Haven't heard the J&M but I wouldn't expect much from them. I have Polk Audio MM series component speakers with the addition of a aftermarket amplifier and also a sub.
Haven't heard the J&M but I wouldn't expect much from them. I have Polk Audio MM series component speakers with the addition of a aftermarket amplifier and also a sub.
"Go sell crazy somewhere else, we're all stocked up"
Project complete! I bought the 5.5 Polk speakers and made frames from plywood. Put the left crossover under the left compartment and put both the amplifier and the right crossover in the right compartment. Now I just need to give it a go on a ride. In the garage with earplugs in I didn't detect any noticeable increase in volume, but a road test will be the best judge.
Make sure you don't have the switch on the crossovers set for the -3 db cut. If you have everything hooked up as I do, you should have a tremendous difference. I measured over twice as loud than with the OEM amplifier.Originally Posted by SoCal Rich
"Go sell crazy somewhere else, we're all stocked up"
So, I've been able to do my road test, so here is a report:
First, a summary of my installation:
1. Polk DB 5251, no sub woofer, used existing tweeters
2. NVX MVPA4 amp
3. Connected via headset plug
So, the volume is definitely higher than the original. Jimmy measured 2x, but I would guess 1.5x in my case.
AVC no longer works; I'm guessing that AVC only works when speakers are chosen as the output; but not when headset is chosen.
Sound quality is not as good, probably because I did not install a sub woofer.
So, would I do it again knowing what I now know? Jury is still out.
Will I uninstall? Definitely not, I really wanted the extra volume.
Wish it sounded a little bit better, but I'll get used to it.
FWIW, the DB series is 92dB and 4 Ohms while the MM series is 94db and 2.7 Ohms.
3dB is a doubling of power, but not a doubling of perceived loudness (need @ 10dB for that).
The 2.7 Ohms will also source more power (than the 4 Ohms) through the amp which will also make the speakers sound louder (if the amp is up to the load).
Sorry your results are less than what you expected. I don't have any ideas for you off the top of my head. Other than the amp, you chose different speakers, installation etc.... It doesn't surprise me that your results would be different.
You chose speakers with a 4 ohm nominal impedance as opposed to the 2.7 ohm of the MM series speakers. This difference alone will mean that you are losing output/volume with the same rated amplifier.
Yes the AVC only works as I have done mine.
Have you turned the gain up on the amplifier?
I have a hard time understanding the sound quality thing. You say you left the stock tweeters in play?I wish you were somewhere near me, I could let you hear mine.
My measured volume was with a sound pressure meter.
"Go sell crazy somewhere else, we're all stocked up"
Keep in mind, if you've read my thread about the process I went through to get to my results, you should understand that I did the trial and error thing . I attempted easier solutions to reach the desired results and they were unsatisfactory.
I carefully selected the components I used to match. If you change the ingredients in the recipe, you're going to come out with a different flavor.
"Go sell crazy somewhere else, we're all stocked up"
Made a mistake . I installed MM5251, not DB. I had considered DBs but decided against. (Just went to verify)
And, no need for apologies, I love tinkering with this stuff, just wanted to share my observations. I really appreciate all the help you gave me.
I used 18 guage speaker wire, too. That should be enough, right?
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