I'm looking for better SQ, but not big money. I like to get clear and powerful sound, but I'm not going nuts on either of these projects.
Two cars in question:
First is a 98 F150. I'm in the process of replacing the four 6x8 factory speakers with some good efficient 6x9s. Just curious if anyone knows the stock receiver's RMS wattage. A ballpark range is OK. I may upgrade the HU later, but for now I just want speakers that don't suck, and knowing what the factory HU puts out will help me pick speakers.
Second is a 96 Impala SS undergoing a restoration. I want to use a factory HU for the sake of originality, but I want to keep the expandability of having pre-outs. I found a few guys who can add pre-outs to my factory CD player, but wondered if its worth it. I prefer higher voltage outputs because the amps pick up a TON of noise from the fuel pump in these cars. I've tried ground loops, re-routing the RCAs, noise filters, the works. The only thing that seems to work is 4v or more. Anyone know what I can expect for pre-out voltage? I can put an aftermarket HU back in and then swap back to the factory HU later, but I wondered if its worth my time to have the pre-outs added to the factory HU.
Replies (5)
swez on 03/2/2009 15:14:49
Hello again Curtis. Welcome back to CK!
On the Ford truck, consider a set of Infinity Reference, 2-way 6x8's for this project. I've installed them on an F-150 before and when amped adequately, they sound great. The link below, shows the 2 ohm version and a modest 4 channel amp is all that is needed:
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=18369
They also come in a 4 ohm version and a little web searching should net good results. The factory HU is a modest 8-12 watts per channel and may not do well with 2 ohm speakers. (too much heat) You can expect good MB from the Ref series and plenty of highs as well. They have external crossovers and internal attenuators if you need to tone them down a few dB.
Impala SS: You can use the factory radio and install what's called a Line Out Converter. This converts speaker level voltages to RCA level voltage and RCA hardware too. The better ones have adjustments to controls to regulate the voltage levels to the amp you plan to use. They come in 2 or 4 channel versions as needed and you can install it yourself. Like this one:
http://www.crutchfield.com/p_142SLC4/Scosche-SLC4.html?search=Line+Out+Converters
Note this LOC has both Speaker Out and Line Out Adjustments as well. With a little tweaking, this should give you that 4 volt + RCA power desired. Read this for some additional background on how to use this product:
http://www.crutchfield.com/learn/reviews/20030812/oem_amps.html?page=3
Finally, mount all amplifiers as far from the fuel pump as possible and keep your RCA's on the driver's side rails and power feed line on the passenger side. That's the best strategy to reduce and eliminate unwanted noise.
Comments/Questions?
Swez
curtis73 on 03/7/2009 02:35:46
I thought converting speaker level to line-out was a big noisy no-no.
swez on 03/7/2009 07:55:44
Think again... the trick is the isolation transformers used by better LOC's, eliminate noise at the source unit. Transformers, (Coils) pass AC but block DC signals that often create noise. Proper grounding eliminated ground loops that often bring engine whine, pops and ALT noise into the audio chain. Improper grounding, [Ground Loops] are the biggest contributor to noise intrusion)
When we combine that with clean, adequate Audio Gain signals above the noise threshold, the noise is muted to the point that clean audio signals are the end result.
Finally, quaility RCA's often employ twisted pairs of wire and shielded internally by a metallic jacket. (some use dual shields) The twisting of signal lines, cancel out noise that may be in the background from the source unit. The shielding blocks outside RF signals signals that may be present along the wiring pathway.
We use this principal all the time in Commercial Audio installs. More often than not, we are sending audio/video signals through conduit that contain many bundled wires. Some of which are very prone to noise problems. We obtain clean audio and video because the signal to noise ratios are so wide, the noise is barely amplified to audible levels and signal line gain is high enough to blank out the noise. The same concept is applied to quality Mobile Audio gear installs.
Simplified: Low noise, high signal gain = a noise free system.
Try it and see,
Swez
curtis73 on 03/11/2009 01:20:26
Ok... will do. Thanks for all the help and its good to be back.
ttocs on 03/11/2009 01:23:59
a good loc is very important but with the right stuff now you can get good sound out of one. I also recomend tapping the signal behind the radio as it has not had a chance to pick up noise in the system behind the radio. It is also good because if you ever switch the deck out for an aftermarket(and it seems we always do) then you can just plug them in.
