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Thread: A few questions: amp rms to match speaker rms? |
    
Bronze Member Username: Manhattan01
Vancouver,
BC
Canada
Post Number: 17
Registered: Aug-05
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| Posted on Tuesday, April 29, 2008 - 08:34 pm: |
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So I'm no car audio nut but I cannot stand driving my wife's car because the stock sound in her Mazda 3 is AWFUL. I want to drop an amp in there and replace the 6 speakers. Stock speakers are a pair of 6x8's in the rear, a pair in the front and a pair of tweets. I was thinking of just replacing the 2 pairs of 6x8's and removing the tweets - no subs - don't care for (heavy, penetrating) bass as it doesn't suit the music.
Ok, first question: do I need to match the RMS from an amp to my speakers? If my speakers are rated 40w RMS, should I get an 40w RMS @ 4ohm amp or go up to 60w per channel? Cost is a factor so ideally, if I can stay close to what the speakers are rated, that's ideal. I think I've read that underpowering speakers isn't a good idea.
Secondly, should I use components in the fronts since I have a spot for a tweeter? I'd imagine that my choice of amp is blown out of the water and my price range just goes way up now but is it worth it?
Thirdly, what's the best way to do this...pick an amp first then match the speakers or speakers first then amp? I've been doing it amp first because that's usually more expensive than the speakers.
Cheers all for the help.
BTW, here's what I'm thinking:
AMP: Kenwood KAC-6404 or JBL CS60.4
Speakers:
Eclipse SE6800
Eclipse SE8385
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Relevant Product Info
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New member Username: Me123456
Post Number: 9
Registered: Apr-08
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| Posted on Tuesday, April 29, 2008 - 08:40 pm: |
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pick your spearkers then see what they are rated for then get your amp.under powering your spearkers is not bad they work better if you do but dont under power them alot. |
Bronze Member Username: Manhattan01
Vancouver,
BC
Canada
Post Number: 18
Registered: Aug-05
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| Posted on Tuesday, April 29, 2008 - 08:43 pm: |
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Underpowering isn't bad? I thought that would lead to distortion or clipping which would overheat the voice coils? But I guess I could have read wrong. I figured I'd err on overpower and adjust the gain on the amp. Anyway, my speaker choices are above but I'm open. |
New member Username: Me123456
Post Number: 10
Registered: Apr-08
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| Posted on Tuesday, April 29, 2008 - 09:22 pm: |
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it might not be the same with components but i know with sub its better to under powere them |
Gold Member Username: Safe_cracker
Chicago,
IL
US
Post Number: 4439
Registered: Jan-06
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| Posted on Tuesday, April 29, 2008 - 10:21 pm: |
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I don't care what it is, I prefer to be overpowered then not to have enough but you must be trained to do so, noobs should stay underpowered. Polo. |
Platinum Member Username: Glasswolf
Wisteria,
Lane
USA
Post Number: 12116
Registered: Dec-03
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| Posted on Wednesday, April 30, 2008 - 01:23 am: |
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underpowering speakers is fine. turning the gain too high on an amplifier to make up for that fact isn't fine.
having the amp gain too high to make the speakers louder because the amp isn't big enough to do the job is what causes clipping and kills speakers.
sending less than the speaker's "RMS power handling spec" to that speaker is fine though as long as it turns out to be loud enough for you.
remember the "power handling" rating on a speaker is a thermal rating designed to tell you how much heat (in watts) a voice coil can handle without melting itself. It doesn't mean the speaker needs that much power to operate properly. |
Bronze Member Username: Manhattan01
Vancouver,
BC
Canada
Post Number: 19
Registered: Aug-05
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| Posted on Wednesday, April 30, 2008 - 04:10 am: |
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Thanks GlassWolf...so what you (and others) are saying is that it's safer (for an inexperienced user such as myself) to get an amp that puts out a little less power (RMS rating) than what speakers I get? |
Gold Member Username: N2audio
Lawrence,
Ks
USA
Post Number: 1555
Registered: Mar-04
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| Posted on Wednesday, April 30, 2008 - 02:50 pm: |
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ultimately I would say yes, because if your gain is set too high the higher power amp will be worse than the lower.
