shaun8484

Ok, I have searched some of the threads on here but they tend to go way overboard for what I am looking for. Ill start off by saying I do not want a sub nor am I trying to rattle the bolts out of my car. My question is, would a 4 channel amp to power my dash speakers and rear speakers improve quality at all? If so, where would I pull from for a remote wire for the amp? I am no audio guy so sorry if this sounds stupid.

Here is the amp I was interested in...


Also what gauge wire would I run for the speakers and amp power and ground?

The13Bats

Stock 81 speakers are doggy doo were when new in 81 are now, and i owned 2 81s
If you amp them you have amped doggy doo,
But i sure did love the built in cb radio

Richard the audio guru here might pop by and help you upgrade so you can have your amp and better speakers and sound.

shaun8484

I should have said that I have replaced all 4 speakers, nothing crazy,here are my fronts and rears:

Front:


Rear:

7T1vette

The early C3's had audio systems which grounded the negative lug on the speakers. Modern systems do not ground the speakers, and I don't know which type of system was used in the later C3 cars.

You just need to know that any 'new' stuff being inserted into an older system is compatible, so you need to do a bit of research. Best to check that out in the 'Off Topic' section of the Forum.

Richard454

Hey Shaun-

The amp would help out-However:

I'd look for one that has a "variable high-pass filter on front channels." That will keep the low bass from the front speakers. Smaller speakers really can't handle the bass- taking it away from them electronically is the best way to do it- and they'll sound so much better.

The larger 6 x 9 in the rear will handle what the small fronts can't - and since bass is non-directional - you won't miss it from the fronts. A win-win.

Incorporating this simple feature on the amp will be the best bang for the buck.

You can just use the output for the power antenna to turn on the amp- If you don't have that- one of these $15 devices will sense speaker output from the radio and turn on the amp.



16 gu wire is fine for the speakers- if it's really copper wire. There's a lot of junk out there that's copper coated aluminum (CCA)- stay away from that stuff- brittle and breaks way to easily and doesn't conduct near as good as the real copper wire.

Since the power from the battery will be a short length- and you're going with a relatively small amp- 10gu will be fine - Again make sure it's real copper wire.

Hope that helps-

Richard

shaun8484

Would you recommend grounding the amp directly to the battery and power wire with in line fuse to batt?

Richard454

Yes-

The battery does more than just start your car.

It stabilizes voltage and filters out AC ripple not cleaned up by the alternator. Electronics LIKE both of these.

Richard

shaun8484

Ok, thanks for all the input. Please tell me if this makes sense, since the dash speakers don't do much sound wise, would it be easier to get a 2 channel amp, mount it in the storage compartment and just run the two 6x9 off the amp? How would the wiring look for that? Would I run the two dash speaker wires to the dash speakers from the head unit and RCA from head unit to amp, then wires from amp to rear speakers? Sorry, Back in my day, car audio was doable, haven't done it in so long and wiring just isn't my fav thing to do.

7T1vette

The dash speakers are more important than you realize. Those speakers are aimed at the windshield...and the windshield is a near perfect reflector for high frequencies. So the highs are directed right at the listener(s) as they must be.

With the cockpit as it is and the speaker locations as they are, the dash speakers are about as good as it's going to get for high-freq reproduction. They won't take much power and you DO NOT want any speakers in there that actually reproduce low to lower-mid frequencies; those need to come from the rear. Low frequencies will fill the space regardless of which direction they are sent.

Z06LMB

Sorry, I'm not up on electronics like you guys.
When you say 16 gu, are you speaking of "Gauge" or "AWG" and if so when you say "10 gauge" is is acceptable for the speakers and it's "gauge" - wouldn't that be more than 3X the size since for every 3 numbers going down in AWG value equate to double the size. Again I'm sorry, I'm just ignorant in this area. I hope this makes some sense and I don't sound like a total idiot!

shaun8484

7T1,

Thanks for the input. I don't necessarily mean that are not important, just don't think putting any more power to them is necessary, or is it? As I stated in my original post, I am not looking for an award winning system, just something to bump it up a little bit over the speaker replacement that I have already done.

The13Bats

Back in the 80s i drove a 81 as a daily driver,
I liked the factory stereo okay loved the cb,
Since i was in the music nightclub business there was always some sound guy around, a buddy put new speakers front and rear and amp in my car the rear was like a big sound stage with the bubble butt back glass,
But i complained the front speakers were so damn tinny in my face,
That sound guy buddy then makes in a small radio shack project box, a thing with 4 *****, some type adjustable cross over i guess, but i could fine tune each speaker, i could get the fronts just right to suit me day to day,
Anyone have a clue what that tech made me? Can i make me another?

My vette now is a 69 can i use a later dash top to gain speaker holes as being a convertible the rear is limited

Richard454

Power to the speakers-

Speakers have a rating of efficiency-sort of like gas mileage.

IIRC the front speakers you had purchased are rated at 90dB- one meter away and with 1 watt of power. So they will play that loud under those parameters- the rating is called "System sensitivity." Normal conversation is about 60dB-Stock Corvette running down the highway will have road noise around 80-85dB- sidepipes can approach 100dB!!!

So the gas mileage sounds pretty good? 90dB with just ONE watt?

That one watt is going to play pretty loud?

Unfortunately it doesn't work like that. You have to DOUBLE the power to get a small but noticeable difference of 3dB.

And then there is what's called "headroom"- or the transient audio peaks - without extra power to handle these you could possible damaging the speaker. And to overcome the road noise you will be turning it up louder than you think....

It is a LOT easier to damage a speaker with too LITTLE power than not enough.

Having too little power creates distortion and will actually send DC voltage to the speaker. Audio is AC and sending DC to the speaker will burn the small wire wrapped around the voice coil just like a fusible link.

