prefer an amp or receiver with tons of power because if I decide to bump my gear it will not be a strain on it. Always better to have more power than you need.:)

[Rusnzha]

Car audio amps dont have power supplies since they use the 12V DC off the battery. This is what takes up most of the space in an amp.

[Zilch]

Look also to the comparative efficiencies of the drivers used in car audio application, the woofers and subs, especially, which is where the power goes.

It's all stupid, anyway, guys woofin' at each other. The girls know who's got what.... ;)

[coherent_guy]

Car audio is certainly a world onto its own. I don't know if the FTC amplifier power ratings are applicable to mobile equipment, but as KJ says, a "200 Watt/Ch" car amp for $100, even without the expense of a power supply, is obviously bunk.

Autos do have the potential for some interesting speaker configurations. A trunk makes a pretty good enclosure for a woofer, volume-wise. Given the small "room" size inside a car interior, high SPL levels aren't likely difficult to achieve. I've read about SPL competitions in car audio with numbers in the 130+ db SPL levels! With woofers mounted in the rear deck and firing into the trunk and interior, don't we have something like a band-pass enclosure on wheels?!? That would put one inside the enclosure, hmmm. . . :hmm:

I've noticed in home audio reviews recently that some amps are not passing the FTC requirement of 1/3 continuous power ouput for one hour without shutting down. So it seems the FTC is turning a blind eye now, much to the car audio manufactuers delight and the consumers plight.

I wonder how the Lexus/Mark Levinson system would do on specs vs measurements?

[edgewound]

I've looked at the spec sheets of various car audio amps and have noticed the power ratings.

The buyer need to dig a little deeper into the specs and not just believe what the salesman says.

I've actually seen power ratings that would say something like "500 watts @10% distortion" along with "100 watts @ .1% distortion"

Are they lying? No. Are they taking advantage of the ill informed consumers' desire to always get more for less? Absolutely.

So...who's at fault...the greedy buyer...or the greedy seller?

[Rusnzha]

The suckers or those who exploit them -- Hard to say!

[edgewound]

The suckers or those who exploit them -- Hard to say!

Well spoken... with good, solid, Kansas mid-western values.

[kingjames]

I've looked at the spec sheets of various car audio amps and have noticed the power ratings.
I've actually seen power ratings that would say something like "500 watts @10% distortion" along with "100 watts @ .1% distortion"


Not everyone is as informed as everyone else. The issue here is that most of these amps do not produce what they advertise to do. In light of this for the person who knows nothing about wattage should be able to go to a store and be told the truth.

Reading specs is for the well informed what about the "suckers" who are not so well educated?:blink:

I think we were all there at one time or another!

[edgewound]

Reading specs is for the well informed what about the "suckers" who are not so well educated?:blink:

Education is expensive...lack of education is more expensive.

[louped garouv]

many of the kids i used to hang out with in High School had top notch car audio systems....

and most swapped the entire system out almost annually....

alot of those guys hang out at the shops with their friends learing about what's up....

but it never has been a cheap endeavor, especially if you get into custom, one-off installations with custom fabrication of door panels, fake spare tires to house subs, etc.....

[jim campbell]

many of the kids i used to hang out with in High School had top notch car audio systems....

and most swapped the entire system out almost annually....

alot of those guys hang out at the shops with their friends learing about what's up....

but it never has been a cheap endeavor, especially if you get into custom, one-off installations with custom fabrication of door panels, fake spare tires to house subs, etc.....
unfortunately these days the car audio industry seems geared to the trunk rattling rolling boom box crowd and that god awful drum and bass noise.i recently rode in a very expensive german luxury car and even its factory stereo had that sound.it seems to be all about impressing the guys with how many watts,dollars,db,woofs etc and less about building good sounding systems.

[SEAWOLF97]

Now, having an Ohm F as your avatar on the Lansing Heritage site, well that is . . . different. ;) (Have you fantasized about a JBL built Walsh driver? Could be pretty cool!)

I've wanted to ask you about your Ohm F, is it really a full-range speaker using only the Walsh driver, and what is the bass response like? But I'm afraid that this question might be. . . you know :blink:


well , some people have rocks or dogs or who-knows-what in their avatar, at least I stayed with an interesting speaker.

The OHM's ?? from their website...

made 1972 - 1984
cost originally $900 - $3995 per pair Dimensio
req 100 - 200 watts )4 ohms
FR/sens/room size 37 - 17,000 Hz s87 dB es300 sq.ft.


