Engineering failure .....

[HoseHead]

So I prototyped a system in my '95 Super Coupe.

Ti 500.4 driving Boston 6.53 components.
Ti 600.2 bridged driving qty 3 Boston 10.5LF subs in sperate chambers sealed. LPL connected.

6.5 LF drivers in the front OEM front cavities.
4MR drivers in the rear OEM cavities.
Tweets deep set on the dash next to the windshield - these are velcroed for now and are mobile.

Alpine 9856 HU front stereo outputs through an AC Four1.i - 4 outputs - Stereo signals for front and rear.
The rear channels through an AC Epicentre to the rear inputs of the 500.4.
The front channels directly to the front inputs of the 500.4
500.4 rear RCA outputs to the 600.2 inputs for subs.

500.4 (BA 6.53) is set to band pass. BA X-overs are bi-amped and perform the frequency dividing duties.
600.2 (10.5LF subs) is set to LP.

I have unlimited control over all signals.
Four1.i fader controls bi-amped signal levels between the 4MR/tweets and 6.5LF.
LPL on sub amp.
Epicentre controls bass attenuation duties for the 6.5LF and 10.5LF subs.
HU is flat with static volume set to 28 of 35.
AC components allow balanced signal between Four1.i and the Epicentre @ 7.5 volts peak.

The sound is excellent overall but mid bass gets really punchy when cranked up.
I figured putting the 6.5LF drivers in the front, mid bass would be awesome, but alas I was wrong.

I'll swap the 6.5LF and 4MR drivers around and put the tweeters next to the 4MR drivers in the front and 6.5LF drivers in the rear.
Anything below 60Hz is outstanding.

Pics and swap results coming soon.

HH

[nutxo]

Bummer. Sometimes shit just doesnt work the way you want it to. No way to eq it out eh?

[HoseHead]

As I mentioned, I have pretty well unlimited EQ, but it just don't pop across the full spectrum. Not an issue, just a little dissapppointed with the results is all.

I tried.
I failed.
I will adjust.
I will try again.
I will succeed .......

HH

[stipud]

Hmmm I am not a fan of running midbass in the rear. Above 60Hz the ear can locate frequencies, so if you put them in the back, your bass image will move back with them. In that case i'd say you'd even be better off with a simple 6.5 midrange + tweeter up front, rather than 3-ways.

Instead I would suggest moving your 4MR up to the front, but leaving the 6.5's where they are. Since your tweets are on the dash, you should consider doing fibreglass a-pillar pods for the 4MR and tweeter. The mudiness in your install is understandable if your midrange is coming from the back seat. With everything installed up front where they should be, you should get a much better balance. 3-way components were not designed for running in separate areas of the car!

[dedlyjedly]

I agree with Tom. Midbass up front is the bees knees, but not if you're sacrificing optimal positioning for your midrange drivers. I would also play around with the signal path a bit, as I don't imagine you're gaining much using the epicenter on the midbass signal, but it can easily cause non-linear results relative to your mids and highs. Also, unlike the LPL system that you could utilize on either of your amps, the Epicenter doesn't really attenuate anything at all. It's really designed to boost bass and even add bass to the signal that really isn't there via manipulation of the signals harmonics. That said, I probably wouldn't bother with LPL control on the midbass drivers either and just use it for the subs.

Have fun with your experimentation!

[HoseHead]

Thanks guys and I hear you loud and clear. I don't have room up front for all 6.53 drivers unless I fab something to house the 6.5 LF's. As mentioned by Eric. BA makes well engineered XOvers and I'd like to deploy them, though I do have enough channels and EQ capabilities to run them all active. I'll move them around as stated and see what's up. The current sound is very good, but the mid bass just don't drive me chest like my 6.5 KEFs do running off an MQ430 in an exact same ride. Standby for results. The change will take a day or two.

I appreciate the comments..........

HH

[HoseHead]

Corrected and results are outstanding. I had one 6.5LF wired in reverse causing the coil to deflect backwards. I also removed the AC Epicentre from the 6.5LF signal path.

When correctly connected, BA 6.53 comps are awesome. Bi-amped using all 4 channels of a Ti500.4 set to Band Pass using a stereo signal of about 7 volts from an AC Four1.i. Input signal split to feed both Front and Rear inputs. BA XOvers perform all signal directing - 250 watts per side - 125 watts feeding each 6.5LF and another 125 watts feeding each 4MR and tweet as a pair. Tweets set to 0db.

Even without a sub connected, the sound is full with great separation and excellent mid bass - the kind what you your chest appreciates.

Added qty 3 BA 10.5LF woofs in separate sealed enclosures of 1.24cuft as recommended by BA powered by an LPL controlled bridged Ti600.2 . I used the rear outputs of the AC Four1.i through an AC Epicentre. It goes boom and stuff now.

Very, very pleased with these drivers.

Thanks to all who have provided advice.

HH

[dedlyjedly]

Glad to hear you're making progress towards getting it dialed in!

When you're ready to get into a more involved fabrication project I would recommend placing the mid and tweeter combo together in the front of the vehicle. Then you'll realize the full potential of those drivers and passive network. That will really pull all the loose ends together seeing as the driver orientation was a MAJOR consideration in the crossover's design.

[HoseHead]

Understood. I'm scavenging a set of door panels to mock up for the complete BA 6.53 comps in the front stage. This winter's project.

I realized a benefit of using the rear outputs from the AC Four1.i for low pass duty only - through an Epicentre then straight into the sub amp. The front outputs drive the BA Comps. I can defeat the subs with the fader control. This allows for comp tuning without disconnecting anything. It also provides another sub level control along with the Epicentre and the LPL.

HH

[Thunderdome]

Understood. I'm scavenging a set of door panels to mock up for the complete BA 6.53 comps in the front stage. This winter's project.

I realized a benefit of using the rear outputs from the AC Four1.i for low pass duty only - through an Epicentre then straight into the sub amp. The front outputs drive the BA Comps. I can defeat the subs with the fader control. This allows for comp tuning without disconnecting anything. It also provides another sub level control along with the Epicentre and the LPL.

HH

I have been using a similar set up for years with a pa-2 to balance amps its really cool as your not adding distortion as your defeating the signal to a certain side not adding gain

sounds like a nice set up, got more pics?