[Bicax]

Sub polarity is reversed, it sounded very boomy otherwise.

The slope on my PDX-F4 is indeed 12 db/oct. I'll try lowering the sub amp LPF to around 55hz, and raise the HPF on the underseats amp to 80hz, and see how it sounds. That's one heck of a gap though, no?

[kaigoss69]

Not really, especially with 12db/oct slopes.

[bmw325i]

Originally Posted by Bicax

Sub polarity is reversed, it sounded very boomy otherwise.

The slope on my PDX-F4 is indeed 12 db/oct. I'll try lowering the sub amp LPF to around 55hz, and raise the HPF on the underseats amp to 80hz, and see how it sounds. That's one heck of a gap though, no?

Set them both to the same frequency. 55hz sounds about right I have mine crossed at 60, but I want to lower that a little.

[Bicax]

I did it in two stages to better understand the impact of each change.

Yesterday before going home I lowered the LPF on the sub to around 55Hz. I could only test for 15 minutes on my drive home, but it did sound better than before (bass and midbass seemed to blend better, any boominess was totally gone no matter the sound level). I didn't notice a gap.

And this morning right before coming to work, like a thief hiding in the shadows of my garage from the preying eyes of my better half (she's understandably slightly fed up with all the hours that I've spent in the car), I increased the HPF on the underseats to ~80hz.

The vibrations coming from the underseats seem to be gone (again, only 15 minutes testing when going to work in the morning). The sound seems cleaner, more precise.

However, I do notice a gap now. Some "thumps" on certain songs (the beginning of Jamiroquai's "Cosmic Girl" for example) are barely perceptible, when they should be felt.

I'll try to increase the LPF on the sub to ~70hz to see how it sounds. If possible, I would really like to avoid lowering the gain on the underseats.

bmw325i: do you also have the Jehnert underseats, and can they handle that low?

[bmw325i]

Originally Posted by Bicax

I did it in two stages to better understand the impact of each change.

Yesterday before going home I lowered the LPF on the sub to around 55Hz. I could only test for 15 minutes on my drive home, but it did sound better than before (bass and midbass seemed to blend better, any boominess was totally gone no matter the sound level). I didn't notice a gap.

And this morning right before coming to work, like a thief hiding in the shadows of my garage from the preying eyes of my better half (she's understandably slightly fed up with all the hours that I've spent in the car), I increased the HPF on the underseats to ~80hz.

The vibrations coming from the underseats seem to be gone (again, only 15 minutes testing when going to work in the morning). The sound seems cleaner, more precise.

However, I do notice a gap now. Some "thumps" on certain songs (the beginning of Jamiroquai's "Cosmic Girl" for example) are barely perceptible, when they should be felt.

I'll try to increase the LPF on the sub to ~70hz to see how it sounds. If possible, I would really like to avoid lowering the gain on the underseats.

bmw325i: do you also have the Jehnert underseats, and can they handle that low?

Yes I have jehnerts. You can use them even without a sub so I don't see why you are worried about them playing too low. It will sound worse with the sub playing up to 70hz.

[kaigoss69]

I agree, it is better to lower the HPF on the Jehnerts. You will get some vibrations of the floorboard, but this is unavoidable.

[Bicax]

I agree with both of you, it sounds a lot better with the Jehnerts playing lower.

Maybe the vibration I'm hearing is coming from the floorboard then. It's a shame you cannot eliminate it...

With that being said, I'm a lot happier on the bass/midbass side of things now Thanks a lot for all the help.

Regarding the highs/mids and the harshness of the center, I'm wondering if it would be worth it buying a different, warmer center? Kai, I know you suggested adding something to filter the higher frequencies, but what exactly did you have in mind? And instead of disconnecting the tweeter (is that possible on the Kappa?), what about adding a LPF around 4k (which is where the RTA shows me a spike now)?

[kaigoss69]

No, I meant there are floorboard vibrations, but in my car you can only feel them on the bottom of your feet and not hear them. If you actually hear some vibrations from that area, go outside the car, close the door and listen underneath the car. It's probably coming from the bottom if the side sill cavities but normally it is inaudible inside the car.

Regarding the tweeter, not sure how you could filter out those frequencies. To reduce the tweeter output perhaps you could cover it partially with some thick tape or even Dynamat...

[bmw325i]

You might need to sound deaden underneath the enclosures. First you need to figure out why it is vibrating.

If the center is too harsh try it without a center channel you might like the way it sounds without it.

[taibanl]

Originally Posted by Bicax

Sub polarity is reversed, it sounded very boomy otherwise.

The slope on my PDX-F4 is indeed 12 db/oct. I'll try lowering the sub amp LPF to around 55hz, and raise the HPF on the underseats amp to 80hz, and see how it sounds. That's one heck of a gap though, no?

Originally Posted by kaigoss69

Not really, especially with 12db/oct slopes.

'm late to the party so not precisely sure why this particular advise is given but 55-80hz is about half an octave! (40-80hz is 1 octave)- you wouldn't recommend gapping mids between 550-800hz- which his an equal sized gap just to put things in perspective.

to top it off those freq.'s (55/80hz) are already the -3dB points so you are looking at ~-9dB at the new effective crossover point of say 65hz

[kaigoss69]

You are forgetting that the corner enclosure likely has a natural peak in that area. Gapping is nothing new. Many SQ competitors use it. I used to run a gap between 50 and 70hz iirc and it sounded good. But every car and every ear is different.