The Ohm F was the most popular of the first generation Walsh speakers. It used a 12'' inverted omnidirectional driver operating from 35 - 17,000 Hz. Some of the earliest Ohm Fs had Ohm A serial number plates, but the much smaller driver is of importance. The Ohm Fs were internationally recognized as ''one of the best...if... not the best...speaker in the world''. It received reviews from as far away as Australia and Thailand as well as throughout Europe and America.
Ohm F owners are a loyal group. Most find it hard to believe we've improved the speakers until they audition the top of the latest generation in their homes.


-----------------------------------------------------------
If you have not heard them, I think my best description wud be "like a Martin-logan, but with real bass and a very wide sweet spot"

I get the same image feeling that I did with my Janszen electrostats, but their sweet spot was about 3 inches wide. The F is the only OHM Walsh driver (besides the hardly ever seen "A") that has a moving cone. It is essentially a 12 in. firing into a 4.3 CF cabinet. Capable of very substantial bass. Most people look at them when I take the tents off and ask "where is the sound coming from" ?? The chart above shows 37-17k response, I wud call that full range.

Still own enuff JBL's (L26,L36.L100,4410,4412) that I think I can still belong to the forum, tho the main speakers have changed.

If ever in Portland ,Oregon, stop on by...I'll give you a demo.

PS..Loach71/Tim has a pair also. Maybe he can elaborate on the sound ?

[kingjames]

Education is expensive...lack of education is more expensive.

I totally agree,but let's face it there are still many not so informed and an education should not be a prerequisite to getting an honest deal.

[Baron030]

I have seen a car amplifier that claims that it had an 800 watts/channel power rating.
What was clearly visible from the outside of the box was that the amplifier had two LM12 National Semiconductor IC chips in it.

A LM12 IC chip under ideal conditions can deliver 80W of sine wave power into a 4 load with 0.01% distortion.

But, if you short the chip's output, use the highest possible power supply rail voltage, and keep the chip temperature low, then for a brief period of about 0.1 milliseconds the LM12 chip can have a peak dissipation of 800 Watts.

That is not 800 watts going to a speaker!
That is 800 watts of power just heating up the LM12 chip for about 1/10,000 of a second!

Considering the extremes of temperature found in a car, any amplifier using the LM12 chip is most likely going to produce no more than about 40 to 50 watts of real power to the speakers at best.
The other 750+ watts/channel is just :bs:
So, watch out for those peak dissipation ratings...

Baron030

[Rusnzha]

Originally written By jim campbell


unfortunately these days the car audio industry seems geared to the trunk rattling rolling boom box crowd and that god awful drum and bass noise.i recently rode in a very expensive german luxury car and even its factory stereo had that sound.it seems to be all about impressing the guys with how many watts,dollars,db,woofs etc and less about building good sounding systems.

I hear a lot of this, but I don't think they need to sound this way. I think people set them up to play this way on purpose. Maybe their ears have a different response to sound or do they need more boom than the next guy? It's a strange kind of conformity when people spend so much on the same crappy sound.

[SEAWOLF97]

Maybe their ears have a different response to sound or do they need more boom than the next guy? It's a strange kind of conformity when people spend so much on the same crappy sound.

I happened by one of their car stereo competitions.
Fidelity ? dynamic response ? NO. the winner is the guy with highest SPL in a closed auto where no one cud withstand the environment.

[SEAWOLF97]

(Have you fantasized about a JBL built Walsh driver? Could be pretty cool!)

Lincoln Walsh's heirs owned the patent. It shud be over by now, but..

only 2 companies in the world are licensed to produce the Walsh driver. OHM and German Physiks. Both can be rather expensive. Way above popular prices. Infinity , I have heard , had a walsh tweeter.

OHM is still produced in NY.

I get email tech support from OHM's president, that might change if JBL/Harmon produced it ?

the F's last price in 1984 was $4,000.

$7,764.31 in the year 2006 has the same "purchase power" as $4000 in the year 1984.

[coherent_guy]

well , some people have rocks or dogs or who-knows-what in their avatar, at least I stayed with an interesting speaker.

The OHM's ?? from their website...

made 1972 - 1984
cost originally $900 - $3995 per pair Dimensio
req 100 - 200 watts )4 ohms
FR/sens/room size 37 - 17,000 Hz s87 dB es300 sq.ft.


