[jontski]

Hi,

I installed last week the Focal IFBMW-S 2-way kit in my car, 2x front speakers 2x front tweeters. My car is a E90 2008 with Top Hifi.

I'm really dissappointed, in my opinion the original Top Hifi front speakers sounded better than the IFBMW-S set

Can you guys tell me is it even worth upgrading a Top-Hifi car with the focal set, or can it be that they should be running of a separate amplifier?

Thanks

[kaigoss69]

Separate amp would be better, but first try it with logic 7 off.

[kaigoss69]

Also keep in mind, speakers need time to break in.

[Socket]

Originally Posted by jpihlstrom

Hi,

I installed last week the Focal IFBMW-S 2-way kit in my car, 2x front speakers 2x front tweeters. My car is a E90 2008 with Top Hifi.

I'm really dissappointed, in my opinion the original Top Hifi front speakers sounded better than the IFBMW-S set

Can you guys tell me is it even worth upgrading a Top-Hifi car with the focal set, or can it be that they should be running of a separate amplifier?

Thanks

I am considering getting a focal upgrade, but reading your post has me second guessing... Can you let us know how it turns out

[jontski]

Okay thanks for the answers, I will let you know. It's not that bad but I think the treble is not as nice as with the OEM speakers... And also at high volume the focal does not sound like the oem did. I will try changing some EQ settings next

[bmw325i]

You replaced the 2 ohm speakers with 4 ohm so they are getting half as much power. The logic7 amp isn't very powerful to begin with.

[jontski]

Originally Posted by bmw325i

You replaced the 2 ohm speakers with 4 ohm so they are getting half as much power. The logic7 amp isn't very powerful to begin with.

Why would focal sell 4ohm kit for direct direct replacement speakers, when the oem are 2ohm?

[Technic]

Originally Posted by bmw325i

You replaced the 2 ohm speakers with 4 ohm so they are getting half as much power. The logic7 amp isn't very powerful to begin with.

Although the Logic7 OEM amp is rated at 45W at 2ohms for the mids/tweeters the actual mid/tweeter impedance is 4ohms -the tweeter is connected in parallel to the mid with a cap in between. The cap keeps the total impedance close to the 4ohms of the mid driver.

I have no idea of why these Focal speakers do not sound like $700 speakers in this particular system. What I do know is that I once tested a set of $700 Morel components in an Individual Audio system and I was disappointed as well. These Top HiFi systems are 100% matched, starting with the OEM amp. Aftermarket speakers designed to be used in all types of BMW audio systems will have a difficult time in significantly increasing the audio quality of these premium systems.

In particular, I have a problem with these Focals as they do not offer tweeter attenuation for non-OEM amp (Stereo)/non-tweeter systems, however they include a dedicated tweeter mount for non-OEM amp/non-tweeter systems installs. That may sound like crap without DSP correction.

And before mentioning BSW speakers... I think that they designed their speakers first with the Top HiFi system and then offered the speakers in other systems. A much better approach, IMO.

[bmw325i]

Originally Posted by jpihlstrom

Why would focal sell 4ohm kit for direct direct replacement speakers, when the oem are 2ohm?

There is more than one stock system. Also I doubt focal really cares that the stock systems are underpowered as long as their kits sell. I would just replace the amp. To do that you'll need to recode to hifi, get a da2, or replace the headunit since you have logic 7.

[ctuna]

Also anybody got a definitive answer on RMS versus Peak
power for BMW systems. I always assume its Peak when it
isn't clearly stated as RMS. Most aftermarket stuff always at
least has the RMS rating .
Marketing departments like to state the big number for sales
reasons.
But e90 speakers for BSW are only in the Top Hi Fi design(right?)
only one type so results with the others will be not as good
do to lack of power.

[david in germany]

Originally Posted by Technic

Although the Logic7 OEM amp is rated at 45W at 2ohms for the mids/tweeters the actual mid/tweeter impedance is 4ohms -the tweeter is connected in parallel to the mid with a cap in between. The cap keeps the total impedance close to the 4ohms of the mid driver.
.

Actually I think you are incorrect. The tweeter and mid are wired in parallel and the cap is only for the tweeter. Easy way to check this is simply unplug the tweeter and if the mid still works, parallel. Without the cap they are 1.333 ohm nominal but I think the cap should get them back up around 2 ohms. I will measure a set to verify though.

[david in germany]

Ok, just verified. 2.4 ohm for the pair.

[Technic]

Originally Posted by david in germany

Actually I think you are incorrect. The tweeter and mid are wired in parallel and the cap is only for the tweeter. Easy way to check this is simply unplug the tweeter and if the mid still works, parallel. Without the cap they are 1.333 ohm nominal but I think the cap should get them back up around 2 ohms. I will measure a set to verify though.

