I am running a set of boston pro 3 ways in my civic. The mid and tweeter are in the kick panels, the 6" is in the door. They do sound good, but they semm to lack a bit of midbass. The drivers are mounted onto a 16mm mdf baffle, and the door is properly deadened and sealed. Now they are being run actively off a ss 500-2, band passed between 80 and 365hz. They are getting about 150wrms, so i don't think power is the problem. When i lower the crossover frequency to try and get a bit more midbass they seem to have a coronary and start hitting their xmax, so my question is is this simply a matter of tuning (which i admit is bad) or should i look at changing them to 8"?

boston pro 6.5" midbass are pretty decent midbass. I would suggest lowering the HPF down to about 60 to 65hz (should have no problems). However don't go happy on the gains, run them fairly low, you have plenty of power there anyway so heaps of overhead.

how come your not using them off the passive crossover network? I thought the boston's made pretty decent crossovers?

If your running active, what crossover slope are you using?
18dB HPF at around ~60hz is about right. If your using a 24dB HPF, it might be a bit too steep for the midbass which is why you could be noticing a very steep roll off.

below 80hz is more into the sub bass region than midbass...

I have the boston crossover, just never used it, dunno why, just had an active lying around and enough channels so i thought i'd go that way. They are being high pass at 24db/oct by my 9815, i'll drop it down to about 65 with an 18db slope and see how it goes, might even try the passive crossovers and see how they sound.

Thanks for the advice.

watch out when using active...im not sure if the boston passive has zobel circuits or other protection circuits to stop frying your drivers...

They have been running active for about a week now, no probs as of yet. I am crossing the tweeters over at 2.5k, and the mids as mentioned before at 365hz. All slopes are 24db. I'm unsure as to whether the passive crossovers uses any sort of zobel equalization circuit, but all that would do would be smooth out the impedance curve of the speakers anyway, and as far as i can see there is no form of tweeter protection built into the passive crossovers, and i cant see them being any safer to use than an active system? Now all i have to do is rebuild my kicks to get some half decent imaging happening, anyone in wa wanna lend a hand, i have a fridge full of beer?

just a thought, you have checked that your speaker polarity is right haven't you?? If you're lacking a lot of midbass, it could be because you're left and right speakers are out of phase.

As the above posted said try changing the phase on one of the kidbass units you may have a phase problem. If they are wired up correct try one of the midbass units wires the other way round and see if that improves things.

well they are wired up in phase but i'll swap it around anyway and see if it makes a difference. Lowering the gains a little allowed me to drop the high pass to 40hz and the low pass on the subs is now 50hz and that has made a big difference, but i'll try swapping the phase anyway.

you may run into some trouble when playing music a bit louder with a HP of 40hz...what crossover slope did you end up using?
i think you might be putting too much sub bass into your fronts

I had a similar problem when i first installed my dynaudio 240gt's. For the first week or so the midbass was non existant, i was embarassed to show them to my friends. But 2-3 weeks after the install i am happy to say that the midbass has come to life and the definition is so sharp and precise i have now got a tattoo on my ass with a love heart and the dynaudio logo. I never believed in this breaking business until now. Also why not try going passive and see how that sounds? BA didnt spend all that R&D on those pcrossovers for nothing

i found my z6s to be a little lacking in the mid bass compared to my DLS Ultimate Pros, the z6s seem to be more natural where as the DLS are a little exaggerated (relatively speaking!!!!!!!)

maybe the pros are the same?

Well i changed the crossover point to 50hz, using a 24db slope, and turned up the gains a little and now there is heaps of midbass. The only problem is now is that the doors trims vibrate like crazy. I have already put a tin of gspot on each trim, but they still vibrate like mad, does anyone have any solutions for this? or to stop the window winders from vibrating? Also, i tried with the hp down to about 30 hz and it was only at really extreme levels that the woofers were showing any sign of distortion, and even then it was feint. Is it best to leave the crossover point higher and let the subs take care of everything below that, or should i get as much of the frequency spectrum as possible to the front?

that sounds a bit more like the Pro's i know

50htz is more than low enough for the front stage. Just watch out for doubling up of frequiencies by your sub(s)+front woofers.

i use the pro's, and found feeding good power (around 150w) and crossing over around 50hz, AND, using the factory passive networks, did the trick for me. also, you cannot be stupid with the gain/volume levels as this will simply overdrive the woofers and cause the distortion you have heard. basically, the trade-off for good midbass transition is slightly reduced power-handling.

one more thing - keep your subs crossoed over LOW and dont drive them too hard, this helps in supporting that mid-bass punch upfront. boomy, droning subs will usually make any speaker sound thin in comparison.

to get rid of the rattles... sound deadon some more... maybe consider fibreglassing the back of your trims? doors are a real pain with rattles.. but when you get rid of them it makes a huge diffrence!!!