[sparkymarky]

ive just compared the actual figures from this test with the original test where the door mids weren't connected - and yes, there is more response above 140hz then when the doors were not connected (and than when the engine was on), as follows:

With doors and no engine:

@ 140hz +3db
@ 150hz +3db
@ 160hz +4db
@ 170hz +1db (the problem 170hz zone)
@ 180hz +6db
@ 190hz +7db
@ 200hz +5db

[sparkymarky]

Originally Posted by bmw325i

Try 180 then 160. You want your crossover as low as possible, but like you said who knows how low stock speakers can play.

Before you do that I would try reversing the polarity on the door speakers or underseats to see if your dip at 170hz goes away.

Thanks, will try 180hz first.

[sparkymarky]

Hmmm. Just read the amp manual, and the 200hz i've set on the dial is actually 218hz it says. What a rather moronic system where the manufacturer knowingly marks the dial wrong and subsequently corrects it in the manual....

[sparkymarky]

Had this turn up today, so have just spent the last hour prepping a sub box - i opened the box (second hand) and it was chock a block with wadding which must have been impinging on the previous sub..... i've removed enough so there is a covering of the walls but that is all - the pictures look like it is stuffed due to the camera's lack of depth perception but the truth is there is little except for all wood faces.

It's a small box (circa 0.7 c.ft) although, somewhat coincidentally, almost Jl's exact recommended volume.....and i hope good for tight bass rather than deep warbling bass - not my thing at all.

This will be firing through the ski pass hatch when i fit it tomorrow.

[sparkymarky]

PS - the sub amp (alpine mrp-m500 300wrms) has a 24db crossover.

Where should i set this? Thinking around 50hz? Obviously it should interact with the underseats graph which seems to be tailing off at around 60-70hz

[ajaye]

Originally Posted by sparkymarky

PS - the sub amp (alpine mrp-m500 300wrms) has a 24db crossover.

Where should i set this? Thinking around 50hz? Obviously it should interact with the underseats graph which seems to be tailing off at around 60-70hz

This is where things get fun. You're trying to sum a 2nd order BW with a 4th order (blank). Certainly been done a million times before, but to do it right takes either a fair amount of trial and error and tuning or some pretty sophisticated software modeling. Play around with it, if cabin gain plays nice and you can eq to even sub bass out a little you may end up OK at the 50-55ish area on the low pass.

edit: by "right" I'm talking "on paper." In reality you just need to mess around until there are no more songs you can find that have something about the sound that pisses you off when you play them in your car.

[bmw325i]

Originally Posted by sparkymarky

PS - the sub amp (alpine mrp-m500 300wrms) has a 24db crossover.

Where should i set this? Thinking around 50hz? Obviously it should interact with the underseats graph which seems to be tailing off at around 60-70hz

Lol nice cat you got there.

I like my sub crossover set to 55hz. If I set it any higher, then 60-80hz starts to sound annoying to me. Since your sub has less output I would try 60hz to start out with.

[sparkymarky]

.At last. After some trial and error

No engine. Oem 8" hifi underseats and front components. No eq. Jl audio a4300 class a/b amp.
4 plotted lines, crossovers at: 218hz, 200hz, 180hz, 150hz, user manual adjusted crossover points.

[sparkymarky]

So everything is the kept the same except for crossover points on the amp. Looking to the great unwashed (i.e, me) it seems that 200hz gives the best response for this e90: best response at 170hz and the flattest response (albeit not the highest) post 170hz..... correct me if wrong.

here is the actual numerical info:

Freq 218 200 180 150
50Hz 75 75 75 75
60Hz 86 84 84 84
70Hz 88 86 86 87
79Hz 88 86 86 86
90hz 86 84 84 84
100hz 86 84 84 84
110hz 84 83 83 83
120hz 82 80 79 80
130hz 79 80 79 79
140hz 73 72 70 70
150hz 77 77 76 74
160hz 79 77 77 73
170hz 68 74 72 67
180hz 78 74 75 77
190hz 79 75 77 78
200hz 79 74 75 77

[sparkymarky]

Originally Posted by ajaye

This is where things get fun. You're trying to sum a 2nd order BW with a 4th order (blank). Certainly been done a million times before, but to do it right takes either a fair amount of trial and error and tuning or some pretty sophisticated software modeling. Play around with it, if cabin gain plays nice and you can eq to even sub bass out a little you may end up OK at the 50-55ish area on the low pass.

edit: by "right" I'm talking "on paper." In reality you just need to mess around until there are no more songs you can find that have something about the sound that pisses you off when you play them in your car.

Ha i know what you mean about the 'until it pisses you off bit'.

Well i "think" i've sussed that 200hz is the right setting for the mids (see last graph - but welcome your opinion). And tomorrow i'll do the higher frequencies (200hz - 22khz) (although my personal hearing stops at 19khz).

So I take on board your comments and will try as you suggest tomorrow with the sub.

[sparkymarky]

Originally Posted by bmw325i

Lol nice cat you got there.

I like my sub crossover set to 55hz. If I set it any higher, then 60-80hz starts to sound annoying to me. Since your sub has less output I would try 60hz to start out with.

Thanks, his (jasper's) eyes are actually round, not quite as pointy as the blurred photo would have you believe

Ok thats a vote for 60hz. So 50 and 60. Good to see they're all in the same ball park rather than the typical 80hz+.

[Rick328]

Thread resurrection, I know but...Thank you very much sparkymarky!

Just found this thread and it helps a lot to understand the tuning (and the limits) of my XD600/6 on stock hifi speakers.

[sparkymarky]

Originally Posted by Rick328

Thread resurrection, I know but...Thank you very much sparkymarky!

Just found this thread and it helps a lot to understand the tuning (and the limits) of my XD600/6 on stock hifi speakers.