[mike082802]

Originally Posted by Billfitz

I'd venture 90% of those failures are from abuse by kiddies who should be running dual 18" subs in the trunk to reach the levels they crave.

They're no better than stock. If I was going to make a change, and since I don't listen at levels that will make me deaf I have no reason to, I'd make the necessary mods to install 5 inch or 6.5 inch mids. This would shame any and every 3rd party BMW replacement driver on the market:
https://www.parts-express.com/Faital...waAgTbEALw_wcB

Take note of the price. Very high quality speakers don't have to be expensive.

would those drop in or need custom mounting brackets?
thanks

[Billfitz]

You'd have to do a major reworking of the doors, as they wouldn't even fit into the holes. Experience working with sheet metal would be a must.
If you wanted to go all out this one is even better, if you can figure out how to fit it:
https://usspeaker.com/faital%20pro%206pr110-1.htm

[VertigoAtHome]

Billfitz wondering if you could help me understand how to set crossovers/filters. For the setup where we have a mid/tweeter in the door and woofers under the seats, do I set a Highpass filter for the mid/tweeters to the low end of the speakers published FS and a Lowpass filter for the high end of the woofer's FS? Or do I need to bracket both the min/max FS using both filters (i.e. band pass?).

The amp I just installed (Match UP 7/DSP) has a sound setup file that is shown in the pictures below; first is the front mid/tweeters and the second is the woofers. Looks like they have set both a Highpass and Lowpass for all speakers which I guess I understand if they either think the speakers perform best with those settings or perhaps can't handle frequencies outside those settings without damage. I was a bit surprised to see the front mid/tweeters confined to only 1000 Hz. Aren't tweeters supposed to handle up 20 mHz? There's also a gap between the woofer's Lowpass and the mid/tweeter Highpass that I'm thinking is just an error.

[Billfitz]

You want to crossover from the under seats to the doors around 120Hz. Crossing higher than that will take some load off the mids, but you don't want to go too high or you'll lose directional information from the mids that the under seats can't deliver. It's normal to have a gap between the woofer low pass and midrange high pass, but it shouldn't be more than 15-20Hz.

Using a high pass on the under seats prevents cone over-excursion in the lows where they can't handle it. Where to place that depends on the woofer. With the OEM and 3rd party replacements with similar specs, which is almost all of them, 50Hz is prudent. With a low Fs long excursion driver, such as the Earthquake, 35Hz is appropriate.

If it has a crossover between the mids and tweeters that should be set around 4kHz. There should be no lowpass on the tweeters.

[VertigoAtHome]

Originally Posted by Billfitz

You want to crossover from the under seats to the doors around 120Hz. Crossing higher than that will take some load off the mids, but you don't want to go too high or you'll lose directional information from the mids that the under seats can't deliver. It's normal to have a gap between the woofer low pass and midrange high pass, but it shouldn't be more than 15-20Hz.

Makes sense.

Originally Posted by Billfitz

Using a high pass on the under seats prevents cone over-excursion in the lows where they can't handle it. Where to place that depends on the woofer. With the OEM and 3rd party replacements with similar specs, which is almost all of them, 50Hz is prudent. With a low Fs long excursion driver, such as the Earthquake, 35Hz is appropriate.

Ok.

Originally Posted by Billfitz

If it has a crossover between the mids and tweeters that should be set around 4kHz.

So as we covered in an earlier post my understanding is the X5 HiFi tweeters have a filter rather than a real crossover. For some of the replacements I've looked at, they do have real passive crossovers that come with the mid/tweeter pair. They appear to be set at 4 kHz as you stated.

Originally Posted by Billfitz

There should be no lowpass on the tweeters.

That makes total sense, wonder why Audiotec added a lowpass at 1000 hz in the sound file for the G05? Perhaps driving them with more power at high FS could damage them?

Thanks!

[Billfitz]

If there was a low pass at 1kHz the system would sound worse than an AM radio in a '53 Dodge, so I doubt that's the case.

[VertigoAtHome]

Originally Posted by Billfitz

If there was a low pass at 1kHz the system would sound worse than an AM radio in a '53 Dodge, so I doubt that's the case.

Hahaha, got it! I must not understand the DSP display then, cause it looks like it's set to 1000 Hz, it must not be active. Thanks again for your help!

[MrBigB]

Originally Posted by Billfitz

You want to crossover from the under seats to the doors around 120Hz. Crossing higher than that will take some load off the mids, but you don't want to go too high or you'll lose directional information from the mids that the under seats can't deliver. It's normal to have a gap between the woofer low pass and midrange high pass, but it shouldn't be more than 15-20Hz.

