Contour Enthusiasts Group Archives Forums Modifications Audio Need advice from tech savvy individuals

I consider myself knowledgable on audio in terms of knowing some good brand names and having a good ear for quality but I admittedly don't know a lot about technical advantages and disadvantages. My question I have pertains to running PA type speakers off of car stereo amps basically the pro's and cons.

Pro audio amps for dj'ing/live bands are quite expensive. Crown and QSC are 2 of the better known brands and even some of their low end products are expensive. I am interested in knowing how feasible it is to set up a system using an AC/DC power converter to run my Cerwin Vega V-152's. They are 8 ohm speakers rated at 300 watts rms 600 watts peak. They feature 15 inch woofers and piezo tweeters. Particularly I'm thinking about using my Alpine MRD m-500 that I speak so fondly of on here. it puts out 250 watts RMS at 14.4 v 4ohm 500 watts RMS a 2ohm 14.4 volts. First problem is obviously that my 2 speakers in paralell would need 600 watts at 4 ohms to power them, correct?

I would say that you would be much better off spending the money on proamps. To get a converter that can provide the juice you need to run your amps would be very expensive in itself.

Good point. I have a friend that owns a car stereo shop so lets say he was to let me borrow his power converter so that took away the issue, what other potential issues do you guys see with trying to do that? I'm sure there is a good reason why no one is doing it, I'm just curious.

You would probably need some XLR to RCA converters but those shouldn't be terribly pricey. You would most likely only get half the power out of the car amp as its power is rated at 4 ohm rather than the 8 (or worst case 16) ohm that most PA speakers present. Aside from that, I don't see an issue with trying it. One thing to consider would be buying old Pro amps off ebay. Mackie 1400, Crown PS-400, and various other Crown, Crest, QSC and a host of others can be had for fairly cheap and they tend to last forever.

Cool. Here is another thing I thought of. I'm not sure how savvy you are on home audio but phono inputs on a receiver are different than the standard cd or auxiliary inputs. I believe it is the voltages that are different. Is there any difference between say a cd/aux input on on a receiver and the inputs on a car stereo amp? One thing that I am interested in doing to promote my dj'ing is to utilize my car as my system so I would disconnect the speakers from the car and hook up dj speakers using the high pass crossover on the amp then utilize the subs that are already in the trunk for the bass. Would there be any issue with running the output from my DJ mixer (the mixer converts the signals from the turntables into a line level signal that is usable with a cd/aux input) into my car amps? Did this question make sense?

Originally posted by Cappuccino911:

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Cool. Here is another thing I thought of. I'm not sure how savvy you are on home audio..

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dnewma04 knows nothing about home audio...

I hope that is a very big power supply...

300w bridged of Pro Audio power doesn't cost too much. Heck, I paid $360 for 540x2 into 4ohm.

pro audio isn't expensive? 540 x 2 you must have bought a pyramid amp!!! spent 400 for an AB Int. that was 270 x 2 at 8 ohms. Not to mention I'm looking for quality power, for example, you aren't going to be able to by 400 watts x 2 of Crown power for much under 1000

Depends which model Crown. I compared a CE-1000 which I picked up for $400 localy to the other one I decided to keep.

http://www.crownaudio.com/pdf/amps/128389.pdf]CE-1000
450wx2 into 4ohms
270wx2 into 8ohms

900W 8ohms mono

I assure you I have no Pyramid.
http://www.samsontech.com/products/relatedDocs/s1000_spec.pdf]Samson S-1000
540x2 into 4ohms according to the manual
I measured 481w to each of my subs at 20Hz which is enough.

The CE-1000 I would have prefered, but I couldn't get rid of a ground hum which when using the exact same connections the S-100 did not have. The Samson has a quieter fan (good for home theater) and more power, but cannot be bridged into a 4-ohm mono load like the Crown. But that would be only possibly used for future use a few years down the road.

Quality wise, plenty enough for a subwoofer, but maybe not a good choice for powering reference mains.

The middle of the road Pro stuff is very cheap. If I was ready to get a new HT system, I would use mainly pro amps throughout because of the quality and watts per dollar. Since I am cheap, I would probably even go with old used gear.

Originally posted by dnewma04:

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The middle of the road Pro stuff is very cheap. If I was ready to get a new HT system, I would use mainly pro amps throughout because of the quality and watts per dollar. Since I am cheap, I would probably even go with old used gear.

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True, but unfortunately, I am a professional when it comes to this stuff and it means money in my pocket so I want to go with stuff that i know is fully reliable and that generally means top end gear like a Crown k-1 or something. However, you can get good deals on this stuff used and most people that are in this line of work take decent care of their stuff because it is so expensive new, so I will be looking around for pro audio gear I guess!