I am not sure where you draw that conclusion from. The Polk MM series are probably the best sounding speaker out there in the middle of the road category.

I will tell you this, I have a total 8 Polk component speakers being pushed by 1200 watts from 2 Alpine PDX 4 channel amp's. 4 polk MM691 6x9 components and 4 Polk MM6501 components.

I was not 100% satisfied with the final sound quality after the instal and I thought maybe a better speaker would show me if the Polks are lacking or not.
Now I know the high end Focal, Hertz and HAT speakers are awesome but I found a deal on a set of Boston Acoustics SPZ-60 components. For those not familiar with these, they are Boston's Highest end speaker and retail over $1k a set if you buy them in a store.

So for the hell of it I installed the Bostons in the upper fairing and hooked then up in a way that I could isolate the Polks from the Bostons. One BA on the left and one Polk on the right in both the upper and lower fairing. So that both speakers were in identical enclosures for the test.

Both speakers play at full 150 watts from the amp with zero distortion. The Boston SPZ's have a full 1" excursion and therefor have better mid bass than the polks but they did not "blow away" the polks by any means.

The polk speakers sound crystal clear and I would almost bet $$ that you could put them up against a $500 set of Focal's and find they perform almost identical.

I have since installed the BA in the upper fairing and moved the extra set of Polks to the rear pods. I now have 10 speakers, 8 of them are Polk MM series.

I am not saying Polk is the only way to go here, I am just saying that the polks are far from being in the same group as Infinity, J&M, RF or any of the others.

You did hit the nail on the head though when you said you have to push power to these speakers!
I have had these same Polk speakers on another bike with just the head unit and they did not impress me that much. But once I added power to them, they sounded fantastic.

 

I had the infinity Kappas. I thought they were too bright. I like my Polks MM 651s much better.

 

We here at dragonfly only use focal we have spent hundreds of hours trying different amp and speaker combonations to come up with the best motorcycle audio out there and FOCAL is second to none check out FOCAL's commercial with Dragonfly and see for your self

 

Set your amp up correctly and you will blow away a lot of cats out here!!!
I know!!!

 

BigGlevis, i am on the fence between the polk mm691 and the hertz hienergy 6x9. I already have a pdx f6. My plan is a set in the lids and a set in the bags. On paper the polks really look impressive. U said u were not 100% satisfied with these... can u elaborate? I didnt know hat had 6x9s. I have already reconfigured the front 3 times and ended up with 4 hertz and biketronics amp. I really dont want to go through several setups in the rear before I am satisfied. Thanks

 

I can only comment on the MM691's. Those are the first and only 6x9 I have ever used on a bike.
As far as what I said about being somewhat not completely satisfied with the polks? Let me explain what I have learned since then. I am more satisfied with them now then I was a few weeks ago.
I played with the Amp and adjusted the gain a little where the rear speakers reach full power slightly before the front speakers do. I added polly fill in the bags and packed it full.
The result was a little cleaner sound, better, tighter bass and a lot of the "muddy" sound was gone.

I am limited in any info I can give you really because I have nothing to compare it to. I am pretty confident now that it is not so much the MM691 as it is all the other factors.
There is a reason speaker enclosures are made rigid and sealed. When you put 2 6x9 speakers in a thin flexible saddlebag, you are going to lose some quality. And I think that is exactly why my initial impression of the Polk 6x9 was not quite what I thought it would be.
I have tuned it in a little better but I still think that no matter what speaker I put in those bags, they will not perform as good as they are capable of until I build a rigid enclosure for them.

When I crank my system up to max volume, I can stand back and watch the saddlebag flex with every beat. The more it flexes, the more sound is lost and the weaker the bass gets. The sound dissipates out in all directions and sounds muddy.
The only way to make it sound like it should it to either add a fiberglass layer to the inside of the bag to stiffen it up or build a rigid enclosure to put the speakers in then mount them to the bags.

I have already talked to a few guys on here about the bag flex issue and some think that it doesn't matter. That is fine and I respect their opinion but I think it does and I proved it to my self by packing the bags tight with polly fill and heard a very noticeable difference in sound quality and tightness of the bass.

So to sum it up, I think these Polks are great. I would like to try others but buying 4 speakers just to try when I already have these that I know will sound better, just doesn't make much sense financially.
And it is damn near impossible to find someone with the same setup running a different 6x9 to see what they sound like.

And I'll tell you this. You see me talking as if it's not an awesome system but I am just picky. I always have been and always will be, for some reason, everything I do has to be perfect in my eyes.
But I have blown the minds of so many people with this system. It literally sounds like a concert when the bike is parked and not running. The sound is so full and 3 dimensional and crystal clear.

I am sure I didn't answer your question but I hope this helps some.

 

Yes that helps..thank you. Sounds like you have the same affliction as I, ocd. Everything has to be perfect.