Hi everyone. Need some input here. I have 2014 GT with factory head unit. Last summer replaced all 6 speakers with Polk DXI650's in the doors and DXI350's in the dash. Everything was fine till couple of days ago. It sounds like base is gone, some times it sounds normal, most of the times to get the base I have to adjust all the way up (before I had it just pass the middle and it was to much). My dash DXI350's installed with filters. But anyway, everything was working fine for like 6 month. Is it possible that head unit went south or is it something with the speakers. Is it possible that when speakers got replaced they damaged the head unit some how? Thanks.
2014 GT Lost Base on factory head unit with Polk speakers
- Thread starter Monozub
- Start date
You’re overdriving the crappy IC amplifier in the head unit, which probably makes less than 10 watts RMS per channel (more like 6-7). The speakers in the dash are also wired in parallel with the front door speakers. Since you have 4 Ohm speakers installed, your tiny IC amplifier in the head unit is driving a 2 Ohm load, which I'm sure it was never intended for. Those speakers need way more power than your head unit can provide. The 6.5 Polks need 55 watts RMS each! You need to install an Amplifier for the continuous RMS rated power of the speakers assuming you didn’t cook the amplifier in the head unit yet.
Alpine makes a class D amplifier that you can wire into the back of your head unit called the Alpine KTP-445U Power Pack. The Alpine power pack is nice because you can use the factory wiring and tuck the amplifier behind the unit in the dash. You can also use the Audio controls LC6 to take the high level from your speaker wires and covert them to low level high quality outputs for your amplifiers if you want separate amplifiers. You can also buy Amplifiers with speaker level inputs too. http://www.crutchfield.com/p_161LC6IG/AudioControl-LC6i-Gray.html
When I installed my Polk dxi 6500 components in my front doors I tried the head unit just to see how they would sound. They were clear but had no bass (not base) and sounded lifeless. Once the Amplifier was hooked up it was truly awesome sounding and they had decent mid bass too.
Alpine makes a class D amplifier that you can wire into the back of your head unit called the Alpine KTP-445U Power Pack. The Alpine power pack is nice because you can use the factory wiring and tuck the amplifier behind the unit in the dash. You can also use the Audio controls LC6 to take the high level from your speaker wires and covert them to low level high quality outputs for your amplifiers if you want separate amplifiers. You can also buy Amplifiers with speaker level inputs too. http://www.crutchfield.com/p_161LC6IG/AudioControl-LC6i-Gray.html
When I installed my Polk dxi 6500 components in my front doors I tried the head unit just to see how they would sound. They were clear but had no bass (not base) and sounded lifeless. Once the Amplifier was hooked up it was truly awesome sounding and they had decent mid bass too.
Thanks for reply to my post. I'm not the only one with this upgrade, I did not see any complains from people who installed the same speakers without amp. Also I talked to Crutchfield about my install and they did not see any problems with this configuration. They mention that with the amp it will sound better but it sounded fine before, now bass is significantly reduced.
You could check the connections. You could also check the phasing by fading the speakers to the left or right. If the speakers bass response increases when you fade them to the left of right than its likely they are wired wrong. Try doing this with the front and then rears only.
It sounds like the bass is in and out. We had very cold weather lately(Chicago). That is when I noticed that the speakers sounded kind of flat. So when they sound flat they stay flat for some time and than they sound normal. I made connectors out of the original factory speakers, so before I install them I checked negative and positive cables on every speaker, also like I mention before everything was working fine until we got very cold weather. Now it's got much warmer outside and they sound like before(normal bass response). I never had similar situation before with aftermarket speakers. I will definitely check everything when it's warm outside. I don't really like to take door panels apart again but if I have to I will. Also even when they sound normal they are still to boomy. What do you people think about that Alpine Power pack unit KTP-445U? Do you think if I ran it with the factory head unit is it really going to improve the sound? Thanks.
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- 2014 Mazda CX-5 GT w/ Tech
stock head units can not drive aftermarket speakers because of the additional rims, the ohms ratings might not even be the same...
have you tried what v8toilet suggested? It could be that you reversed the polarity by mistake.
