globbits

Okay, the Legacy install is nearly finished now. Got Alpine DDDrive 6" + tweeters in the front and a pair of PPI flat-piston 10"s in the boot. System images nicely (that'll be time-alignment then ) and the bass from the subs is more than enough. Trouble is, have I got mid-bass? Have I BUFFALO!

I've tried fitting the DDDrives on simple collars, partly-sealed (small) enclosures, soundproofing the door, all sorts, but I just can't get any tuneful bass at all . The speakers are more than capable - they used to kick like mules in my 406 install I did before - but they just won't play in the Legacy.

Anyone got any ideas? Before I start mullering the leather door panels and making cabinets for the bottom of the doors?!!!!

Thanks guys

audio g man

A, Threaten them.

B, Shout at them.

C, Check phase.

D, Check they are both working.

E, Try a different mounting.

F, Buy a different car.

G, Wait for more responses.

chiark

Option C would normally be first point of call for midbass, or lack-of. Not sure if time alignment could affect that...

Check phasing first, then start playing around with phasing...

globbits

Like the suggestions
A) Didn't work - they said they knew where I lived and that, if I knew what was good for me, I'd leave 'em alone
B) They're louder than I am
C) Time-alignment should cater for that, but it's definitely worth a go. The odd thing is, when I run the system with no subs, there's still no bass-response
D) Yup - they are
E) They're mounted about as solidly as possible. Only thing I can try is a bigger cabinet, but that means chopping the door about
F) Unless someone's got a GT-B they want to swap for my LPG Legacy, I don't think that's an option!

Thanks - will try phasing this afternoon, but keep coming up with suggestions please!

chiark

Try playing with your balance control: full left, then full right, then centre balance. Does bass disappear when you go from one side to centre? If so, it's definitely phasing.

If not, make sure you're isolating the back of the drivers from the front as much as possible...

globbits

Isolating the back from the front? You mean to stop reflections/resonance? The likelihood is that that's the problem - the "cabinets" they're in are absolutely tiny (and thin) because there's no room inside the door skins for any expansion, and the hole where the speaker fits through the door card is small too

Ho hum - more playing

globbits

Well, it's not phasing! Just tried reversing the phase on either/both front drivers and no difference. Disconnected the subs and the bass is still low.

Played around with the time-alignment, and things have improved a bit, but not an awful lot

Chiark - did I understand you right about isolating the speakers from the back of the cab?

chiark

Naah, all i mean is that the air from the back side of the speaker cannot interfere with air from the front, as that'll kill you bass...

globbits

Bummer - in which case, I'm in stump-mode
I'm guessing it's resonance problems - the "cabinets" are only about 2cm deep, as that's all the depth available - the magnet and parts of the frame extend out of the back, through the original speaker hole.
I think what's happening is that the cone is getting hit with the sound reflection, when it's travelling back into the "cab". Looks like I'm going to have to open out the cab through the original hole.
Bum - thought I'd nearly finished the install!

globbits

Found some!!!!

Not as much as I'd want, but I increased the gains on the amp (all channels, from about 1/4 to about 1/2) and dropped the head unit output. End result is much better bass-response.

The only explanation I can think of is that the amps weren't actually coming in properly, so the low power stuff was getting lost. Of course, when you cranked the volume up, it was loud (and bassy) enough, just not at sensible listening levels.

So, not sure why, but seems to have made a difference.

As an aside though, anyone got recommendations instead of 6" Alpine DDDrive components, to give bass response up front in the car?

chiark

You've not got your head unit's loudness on or off compared to your usual setting have you???

globbits

Oh come on, chiark - give me some credit!!! :P
My system doesn't even HAVE a loudness setting!!!!

Alpine MD-TV head unit, PXA-H400 crossover/time-alignment unit, PPI 5440 amp..... (Soon to be changing to the PXA-H700 as soon as I can source one )

No, the mids are getting from 90Hz to 4KHz and I've put +2dB on the bass. Got some mid-bass now, but I think I'm suffering with cancellation. Trouble is, the solution is to angle the mids upwards at about 30 degrees. But, to do that, I've got to make some stupid builds that extend about 5" into the footwells!

If the H700 can't sort it out (it's got auto-setup with a mic) then I might try doing some builds to fit over the front wheel-arches, but I really didn't want to have to play that sort of game

audio g man

Well done Glob.

I fitted my DDDrive's on saturday and then promptly fell ill. Back to work today though.