Subwoofer crossover recommendation

scottyf

I was wondering what a good xover point for my system would be in my 2002 Tundra.

System:
Front speakers SR6500 (powered by SoundStream Ref 300SX amp)
Rear speakers MMC6500 (powered by a pair of Xtant 1.1i's)
a pair of MM2084DVC in a Q-Logic box (powered by Autotek SS490.2)

My Pioneer 8600mp has
-- Subwoofer xover points at 50, 63, 80, 100, 125, with slope choices of 6, 12 and 18 db. I can also reverse the subs.
-- Front speaker xover points at 50, 63, 80, 100, 125, with slope choices of 6 and 12 db
-- Rear speaker xover points at 50, 63, 80, 100, 125, with slope choices of 6 and 12 db.


Things sound good, but I think they could sound better. Any suggestions?

Greg Peters

What have you got everything crossed over at right now?

A good starting point would be to set your high pass crossovers at 80hz (with the 12db slope) for front and rear speakers, and your low pass at 80hz (with the 12 or 18db slope) for subs.

If the bass appears to be coming only from the rear of vehicle, or upper bass frequencies sound muddy, try lowering the cut off for your low pass to 63hz and see if things improve.

You may want to consider crossing over your rear speakers a bit higher than your front stage if your mid-bass sounds muddy or boomy, as depending on mounting locations, they may cause some cancellation with your subs at lower mid-bass frequencies.

Reversing the phase of your subs is worth a try if sub output seems weaker than it should- use whichever setting produces the most output. You should also make sure that your two subs are in phase with each other, as in both cones pushing/pulling in unison on a given bass passage (provided they are mounted in a traditional ported or sealed box and both woofers on same axis). If they are not in phase with each other in these types of enclosures, subs will cancel each other's output causing weak sub response.

Peter J

I would use 50Hz/12db for the SR6500 kit and the rear to go from 80Hz/6db.
The sub i would try with 63Hz/18db.
The SR kit has the cappabillities to play a lot of clean and powerful bass and midbass.
The MMC has probably not the same power inthe bass area so thats why i would use a higher frekvense. The subfreq. is set to make it hard for the basstunes to sound from the rear in your car and to make sound like it coming from the front of the car.
You may have to try shift phase of the sub and use a little timeallignment to make it really good.

I have the SR6500 kit in my car and i use 40Hz/24db as a subsonic to protect the kit.
It works great and i have a lot of power in my system. My subwoofer plays up to 78Hz/72db.

MacLeod

Greg's pretty much got ya covered except for the flopping the polarity of the subs. I cant speak for everyone but every single time Ive done this (usually on accident) it kills my bass response do to massive cancellation. But like he said, try it and if it sucks you can always switch back.

By the way, how you like those little Xtants? Theyre pretty bad **** arent they? If I were you, Id run the SR's off of them.

Peter J

You are right Mr MacLeod, but it would be a right thing to try, if it works great, if it doesn`t its easy to switch back! It depends on how the sub are mounted and how far the distance are from the sub to the frontsystem.

In the Northen countrys and most of Europe its wery selldom that we come across cars with rear speakers. It happens but its not so often.

MacLeod

A lot of people like them as they haul passengers around a lot and like for them to have some music as well. Plus it does fatten up the sound a bit although it kills the soundstage and cancels out some detail but to each their own.

1996blackmax

I will be adding a little rear fill in the near future . Curious to see how the SRS surround works on my HU.

Greg Peters

Swapping the subwoofer polarity with the H/U is an easy thing to try. I agree that most times output decreases when reversing polarity, but you would only try this if something is not sounding right in the first place.

If by chance subs do put out higher output "out of phase", it may mean polarity of subs were wired incorrectly between amp and woofer, or even woofer and terminal cup on inside of enclosure (stuff happens).

Sub polarity may make more of a difference if your subs are in a complex bandpass enclosure or a push/pull clamshell configuration etc.

As far as playing the sr6500s down in the range of 40hz, I don't doubt that they are capable of doing so to a degree, but that doesn't mean that they won't sound best crossed over higher when used with subwoofers.

That's the beauty of digital crossovers built into the head unit. If you feel the urge to set the crossovers down lower on your srs and mmcs, they will likely handle it at lower volume but may bottom out/distort if turned way up, so be careful. Your subs are probably good to 125hz or so, so there is not much point in trying to get 6 1/2" speakers to play those lower frequencies.

These speakers are mostly what I'm planning on upgrading to- sr6500s in doors and mmc650s in rear sound bar, so please post how it all works out in your Toyota.

scottyf

I'm still experimenting with everyone's recommendations. These speakers are gonna break in eventually!

Greg, I put the Momo's in the back because I had them. They were my original front speakers until I got the SR's on Saturday. They do add weight to the overall sound, but mess up the sound stage as McCleod said. Last night, before I read all of your responses, I faded out the rear speakers and was much happier with the sound. I'm beginning to wish I had come up with a better solution for them. I'm thinking they are a real waste back there where my dog rides....especially if I keep them faded out!

Overall, the truck is much easier to balance, sound-wise, without them.

McCleod -- I haven't had a chance to form a complete opinion of the xtants. I know from experience how that Sound Stream 300SX sounds (one of the very best I've ever heard), so it won the honor of running the SR's. Originally, I had the xtants running the midbase of the Momo's and a Phase Linear running the tweeters, but I can only fit 4 amps and two crossovers behind my seat. From this exposure, though, the xtants are very, very nice and are definitely in the same class as the Soundstream.

When I got my LSi15's, it took a while to break them in, so I expect I will need to do a lot of driving before the SR's are broken in. Still, they sound pretty good right out of the box.

My Pioneer has an auto calibration setting with microphone, but it just didn't seem right -- hence the post. Thanks again, everyone, for the advice!

neomagus00

the auto calibration is a great place to start, but is by no means the end (and do try to tune without any time alignment... i have a p860mp, and i've heard other complaints too, that the time alignment screws with your eq... much better to do it the old fashioned way)

and greg peters is right - yes, the SRs can probably play down to 40 Hz, but they'll be louder and cleaner with a higher xover... less excursion is better (witness McIntosh's line arrays... there's a reason they have 60 drivers apiece, it's to keep the speakers right in their linear operating range...)

1996blackmax

neomagus00 wrote:

the auto calibration is a great place to start, but is by no means the end (and do try to tune without any time alignment... i have a p860mp, and i've heard other complaints too, that the time alignment screws with your eq... much better to do it the old fashioned way)

Now that I sold my P8600 I do not have that problem any more . I use the T.A. feature on my CD8455 and it does not screw anything up .

neomagus00

ah, yes, you said that... now i hate you for getting a REAL auto-TA...

1996blackmax

Oops! I guess I did mention that before. I am just pretty stoked with the unit .