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- 2014 & 2019 CX-5 Touring(s)
Ok, well that bit is a little bogus. The 650's are rated at 60watts RMS MAXIMUM (and even that is very misleading, 'cos you'll burn them out way lower than that if your amp is clipping). In fact, since they have a 92dB efficiency, they can be driven quite loudly by a smallish amp.
Now, having said all that, your point about parallel speakers and the resulting 2 ohms impedance may well be correct - I have not checked if this is the case. I can say that I have the 650's in my car, but with the stock tweets, and it goes plenty loud enough. It does NOT sound any much better than stock though, and it may well be that added amplification could improve that. I have doubts though, that anything other than a new/better head unit will help, so have not wanted to risk throwing money away on a new amp.
But back to the original question, if it sounded OK at one time, but now lacks base, are you sure the connections to the door speakers have not come away? Open the door and stick your ear against the speaker and then turn the sound up. Can you hear sound from the door speakers at all? If not, check the connections. If you can, then maybe the head unit amp is fried
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Ok, well that bit is a little bogus. The 650's are rated at 60watts RMS MAXIMUM (and even that is very misleading, 'cos you'll burn them out way lower than that if your amp is clipping). In fact, since they have a 92dB efficiency, they can be driven quite loudly by a smallish amp.
He said he has the slim line version denoted by the suffix s as in DXI 650s, which is rated at 55 watts RMS. The regular DXI 650 are rated for 60 watts RMS but do not fit inside the door of the CX5 without modification. The RMS rating is the maximum continuous power that the speaker needs to run at its optimum but should not be exceeded by much if at all. Running any speaker with a lesser powerful amp can actually cause more damage to a speaker than a more powerful amplifier because you have less headroom and can run into clipping at higher levels. Its the distortion from the clipping amplifier that ruins the speaker. The speaker will also produce the best sound with better bass, more depth, and clarity with a decent amplifier that is matched to the speakers rated RMS power. Nothing sounds as good as a properly amplified speaker system. There is nothing bogus about these facts!
Ok, well thatNow, having said all that, your point about parallel speakers and the resulting 2 ohms impedance may well be correct - I have not checked if this is the case. I can say that I have the 650's in my car, but with the stock tweets, and it goes plenty loud enough. It does NOT sound any much better than stock though, and it may well be that added amplification could improve that. I have doubts though, that anything other than a new/better head unit will help, so have not wanted to risk throwing money away on a new amp.
You can get great sound with the factory unit even using speaker level inputs on a newer amplifier. The use of a line driver like the Audio Controls LC6 to integrate an amplifier to your factory system will give your amplifiers a stronger signal than even some of the best new head units with up to 9 volts of signal. Add an inline active equalizer to the system and you'll be able to further customize the sound to the acoustics of that particular vehicle or speakers. At the bare minimum though, like I said above nothing beats the clarity and power of amplified sound. Just ask anyone with the optional Bose system in their CX5 because it has more powerful speakers that are and need to be amplified. The downside to the slim line version of these speakers is they dont produce a lot of bass. I think they only go down to 50 hertz before they taper off. I have these in my rear doors with 60 watts RMS being sent to them and I still had to install bass blockers because they made too much bass in conjunction with the subwoofer and DXI 6500 up front. Trust me I've run these speakers off the head units power for the hell of it and with the Amplifier pushing them its like a new speaker.
The reason why I mentioned the Alpine Power Pack is because its about the simplest way to amplify your speakers on a budget without tearing out your interior and running wires all over the place. Just make sure you use a dedicated power wire to the battery and ground to chassis with at least 12 gauge wire (10 is better) despite the fact that Alpine says you can use the power from the head unit. Doing this will reduce the chances of the amp running into clipping and or overheating because voltage drop in a 12 volt system wreaks havoc on power hungry devices, even class D.
Ok, well thatBut back to the original question, if it sounded OK at one time, but now lacks base, are you sure the connections to the door speakers have not come away? Open the door and stick your ear against the speaker and then turn the sound up. Can you hear sound from the door speakers at all? If not, check the connections. If you can, then maybe the head unit amp is fried
This is a great point!!!
