[bdubz7]

Originally Posted by snekjumpr

Can you elaborate what you mean by airy?

Like vocals are added onto some beats. I'm not sure if that's the correct way to describe it.

Could be song-specific... I'm not sure?

Don't get me wrong, I think it sounds great in general

[snekjumpr]

If it’s what’s sometimes referred to as the high end being a little too bright, I think adding the 120 high pass filter to the doors and center speakers per the Audiotec Fisher recommendation might be helpful.

It’s fairly easy in the DSP tool, under the Outputs tab, where it says Highpass, you set Frequency to 120, Slope to -24db, and Characteristic to Butterworth or Linkwitz. What that should do is keep the lower frequencies out of all those mid and tweeter speakers, cleaning up the high end. Worth a shot as I thought it helped a lot.

[bdubz7]

awesome, thanks for that.

I'll give it a shot

[m440i804]

Originally Posted by bdubz7

Like vocals are added onto some beats. I'm not sure if that's the correct way to describe it.

Could be song-specific... I'm not sure?

Don't get me wrong, I think it sounds great in general

What are you crossover points set at for your under seat woofers?

[snekjumpr]

Originally Posted by m440i804

What are you crossover points set at for your under seat woofers?

Good point, a LPF on those would keep voices and higher frequencies out of the woofers. There's probably no filter by default. Went with 80 myself, hbu?

[snekjumpr]

I found that if you give the under seat channels a 3db gain boost in the DSP PC-Tool, you can feel a slight vibration in the seats, which is nice. You can find the slider on the righthand side of the Subwoofer 1 and 2 Outputs tab labelled Output Gain and Output Level.

[RCM78]

Originally Posted by snekjumpr

Messing around today with the DSP, for now I’ve settled on HP at 20 and LP at 80, just like the trunk subs. Also set input signal to 50% sub1 + 50% sub2. You lose some of the higher frequencies, but the bass feels tighter and more thumpy. Will be curious what others settle on.

So you're running both under seat subs in mono?

[dombi]

There are several thing that could help you guys.


1. Factory input signals.

I have an X5 with HK. iDrive 7.
So my system might be a little bit different.

The factory signals in my car are already "EQd".
Meaning they already have crossovers applied.

Green - Woofer input signal / Red - Front Full range speaker.


That said, I am using a LP of 170Hz, 24dB/oct on the Woofers.


2. EQ
Ideally, you want your Woofers (Left and Right) EQd the same way.
If they are not EQd the same, then in some areas they will help each other, while in other areas cause dips (or even nulls).

3. Time alignment
Speakers should be time aligned. If the sound from the Woofers arrive to you at different time, it will not sound good.

Time alignment is relatively simple in PC Tool.
You have to measure the speaker cone's distance to your listening position, and then enter the values in PC Tool.

4. Levels
You want to level match the Left and Right Woofers. They should be playing the same level (Left and Right side), measured from your listening position.

5. Check the Woofer's polarity.
This is also critical. The Woofers will have areas where they overlap with the Mids. If the Woofer's polarity is wrong, then the Mids and Woofers will cancel each other out. This will result in weaker "Bass" in that region.

You can try to play just the Front L + Woofer L for example, and flip the polarity of the Woofer. You might notice the Bass sounding better in one way or another.

Usually, if the Woofers were wired corretly, then the other Woofer should have the same polarity setting in PC Tool. But verify this by listening to them.


These are the basics.
If you want to make the system sound great, all these things have to be set for each speaker.

But since you guys are only talking about Woofers, these points might help you look for ways to improve the sound.

Ideally, when your speakers have the correct crossovers, are EQd, time aligned, level matched, with the correct polarities... you should have a pretty decent sound.

If you want to tune the system, then you might want to look into getting a measuring Mic, like the UMIK-1. Then with REW you could set and verify all of the above...

[snekjumpr]

Originally Posted by RCM78

So you're running both under seat subs in mono?

I think that's probably right. When I added the Front Full input to the Subwoofer signal, I could hear the higher frequencies going to those 2 woofers (the Ci5s can play up to 500hz), but I didn't think it was worth it. They seem to hit harder if you use only the subwoofer 1 and 2 signals.

[I800C0LLECT]

Here ya go...tuning guide

ttps://drive.google.com/file/d/1uckbRBGsdTVIl17XxINVf_DDoDyhHfVp/view?usp=drivesdk

[RCM78]

Originally Posted by snekjumpr

Bit the bullet and braved the cold. Really wasn't too bad after warming up a little.

Installation was super easy. Make sure you push the harness plug all the way until it clicks, which is obvious but you have to push it in firmly. Also, you don't have to remove the speaker frame that's bolted to the chassis, but you may need a pry tool to remove the OEM speaker and its attached mount once the 4 T20 screws are removed. They come out as one piece easily enough with some fiddling.

Sound-wise, I'm fairly happy with them so far. You can't low pass above 300hz with the DSP tool, but if you mute the other speakers, it definitely plays up to that range. It's particularly noticeable if you alternate between a trunk sub only low passed at 80hz and the under seat woofers at 300.

I may try 33% sub1, 33% sub2, and 33% Front Full L, just 50/50 sub1 and sub2, or maybe sub1+2 and Full Front L+R (25% each) as input signals to see if those options deliver more thump in the front sound stage. Might try to 120hz low pass to blend with the doors. Otherwise they're a solid thumbs up.