The Ohm F was the most popular of the first generation Walsh speakers. It used a 12'' inverted omnidirectional driver operating from 35 - 17,000 Hz. Some of the earliest Ohm Fs had Ohm A serial number plates, but the much smaller driver is of importance. The Ohm Fs were internationally recognized as ''one of the best...if... not the best...speaker in the world''. It received reviews from as far away as Australia and Thailand as well as throughout Europe and America.
Ohm F owners are a loyal group. Most find it hard to believe we've improved the speakers until they audition the top of the latest generation in their homes.


-----------------------------------------------------------
If you have not heard them, I think my best description wud be "like a Martin-logan, but with real bass and a very wide sweet spot"

I get the same image feeling that I did with my Janszen electrostats, but their sweet spot was about 3 inches wide. The F is the only OHM Walsh driver (besides the hardly ever seen "A") that has a moving cone. It is essentially a 12 in. firing into a 4.3 CF cabinet. Capable of very substantial bass. Most people look at them when I take the tents off and ask "where is the sound coming from" ?? The chart above shows 37-17k response, I wud call that full range.

Still own enuff JBL's (L26,L36.L100,4410,4412) that I think I can still belong to the forum, tho the main speakers have changed.

If ever in Portland ,Oregon, stop on by...I'll give you a demo.

PS..Loach71/Tim has a pair also. Maybe he can elaborate on the sound ?

Well thank you for your offer to listen to them, I don't know when I'll be able to do so but I appreciate it very much!! :D

I was just pulling your leg over your avatar, and it certainly is better than mine . . .

I've never heard a Walsh driver which is why I ask about it. I've always been facinated by any of the non-moving coil loudspeaker technologies, excluding electrostatics and planars. Then again, a Walsh driver may have a somewhat conventional voice coil?

I owned an ESS speaker with the Heil tweeter, 'though all that remains of them is one Heil tweeter. The Heil tweeter is back with a new line of speakers, super expensive unfortunately. Here is a review and pic of one of the new speakers with the Heil tweeter:

http://www.enjoythemusic.com/superioraudio/equipment/0904/heilkithara.htm

I recall reviews of Ohm speakers in Stereo Review done by the late Julian Hirsch. As I recall they were well liked by him.

All the unconventional driver technologies seem to be lacking in the bass frequencies but it seems the Walsh is an exception to this. They may also be limited in the UHF range, but 17kHz is plenty high in my book, my ears seem to give out above 15kHz. I have a speaker I'm listening to now that uses 2402s and I don't feel I'm missing much if anything.

Are the Walsh drivers fragile in any way? What breaks on them? It seems Ohm supports these drivers, or what? I haven't checked their website yet, so I don't know if they still make them. Aren't they omni-directional radiators? A full range driver with no crossover? Facinating . . .

I would never think of excluding you from this forum because of your love of Ohm speakers, not that I could if I wanted to. Besides, who else do we have to ask dumb questions? ;)

[SEAWOLF97]

All the unconventional driver technologies seem to be lacking in the bass frequencies but it seems the Walsh is an exception to this. Are the Walsh drivers fragile in any way? What breaks on them? It seems Ohm supports these drivers, or what? I haven't checked their website yet, so I don't know if they still make them. Aren't they omni-directional radiators? A full range driver with no crossover? Facinating . . .


The F driver does move, unlike the other walsh drivers. It has a foam surround on the bottom and tho I havnt seen it , there is some type of gasket/ring at the top. They do wear out.
The bass is roughly similar to my 4412's. Tho the larger 4.3CF box seem to help.
Since they radiate off the OUTSIDE of the cone, yes they are 360 degree dispursion, thats what gives the huge soundstage. Later models have a curtain in the rear to minimize rear reflections. Because the cone radiates h/m/l , but it is a cone and the H is from the small end, mid from the mid and low from the low end. it is considered a coherent source. The different freqs are produced from different materials. Highs are from a titanium band, mids from a SS band and lows from a paper band.
OHM no longer will repair these, but will give $4,000 trade in towards new speakers. Their new drivers are made to fit right to the F base.

pic below will illustrate what I mean by the different materials of the cone

[SEAWOLF97]

I recall reviews of Ohm speakers in Stereo Review done by the late Julian Hirsch. As I recall they were well liked by him.