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- 2014 & 2019 CX-5 Touring(s)
Au contraire, I have the regular (non-slim) 650's in mine. They fit fine, with about 1/4" 'headroom' to spare
UPDATE: Apologies, I just re-checked. I have the regular/non-slim Polk DB651 speakers. Maybe the older 650's were bigger (?)
Not true. The RMS ratings of speakers are mostly bogus, but theoretically, it is the maximum clean continuous power the speaker can handle without warping or frying the voice coils. Having a lower power amp driving them is just fine, given a lower output volume and that the amp is not clipping (see below).
UPDATE2: Good read here. See especially page 3, section 4 (A, B and C) for info on amp power vs. max speaker rated power: http://www.jblpro.com/pub/technote/spkpwfaq.pdf. Bottom line, it all depends on how loud you want to go without breaking things
Largely agree, and I already said that in my previous post. [Though, actually, it's the excess current driven through the voice coil WHEN the amp is clipping that's the issue (area under the curve), not the distortion per se. Tomato-tomahto.]
I'll agree with the "decent amplifier" point. But not the "matched to the speakers rated RMS power". That last bit is meaningless.
Yup!
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Good read! (thumb) That JBL article, if I'm reading it right seems to harp more on peak numbers and can be confusing to some. Here are a few articles from Crutchfield that put things into laymans terms for those who want to learn more.
Car Speakers and what to look for http://www.crutchfield.com/learn/learningcenter/car/speakers.html?c=3
This is a good article on car amplifier shopping and explains what the RMS power ratings mean and how to select them for the given speaker you have. http://www.crutchfield.com/learn/learningcenter/car/amplifiers/shopping_guide.html?c=3
There are many more listed here http://www.crutchfield.com/lc_3/Car-Audio-Video-GPS-How-To-FAQ-and-Shopping-Guides.html
Lastly here is a typical specification from JL Audio, which is arguably one of the best manufacturers of subwoofers on the market. This specification is for the 8W3v-4 8" subwoofer, which I own. Take a look at the graph under "specifications" where it shows the optimal RMS power for that subwoofer and above that the danger range. http://www.jlaudio.com/8w3v3-4-car-audio-w3v3-subwoofer-drivers-92148 I originally put a 300 watt RMS Pioneer amplifier on this because everyone said that the RMS ratings were bogus or just a guide and that its OK to add more power than what the manufacturer rated it for. Well let me tell you my experience wasnt good. The subwoofer sounded like crap, and bass was sloppy and over exaggerated even at low volumes. It just sounded terrible. I remember watching the cone moving like crazy and thinking is it supposed to move that much at such a low volume? For the longest time I couldnt figure out why it sounded like this until I went to JL Audios website and saw that graph. I decided to try my 20 year old Alpine 2 channel amplifier rated for 160 watts RMS bridged into 4 ohms on it and WOW it sounded totally awesome. Nice tight clean bass that was very accurate and plenty loud. If you look at this graph you'll see that 150 watts RMS is the sweat spot for this subwoofer and anything over 250 watts puts it into the danger zone. I was lucky I didnt blow my very expensive subwoofer.
When you are looking at amplifiers it helps to look for manufacturers that meet the CEA 2006 compliant rating or Consumer Electronics Association, which is a testing & measurement method for mobile audio amplifiers and is a voluntary standard for a uniform measuring method for determining an amplifier's RMS power and signal-to-noise ratio. Long story short amplifiers that comply with this standard can be accurately compared to each other. Without this standard there is no real way to know if what the manufacturer claims is true without testing it yourself on a scope. Dont pay attention to peak wattage numbers for speakers or appliers, they mean nothing, but many uninformed customers with the bigger is better mentality will buy based on those numbers alone.
