[Billfitz]

Learn how to use speaker modeling software and you won't have to use trial and error to know how any driver will perform, provided you can get the specs. The P3-S is another example of a driver that complete specs are not available for. They provide most of them, but not all.

[egrimisu]

Originally Posted by Billfitz

Learn how to use speaker modeling software and you won't have to use trial and error to know how any driver will perform, provided you can get the specs. The P3-S is another example of a driver that complete specs are not available for. They provide most of them, but not all.

I would like some tips or point me to some basic documentation please.

[Billfitz]

Start here:
http://techtalk.parts-express.com/fo...building-bible

This is one of the loudspeaker modeling software programs that I use:
http://www.linearteam.org/

If you search WinISD you'll find many resources, including youtube tutorials.

[instalher]

Selling car so pulling the fosgates out and selling them. 300 plus shipping for someone.

[Pepppie]

So if I’m understanding it right; there’s no need to replace the subs under the seat? I’m planning to replace my amplifier (hifi-system, option S676A) with an Audison AP 8.9 BIT.

Of course I will replace the front door speakers with Audison APBMW K4E (with tweeters).

[Billfitz]

There's no need to replace any of the drivers if you have the hi-fi or H-K option. The OEM hi-fi driver works better than the APBMW K4E. The BMW amp can be improved upon, but not by the AP 8.9 BIT. The Audiotec Fischer Match Up 7BMW is better. If you still find the bass lacking it has enough power to get the most out of the only woofers I've seen that are a worthwhile change, the Earthquake Sound SWS 8X.

[Pepppie]

Originally Posted by Billfitz

There's no need to replace any of the drivers if you have the hi-fi or H-K option. The OEM hi-fi driver works better than the APBMW K4E. The BMW amp can be improved upon, but not by the AP 8.9 BIT. The Audiotec Fischer Match Up 7BMW is better. If you still find the bass lacking it has enough power to get the most out of the only woofers I've seen that are a worthwhile change, the Earthquake Sound SWS 8X.

The original door speakers without tweeters are better than the APBMW K4E?!

[Billfitz]

If you have the hi-fi system you already have tweeters in the front door 'A' pillars. The rear doors benefit from adding tweeters, placed as high as possible. I added a pair of these:
https://www.amazon.com/JBL-GTO19T-Pr.../dp/B00881CT1Q

This is how they look installed:

[Pepppie]

Nope.. mine only has woofers, no tweeters!

[Billfitz]

F30s with the hi-fi option do. You're in the wrong forum. In any event just add front tweeters too. If yours has 'A' pillar trim similar to the F30s you can mount them there.

[Pepppie]

Strange.. thought F30 and F31 are the same

[Billfitz]

They are. Your profile says you have an X2.

[Pepppie]

Indeed! And also a X6.. Some people have more cars 😉

[zedsterr]

I have the Harman Kardon speaker system in my F36, from what i'm reading its not worth upgrading the speakers themselves...

However, is it worth upgrading the amp? if so any suggestions or improvements would be appreciated.

Thanks in advance.

[GregorymBarela]

I installed the Rockford Fossgate direct replacement 8" under the front seats without an amp and it's great. Definitely want to get an amp ASAP because from what I read the stock subs under the seat are fine and can be ran with an amp and supposedly sound fine. I didn't care too much for them. My rear view mirror finally shakes the slightest bit after breaking in the sub

[Billfitz]

The Rockford Fosgate T3 isn't as loud as the stock BMW eight, in either the hi-fi or H-K configuration.

I have the Harman Kardon speaker system in my F36, from what i'm reading its not worth upgrading the speakers themselves...
However, is it worth upgrading the amp?

From a power standpoint the H-K isn't bad, but the very limited EQ capability can be improved upon with some aftermarket amps. The down side is that their EQ can't be adjusted in iDrive, only with an external PC. A plug and play amp with 15 or more bands of EQ that interfaces with iDrive would be ideal, but none exists that I'm aware of.

[Zack1uk]

Mmmmm, was about to pull the trigger on some replacement subs (either the Matchs or Gladens), but after reading this I'm of a second mind. I only have the UK base system, so it seems that I'd be better off with a pair of standard hifi level drivers under the floor (particularly as they can be picked up 2nd hand for circa £40 a pair). Please correct me if I'm wrong?

