[MOB]

Me and the wife both have a 1 Series each, with basic stereo (no amp, no tweeters, just 4x 4" speakers and 2x 6.5" subs

Hers had Pro Head Unit, mine had Business Head Unit (both without Nav)

Hers has BT and USB, mine has neither

I have since;

- changed my H/U to a Pro one
- added L7 tweeters
- added L7 mids in the front doors

Whilst mine is now certainly better quality than hers, she has way more deep bass than me, mine is nearly non-existant

Any ideas why this might be the case?

My gut feel is something funny going on with the mids, perhaps somehow preventing the lows getting to the subs?

It will be having a Blaupunkt THA555 amp and SWS-8 combo soon so that should resolve it, I'm just curious as to why there is such a difference

[fdriller9]

What model year are they? The base system in all 3-series suck. Period. L7 is decent but the lows an mids aren't that great. Highs are pretty good but can be better. I know you don't have L7 but it is one of the better systems from BMW and it still isn't that great, compared to other manufacturer's premium systems.

[fdriller9]

Btw if you have 6.5" underseat woofers then those SWS-8s won't fit. They are 8".

[MOB]

Both 2008 cars, both now have OEM Alpine CD73 Pro Head Units

SWS-8's do fit whether you have 6.5 or 8" subs

My concern is why my wife's car has way more bass than mine, despite having the same crap system as mine, other than the changes I've made to mine as above

[Technic]

Originally Posted by MOB

Me and the wife both have a 1 Series each, with basic stereo (no amp, no tweeters, just 4x 4" speakers and 2x 6.5" subs

Hers had Pro Head Unit, mine had Business Head Unit (both without Nav)

Hers has BT and USB, mine has neither

I have since;

- changed my H/U to a Pro one
- added L7 tweeters
- added L7 mids in the front doors

Whilst mine is now certainly better quality than hers, she has way more deep bass than me, mine is nearly non-existant

Any ideas why this might be the case?

My gut feel is something funny going on with the mids, perhaps somehow preventing the lows getting to the subs?

It will be having a Blaupunkt THA555 amp and SWS-8 combo soon so that should resolve it, I'm just curious as to why there is such a difference

Did that Professional HU came from another car (used) or it is new?

[MOB]

It was used, but from a car with the same spec as mine

[VP Electricity]

Originally Posted by *********

Btw if you have 6.5" underseat woofers then those SWS-8s won't fit. They are 8".

Negative, Ghost Rider. The 6.5" have 8" frames and fit in the same enclosures. Same mounting holes.

I'm guessing that your system has a spectral tilt toward the highs to it, which hers doesn't have.

That HU might be coded incorrectly (is there a diag screen on a Pro HU? Turn HU off, then on and immediately press "M" for 12 seconds?)

[Lee Rambler]

I enjoyed the ghost rider comment

the L7 drivers may be more efficient, add to the exxagerated top end from tweeters combined with the top end eq boost in the basic system may make the bass seem weak by comparison.

did you do anything at the woofers when installing the L7 drivers? ie, did you mess with the wiring under the seats? you could have rewired something out of phase...

the 6's are built on an 8" baffle, that's why the earthquake fit

[MOB]

Originally Posted by VP Electricity

That HU might be coded incorrectly (is there a diag screen on a Pro HU? Turn HU off, then on and immediately press "M" for 12 seconds?)

Did the "M" thing, loads of info came up, what am I looking for?

[MOB]

Originally Posted by Lee Rambler

did you do anything at the woofers when installing the L7 drivers? ie, did you mess with the wiring under the seats? you could have rewired something out of phase...

Didn't touch the wiring under the seats at all.................

[ctuna]

Try biasing the fader to the front. Since the front two channels control the woofer I think.
Fixed Cap in the crossover needs to be a different value to accommodate the new speakers?

[VP Electricity]

When I've done it, I've had a screen that told me what sort of system it was programmed to. Maybe you have to scroll to Audio... different MY have had slightly different menus.

[fdriller9]

My bad. I've only worked with my system, which has the 8" woofer. Didn't know he 6.5" had a 8" frame. I just assumed.

[Technic]

Although the idea of the cap is to keep the 4 ohms impedance within the tolerance of the OEM HU outputs when connected to the parallel connection of the front and underseat speakers, by replacing the Stereo mid/full range (4 ohms) with the Logic7 4" component set (2 ohms) you must have changed the total impedance of your system and thus the amount of power going into each speaker.

Thus less bass than before.

I would check as well if your Professional HU really matches your VO.

[lachance]

Weak bass sure sounds like classic phase cancellation. I would definitely make sure the wires match up.

[MOB]

UPDATE

Fitted a Blaupunkt THA555 Amp & Harness, sounds nicer, but no improvement in bass.

The 4 channels of the amp are feeding the fronts (tweets, mids, subs) and the rears

I assume the issue is that the fronts & subs are sharing a channel as Technic mentioned above), so I need to pull my finger out and fit my SWS-8's asap, and power them from the 5th channel of the amp.

Also have alternator whine now, this is becoming annoying..............