Using a high pass on the under seats prevents cone over-excursion in the lows where they can't handle it. Where to place that depends on the woofer. With the OEM and 3rd party replacements with similar specs, which is almost all of them, 50Hz is prudent. With a low Fs long excursion driver, such as the Earthquake, 35Hz is appropriate.

If it has a crossover between the mids and tweeters that should be set around 4kHz. There should be no lowpass on the tweeters.

Those are really useful information for me, much appreciated!

I have Matchup 7 BMW and am on the stage to set up the crossover point from trunk sub to under-seat sub to mid-range. I replaced all the drivers with Audison kit along with some high quilty Morel tweeters and even using custom x-over between 4" mids and tweeters since from my understanding the factory wired 4" mids only has a high pass filter which means it will play all the way up to 20k.

Tried multiple settings but still can't blending the trunk sub with the underseat sub well, I feel like the under-seat sub is too weak to bring the bass to the dash even I set high pass at 60hz for it. The other thing is I tried to set the cross point for mid-range and under-seat sub at 150hz, but still can't enjoy how it sounds, I will try to set low pass at 120 for the under-seat and leave the gap less than 20hz, coz I know normally the less bandwidth the better sound, right?

I would say I really hate how BMW decided to use the 8" under-seat sub instead of the 6.5" door mount mid-bass, it also limited the upgrade option since you can't directly install the aftermarket 2way or 3way kit.

[Billfitz]

I'd cross to an Audison APBMW underseat at 60Hz. Getting the balance right is going to take a combination of dialing in the EQ and the levels. The main problem you probably have is that the Audison has very low sensitivity, so it needs a lot more power than the stock woofer to reach the same levels. You might find putting the OEM back in works better.

The stock 8 inch under seats work better than 6.5 inch in the doors because the doors as enclosures can't be tuned to deliver a good result below 100Hz. If I was to go all out with 6.5 inch Faital Pro in the doors I'd still run them only down to 100Hz, with Earthquake underseats handling the low end.

[MrBigB]

Originally Posted by Billfitz

I'd cross to an Audison APBMW underseat at 60Hz. Getting the balance right is going to take a combination of dialing in the EQ and the levels. The main problem you probably have is that the Audison has very low sensitivity, so it needs a lot more power than the stock woofer to reach the same levels. You might find putting the OEM back in works better.

The stock 8 inch under seats work better than 6.5 inch in the doors because the doors as enclosures can't be tuned to deliver a good result below 100Hz. If I was to go all out with 6.5 inch Faital Pro in the doors I'd still run them only down to 100Hz, with Earthquake underseats handling the low end.

I see, the reason I like 6.5" door mid-bass more is it easier to set the crossover point between the mid-bass and mid-range of a 3-way system. Anyway, for the system I have right now I'm really straggling on setting the crossover for under-seat to door speakers, coz I don't have confidence on my 4" mids to play anything lower than 150hz, it sounds a bit dry when I cross it lower. Also, I don't want to cross the under-seat too high since it sounds bad when I cross it higher than 200hz, I think I will just leave the gap between and see how it works.

[Billfitz]

Running the underseats to 200Hz isn't going to work well. If you've got the APBMW K4E mids I can understand why you don't like taking them lower than 150Hz. They're not well suited to mounting in a door, so they start rolling off at 250Hz, and the excursion capability is a quarter what it should be. It's not that all fours can't go comfortably to 120Hz, it's that this one can't.

[MrBigB]

Originally Posted by Billfitz

Running the underseats to 200Hz isn't going to work well. If you've got the APBMW K4E mids I can understand why you don't like taking them lower than 150Hz. They're not well suited to mounting in a door, so they start rolling off at 250Hz, and the excursion capability is a quarter what it should be. It's not that all fours can't go comfortably to 120Hz, it's that this one can't.

Yes I have got the K4E kit for doors, but I'm only using the mid-range driver from the kit, I have my own passive crossover connected with better quality Morel MT350 tweeters. In this case, I don't mind swapping the mids to the one with more low-end capability, I can do 3D printing mount adapters as well. Any recommendations on the mid-range driver? Thank you!

Btw, I leave the center channel off at the moment since I can't set it up properly w/o hurt the stage width, do you guys running the center channel or just mute it?

[Billfitz]

I have yet to find a mid that specs out better than the OEM. They may be out there, but when it comes to getting the full set of Thiele-Small specs and SPL charts on third party replacement drivers it's 'Where's Waldo?' time. Most don't have them.

