[DEE-83]

Hi All,

What would you recommend for the HP & LP settings on a BIT Ten for the following equipment installed in a bmw e93.

MB Quart Nsc475 4ch Amp - MB Quart QM200.3BMW

MB Quart Nsc750 Mono Amp - MB Quart PWH 302 - 12" Dual 2-ohm Subwoofer

I currently have the settings as follows,

Mids - Hi - Passed @ 200 Hz
Woofers - Band Pass - ( Lo - Passed @ 200 Hz & Hi - Passed @ 80 Hz )
Sub - Lo - Passed @ 80Hz

All slopes have been set 12 dB. I'm I right in assuming that the actual HP / LP settings on the amps should be matched to those on the BIT ten or are these overridden by the bit ten.

Any pointers would be welcomed.

[Thumperx]

Looking through you thread, if your Bit Ten has crossover capabilities, then use DSP crossover than amp's crossovers. Active crossovers are preferred than passive crossovers.

Look at your high level stats, your mids are crossed too low, raise your crossover values up to 400 hz. You've not mention this, I will assume your mid speakers are actually coaxial which combines tweeter & mid.

Then "woofer" will control mid-bass range (400hz-140hz). This range emphasize cellos, bassoon, French Horns, and male voices. Don't be afraid to experiment with a small amount of cross overover lap to fill up the crossover dips. If DSP or amp crossover have slope capabilities of 24 or 36db, then steeper slopes maybe more useful than 12 db.

If DSP or amp have speaker phase switch (0-180 deg) assigned to each channel, then experiment if voice improves sound stage or not. Voice will be fuzzy and lack depth if out of phase. If in phase, the voice will be sharp and natural.

If you decide to continue using 12 db slopes, which offer smoother speaker transitions (sometimes), then I encourage you to experiment aggressively with the crossover overlap.

After crossover setting have been finalized, then begin working with EQ. Once here, your system should very close to optimization. EQ'ing is small amounts of cuts (mostly) and boost.

One last thing, don't forget to set your gain structure appropriately before you starting crossover and eq settings. You are tackling the most difficult parts of sound settings. Take your time and give your ears break time. Towards the end, it should be sounding very good.

Have fun.

[DEE-83]

Thanks for the reply Thumperx

[Thumperx]

Dee, thank you for the thank you, however I hope you understood most of what I've said.

[DEE-83]

Originally Posted by Thumperx

Dee, thank you for the thank you, however I hope you understood most of what I've said.

I did thanks, all i can say is Tin Pan Alley is sounding amazing.

[Thumperx]

Originally Posted by DEE-83

I did thanks, all i can say is Tin Pan Alley is sounding amazing.

Cool beans.

One last item, consider lowering your woofer / sub crossover point at 60 Hz. Most subs capabilities don't have the upper range extension compared to a woofer. Your mid bass response should improve subtlety. Also, bass shouldn't muddy mid-range.

Once done. Be happy and LEAVE your system ALONE & enjoy! Hahaha

Cheers

[DEE-83]

Thanks again, everything is sounding so much better with your last recommendation. I was really considering changing the speakers etc before this.

[Ali-E90]

Originally Posted by Thumperx

Cool beans.

One last item, consider lowering your woofer / sub crossover point at 60 Hz. Most subs capabilities don't have the upper range extension compared to a woofer. Your mid bass response should improve subtlety. Also, bass shouldn't muddy mid-range.

Once done. Be happy and LEAVE your system ALONE & enjoy! Hahaha

Cheers

Having read your two posts, it looks like you've left a gap between 60 and 140Hz.

What works for me is:
Sub: 60 or 80 LPF
Woofers (under seat): 180 to 60/80 BPF (match HPF with sub LPF)
Mids/tweeters: 180 HPF (with component crossover doing duty for separating mids from highs)

Different speakers may or may not be able to play down to 180 in the doors, but the key is to have coverage for the whole spectrum and not leave any gaps.

So if your doors don't play below 250, you'd want your under seats to start playing at 250 instead of 180.

