RTi A1 Vs. A3 Crossover

dnoyeB

The RTiA1 has a 1800Hz LPF and a 5 1/4" woofer.
The RTiA3 has a 2600Hz LPF and a 6 1/2" woofer.

Does this seem backwards to anyone else?

thesurfer

I believe the crossover point on the rtiA1, Has more to do with Getting as much low end as possible, out of a small midbass driver??? But, not sure, give it time, im sure someone knows exactly why,, and will post,

ShadowTowel

That does seem backwards... As an owner of the A3's, I'm quite curious about this.

Are those numbers 100% verified as true?

dnoyeB

I can't verify the numbers, but they are as listed on the Polk website.

dnoyeB

Hmm, if you look at the floor standers you get the same thing.

I think the individual speakers are designed to handle a particular frequency.

The RTiA9 has a 1800Hz LPF and 2x 5 1/4" mid-woofer. (like RTiA1)
The RTiA7 has a 2700Hz LPF and a 6 1/2" mid-woofer. (~like RTiA3)

This makes me feel like the A3 is probably going to sound significantly better than the A1. Just based on stats. The A9 of course does not have a problem using the 5 1/4" because it has so many other speakers to fill the range out.

ShadowTowel

dnoyeB wrote: »

This makes me feel like the A3 is probably going to sound significantly better than the A1.

It does.



And that is based on my A/B comparisons.

ShadowTowel

DSkip wrote: »

Again, that's debatable

I believe it has more to do with the harshness of the upper end with the 5.25" drivers. Running active with the SR's in my car, I've found that the higher the mids go, the harsher the sound gets. I think it has to do with the fact that they can play that high and don't have a huge roll-off in those frequencies. My assumption is that the 6.5" woofers have a more natural roll off at those frequencies and blends with the tweeters better, so you can cut them higher and not have the overly bright sound of the smaller driver.

Yeah, I acknowledge it is a very subjective statement I made. I don't have the scientific know-how you guys have, and I just go by what my brain interprets from the sound waves hitting my ears... It is also worth mentioning that I use them almost exclusively for movies. So we could differ on our opinions due to that as well. I just know that I would always take the A3's over the A1's if money and space were not factors.

Face

DSkip wrote: »

My assumption is that the 6.5" woofers have a more natural roll off at those frequencies and blends with the tweeters better

You know what happens when you assume, right? :biggrin:

Yes, larger woofers generally roll off earlier, but also have poorer off axis response at higher frequencies(over 2500hz), making the 5.25" woofer a better candidate for a 2 way.

Face

DSkip wrote: »

I understand your statement, but don't understand how it relates to the 5.25" having a lower xover point than the 6.5". Does it have more to do with the bottom end rather than the top? With no xover down low, does the 5.25" struggle with details in the upper frequencies due to the strain of producing the mid-bass punch?

I don't understand Polk's decision to use a lower crossover point with the 5.25" either.

I'm basing all this purely off my experiences with an active setup, and what I know is the lower I can cut the tweeters, the better the overall sound becomes. Right now the SR ring radiators are cut off at 1.6khz as well as the mids and can rival the sound quality of my LSi7s. I've tried higher and it just doesn't seem to mesh well no matter what I do. This might have more to do with the car atmosphere than anything though.

Yep.