2nd amp
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=60631
Printed Date: May 19, 2024 at 10:52 PM
Topic: 2nd amp
Posted By: Steelcity
Subject: 2nd amp
Date Posted: August 03, 2005 at 7:43 PM
Getting ready to add a second apm to a vehicle and have a couple questions. Currently running usx2050 160 total watts. Have 8 guage power and grounds. Going to add a power distribution block. Looking to add another a amp for sub somewhere between 150 and 300 total watts. Will the 8 guage power wire be ok? I currently have a 40 amp fuse after the battery do I need to upgrade that? Will a 150 watt rms sub produce decent bass? Probably looking at a 12" sub in a sealed box.
Replies:
Posted By: Steelcity
Date Posted: August 03, 2005 at 9:10 PM
also is it better to have 2 10" subs or 1 12"?
Posted By: boardinbum
Date Posted: August 03, 2005 at 10:04 PM
The first thing that came to my head when you said "150 watt rms sub" was this Kicker Comp sub. They're buy one get one free right now for $79. Or the buy one get one free 12's for $89 here
Posted By: Steelcity
Date Posted: August 03, 2005 at 10:36 PM
Yes I have seen those but I have a space issue, and I believe I would need a larger amp to drive both of those along with larger encloser putting me well over $200 then. Trying to stay around 150-175 for everything.
Posted By: godblessdremil
Date Posted: August 03, 2005 at 11:34 PM
General rule about fuses is the one behind the battery should be equal to to the total sum of the amps of fuses on the amps so if ya got 2 amps that bolth have 40 amp fuses put an 80 behind the battery. As for the gauge depends on distance but dealing with low watt's like this i think the 8 gauge will be fine, i believe on this site there is a watt/distance chart.
Posted By: stevdart
Date Posted: August 03, 2005 at 11:53 PM
I think your 8 gauge should be fine, too, because I run a setup similar to that in my car and the 8 gauge is plenty. I also use a 40 amp fuse on the power wire, but the "real" rule for fusing wires is to use a fuse that is rated for the wire gauge....not for the amplifier load at the end of the wire. And you should be looking for close-outs of decent brands with that budget. Try to find a 12" with an efficiency factor that is pretty high, around 90 db/ 1 watt...and a mono sub amp instead of a two channel. You'll get the most sub volume for the least amount of power consumed when you're talking about a 200 watt and below range. And you can still use a sealed box 1 cu. ft. or so. Choose either SVC 4 ohm or DVC 4 ohm sub depending on the amp you find and its power output rating. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: godblessdremil
Date Posted: August 04, 2005 at 12:06 AM
Thanks for fixing my mistake. I learned from simply working at a shop and that was a rule of thumb they taught me. Learn something new everyday 
Posted By: Steelcity
Date Posted: August 04, 2005 at 8:38 AM
Ok would the effeciency factor be what is called sensativity on the spec sheets? I think I am looking at this combonation: https://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?Productid=12353 https://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?Productid=13948 Unless I find something cheaper. Only question when they give the bridged amp wattage at what ohm would that be?
Posted By: Steelcity
Date Posted: August 04, 2005 at 8:46 AM
Also what is difference between a single voice coil and a double? I'm not seeing a price difference between similar models, all things equal for the same cost which is better to have?
Posted By: TruckSystem
Date Posted: August 04, 2005 at 9:32 AM
Only difference between single and double voice coils is the way they can be wired to an amp to get different ohm loads.