[Bicax]

I'll listen more carefully whenever I get the chance, but this morning while driving to work I did get the feeling that the rattling/vibration is only coming from the passenger's side. I'm afraid it might be the right Jehnert underseat that possibly got damaged by the previous MS8 (or rather, the previous MS8 PCB).

Regarding the harshness, on a song with the guitar coming from the right hand side the sound really hurts my hears. I'm wondering if the harshness is also due to the Jehnert tweeters, and if adding the extra resistor that came with the Jehnerts to soften the tweeters would be worth it.

I'll start by trying to calibrate without the center after the Easter holidays and see how it sounds. Right now, I get a lot of sibiliance on any singer...

[taibanl]

Originally Posted by Bicax

I'll listen more carefully whenever I get the chance, but this morning while driving to work I did get the feeling that the rattling/vibration is only coming from the passenger's side. I'm afraid it might be the right Jehnert underseat that possibly got damaged by the previous MS8 (or rather, the previous MS8 PCB).

Regarding the harshness, on a song with the guitar coming from the right hand side the sound really hurts my hears. I'm wondering if the harshness is also due to the Jehnert tweeters, and if adding the extra resistor that came with the Jehnerts to soften the tweeters would be worth it.

I'll start by trying to calibrate without the center after the Easter holidays and see how it sounds. Right now, I get a lot of sibiliance on any singer...

Turn L7 off. Center wont be used and the only other difference is you wont have reversed phase info coming from rears (helps with imaging) but will give you an idea of a properly timed/tuned no center system.

[Bicax]

I unplugged the center and re-calibrated, and the sibilance/harshness was still there. Interestingly enough, it sounded a lot worse with processing defeat than with processing active (a lot less midbass), which is not always the case when I calibrate with the center on...

I've plugged the center back in, re-calibrated and removed 5db of the 5k-7k frequency range with the equaliser, and it made the sibiliance better, but it's still too harsh to my liking.

Did any of you with the Jehnert kit (mids + tweeters) install the extra transistor that came in the package? In the instructions it said to only add it if the highs were too strong, I'm wondering if this would be the solution (or one of the solutions) to my problem.

I've also calibrated for the front instead of the driver's seat. My better half was complaining a lot about the drums being too strong (how ironic), and indeed when sitting on the passenger's seat it was unbearable. So now I'm trying to find a way to optimise the sound for the front...

I'm also starting to think that I'll never be able to replicate the sound I had in my X5 due to the smaller volume and different angles of the E91.

[bmw325i]

Originally Posted by Bicax

Did any of you with the Jehnert kit (mids + tweeters) install the extra transistor that came in the package? In the instructions it said to only add it if the highs were too strong, I'm wondering if this would be the solution (or one of the solutions) to my problem.

It should help. The tweeters are on axis and the mids are off axis.

I can almost guarantee you'd have better results if you got rid of the ms8 and replaced it with a da2 or Alpine H800. I was having alot of small issues like you are describing with the ms8, and now it sounds 10 times better unprocessed.

Edit- you already have a da2 have you tried bypassing the ms8?

[kaigoss69]

If it sounds better to you unprocessed then the MS-8 was not for you anyway.

[taibanl]

Finally fed my MS8 a clean signal and voilÃ*, things are back to sounding great again

[kaigoss69]

Originally Posted by taibanl

Finally fed my MS8 a clean signal and voil*, things are back to sounding great again

Congrats! New HU or are you streaming from your iphone?

[taibanl]

Originally Posted by kaigoss69

Congrats! New HU or are you streaming from your iphone?

Air enabler. I still need to upgrade the DAC, I have a couple options on order right now

Edit: I plan on having the head unit replaced a second time now that I have a brand-new (march 14) service bulletin in hand

[Bicax]

I've been running the ms8 calibrated for the front stage for a few days now, and it has never sounded this good before. As soon as I set it for the driver, everything is more centred, but I lose a lot of feeling. I'm not sure how to describe it, but one of the consequences is that midbass is more muted. Centered, but a lot less present.

I haven't tried using only the da2 since that would imply going to the store (I don't trust my skill, or lack of), and getting rid of a 600€ investment...

But I'm thinking that indeed the ms8 might not be for me, especially since I'm a lot happier with the front setting rather than the driver setting...

[kaigoss69]

That doesn't make any sense! The front setting is a compromise between the driver's and passenger's seat. The imaging is similar to the BMW L7 stock system, where the singer sits near the left sail panel...not good! But then again I do remember reading about some people preferring front over driver. I don't get it unless for some reason the imaging ends up being different somehow from what I have. In my mind the only way that could happen is if the mic was put on the wrong way. Also, mid bass should normally not be centered, in most recordings it is spread out over the front stage without a specific location. There are some exceptions, especially on live recordings, where you have distinct right or left drum hits, or it can roll from one side to the other like in Dave Mathews "Say Goodbye" live version (which sounds very cool btw), but generally you should not be able to tell a specific location for the midbass.

[bmw325i]

Originally Posted by Bicax

I haven't tried using only the da2 since that would imply going to the store (I don't trust my skill, or lack of), and getting rid of a 600€ investment...

I'm not sure what you mean by this you just need to use RCA cables from the da2 to the amp and set your crossovers on the amp instead of the ms8. You don't have to uninstall the ms8 completely to test it out.