Two cars in question:
First is a 98 F150. I'm in the process of replacing the four 6x8 factory speakers with some good efficient 6x9s. Just curious if anyone knows the stock receiver's RMS wattage. A ballpark range is OK. I may upgrade the HU later, but for now I just want speakers that don't suck, and knowing what the factory HU puts out will help me pick speakers.
Second is a 96 Impala SS undergoing a restoration. I want to use a factory HU for the sake of originality, but I want to keep the expandability of having pre-outs. I found a few guys who can add pre-outs to my factory CD player, but wondered if its worth it. I prefer higher voltage outputs because the amps pick up a TON of noise from the fuel pump in these cars. I've tried ground loops, re-routing the RCAs, noise filters, the works. The only thing that seems to work is 4v or more. Anyone know what I can expect for pre-out voltage? I can put an aftermarket HU back in and then swap back to the factory HU later, but I wondered if its worth my time to have the pre-outs added to the factory HU.
Replies (5)
swez on 03/2/2009 15:14:49
Hello again Curtis. Welcome back to CK!
On the Ford truck, consider a set of Infinity Reference, 2-way 6x8's for this project. I've installed them on an F-150 before and when amped adequately, they sound great. The link below, shows the 2 ohm version and a modest 4 channel amp is all that is needed:
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=18369
They also come in a 4 ohm version and a little web searching should net good results. The factory HU is a modest 8-12 watts per channel and may not do well with 2 ohm speakers. (too much heat) You can expect good MB from the Ref series and plenty of highs as well. They have external crossovers and internal attenuators if you need to tone them down a few dB.
Impala SS: You can use the factory radio and install what's called a Line Out Converter. This converts speaker level voltages to RCA level voltage and RCA hardware too. The better ones have adjustments to controls to regulate the voltage levels to the amp you plan to use. They come in 2 or 4 channel versions as needed and you can install it yourself. Like this one:
http://www.crutchfield.com/p_142SLC4/Scosche-SLC4.html?search=Line+Out+Converters
Note this LOC has both Speaker Out and Line Out Adjustments as well. With a little tweaking, this should give you that 4 volt + RCA power desired. Read this for some additional background on how to use this product:
http://www.crutchfield.com/learn/reviews/20030812/oem_amps.html?page=3
Finally, mount all amplifiers as far from the fuel pump as possible and keep your RCA's on the driver's side rails and power feed line on the passenger side. That's the best strategy to reduce and eliminate unwanted noise.
Comments/Questions?
Swez
curtis73 on 03/7/2009 02:35:46
I thought converting speaker level to line-out was a big noisy no-no.
swez on 03/7/2009 07:55:44
Think again... the trick is the isolation transformers used by better LOC's, eliminate noise at the source unit. Transformers, (Coils) pass AC but block DC signals that often create noise. Proper grounding eliminated ground loops that often bring engine whine, pops and ALT noise into the audio chain. Improper grounding, [Ground Loops] are the biggest contributor to noise intrusion)
When we combine that with clean, adequate Audio Gain signals above the noise threshold, the noise is muted to the point that clean audio signals are the end result.
Finally, quaility RCA's often employ twisted pairs of wire and shielded internally by a metallic jacket. (some use dual shields) The twisting of signal lines, cancel out noise that may be in the background from the source unit. The shielding blocks outside RF signals signals that may be present along the wiring pathway.
We use this principal all the time in Commercial Audio installs. More often than not, we are sending audio/video signals through conduit that contain many bundled wires. Some of which are very prone to noise problems. We obtain clean audio and video because the signal to noise ratios are so wide, the noise is barely amplified to audible levels and signal line gain is high enough to blank out the noise. The same concept is applied to quality Mobile Audio gear installs.
Simplified: Low noise, high signal gain = a noise free system.
Try it and see,
Swez
curtis73 on 03/11/2009 01:20:26
Ok... will do. Thanks for all the help and its good to be back.
ttocs on 03/11/2009 01:23:59
a good loc is very important but with the right stuff now you can get good sound out of one. I also recomend tapping the signal behind the radio as it has not had a chance to pick up noise in the system behind the radio. It is also good because if you ever switch the deck out for an aftermarket(and it seems we always do) then you can just plug them in.
Copyright ClubKnowledge 2009 * All Rights Reserved