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2003 Chevrolet Silverado Standard Cab ~ Alpine CDA-9851
Diamond Audio D3600.1 ~ 2x Diamond Audio TM310D4
Diamond Audio D3400.4 ~ Diamond Audio Hex S600s
AstroStart RS5204 Remote Start/Alarm
Posted By: stevdart
Date Posted: August 04, 2005 at 9:46 AM
That combo won't work. The sub is DVC 4 ohm, not DVC 2 ohm which is implied in that ad (see https://www.cerwinvega.com/products/mobileaudio/index.html). You need a SVC 4 ohm for a two channel amp. The amp will take a 4 ohm load bridged. I would suggest, however, that you look for a 12" instead of a 10". And yes, sensitivity is what I meant. And always double-check manufacturer's sites for specs when shopping online ads. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: boardinbum
Date Posted: August 04, 2005 at 1:57 PM
stevdart - Just out of curiousity, if he hooked one channel to each voice coil, what kind of load would the amp see?
Posted By: lazyinjin
Date Posted: August 04, 2005 at 2:09 PM
If each voice coil is 4ohms, and each were wired to a stereo amplifier separately, the amplifier will see a 4ohm load on the left and right channels seperately.
Posted By: lazyinjin
Date Posted: August 04, 2005 at 2:14 PM
To the original poster: try finding a 12" with Dual 4Ohm voice coils and wire them in parallel to a mono amplifier. This will produce a 2ohm load, which most subwoofer(mono) amplifiers will handle. and defintely get a class D mono amp in the 300Watt RMS range. IMHO more money should be spent on the amplifier than the woofer or enclosure combined(thats not to say buy a wal-mart subwoofer and crown amp)
Posted By: Steelcity
Date Posted: August 04, 2005 at 8:49 PM
Posted By: stevdart
Date Posted: August 04, 2005 at 9:13 PM
boardinbum wrote:
stevdart - Just out of curiousity, if he hooked one channel to each voice coil, what kind of load would the amp see?
It would be the amp rating of 115 watts X 2 at 4 ohms. It would be a stereo sub, I guess. ;) ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: stevdart
Date Posted: August 04, 2005 at 9:22 PM
Steelcity wrote:
Let me know your thoughts especially on the sub.
That is one goofy-looking speaker if I ever saw one. But I can't say I've listened to any Kenwood subs lately. Can't you find another Cerwin Vega? I know from experience that they are worth the money spent. 
My $49 CW rocks!
Posted By: Steelcity
Date Posted: August 04, 2005 at 9:33 PM
There were a ton of good reviews of it on onlinecarstereo.com. It has a 93db rating and will goto 400 watt rms, which is probably a little more than I need. And your right its unique looking.
Posted By: Steelcity
Date Posted: August 04, 2005 at 9:46 PM
here is the reason for the googy look? Overlapping ribs on cone surface for improved rigidity and dampened resonance sounds good to me?
Posted By: Steelcity
Date Posted: August 04, 2005 at 9:49 PM
Stevdart is that the hed 12 (svc or dvc) if so what are you powering it with and how many watts?
Posted By: stevdart
Date Posted: August 04, 2005 at 10:01 PM
Yes that's the HED DVC 4 hooked to a USB600D, set to 200 watts. Once in a while you'll find a closeout U.S.acoustics amp on one of the online suppliers. I got that one last year from Crutchfield. They only had some for a few days. Very small but puts out some power for its size. I suspect that sensitivity rating on that Kenwood. Some of the manufacturers (Infinity, for one) are using some crazy "in car" sensitivity rating now that makes it hard to compare apples with apples. You might think that pushing those overlapping ribs would decrease the sensitivity a bit ;) ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: boardinbum
Date Posted: August 04, 2005 at 10:01 PM
stevedart - So what would be wrong with that?
Posted By: Steelcity
Date Posted: August 04, 2005 at 10:27 PM
I have been debating how much power in an amp I really need. There are some real affordable 2 channel amps that bridged would get me to 160 rms or so. I currently have the usx2050 running my components at 50 x 2 rms. It seems to be a good little amp. I have not even felt it get warm yet. what do you think 160 watts pushing that hed 12 would sound like? Also look at this blaupunkt. What do you think of this. It could be just like in fast times the quadrfonic blaupunkt. https://www.sonicelectrnix.com/item_3500.html
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