wvince

Since March this year I've been tweaking my system. Quick background: Started in March with Pioneer Premier HU, JL 12" sub in sealed box, 4" and tweets in front doors, 3-1/2" and tweats in the rear deck, all running off 1 4ch amp. Sub was bridged off rear channels and all mids and highs were running off the other 2 channels. Sounded ok. Was a rough install but looked stock with no visible wiring or speakers peaking out anywhere. Fried the amp doing things ought not to be done with an old school Alpine. Purchased a JL Slash 300/4 and added a small 2ch amp bridged to run the sub. Sounded good but could tell the old speakers collected more than just dust over the past 15 years. Didn't have depth. Took out the 4" from the doors and added kicks with 6-1/2" and soft dome tweats. Sound was much better but not as loud as I had anticipated. Added a 5-1/4" mid in the door figuring it would help with fill. Meh. Was ok. Took the 3-1/2" out of the rear deck and installed the 4" since they were a better quality. This helped more with a better sound quality overall. Not happy with the imaging I added tweaters to the sail pannel on the front doors aiming towards the center of the opposing window. This was going in the right direction but no near enough for my liking. Got rid of the 4" in the rear deck and installed 5-1/4" with soft dome tweats. They are the same model as what is in the kicks. Very nice sound and actually sound louder than the 6-1/2's in the kicks even though they are further away. So I have them tuned down to keep the front/rear balance more to the front. I've also added a class D mono block amp for the sub and purchased a class D 4ch amp, JL HD600/4. I'm using the 4ch and mono block in the system currently but have the Slash 4ch sitting there. All this is running on passive crossovers accept for the sub which is amp filtered.

I want to go active on everything. Since the slash is sitting there doing nothing I would like to run the tweaters with it since it is able to cut off at 500hz all the way up to 5k. Not that you would want to run a tweater at 500hz but realistically around the 3500 to 4000hz range. So that amp is good for tweaters.

Now on to the HD600/4 4ch amp for the 4 midrange drivers. It has similar active filters as the slash. I would crossover at 80hz. But what can be done for the high frequencies being sent to the drivers? Use a cap? The amp does not have the option to filter out high and low frequencies at the same time leaving only the mid.

Eventually I want to get another amp and run midbase active in the kicks and move the midrange and tweaters somehow to the dash or pillars, staying out of the doors as they sound very muddy with poor staging and imaging in the stock locations.

Suggestions on the midrange filtering? Is it possible in this active setup?

andrewsfm

iTrader: (3)

I think for the woofers, you're going to need a passive coil in the mix regardless.

The amp can do the high pass cutoff at 80Hz or so, but the coil will have to do the low pass under 4000Hz.

This is how I plan to run my Polk MM6501s.

Natban

Can your HU do a 3 way active system (Low/Mid/High) instead of SubW/Front/Rear with the 3 sets of RCA cables?

What kind of car is this in?

wvince

The HU can only do front/rear/sub configuration. It only has low and high pass filtering capabilities. This is in a 96 civic sedan. I am entertaining a new HU just to acheive what you're talking about.

For midbass would it be ok to use the preout filtered signal from one of the other amps (such as the mono block which is capable of passing a full range singal plus eq'ing) that allows everything above 50hz. Then feed it to the Slash with the low pass filter set at 200hz or so. Essentially giving a frequency range of 50hz to 200hz. Would I be risking midbase sound quality by doing this?

Is there an amp that will do active crossover points for midrange only?

Got another roll of sound deadening today. Guess what I'm doing Saturday.

Natban

You can see my HU set-up in my sig.

I just went through what sounds like a similar thing you're going through now. I'm still in the process of tuning my new set up.

I was always a fan of rear fill but now that I tried without them I realized the rears were only there to make up for the deficiencies of my front set up. I will never go back to rear fill again. Here's what I did with speakers and amp I had lying around since I don't have the big bucks for brand new 3 way component speaker system. My car is a 4 door sedan.

I removed the rear 6x9's, now there's 2 holes in my rear deck with the stock speaker grill covering them. This allows way more bass to enter the cabin as the Germans did a good job sealing up the trunk to limit road noise in my BMW and cleans up the sound staging.

I have 5.25" components with the woofer in the kick panels and tweets in the upper door panel. The passive cross over is something like 3.6khz @ 12db/octave to split the woofer and tweet and to have as high as 3.6khz coming from the kick panels facing my feet is why it needed the rear fill before. So I added a set of 3.5's in my doors just below the tweets (Infinity Reference, same as the 5.25's).

This also sounded like with the front RCA's driving the 5.25's and the rear RCA's driving the 3.5's. Then I realized how I could use my HU in the 3 way active system that it's capable of and it sounds great. Especially considering there just Infinity Reference with 60Wrms per channel x 4 Channels.

Here's the deal with the 3way set up.

Low RCA feed mono amp for 2 12's (LPF@80hz)
Mid RCA feed Channels 1 & 2 for the 5.25 woofers only(HPF@100hz & LPF@1khz)
High RCA feed channel 3 & 4 for the 3.5's and tweets(HPF@1.2khz)

Then I've used the passive crossover for the 3.5's and tweets. It keeps the 3.5s to a range of about 1.2khz to 3.6khz.

My SQ increased a lot when I wired them up like this.

Anyway maybe some of these ideas will help you. It sounds like you have enough speakers, amps and crossovers to mess around with something like this.

wvince

Thank you for posting this info. I was hesitant having crossover points in the middle of the voice frequency band but you confirm that it sounds better than with a wider pass to the kicks.

I've added the rear deck speakers just as you have experienced, the front kicks have deficiencies and the rears are making up the difference. Ideally a driver that faces you is likely to give the best SQ. Probably why my door speakers sound like crap in the stock location. But you have shed some new light on that subject.

I really do like the sound of the 6.5". Not that the 5.25" are bad sounding but they have a little more harsh sound, even though they are the same brand and product line.

Thanks again for helping. I've about worn out my welcome at the local car audio shop even though I've purchase an amp, HU and sub w/box from them. Basically they tell me I'm overthinking my system. I don't what just a loud system. I want clear, precise, near orgasmic live like sound coming from within my car when I sit in the drivers seat. The kind of sound that makes you want to sit in your car in the driveway for another 1/2 hour after getting home listening to various tracks that just sound great!

Natban

I know what you mean.

With the crossover points on my active deck there is a ton of adjustments between frequency, slope and gain setting for each set of RCA's. This will probably allow you to set the sound you're looking for.

wvince

Would a stand alone active crossover be worth getting/installing? I've seen the Alpine unit. Looks like it would do what I need.