As long as you learn a little something about gain setting you can safely run quite a bit more than rated rms power to a speaker because what an amp actually delivers to the speaker when playing music is significantly less than the RMS rating of the amp.
Amplifier power ratings are derived from test tones. Music requires no more than 1/3 as much power, and that's at full volume. |
Gold Member Username: Juliob
Santo Domingo
Dominican Re...
Post Number: 5307
Registered: Dec-05
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| Posted on Wednesday, April 30, 2008 - 03:42 pm: |
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your front speakers are 6x8 too??
I'll give you a good setup idea. |
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Bronze Member Username: Manhattan01
Vancouver,
BC
Canada
Post Number: 20
Registered: Aug-05
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| Posted on Wednesday, April 30, 2008 - 05:55 pm: |
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juliob...yes..all speakers are 6x8's except for the tweets which I don't care too much for.
BUT...must keep this affordable.  |
Gold Member Username: Juliob
Santo Domingo
Dominican Re...
Post Number: 5315
Registered: Dec-05
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| Posted on Wednesday, April 30, 2008 - 07:37 pm: |
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http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14551
i think those ones will do the work you want.
A good 80 or 70w rmsx4 amp will work |
Bronze Member Username: Manhattan01
Vancouver,
BC
Canada
Post Number: 21
Registered: Aug-05
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| Posted on Wednesday, April 30, 2008 - 08:21 pm: |
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70 or 80 RMS amp? I can't find one in my budget. I'm looking at about $150 max for a 4x amp...so that puts me in the 40-60 RMS range...I think. Can something like that drive the Pioneers you linked to? I did see those before and do like what the seem to offer. |
Gold Member Username: N2audio
Lawrence,
Ks
USA
Post Number: 1562
Registered: Mar-04
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| Posted on Friday, May 02, 2008 - 11:22 am: |
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http://www.millionbuy.com/prfap1040.html
This should be $100-$110 shipped. Well worth the cost. Probably won't give you the 75w per channel it's rated for, but 60-70 is within reason. They've proven to be pretty durable amps. |
Platinum Member Username: Rovin
1 15 = 149.1DBs
Trinidad & T...
Post Number: 13692
Registered: Jul-05
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| Posted on Friday, May 02, 2008 - 11:20 pm: |
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for speakers (not subs) i rec matching wrms or slightly above like 20% more than required power ...so if ur speakers are rated 50wrms get a 50wrms x4 or 60wrms x4 at 4ohms ...
hifonics makes decent amps so http://www.onlinecarstereo.com/CarAudio/ProductList.aspx?CategoryID=3&Manufactur erID=613
so something like this http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16353 should be good ... |
Gold Member Username: N2audio
Lawrence,
Ks
USA
Post Number: 1564
Registered: Mar-04
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| Posted on Saturday, May 03, 2008 - 12:52 am: |
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nothing wrong with HF on a budget, but I think the profile's are better dollar for dollar. |
Gold Member Username: Juliob
Santo Domingo
Dominican Re...
Post Number: 5320
Registered: Dec-05
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| Posted on Saturday, May 03, 2008 - 05:19 pm: |
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there you go. |
Bronze Member Username: Dirtrider125
Post Number: 76
Registered: Apr-07
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| Posted on Saturday, May 03, 2008 - 09:09 pm: |
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this would be alot better than any of those amps and only $20 more http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16883 |
Platinum Member Username: Glasswolf
Wisteria,
Lane
USA
Post Number: 12122
Registered: Dec-03
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| Posted on Saturday, May 03, 2008 - 11:30 pm: |
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50-75 watts per channel for door speakers is usually fine. if you hear distortion when playing the system, turn the volume down.
its just common sense in protecting the speakers. |