You can low pass wherever you want. Just manual enter the frequency instead of using the slider.

[snekjumpr]

Originally Posted by RCM78

You can low pass wherever you want. Just manual enter the frequency instead of using the slider.

That makes sense, thanks. I tried them at 300 and already thought that was too much info getting thru. And the bass sounded muddy until I got the LPF down to 80hz.

Basically I think they're best run as subwoofers only and not as dual sub/mid drivers. YMMV

[m440i804]

Are the front mids on your cars actually mounted into an enclosure in your door, or just kind of mounted to the bracket like free air?

I pulled my front door cards off today on my 440 and was surprised that the mids were just mounted to a bracket with nothing behind them. I think it will be hard to get any bass out of them that way. Seems like a bad design for performance. Have a set of es100ke’s enroute but probably won’t use them.

[dombi]

Originally Posted by snekjumpr

That makes sense, thanks. I tried them at 300 and already thought that was too much info getting thru. And the bass sounded muddy until I got the LPF down to 80hz.

Basically I think they're best run as subwoofers only and not as dual sub/mid drivers. YMMV

Ideally you want the Sub and the Woofers to play their own frequency ranges, and the crossover area between then to "blend".

This is not so easy to do without measuring the speaker's responses.

Depending on the situation, overlapping crossover regions can make the sound muddy. Or even weak (if there are cancellations).

Subs are usually not played very high for various reasons. They are most efficient, and sound the best in the lower fr. regions. The LPF 80 is generally where people cross them at.

So lowering the LPF on the Sub sounds about right. But without measuring, you won't really know what the situation is in the crossover area.

[dombi]

Originally Posted by m440i804

Are the front mids on your cars actually mounted into an enclosure in your door, or just kind of mounted to the bracket like free air?

I pulled my front door cards off today on my 440 and was surprised that the mids were just mounted to a bracket with nothing behind them. I think it will be hard to get any bass out of them that way. Seems like a bad design for performance. Have a set of es100ke’s enroute but probably won’t use them.

BimmerTech has a detailed speaker upgrade YT video for the G20:

[m440i804]

Originally Posted by dombi

BimmerTech has a detailed speaker upgrade YT video for the G20:
https://youtu.be/HRXV5e-6BTA?t=168

Thanks for the response, but my door cards are not the same as the G20. I’m trying to get information on my 2dr m440i.

[snekjumpr]

Yea that’s the plan with my umik mic. I may bring them up to 120 to blend with the doors HPF. I was just going by ear while muting all the other speakers for the time being.

[I800C0LLECT]

Originally Posted by snekjumpr

Yea that’s the plan with my umik mic. I may bring them up to 120 to blend with the doors HPF. I was just going by ear while muting all the other speakers for the time being.

Level matching the speakers will change the overall response of the system in the best way possible. That mic will help but you can try to use an iphone and an app if you have one laying around.

**I really have no idea** what you're running the 4" mids down to, 160Hz? You could probably hit 120Hz @ 24dB but they're running out of steam due to xmax.

Without a trunk sub there's physical limitations due to the size of the drivers under the seat. Most of these aftermarket drivers can't do much below 50Hz (same as factory). If you can put a filter at 40Hz and 24dB slope on the underseat speakers you will find that you can push them much harder without reaching their xmax and it sounds great. Matter of fact, I'm thinking about downsizing and removing my AuiodFrog GB10 subwoofer. That's how good the underseat speakers can be. There's just way too many rattles in this car to keep me happy down to 20Hz. I'm not in the mood to track down all the vibrations either.

[snekjumpr]

Yea I set a high pass on all the doors at 120 per the Audiotec rec.

[Raghza]

I really like the design of those Helix subs. How do they compare to Earthquake SWS-8xi? Better? Worse? About the same?

[snekjumpr]

I didn’t see the frequency response on Amazon, but the Xmax looks more impressive on the Earthquakes, almost 1 inch in each direction. My guess is you’ll feel more air displacement with that kind of movement of the driver.

[I800C0LLECT]

here ya go...

https://f30.bimmerpost.com/forums/sh...cal+K2&page=40




EDIT: Bill Fitz is a hero...but these aren't in-car measurements. You will get a better response in car due to cabin gain but the performance gap will remain

Originally Posted by Billfitz

This is the response of the original OEM BMW hi-fi woofer and the others in the same enclosure with the same amp, same drive level, in this case 1.5 volts:



All three are almost identical in the lows below 50Hz. However, most bass content is between 50 and 120Hz, and in that range the BMW driver is decidedly louder. If you're not upgrading the amp the BMW driver is the best of the bunch.

This chart shows the maximum output of those same drivers, which takes into consideration both their electrical and mechanical power limits:



From 70-120Hz the BMW driver remains the loudest. Below 70Hz the BMW and Audison are the same, so there's nothing to be gained from switching to the Audison driver. Below 70Hz the Earthquake is considerably better. However, you won't get that additional output unless you have an upgraded amp that can deliver at least 150 watts per woofer.

This is the type of data comparison that professional audio engineers like myself use to decide on drivers for their projects. I would not invest in any replacement driver, be it a woofer, midbass or tweeter, where I could not do a similar comparison. That requires having the full Thiele/Small specs on the drivers. Luckily for the OP they're available for the Earthquake and Audison drivers, while I measured the specs for the BMW driver myself. Most after market drivers don't list Thiele/Small specs.