Edit: Researching another query I did come across a mid with full specs, the Audio Frog GB40. As is usually the case it's no better than stock in frequency response and sensitivity, almost identical in fact, so just swapping them in won't sound better or louder with the stock amp. They do have longer excursion capacity than stock, so if you have a more powerful amp they can go louder than stock. But at $549 a pair it's a steep price to pay for another 6dB.

[MrBigB]

Originally Posted by Billfitz

I have yet to find a mid that specs out better than the OEM. They may be out there, but when it comes to getting the full set of Thiele-Small specs and SPL charts on third party replacement drivers it's 'Where's Waldo?' time. Most don't have them.

Thanks for the input, I will cross the mids as high as I can and the under-seat as low as possible, and both with a 12dB/octave slope. It doesn't make sense to have the gap for me but hopefully, this will help the system sounds cleaner.

[Billfitz]

If you have the option for 18dB high pass on the mids use it. That reduces stress on them and allows them to be crossed over lower than with 12dB.

[Onizukachan]

Billfitz they actually go up to 30db/oct slope and choice of xover type, Bessel, etc.

Reading above confirmed what I heard yesterday during tuning, sws are 140 or below and mid can go down to 80 but no authority except from 100 up… so that’s how mine are set now, mids at 110 with 30db xover, amd slight overlap with sws at 125 or 130, sws are hp at 30db at 29 hz.

[Billfitz]

Very high slopes do result in maximum output capability above the crossover frequency, but that also reduce pass band overlap, which may not work as well as lower slope. Another way to approach it is with lower slopes and wider gaps, like low passing the subs at 100Hz while high passing the mids at 130Hz with 12dB slopes on each. The only way to know what works best in a particular installation is by trial and error.

[Onizukachan]

Yep. They were messing up the imaging and pulling soundstage down when I tried it the traditional 12-18 db softer slope, and left a hole if didn’t have some intentional overlap because of the poor mid bass of sws and lower output of the 4.
It was fun to tune them!

[Billfitz]

The SWS doesn't have poor midbass, it's just less sensitive in the midbass than stock. You can address that by either boosting the EQ in the 80-100 range or cutting the EQ below that and increasing the gain. There's always at least two ways of getting a desired result.

[Onizukachan]

Originally Posted by Billfitz

The SWS doesn't have poor midbass, it's just less sensitive in the midbass than stock. You can address that by either boosting the EQ in the 80-100 range or cutting the EQ below that and increasing the gain. There's always at least two ways of getting a desired result.

The later is what I happened to do. Nice to know I’ve been happening into the right solutions by following my ears.

[MrBigB]

Originally Posted by Billfitz

I have yet to find a mid that specs out better than the OEM. They may be out there, but when it comes to getting the full set of Thiele-Small specs and SPL charts on third party replacement drivers it's 'Where's Waldo?' time. Most don't have them.

Edit: Researching another query I did come across a mid with full specs, the Audio Frog GB40. As is usually the case it's no better than stock in frequency response and sensitivity, almost identical in fact, so just swapping them in won't sound better or louder with the stock amp. They do have longer excursion capacity than stock, so if you have a more powerful amp they can go louder than stock. But at $549 a pair it's a steep price to pay for another 6dB.

I get a chance to A/B compare the stock mids and Audsion K4E kit the other day, with the same gain and High pass filter at 150hz/12db octave, the lower end of the stock driver do sound richer and a bit louder. I have to say in this case the aftermarket audio gear even from a well-known brand not always a better sound.

[VertigoAtHome]

Billfitz I'm using a Butterworth filter with a 12dB slope for my crossover of both the mid (@ 140hz) and the woofer speakers (@ 125hz). I read that using a Linkwitz-Reily filter using a 24dB slope is preferable over a Butterworth at 12db since its LR filter is flat over the crossover region vs a 3dB bump (phase issues?) using Butterworth. While I basically understand (as in very basic) why one would use a 12 vs 18 vs a 24db slope, and what the various filters are trying to achieve, but how do you determine what's best by looking at the speakers specifications? I did read BCAE Passive Crossover Slopes, but given my limited experience with this stuff, it's hard to know what would be better for my system. Later this week I'll try it, but I was wondering what your thoughts are on this for a car audio application, an SUV in my case if that matters.

Second question is about using the speaker's Fs to determine a good starting point for the crossover. I read something about a rule of thumb being 2 x Fs but that seems extreme. Also read that you should set it just beyond the point where the impedance curve peaks and starts stabilize/flatten in a frequency response graph. From what I can see it looks to be maybe 1.3 x Fs value from what I see in some graphs I've looked at for 4in speakers. Is this the correct way to approach this?