Car Speakers and what to look for http://www.crutchfield.com/learn/learningcenter/car/speakers.html?c=3
This is a good article on car amplifier shopping and explains what the RMS power ratings mean and how to select them for the given speaker you have. http://www.crutchfield.com/learn/learningcenter/car/amplifiers/shopping_guide.html?c=3
There are many more listed here http://www.crutchfield.com/lc_3/Car-Audio-Video-GPS-How-To-FAQ-and-Shopping-Guides.html
Lastly here is a typical specification from JL Audio, which is arguably one of the best manufacturers of subwoofers on the market. This specification is for the 8W3v-4 8" subwoofer, which I own. Take a look at the graph under "specifications" where it shows the optimal RMS power for that subwoofer and above that the danger range. http://www.jlaudio.com/8w3v3-4-car-audio-w3v3-subwoofer-drivers-92148 I originally put a 300 watt RMS Pioneer amplifier on this because everyone said that the RMS ratings were bogus or just a guide and that its OK to add more power than what the manufacturer rated it for. Well let me tell you my experience wasnt good. The subwoofer sounded like crap, and bass was sloppy and over exaggerated even at low volumes. It just sounded terrible. I remember watching the cone moving like crazy and thinking is it supposed to move that much at such a low volume? For the longest time I couldnt figure out why it sounded like this until I went to JL Audios website and saw that graph. I decided to try my 20 year old Alpine 2 channel amplifier rated for 160 watts RMS bridged into 4 ohms on it and WOW it sounded totally awesome. Nice tight clean bass that was very accurate and plenty loud. If you look at this graph you'll see that 150 watts RMS is the sweat spot for this subwoofer and anything over 250 watts puts it into the danger zone. I was lucky I didnt blow my very expensive subwoofer.
When you are looking at amplifiers it helps to look for manufacturers that meet the CEA 2006 compliant rating or Consumer Electronics Association, which is a testing & measurement method for mobile audio amplifiers and is a voluntary standard for a uniform measuring method for determining an amplifier's RMS power and signal-to-noise ratio. Long story short amplifiers that comply with this standard can be accurately compared to each other. Without this standard there is no real way to know if what the manufacturer claims is true without testing it yourself on a scope. Dont pay attention to peak wattage numbers for speakers or appliers, they mean nothing, but many uninformed customers with the bigger is better mentality will buy based on those numbers alone.
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- 2014 & 2019 CX-5 Touring(s)
Oh I absolutely agree you shouldn't drive a speaker ABOVE it's rated power, yes. But you can use a high power amp, if you keep the volume down, and you can certainly use a lower power amp (at lower volumes) as long as it's not being driven into clipping. Most car audio (non-aftermarket) are like this. You have crappy speakers with relatively high max power ratings driven by tiny amps with lower power (generally 10-18W RMS).
I also agree totally about ratings of amps (and speakers). To paraphrase: "There's lies, damned lies and power ratings"
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- 2014 & 2019 CX-5 Touring(s)
Probably not. Most Bose systems have an amp built in to each speaker enclosure, in which case the added amp will make things worse by overdriving the inputs. Not sure about the CX-5 system, but it probably won't help anyway unless you remove/replace the Bose amp(s).
Yes I think if you install it before the factory amp in place of the Bose amp but I have no experience with the Bose system. You'd have to look at a wiring diagram because the Bose system is a 9 speaker system I believe and the Alpine Power pack only has 4 channels. I'm not sure why you'd want to do that though. Doesn't the Bose system sound pretty good? I've heard the Bose system in my brothers 2013 6 GT and it sounded pretty good, although a bit mid bass heavy and a little weak in the low lows. You might be better off just adding a subwoofer like the JL Audio Microsub and maybe replacing or adding a few tweeters. You can tap off the rear speakers for an amplifier that has speaker level inputs for the sub.
ThirdMazda
Member
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- CX-5
What is the impedance of the stock speakers ? If he didn't change the wiring then the front two pairs were wired in parallel to begin with, no ?
I see where you're going with this and yes the stock 25 watt speakers are also 4 ohms. Do me a favor and read this article from Polk speaker engineers and then come back and tell me that the electrical demands are the same for the new Polk coaxials vs the stock speakers and why. http://hometoys.com/emagazine.php?url=/htinews/feb04/articles/polk/impedence.htm