If anyone ever finds a copy of that review, I wud really love to read it. According to the web, it is November 1973

[JBL 4645]

Car audio is certainly a world onto its own. I don't know if the FTC amplifier power ratings are applicable to mobile equipment, but as KJ says, a "200 Watt/Ch" car amp for $100, even without the expense of a power supply, is obviously bunk.

Autos do have the potential for some interesting speaker configurations. A trunk makes a pretty good enclosure for a woofer, volume-wise. Given the small "room" size inside a car interior, high SPL levels aren't likely difficult to achieve. I've read about SPL competitions in car audio with numbers in the 130+ db SPL levels! With woofers mounted in the rear deck and firing into the trunk and interior, don't we have something like a band-pass enclosure on wheels?!? That would put one inside the enclosure, hmmm. . . :hmm:

I've noticed in home audio reviews recently that some amps are not passing the FTC requirement of 1/3 continuous power ouput for one hour without shutting down. So it seems the FTC is turning a blind eye now, much to the car audio manufactuers delight and the consumers plight.

I wonder how the Lexus/Mark Levinson system would do on specs vs measurements?

Car audio is used in small spaces and really peak levels up to 130db or even 170db is MAD! I hope the silly buggers go deaf in there young age!:screwy:

[coherent_guy]

Fantastic pic of the Ohm drivers cones and VC!! They are more of a cone than typical "cone" speakers are. I'll bet that picture is from the hey-day of audio, sometime in the 70's (I better be careful with that statement . . .) Looks to me like Ohm made more than a few units, didn't they?!

Those cones look pretty strong and are made of exotic (partially titanium?) materials for their time, as well as the use of metallic materials that are still not common in speaker diaphragms. The VCs look large, about three inches I'd say. I wonder if T/S parameters are applicable to those critters?

I didn't find the review proper, but it looks like I found a source. Check this out:

http://www.roger-russell.com/magrevsr.htm

Click on "1973" on that page, or the link below, the review is in the November issue as you said.

http://www.roger-russell.com/magrevsr.htm#sr1973

The name Roger Russell is ringing bells in my head, but beyond that nothing else comes out. Must be to much of the 70's catching up with me . . . :blink:

[SEAWOLF97]

Those cones look pretty strong and are made of exotic (partially titanium?) materials for their time, as well as the use of metallic materials that are still not common in speaker diaphragms.

Titanium was quite rare/expensive in 1973. Was mainly going to NASA. The cost helped kill production of the F. Even at 4K/pr. they were not making normal money.

Little known fact. The US was mining titanium fast as they could while in Vietnam, 1960's.

[coherent_guy]

Car audio is used in small spaces and really peak levels up to 130db or even 170db is MAD! I hope the silly buggers go deaf in there young age!:screwy:


Indeed sir, we could go deaf being in proximity of such nonsense! I believe I learned of this from a magazines coverage of an "SPL Shootout" competition. The vehicle used in this case was a US mini-van loaded with a wall of speakers backed up with a collection of amps and a dozen or more car batteries. The sole purpose of this creation is to produce an extreme SPL level, nothing about FR or sound quality is involved.

I always smile when I see the equipment used in these monstrocities, 1/0 gauge wire in the power supplies, One Farad capacitors as well. Extremely extreme as the current vernacular goes.

I've always thought it wouldn't be to difficult to achieve these SPLs with some JBL components. Several of the large compression drivers, a few 2241s, a hundred watts to each, and you've got LOUD!

Hmm, at about five inches square, you could fit 49 2402s on a three foot by three foot baffle board ( 7 X 7 ). Matching this with low frequency drivers is a bit of a challenge. . . :hmm:

[louped garouv]

there are folks that have installed TAD 4001s in their vehicles....

so some must be worried about SQ.....

[louped garouv]

http://www.iasca.com/rules_downloads/01-22-2007-sq.pdf

interesting stuff (judging criteria/rules) starts on page three


ah.... any IME most folks very serious about their auto sound are also very serious about hearing protection......

[SEAWOLF97]

I've wanted to ask you about your Ohm F, is it really a full-range speaker using only the Walsh driver, and what is the bass response like?

found this on audiogon...