I've just bought an 2nd hand audison Prima AP5.9 for a good price and was thinking about running a pair of Audison prima or Focal components actively in the door (2x20W tw, 2x50W Mids), and then using the single sub out to run a pair of subs in parallel (270W @2 ohm).

I see that the hifi subs have been measured by billfitz at 3.4ohm so two in parallel would be 1.7 ohm. is that going to push the Audison AP5.1 too much?

[Billfitz]

As I recall the UK base system has 6.5 inch under seats, so even without a more powerful amp the OEM 8 inch will be better. Someone here did that, a search should turn it up. I believe the stock base head unit has separate amps for the under seats, and most aftermarket amps do as well. If you have an aftermarket with only one sub amp but it's rated for 270 into 2 ohms you're probably OK if you don't overdo it with the volume.

[Zack1uk]

Originally Posted by Billfitz

As I recall the UK base system has 6.5 inch under seats, so even without a more powerful amp the OEM 8 inch will be better. Someone here did that, a search should turn it up. I believe the stock base head unit has separate amps for the under seats, and most aftermarket amps do as well. If you have an aftermarket with only one sub amp but it's rated for 270 into 2 ohms you're probably OK if you don't overdo it with the volume.

Thank you. No, my days of loud listening are long gone...although I do still have a Focal Utopia 27Wx and a Focal Solid sub amp that I'm toying with the idea of doing a removable 'all in one' box for the boot. If only there was enough room to discretely fit my Genesis Profile 4 Ultra amp in, life would be grand!!!

[Zack1uk]

Originally Posted by Billfitz

As I recall the UK base system has 6.5 inch under seats, so even without a more powerful amp the OEM 8 inch will be better. Someone here did that, a search should turn it up. I believe the stock base head unit has separate amps for the under seats, and most aftermarket amps do as well. If you have an aftermarket with only one sub amp but it's rated for 270 into 2 ohms you're probably OK if you don't overdo it with the volume.

One more question if you don’t mind.

I’m going active and remember seeing somewhere that the stock subs should be crossed for LP somewhere between 100 and 150. The 4” components that I was going to use should be crossed for HP at 500hz (that’s what the passive x-overs crossed at). Most mid range components are similar it seems. Can the stock hi-fi woofers be crossed any higher without degrading the sound or do I need to look for a full range 4” (eg Dayton Audio rs100) rather than a mid range (eg DA RS100p) to take the HP value down to 150HZ?

Or am I worrying about nothing and all 4” are fine at 150Hz?

[Billfitz]

500 Hz is way too high, 120-130Hz is about right for the transition between the underseat woofers and the door midranges. By no means are all 4" fine at 150Hz, that's where software modeling comes in. Also, the Dayton Audio probably won't fit in the door, due to the large ceramic magnets. The OEM drivers have neodymium magnets to keep the size down. To the uninformed that makes them look cheaper than replacements with large magnets. In fact neodymium greatly increases the cost of the driver.

[Zack1uk]

@Billfitz Apologies, for taking this slightly off topic, but I’d really appreciate your further advice.

I completely get what you are saying about branded component speakers and the snake oil associated with the industry, so not only have I followed your advice re the hifi subs but i’m Going to do the same with the components in the front doors.

I can get the standard 4inch hifi speakers (2nd hand) very cheaply and a pair of logic 7 drivers for not much more. For some reason the HK ‘branded’ ones go for a lot more in Europe, even though (I understand) they are the same as the L7. I can’t find it now but I recollect that the L7 and HK units were quite high ohms. If you were in my position of dumping the stock base speakers would you replace them with hifi level or L7?

Also re tweeters, I have a pair of Infinity emit ribbon tweeters (thought by some to be un-bettered, but by others to be a bit bright) and also a pair of well regarded DLS t20. Would you consider using either of these or just going for the HiFi or L7 tweeters based upon which 4” I get?

The tweeters will be powered by the 50w per channel from the Audison AP5.9, whilst both the mids and the underseat woofers will be from a second 4 channel amp.....possibly an Audison AP4d (4x70w@1%), but most likely a 4x100w@0.1x% Genesis Profile 4 ultra that I have safely stashed away.

Thanks in advance.