[Beisofmarko]

Hey,

I have 2006 E92 that came with base system from the factory and
i have done quite big upgrades to it but it still could be bit better.
Now that i have everything working and done some dsp tuning
i'm facing a problem wheres the 4" midranges are playing too quiet
and it feels like they are suffocating / missing crispness compared to rest.

What would be the right approach here?
- Does aiming the speakers help alot? i can hear some improvements in crispness if i stick my head down infront of them.
- Or do i just need more power to midranges and maybe tweeters? Is there a 8-channel amp with dsp with more than 55w rms @4ohm?

My setup:
- Jehnert Flatline Kit (tweeters, 4" midranges, 8" underseats)
- Jehnert Doorboards (6x 6,5" midbasses)
- Helix match pp82dsp (8ch dsp 55w rms @4 ohm, 6 of the channels going -> 1ch per tweeter, 4" mid, 8" underseat)
- Audio System X-330.2 (2ch 850w rms @1ohm, 1ch per 3x 6.5" midbasses)
- Technic 4/6 stereo harness
- Mr12volt bluetooth box in MOST loop
- HU recoded to Hi-Fi
- Dampened doors

I have tried playing with channel gains on pp82dsp but even setting gain to
max of +5db, there is no distortion at all but the crispness from 4" midranges is missing
since they sort of fade under everything else.


Crossovers and gains are set around;
- 8" underseats 45hz - 180hz (+3db gain)
- 6,5" doorboards 55hz - 252hz (2/10 gain)
- 4" midranges 252hz - 3000hz (+4db gain)
- tweeters 3000hz - 20 000hz (+2db gain)

I see helix V eight dsp has 8x 75w rms @4ohm but does 20w rms make a big
difference? it's 1000 euros after all..

OEM HU, 8-channels, having a dsp and technic harness being limiting factors
on what kind of amps i can connect.

And lastly, this system sounds insanely clean/good allready compared to start, also much better than Hi-Fi system on F11 that i got to listen.
But it could just have bit more crispness on vocals and highs. Then it would be closer to perfection.

So i'm up for suggestions if theres some and then i'll see if it's worth pursuing.

Thanks in advance!

[ctuna]

I think the Jehnerts guy's suggest you use two channels between
two of the 6.5's and on split between one of the door 6.5's
and the on under seat that is on that same side. Plus another
channel to the the normal factory 4 inch plus tweeter position.
I am not sure if this is series parallel but there is a thread that
discussed this somewhere here .
Or was that you that started that thread ? It's been awhile.

Kind of not surprising that the 4 inches can't keep up with the 6.5's
I wonder if better 4 inch speakers would help maybe morels.

Maybe some tuning would help.
If its a matter of volume not being enough then more power would help.
But you do have a lot of mid ranges competing against one 4 inch and a tweeter.

[Ali-E90]

Not quite related, but is it "normal" to have such a huge overlap of frequencies between the 8" and 6.5" speakers?

Maybe isolating those frequencies will mean less cancellation, allowing you to lower the midbass further, and not over power the mids as much? Maybe currently the midbass are too high, because of the cancellation for a large part of the crossover range.


Am I out to lunch, or does that make some sense? (I'm not a pro, but have been into car audio for a long time).

[kaigoss69]

I think 55w should be enough under normal circumstances, but I can clearly see that they have no chance of keeping up with the 850W going to the door boards. You should try using an RTA app to get a frequency response (playing pink noise) to see if there is a big level mismatch. Perhaps there could also be a wiring problem (phase), which the RTA would help uncover.

I also agree that having overlapping frequencies between the door and underseat woofers is perhaps not ideal, and can cause cancellations and muddy the overall mid bass response. I would cut the understates completely out in this case. However, this has nothing to do with the midrange.

[kaigoss69]

Oh, and you could try raising the crossovers to somewhere around 400-500Hz, which would reduce the amount of power required by the midranges, as long as that does not affect your imaging too much.

[Emilime75]

The door mid bass and underseat overlap isn't necessarily the problem...there could be issues there, but any phase issues and cancelation would be in the frequency range they're playing, not higher up in the midrange.

I don't know what the Jenhert midranges are supposed to sound like. Are they considered an efficient driver? What is their frequency response like? Maybe they're dull midranges to start?

Aside from that, you have a ton of drivers and power in the bass/mid bass region, and very little in the midrange. Additional tuning may be needed. What type of eq does the pp82dsp have? Is it graphic? Parametric? How many bands?

Of course, there's always the issue of phase between all drivers and timing to the driver's seat/ears. It's less noticeable the higher in frequency you go, but it can still be problematic. Does your DSP have adjustable time delay? Speaking very generally, the closer a driver is to your ears, the more it has to be delayed in order to reach your ears at the same time as the rest. This is more for imaging and staging, but it can also effect nulls in the overlap between drivers. Don't forget that crossover settings aren't brick walls. Depending on slopes, a driver will play frequencies beyond what you set the crossover to. What options for slopes does your DSP have?

Furthermore, "crispness", to me, means upper midrange when talking about a 4" driver. This leads back to the driver's parameters and frequency response. Turn off your midbasses and listen to the mids and highs on they're own. How do they sound? Use EQ to tailor their response, then bring the mid basses back up slowly and see what happens. Is there a point where you lose midrange?

[Beisofmarko]

Thanks for the replies guys! Been busy with the work so haven't been able to update this.

Originally Posted by kaigoss69

Oh, and you could try raising the crossovers to somewhere around 400-500Hz, which would reduce the amount of power required by the midranges, as long as that does not affect your imaging too much.

Good point, i will try this and see how it affects. Going to do a new fresh tune
anyway soon as i have spare day or two to sit in car with RTA mic and laptop.

Originally Posted by kaigoss69

I also agree that having overlapping frequencies between the door and underseat woofers is perhaps not ideal, and can cause cancellations and muddy the overall mid bass response. I would cut the understates completely out in this case. However, this has nothing to do with the midrange.

What do you mean but cutting the understates completely?

Originally Posted by Emilime75

What type of eq does the pp82dsp have? Is it graphic? Parametric? How many bands?

It has 30 bands each channel. graphic, fine, parametric eq.
Has plenty of room for tuning.

I'll start with tuning and see if i can get it better that way and
go from there. Maybe that will do the trick and i don't actually "need" more power.
Thanks again!