My experience with the F's is that they have tremendous bottom end. Then again, they have a huge radiating surface area that is equivalent to multiple woofers. In a direct comparison to the mains that i'm using in my HT system ( two 12's per sealed cabinet, 4+ cu ft box with a Q of .5 ), the F's have both more bass and greater extension. While the bass of the F's is not as tight or as well defined, it is very apparent that they are capable of prodigious bottom end. The fact that i can input a digital 5 ( five ) Hz signal into them and the house shakes as the Walsh drivers flail about tells me that i'm not imagining things. If one were not worried about achieving levels over about 92 - 94 dB's at a distance of 8 - 10 feet, these would make excellent subwoofers.

[just4kinks]

I have to chime in here....

There's no limitation to the amount of power a car amp can put out. They use switching power supplies to get +/- 40-50V (or more) rail voltages. And they can use multiple output transistors in parallel to get all the power handling they need.

There is a lot of marketing and hype in the car audio industry, but there are some legitimate good products out there. Don't buy anything that doesn't have a published "RMS Power" spec. And if it says "1000W RMS", take it with a grain of salt... but there are amps out there that can do it.


Another thing, about the power ratings...

100 Watts RMS at 3000Hz from a JBL high frequency horn would be enough to make your ears bleed. But 100 Watts RMS at 40 Hertz from low-efficiency car subwoofer is... not really all that much.

[coherent_guy]

Lincoln Walsh's heirs owned the patent. It shud be over by now, but..

only 2 companies in the world are licensed to produce the Walsh driver. OHM and German Physiks. Both can be rather expensive. Way above popular prices. Infinity , I have heard , had a walsh tweeter.

OHM is still produced in NY.

I get email tech support from OHM's president, that might change if JBL/Harmon produced it ?

the F's last price in 1984 was $4,000.

$7,764.31 in the year 2006 has the same "purchase power" as $4000 in the year 1984.

Umm, getting email from James B. would be surprising, although not because he's normally ignoring customers. . .

But I do see what you mean. I received an email support response from JBL once, though it didn't help much and was rather terse, as in one sentence. I imagine they get a fair amount of requests :blah:

Below is German Physiks version of the Walsh driver.

They have many nice pics of their products here: http://www.german-physiks.com/

[SEAWOLF97]

They have many nice pics of their products here: http://www.german-physiks.com/

did you catch their veneers ??

http://www.german-physiks.com/NewFiles/Veneer.html

[mech986]

I have to chime in here....

There's no limitation to the amount of power a car amp can put out. They use switching power supplies to get +/- 40-50V (or more) rail voltages. And they can use multiple output transistors in parallel to get all the power handling they need.

There is a lot of marketing and hype in the car audio industry, but there are some legitimate good products out there. Don't buy anything that doesn't have a published "RMS Power" spec. And if it says "1000W RMS", take it with a grain of salt... but there are amps out there that can do it.


Another thing, about the power ratings...

100 Watts RMS at 3000Hz from a JBL high frequency horn would be enough to make your ears bleed. But 100 Watts RMS at 40 Hertz from low-efficiency car subwoofer is... not really all that much.

Exactly right. During the 40's and 50's, tube type radios depended on either generators or voltage doubling circuits to get enough single ended rail to drive tubes or used fairly low voltage tube circuits to get some power (typically less than 5 watts). With the advent of low voltage transistors in the late 50's, car audio now had compactness, low heat, and some level of power. Even through the 60's, the max power was limited to about 25 watts/channel with bridged amp circuits or early flat pack transistor amp arrays running off the 12-14 volt nominal rail. However, poor speaker design, lousy acoustic environments, and the emphasis then on limited quality AM radio as the primary sound source prevented much development of Car Audio.

With the growth of higher intrinsic quality FM radio, and the incorporation of better quality portable music sources that one could program themselves (8 track tape, cassettes, even an occasional portable turntable!! and then finally CD's), manufacturers started exploring what could be done in the aftermarket Car Audio sector.

In the early 70's, the development of switching power supplies (developed for aerospace apps) gave impetus to higher voltage bi-polar power supplies that could run more conventional home/commercial type amp circuits in a car environment. I acutally built a couple of designs for car amps that were published by Popular Electronics that worked halfway decently. As further improvements in high power switching transistors and magnetic core/transforer design became reality, the power supplies could then supply upwards of 200-600 watts of energy with better than 70% efficiency, assuming a decidedly stiff 12-14 volt supply from the alternator/battery and then caps. I built a DIY version of such an amp from Randy Vikan published in Audio Amateur/nee Audio Express and its amp could have been used as a home amp.

