Bass blocker cut off frequency help

[starks3x]

Hello. I am a complete newbie to car audio, but basically im replacing my stock toyota avalon speakers with Alpine SPS-10C2 (only 4" in the front and back) and im also adding a Kenwood KSC-SW1 compact subwoofer (I realize that this wont add earth-shattering base, but I just want some bass for a cheap price without taking up space in my trunk)..

my question is basically, do i need bass blockers for my four alpine speakers?? (Im pretty sure my alpine speakers dont have a crossover and I don't want them to pop when im listening to music with heavy bass)..

secondly, if i do get bass blockers (which im pretty sure i will considering the speaker size is only 4" in the front and back)..what should the cutoff frequency be for them? Crutchfield advises to get 600Hz for 4" speakers..but I think thats way too high. I was thinking of getting 300Hz for the front and 150Hz for the back (only bc the kenwood subwoofer frequency range is only up to 150Hz, and that's the reason I didnt want to get 300Hz bass blockers for the back, bc then it seems to me that I wouldnt hear any frequencies between 150-300Hz)..

do you guys agree? or should i do 150Hz bass blockers for both front and back? or 300Hz for both front and back? or something totally different? any input is appreciated.

these were the bass blockers i was looking at:

http://www.crutchfield.com/S-juvrNFH3a8I/cgi-bin/ProdView.asp?i=127BB300A2&cc=01&g=761

Thanks!

Click to read more...

 

[starkfu 10+ year member]

are you running this off of a factory deck? if not, most HU's have HPF on them. If not, I would cut off safely at around 200, remember, in frequencies, it isn't a sharp "oh no frequencies below 200 will play" type of thing. The frequencies will still play, just at a reduced volume. I would do them at 200.

 

[starks3x]

Thanks for the response starkfu. I am running the speakers off a factory deck. Ill take ur advice and buy bass blockers that have a cutoff at 200Hz (I knew 600Hz sounded alittle too high).

Thanks again!

 

[starkfu 10+ year member]

no problem.

 

[adas Pro Seller]

at 6db/octave rolloff, 600hz is a better option. That is NOT a sleep roll off, even with 600hz bass blockers, the 4" speakers are going to be noticibly playing down to 80-100hz. I would say 200 with a 6db/oct rolloff is going to KILL those 4"ers playing any bass heavy songs. Just for reference I have my 6.5" crossed at 160hz 12db/oct and they still are at almost full excursion during very bass heavy songs at full volume...

I really recommend at least 300. Or, for $10 more buy both 150 and 600 and see which one's do better

 

[starkfu 10+ year member]

he is running the factory deck..... with 4 4", at that level of crossover, it won't even reach 200hz @6db/octave. I think 300 is conservative for his application, 200 being the better choice. otherwise you are missing out on a large range of sound. Assuming the sub is crossed at 80-100hz.

 

[Louisiana_CRX 5,000+ posts]

I've seen the bass blockers blow the outputs in decks before and they were hooked up properly....

 

[adas Pro Seller]

he is running the factory deck..... with 4 4", at that level of crossover, it won't even reach 200hz @6db/octave. I think 300 is conservative for his application, 200 being the better choice. otherwise you are missing out on a large range of sound. Assuming the sub is crossed at 80-100hz.

That's assuming the stock deck has a xover, and not just a bass blocker on the stock speakers with full range signal. If it does have a xover, then yeah, i agree 200hz would be fine. I just rather not assume that

 

[starks3x]

Thanks for all the responses guys. This forum has been really helpful. So I guess if I have a "xover" (Im not sure what that is) on my stock head unit, then 200Hz is fine. If not, then I should go with 600Hz. The problem is, does anyone know any website or resource where I can find out if I have a xover or not? I guess if I can't find out or no one knows, Ill just play it safe and go with the 600Hz bass blockers.

Thanks alot guys!