DiyMobileAudio.com Car Stereo Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter #1
I'm looking at the polk mm6501 component system which is rated at 125W RMS and my fosgate pbr300x4 is rated at 75W RMS with the test sheet showing like 84W RMS.

Would this be an ok match or would you guys suggest stepping down a level?

Crutchfield advisor recommended the DB series but said the MM would be fine as well with that amp.

What are the thoughts from the pros here?
 

·
Registered
Joined
·
243 Posts
we get too caught up in small differences in power. You can't tell the difference between 75 watts and 84. The MM is a better speaker, but either will be fine with the amp.
 

·
Registered
Joined
·
176 Posts
How sensitive are the polks?
Thats the "db" on the specs (spl)as in how load should they get per watt.
You can always upgrade the amp down the road.
I can't see them not sounding good with 80w coming at them.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #4
How sensitive are the polks?
Thats the "db" on the specs (spl)as in how load should they get per watt.
You can always upgrade the amp down the road.
I can't see them not sounding good with 80w coming at them.
Sensitivity on the MM's is 94db.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #5
we get too caught up in small differences in power. You can't tell the difference between 75 watts and 84. The MM is a better speaker, but either will be fine with the amp.

I just wasn't sure if it was pointless to go with MM series if they were going to be underpowered.
 

·
Registered
Joined
·
898 Posts
MM's
 

·
Registered
Joined
·
2,777 Posts
Note that that the nominal impedance of Polk MM speakers is 2.7 ohms. This means that your amp will send a lot more power compared to running in 4ohm mode. If the amps were rated at 2.7-3ohm impedance, I assume your amplifier would have around 100watt RMS rating. You can also try to run higher quality speaker wire. Try lower awg wire if you have thin factory wires right now (lower than 18awg is probably overkill too but will not hurt). This will deliver more power to speakers. Also, consider bridging your amplifier. Before I bridged my 60watt amplifier, my 100watt speakers were running fine, but noise floor was audible on some tracks. After bridging, it was less audible.
 

·
Registered
Joined
·
530 Posts
Note that that the nominal impedance of Polk MM speakers is 2.7 ohms. This means that your amp will send a lot more power compared to running in 4ohm mode. If the amps were rated at 2.7-3ohm impedance, I assume your amplifier would have around 100watt RMS rating. You can also try to run higher quality speaker wire. Try lower awg wire if you have thin factory wires right now (lower than 18awg is probably overkill too but will not hurt). This will deliver more power to speakers. Also, consider bridging your amplifier. Before I bridged my 60watt amplifier, my 100watt speakers were running fine, but noise floor was audible on some tracks. After bridging, it was less audible.

the only problem i see with what you're saying is bridging his amp to his components. i don't know of too many amps that will take a 2-3 ohms load happily. Let alone, his amp is not bridgeable. rockford says it right on their product page it is not, that and the amp is only 4 ohm load stereo. not capable of 2 ohm or bridgeable.


OP, just from the quick search for the fosgate amp, i would suggest either different speakers or an amp with more features such as 2 ohm stereo load capabilities.
 

·
Registered
Joined
·
324 Posts
I'm looking at the polk mm6501 component system which is rated at 125W RMS and my fosgate pbr300x4 is rated at 75W RMS with the test sheet showing like 84W RMS.

Would this be an ok match or would you guys suggest stepping down a level?

Crutchfield advisor recommended the DB series but said the MM would be fine as well with that amp.

What are the thoughts from the pros here?

I bet that "125w" is actually the rating for the PAIR of Polk speakers and not each individual driver. Look for a * and read the fine print. Polk also gets really creative with their power ratings for their amps too.
 

·
Registered
Joined
·
2,777 Posts
the only problem i see with what you're saying is bridging his amp to his components. i don't know of too many amps that will take a 2-3 ohms load happily.
Oh, I apologize. What I meant to really say is that I have no reservation about bridging a lower power bridgeable amplifier to power lower sensitivity speakers with 4 ohm nominal impedance. Bridging to drive these 2.7 speakers is probably not necessarily safe.
 

·
Registered
Joined
·
2,777 Posts
I bet that "125w" is actually the rating for the PAIR of Polk speakers and not each individual driver. Look for a * and read the fine print. Polk also gets really creative with their power ratings for their amps too.
There is no mistake. That's for individual speakers.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #13
the only problem i see with what you're saying is bridging his amp to his components. i don't know of too many amps that will take a 2-3 ohms load happily. Let alone, his amp is not bridgeable. rockford says it right on their product page it is not, that and the amp is only 4 ohm load stereo. not capable of 2 ohm or bridgeable.


OP, just from the quick search for the fosgate amp, i would suggest either different speakers or an amp with more features such as 2 ohm stereo load capabilities.
Manly basing my choices on crutchfield support since I have about zero knowledge when it comes to this stuff.

The amp will have to do as it's going inside the fairing of my bike and I need that small footprint.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #14
That match is just fine, as long as you like the sound of the speakers.
Liking the sound is what has had me not buying anything in the months I've been looking. Being a motorcycle I want to make sure what I buy can be heard fairly well but I'm starting to think that just about anything should sound good with 6 speakers in my face
 

·
Registered
Joined
·
17,149 Posts
When discussing Sensitivity figures it's also important to see if they are rated at 1W or 2.83V, because 2.83V is only one watt into 8 ohms, when rating lower impedance figures sometimes the 2.83V number is used to make them look good... And this can skew things to the high-side ;) like 3dB high.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #16
When discussing Sensitivity figures it's also important to see if they are rated at 1W or 2.83V, because 2.83V is only one watt into 8 ohms, when rating lower impedance figures sometimes the 2.83V number is used to make them look good... And this can skew things to the high-side ;) like 3dB high.
Man you guys are a wealth of knowledge. So there is a possibility that the power fosgates might be just as good since they are rated at 1w/1m. I currently cannot find if the polks are rated at 1w or 2.83.
 

·
Registered
Joined
·
1,665 Posts
I will say this - for the most part, the higher the sensitivity, the worse the bass performance. You will not find 6.5"s that are, say, 94dB 1W/1m that will have good bass. Hoffman's Iron Law says so.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #19
I will say this - for the most part, the higher the sensitivity, the worse the bass performance. You will not find 6.5"s that are, say, 94dB 1W/1m that will have good bass. Hoffman's Iron Law says so.
Correct me if I'm wrong but going for bass on a motorcycle application is kinda pointless isn't it? It seems to me any speaker would have a hard time producing decent bass in those conditions doing 70MPH down the highway.

That's why I haven't really tried focusing so much on bass.

Now I'm trying to decide if I should stick with stock size 5.25, use an adapter for 5x7 or use an adapter for 6.5
 

·
Registered
Joined
·
17,149 Posts
The amp will have to do as it's going inside the fairing of my bike and I need that small footprint.
Correct me if I'm wrong but going for bass on a motorcycle application is kinda pointless isn't it? It seems to me any speaker would have a hard time producing decent bass in those conditions doing 70MPH down the highway.

That's why I haven't really tried focusing so much on bass.

LOL... SWISH!
 
1 - 20 of 25 Posts
Top