Innovative manufacturers, especially those with a hand in the consumer side, built pretty good, conservatively rated amps that were quality items. Ones I admired were ADS Powerplates, Linear Power, Zapco, Soundstream (some designed by Nelson Pass, esp. the Class A designs) and others. Some Head unit makers like Alpine, Sony, Sanyo, Pioneer, Kenwood had some decent products but theirs tended toward the middle end of things. One thing the above manufacturers did, at least for a while, was to maintain decent reliability and service since their name was associated with higher quality. However, some companies, notably Soundstream, ran into cost issues and had trouble with certain lines of product that weren't built or specified as well as before and tended to grenade when pushed hard or with low impedence loads.

Another trend which changed the power ratings race was the move, both in automotive and home consumer market, from the traditional 8 ohm speaker to the 4 ohm and lower impedence speakers. Savvy marketing folks realized the same amp delivering X watts into 8 ohms, could, as mentioned above and with a well designed power supply, deliver up to 2X watts into 4 ohms, and more into 2 and 1 ohm speaker loads. As more speaker makers wound much lower impedence voice coils or paralleled dual voice coil subs, and the emphasis on low frequencies began in earnest, the focus was on how many watts you could proclaim your amp and speakers could deal with. High Current draw/delivery and ultimate SPL, regardless of quality, IMHO, became the buzzwords, rather than smooth, believeable and ENJOYABLE listening experiences within an automotive environment, admittedly a tough place to get goud sound.

Now, with the influx of multitudes of inexpensive, offshore produced power amps (all the Asian countries have their own hordes of car audio fanatics/freaks too!), there is a lot of marketing hype and mystique. I agree that there still are some very well engineered products out there that will deliver the goods over the entire frequency range, but they have to fight for recognition that quality is the objective.

IMHO, the current generation of "car audio" has gone the same direction as the music they listen too - very one sided, very one note, ultimate macho hype (sub size, number of drivers, highest SPL at a low freq, how many amps can I draw before my amps/speakers/electical system shorts out) and the, ahem, ADOLESCENT image of "look at me, I'm bad". I mean, when was the last time you saw a loud, thumping car system with its windows closed, or the driver wasn't looking around to check if anyone was looking at them.

Rant on "I (me) don't want you to share (force me to listen to) your music!" How I wish I had a device to either automatically rolls up their windows and then set their volume to 10, or a focused EMP burst to shut their whole car down for an hour. Would you guys pay for the development of said device? Rant off. I feel better now. :biting:

A great sound system, well balanced, well thought out, that can image in a car, shut out most road and engine noise, and provide that "special" emotional midrange can make the driving and traveling experience SUBLIME! I've spent hours alone or with family and fun music, presented well, can help pass the time as well as educate the kids. That's why my children can sing classic Broadway/Hollywood showtunes and oldies - they're fun and they still have their hearing!!

I've probably said too much already but I thought I'd add some history to this discussion.

Regards,

Bart

[coherent_guy]

did you catch their veneers ??

http://www.german-physiks.com/NewFiles/Veneer.html


No, not until you pointed them out! I love nice wood like that, it's a shame you don't see much of it anymore, or it's priced beyond grasp. I've never heard of some of those woods. Imagine a Paragon in that French Walnut or Canadian Maple!!

They mention something about their speakers being made of wood but then talk about veneer?? Might be a translation problem, some of the wording is not very clear.

It looks like their Walsh drivers are all metal (?) I need to check it out more. . .

[coherent_guy]

Exactly right.
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I've probably said too much already but I thought I'd add some history to this discussion.

Regards,

Bart

Nice post and very informative, I wondered if the car audio insanity was only an American phenomenon. I agree with your opinions too.

I would say (and hope) that JBL's offerings in auto sound are not of the "one note bass" genre, but I'm not familiar with all their products.

[louped garouv]

JBL auto sound subbass is very nice IME... not one note...

never hear a full range car system with JBLS tho'

[SEAWOLF97]

Rant on "I (me) don't want you to share (force me to listen to) your music!" How I wish I had a device to either automatically rolls up their windows and then set their volume to 10, or a focused EMP burst to shut their whole car down for an hour. Would you guys pay for the development of said device? Rant off. I feel better now. :biting: Bart

where do we send the $ ?
On the natnews, they had a story about a handheld device that shuts down all cell phones in a 30 foot radius. Resturant and concert goers love these things. :applaud: