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Question about CDT Speakrs

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Old 11-23-2010, 10:39 AM
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I see a lot of people on here are running CDT's, I had some in my mustang and liked the sound. My question is, do they make any 2ohm speakers? Preferably a component set. The G8 HU is 2ohms and I dont want to put a 4ohm speaker in there bc it wont be as loud as the rest of the speakers.
Old 11-23-2010, 02:48 PM
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You're focusing too much on the impedance rating, and not the sensitivity.

If the impedance goes up, your amp will have an easier time. Here's a good discussion on the subject with respect to home audio, but still applicable to mobile audio.


http://www.polkaudio.com/forums/archive/index.php/t-52722.html
Old 11-23-2010, 05:02 PM
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Actually, there's an awful lot of baloney and mis-information in that link. You are right, impedance is not nearly as important as sensitivity/efficiency as long as you don't use a speaker with an impedance that makes the amp unstable.

Doubling the impedance cuts power in half. Half power represents about a 3dB drop in output all other things being equal. 3dB is noticeable but nowhere near half of the volume. Think of it as about one click on your volume dial.

This is where sensitivity comes in... if your new 4-ohm speaker is at least 3dB more sensitive than the 2-ohm speaker you're replacing then you lose no volume at all. Factory speakers are notoriously inefficient so almost any decent aftermarket speaker will be at least 3dB more sensitive than the factory speakers.

Oh, and impedance has nothing to do with how hard your amp "works". Amps are rated at different power levels for different impedance loads in order to control heat (heat is one of the greatest destroyers of electronics). Lower impedance creates greater current flow and heat at any given voltage (Ohm's Law) so an amp will be rated for maximum and RMS output into different loads based on how much current it can flow without overheating.
Old 11-23-2010, 08:41 PM
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Originally Posted by WhiteBird00
Actually, there's an awful lot of baloney and mis-information in that link. You are right, impedance is not nearly as important as sensitivity/efficiency as long as you don't use a speaker with an impedance that makes the amp unstable.

Doubling the impedance cuts power in half. Half power represents about a 3dB drop in output all other things being equal. 3dB is noticeable but nowhere near half of the volume. Think of it as about one click on your volume dial.

This is where sensitivity comes in... if your new 4-ohm speaker is at least 3dB more sensitive than the 2-ohm speaker you're replacing then you lose no volume at all. Factory speakers are notoriously inefficient so almost any decent aftermarket speaker will be at least 3dB more sensitive than the factory speakers.

Oh, and impedance has nothing to do with how hard your amp "works". Amps are rated at different power levels for different impedance loads in order to control heat (heat is one of the greatest destroyers of electronics). Lower impedance creates greater current flow and heat at any given voltage (Ohm's Law) so an amp will be rated for maximum and RMS output into different loads based on how much current it can flow without overheating.
Hmmm.. well most people are putting in polk db65s(4ohms) in the g8 doors. I've listened to that setup and the doors are noticeably quieter than the rest of the speakers(especially the center). What sensitivity rating difference is equal to roughly 3db? Does that mean a speaker with a sensitivity of 88 vs 91 the 91 will be 3db louder?
Old 11-24-2010, 07:42 AM
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Yes, sensitivity ratings are in dB. So a 3dB difference in sensitivity equals a 3dB difference in volume. Of course, that isn't all there is to the story. Sensitivity is measured at a specified frequency and any given speaker may be less sensitive than rated at other frequencies and in different environments (enclosure and off-axis position account for significant differences). The ratings are useful indicators but they can't account for all circumstances so you may not always get the results you expect.
Old 11-24-2010, 07:45 AM
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Originally Posted by WhiteBird00
Yes, sensitivity ratings are in dB. So a 3dB difference in sensitivity equals a 3dB difference in volume. Of course, that isn't all there is to the story. Sensitivity is measured at a specified frequency and any given speaker may be less sensitive than rated at other frequencies and in different environments (enclosure and off-axis position account for significant differences). The ratings are useful indicators but they can't account for all circumstances so you may not always get the results you expect.
Well **** lol, it cant just be simple can it.
Old 11-26-2010, 07:26 AM
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Prime example is that the CDT 4ohm speakers put out more midbass and sound as loud as the Infinity 2ohm speakers. This also has to do with having smoother highs that are less shrill so you don't get the listening fatigue you get with the Infinity speakers. I've had them side by side before and it was comical that we were listening to a 4ohm vs. a 2ohm knowing that the 2ohm was supposed to be louder but wasn't and didn't sound even close as far as sound quality. Cars were identical WS6 cars. The sensitivity rating on the CL-61CV and the CL-E61CV are 91.6db and 91.2db. On the CL-62 set I use in some Trans Ams it is even higher at 92.3.
CDT makes high end, audiophile grade speakers, subs and amps. That's what they focus on the most.
Old 11-30-2010, 10:56 PM
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I'm certain that all the numbers are very important, but not to me. I can assure you that the 4 ohm CDT speakers from Kee audio work great. Call Ian, tell him what your needs are and he will fix you up.
Old 12-01-2010, 01:37 PM
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Right now it is best to email me at: keeaudio@bellsouth.net or PM me. Those are the 2 best ways to contact me right now and I would be happy to help out any way I can.




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