I'd do the amplifier on the front and rear-with the bass filter.



Yes- cars have several 'resonate frequencies'-speaker placement-surfaces ets... Example- the distance between the front windshield and the rear glass. Say it's 5 feet- you would have corresponding sound wavelength of 200Hz or mid base. That 'sound frequency' would be louder than others- so turning it down electronically would help balance the sound. These days electronics have replaced the old way of capacitors and coils.

shaun8484

Richard,

Sorry for all the questions, how would i run the wiring for the power ant to the amp and still have the ant work? could I just tap into the wire that runs to the ant now and just run that to the amp? Also, I dont know how much "air space" an amp needs to breath, would I be able to mount it in the jack storage compartment? if so, how would I do so?

7T1vette

High frequencies do not require much power to sound loud. You just need to get mid-upper/high frequency speakers that have the right impedance match for your amp and capable of handling 20 watts or so. The rear speakers are a different matter; the lower the frequency, the higher the power required for providing the same sound level to the user. Rear speakers should match amp impedance, also; but they should be able to handle a lot of power (if you are installing a high powered amp).

The existing speaker wires for the dash speakers are plenty big enough. Rear speakers probably need something in the 12 - 10 gauge size, depending on power to them. These high dollar HUGH cable sets (with gold plating!!!) are totally unnecessary for a good sound system. These are 'money maker$' for vendors who know that most folks have no clue about what to get. So they'll sell them Alaska to get ice cubes for a glass of tea!!

Richard454

Yes- just teeing the power antenna lead for the amp turn on is fine. Most radios are rated at ½A . The wire can be relatively small- 18gu is fine as there is very little current required to turn on the amp.


The jack storage would probably be OK since your not really running a big amplifier. But since there is not a lot of air movement, it'd be best to mount the amp as pictured below. As heat rises- it'll will cause hot air to move upward and cool the amp.

You could just use a piece of plywood and some L- brackets to attach it to the storage compartment- then mount the amp to the plywood.

Richard





For high frequencies - correct- but the Shaun will probably be crossing over the dash speakers somewhere in the neighborhood of 300hz...Why that frequency? The wavelength is about 10"- and most peoples ears are about that distance apart- That's why at that frequency, you loose the 'stereo' effect... Albeit a higher frequency if you are a pinhead!!!

In doing so you'll notice the speaker is still going to require about 50%-

7T1vette

300 Hz is pretty low for "tweeters". You'll rattle the dash apart with that much power in there.

But, to each his own.

P.S. I used to play bass in a rock band in the 70's and had a double-stack set of 15" speakers that reproduced bass frequencies very nicely. The amp was 100 watt (RMS...not 'peak') unit that had more power than I ever used..even for large areas.

I had a buddy who was into electronics and wanted to test my amp for how many actual watts it put out along the 0-10 volume adjustment. So we rigged up a test, sent a sine wave signal into it and checked the output at each mark on the volume ****. What a surprise!!!

At a small gig, I'd set the volume at about "3". Actual power output at that mark.... a little over 1 watt RMS. Medium event power about "4". Actual power out...about 3-4 watts RMS. Large events (not open air) would see 6-7 on the ****. Output....about 10 watts.

We actually pumped the thing to max output. Guess what? 100 watts RMS!!!

That little exercise proved to me that what we BELIEVE about sound power required is mostly sold to us by people that sell stuff. So, that 1000 watt amp for putting into your C3 passenger area....a little overkill, I think.

shaun8484

Ok, well my mind is officially blown with all the sound talk and numbers lol. What amp would you guys recommend for the speakers I originally posted, that has the Variable high pass filter and what wattage?

Richard454

You are just looking for some decent tunes- here's a good one that has the filters and would work great in your set-up. A little over $100.

Power ratings are still to this day all over the map...Sort of like that Honda owner that claims 600HP.









Unfortunately that amplifier is rated with what I call- "The ILS Rating"- if lighting strikes...It's not that much power- realistically I'd say 25 watts a channel full bandwidth.

Here's got a midrange AND a tweeter in the dash- trust me it wont rattle with a high pass filter.






That's pretty cool- I didn't get that music gene!!! Bummer I was never a musician - so I had to buy a Corvette to get the girls!!!


I did do a couple of gigs when I worked for Kenwood 20+ years ago- I was fortunate enough to go around the country and do amplifier clinics- Got to test at least a hundred or so of then- various brands and power ratings.

I didn't have (2) 15" but rather (32) 10" !!!

7T1vette

Most modern amps have good signal quality. The "power" issue is a crapshoot as many use different rating systems...just so they can claim big power (when they really don't have it). You only need power for bass frequencies and low mid's; if you don't have adequate power, you get lots of distortion in the lows when you crank it up.

If you don't have a sub-woofer, that's a good thing IMO. Besides not blowing your eardrums out or turning your brain to mush over several years, you're mostly just trying to make a statement to those driver's who are unfortunate enough to be close to you OR to just be noticed. It has little to do with accurate reproduction of sound...and you can't do that anyway inside the passenger area of a C3.

But, for good sounding music with low distortion and accurate sound reproduction you need something in the area of 100 watts RMS or 200 peak. You won't use nearly that much for sound power, but you marry that amp up with some low efficiency speakers that use a lot of that power to move BIG magnets in the bass/mid speakers; that yields good sound reproduction. Maybe 2/3 of the power used is to stabilize the speakers and the rest is to produce sound. Tweeters don't need to handle power, but they do need to be good quality with accurate response over their range. So pay for well made speakers. Bass/mid speakers will likely be 2-way type with bass AND midrange speaker elements. These need to handle power AND have good response curves.

That's the "recipe" for a pretty good sound system in a C3's cockpit. You can still blow your ears out...but it will sound good while you do it.