LPF and HPF settings

Rivers · Post by **Rivers** » Sat Jun 03, 2006 10:08 pm

Folks, I am trying to understand abit more on the relationship between HPF and LPF of different components within my setup. I currently have my subwoofer's LPF set at 80khz (24db slope) with the midbass drivers at 80 (24db slope). This I understand would probably produce 'extra' volume within those two roll-off slopes (and I wouldn't want that).

So what I should really be doing is to setup a gap between the sub's LPF and the midbass HPF. Now the question is, how will I know what kind of gap should I be leaving (considering I have no RTA available) and what kind of slopes would be goodl? I find that having the sub to pass off at 80khz (24db) produces the best punch. I am assuming using gentler slopes would probaby 'blend' the components better?

Also, this 'gap' would probably be applicable to midbass and tweeter crossover configuration as well?

Thoughts much appreciated! I'd really like to get this right. Tuning it is like 1/2 the fun!!

JeremyC · Post by **JeremyC** » Sun Jun 04, 2006 4:04 am

Honestly I like using a sharper cut off for the sub. So I would stay with 80 24 for it.

As for components I like using a 12 db slope . Speckers tend to roll of at 12db an octave anyways, so it always seems to work out well for me.

As for the gap. The best way is with an RTA (as you all ready know). You next bet it to just play with it. I would start out at 100 with a 12 db slope and go from there. If you like where the subs are now. If you want more punch out of your mids you can run them at 80 with a 12db slope, and drop the sub to around 60.

With the tweets, unless your running active, you probably won't need to mess with it. The factory x-over should take care of the blending for you.

Rivers · Post by **Rivers** » Sun Jun 04, 2006 7:20 am

I am currently running an active setup. I am planning on going for a laptop-based RTA but will leave that for another post. :)

JeremyC · Post by **JeremyC** » Sun Jun 04, 2006 7:44 am

Then it depends on the tweets, and how low they can handle. I would stick with a 12db slope, and play with the points. Say 2k for the mid and 2.5k for the tweet.

suleman36 · Post by **suleman36** » Sun Jun 04, 2006 9:31 am

Should we just use the HPF and LPF on the HU or on the AMP or BOTH ????

Always confused about that

JeremyC · Post by **JeremyC** » Sun Jun 04, 2006 1:29 pm

One or the other, not both. UNLESS you do something like set the sub (or mid / tweet) x-over on the headunit to flat so you can use the x-over in the amp (or vise versa).

suleman36 · Post by **suleman36** » Sun Jun 04, 2006 9:33 pm

Well it doesnt look like i can just set the LPF x-over on the HU to off or flat. I have the Pioneer DEH-P860MP and i dont see how i can set the crossovers off. I believe i can set the HPF to full/off but im not sure if i can with the LPF.

Im using a ppi a600.2 which is a great amp with no crossovers so i have my HU set at 12db @ 100hz and its great this way.

For my sub amp i have a arc audio 1500-xxk and i have the LPF on at 24db @ 80hz and i have the HU LPF on at 18db @ 80hz but i want to turn it off so i can just use the amp only.

Rivers · Post by **Rivers** » Mon Jun 05, 2006 3:27 am

Hmm there must be an option where you can set all the LPF/HPF curves to 0 (as opposed to 12/18/24db level; run a no-filter pass), that would be the same as turning it off?

solacedagony · Post by **solacedagony** » Mon Jun 05, 2006 4:15 am

You should also check to make sure the crossovers on your HU are for the pre-amp outs on the back of your HU and not just for whatever's coming through the built-in power amp in the HU. I have a JVC and that's how mine works.

suleman36 · Post by **suleman36** » Mon Jun 05, 2006 4:18 am

Mine has 3 preouts. 1 for the sub, one for the mid/rearfill and one for the fronts