SR5250 Fs & HPF setting

Phillips

In pursuit of the best sound quality I can obtain in my car, with a limited budget, I've been doing a lot of reading online. I just read an article that spoke of the resonant frequency of a speaker.

The article stated that for mid-bass, the HPF should be set higher than the Fs of the speaker you use for mid-bass. In my system, this would be the woofer for the Polk SR5250 component set.

The Fs for the SR5250 is listed as 71hz. Obviously this is only for the woofer, and I cannot find the Fs for the SR1001 tweeter.

I typically run an HPF of 50-63hz. I do this in one of two ways. I either set it on the amplifier, or I use the cross-over in my head-unit. (see system setup in signature if needed) I try varying settings on both devices in attempt to get the sub-woofer and SR5250 woofer in phase which definitely improves the mid-bass from the front driver's seat.

According to this article, I should use an HPF that is higher than 71hz. Obviously the woofer would still play 71hz, but would be attenuated depending on how high I set the HPF. This would be beneficial as the woofer will play 71hz (and I'm sure frequencies around this) louder than others.

Thoughts, opinions? Obviously I am going to try this to see what I think about the result. I am going to pop in a couple test CD's I have that use sine wave sweeps (with and without warble) and see how this effects mid-bass frequencies.

MacLeod

The SR5250's can run down to 50 Hz. I competed all thru 2007 with the SR5250's and I had mine high passed at 50 Hz and they worked fine. 63 would work too but 71 is too high. Properly installed in a well damped door, the 5250 mids can produce very good midbass.

For the tweeter, 4 KHz is the sweetspot. Id low pass the mid and high pass the tweet both at 4 KHz @ 24db/octave to start. I tried a million different combinations and always came back to that.

Phillips

Thanks Mac. With all of the issues that I am having with the front stage in this car, I am changing the position of the tweeters and am thinking about going active. A processor will come later on. I am considering an Arc Audio 4050XXK which I think should have good sound quality, good clean power, and will have the appropriate cross-over needed until I can get a processor in there. (except the slope is only 12db, not 24db)

What do you think of that setup? Would you still recommend Polk's amps and just get a processor later? (I say this as I see you highly recommend Polk amplifiers in your posts) Thanks again.

Edit: Added slope information for Arc Audio amplifier.

MacLeod

A watt is a watt. So long as the amp is well made and has the features you want, youll be fine. MTX, Kicker, Alpine, Rockford Fosgate - all are well made amps. Your head unit has plenty of features so I would use them instead of paying extra for those same features on an amp.

axius0

Hey MacLeod, since you are using a 24db/octave slope for the LPF and HPF, do you reverse the polarity on the tweeters? I could see why you would do it for a 2nd order slope since they would be 180 degrees out of phase, but with a 4th order slope the two drivers are in phase.

MacLeod

Actually yeah, my tweeters are out of phase. Thats because of the mounting locations and not the crossover slope. Having them out of phase made the right tweet blend better with the right mid. It had no effect on the left tweet and mid but having the tweets out of phase with each other didnt work.