[DEE-83]

Ali,

Thanks for the pointers, i'll been struggling to find what the listed Frequency response's are for the mb quart QM200 speakers are.

[Ali-E90]

Originally Posted by DEE-83

Ali,

Thanks for the pointers, i'll been struggling to find what the listed Frequency response's are for the mb quart QM200 speakers are.

I don't know for sure, but I think those should be good to play down to 200 or so. Just feed them with appropriate power.

If you put your underseat woofers playing as high as 400hz, it won't be very clear and may sound boomy or muddled.

[Thumperx]

Agreed Dee, MBQ speaker info is lacking.

Hmm, since OP mentioned that his original crossover points are set at 200 HZ & 80 HZ. I suggested raising it up 400 HZ (low pass, QM200’s tweeter and woofer group), causing OP to band pass 400 Hz through 60HZ for the mid-bass woofer, and lowering sub crossover from 80 to 60 HZ (PWH 302) and listen if there’s an improvement or not. It seems OP reply produced a positive result, not negative. BTW, what gap (@140 HZ)?

As you know Ali, when it comes to car audio, this is a subjective business. There are too many variables: ear types and sizes, small car spaces, many surface angles, low and high reflective surface materials, speaker sizes, power, and overall installation. I advocate, try it out, see if suggested setting works. If so, great. If not, go back to step one and keep trying.

Looking through your comments, as you know, there’s a big difference between crossover setting and EQ’ing. You’ve used a qualifier term “may” which could produce “boomy” or “muddled” sound results. When boosting some of 500 HZ -60 HZ frequencies, this may easily net these types of results.

(This section is for OP than Ali) All crossover (use Bit Ten network system) jobs are to promote a speaker transitions from one speaker type to another. Along with this, a tuner (most of us) may want to emphasize each speaker group's best ability to reproduce natural sound within that given speaker’s range. This is why I suggested limiting 4” woofer (from sub 400HZ range) which may not be able to maintain reproduced sound levels through and down from 400HZ to 250 HZ (or less) frequency ranges (roll-off). If OP mid drivers were 5.25” or larger, this topic would be a moot point. However, most 8" mid bass woofer (underneath the seat) can be extended just above 400HZ.

For now, my suggestions for DEE, achieve the objective task of crossover settings that may lead to an improved sound quality. Once done, then transition into optimizing sound quality. For that, then we can get into the science of EQ’ing, and that’s another discussion. Hahaha

[DEE-83]

Thumperx & Ali, thank you both for your input.

I have tried both settings and Thumperx's latter recommended settings, seem to appease my ears more.

However i have got Ali's settings saved on one of the two profiles on the system and will test them both again.

For now, i have two good starting points to work from.

Thanks again

[Ali-E90]

Originally Posted by Thumperx

Then "woofer" will control mid-bass range (400hz-140hz).

Originally Posted by Thumperx

Hmm, since OP mentioned that his original crossover points are set at 200 HZ & 80 HZ. I suggested raising it up 400 HZ (low pass, QM200’s tweeter and woofer group), causing OP to band pass 400 Hz through 60HZ for the mid-bass woofer, and lowering sub crossover from 80 to 60 HZ (PWH 302) and listen if there’s an improvement or not. It seems OP reply produced a positive result, not negative. BTW, what gap (@140 HZ)?

Thumper, maybe I misinterpreted your first post (captioned above), where it sounded like the underseat woofer was bandpassed from 140-400, which would leave a hole from 60 to 140.

Your second message clarifies that the underseat woofer is playing 400 to 60, so there is no hole, but again, my comment was based on the first caption I have included above.

And yes, you're absolutely right, it is ALL subjective, and there are numerous variables. I was just trying to share what seems to work for me running a 3-way E90 drop in kit, plus a trunk sub. Mine isn't MBQ, so of course different speakers will mean what works for me may not be ideal for OP.

Anyway, posts like this I'm glad that the people on the forum are forthcoming with info, and I just try to contribute where I can to "pay it forward" as they say.

Good luck OP and keep us posted!