That would explain the Logic7 mid/tweeter impedance and why the OEM amp is rated at 2ohms. Stand corrected.

That Logic7 set of yours cap must be of a different value than what I had measured in a Stereo system (mid and woofer in parallel with the cap at the mid) by the way.

Even BMW says that they use a cap to keep the impedance close to 4 ohms in the Stereo system in particular when powered by the OEM HU:

The capacitor acts as resistance to the alternating current, and changes its value according to the frequency. The lower the frequency, the greater the resistance. This means that the total resistance (impedance) of the bass loudspeakers, capacitor and mid-range loudspeakers is in an uncritical range (4ohms) for the audio output stage.

Cap is not used when the iDrive unit (stable at 2 ohms) powers the Stereo system.

[kaigoss69]

To clarify some things that were said above, the tweeter added in parallel to the midrange will only increase the impedance of the speaker system ABOVE the tweeter crossover frequency. Let's say the in-line cap creates a 5kHz crossover and both the tweeter and the mid had an impedance of 4ohm. In general, one could say that above 5kHz, the impedance of the system would be 2 ohm, and below 5kHz it would be 4 ohm. When it comes to amplifier output, you should keep in mind that the majority of the current is used for the lower frequencies anyway, so the "extra" output in the higher frequencies is often negligible.

[david in germany]

Originally Posted by Technic

That would explain the Logic7 mid/tweeter impedance and why the OEM amp is rated at 2ohms. Stand corrected.

That Logic7 set of yours cap must be of a different value than what I had measured in a Stereo system (mid and woofer in parallel with the cap at the mid) by the way.

Even BMW says that they use a cap to keep the impedance close to 4 ohms in the Stereo system in particular when powered by the OEM HU:



Cap is not used when the iDrive unit (stable at 2 ohms) powers the Stereo system.

Every system has different speakers and different caps I would assume.

BTW, your Logic 7 harness is amazing! Thank you!

[bmw325i]

The logic 7 mid measures around 2.3 ohms dc. I'd call it a 3 ohm speaker. I don't remember what the tweeter is and I don't have any to check.

None of the stock systems will power anything worthwhile. Focal isn't going to advertise that more work needs to be done they are just trying to sell an upgraded set of speakers. Since the Focal kit is 4 ohms it is safe to power it with the headunit for those with the base system. It just won't be much of an improvement without an amp and proper eq.

[jontski]

Originally Posted by bmw325i

The logic 7 mid measures around 2.3 ohms dc. I'd call it a 3 ohm speaker. I don't remember what the tweeter is and I don't have any to check.

None of the stock systems will power anything worthwhile. Focal isn't going to advertise that more work needs to be done they are just trying to sell an upgraded set of speakers. Since the Focal kit is 4 ohms it is safe to power it with the headunit for those with the base system. It just won't be much of an improvement without an amp and proper eq.

So you mean it's not safe to use focal with L7 amp? I mean 4ohm speakers using 2ohm amp?

[mathematics]

capacitive reactance below the crossover point is higher, so when you parallel the two speakers, at a point lower than the crossover point, the system impedance is higher than at above the crossover point.

using 8uF for 5kHz @4ohm @6 dB/slope:

two 4 ohm drivers at 1kHz gives 3.33 ohms in parallel and at 10kHz gives 1.33 ohms in parallel (neglecting impedance characteristics of the other driver)

Originally Posted by kaigoss69

To clarify some things that were said above, the tweeter added in parallel to the midrange will only increase the impedance of the speaker system ABOVE the tweeter crossover frequency. Let's say the in-line cap creates a 5kHz crossover and both the tweeter and the mid had an impedance of 4ohm. In general, one could say that above 5kHz, the impedance of the system would be 2 ohm, and below 5kHz it would be 4 ohm. When it comes to amplifier output, you should keep in mind that the majority of the current is used for the lower frequencies anyway, so the "extra" output in the higher frequencies is often negligible.

[jontski]

Is it safe to use 4ohm speakers in 2ohm top hifi system? Or should I change the speakers back to the OEMs?

I don't want the amp to break :S

[Technic]

Originally Posted by jpihlstrom

Is it safe to use 4ohm speakers in 2ohm top hifi system? Or should I change the speakers back to the OEMs?

I don't want the amp to break :S

OEM amp is stable at 2ohms = stable at >= 2ohms.

The only problem that you have is that you do not like how the Focals sound with the OEM amp.

[jontski]

Originally Posted by Technic

OEM amp is stable at 2ohms = stable at >= 2ohms.

The only problem that you have is that you do do like how the Focals sound with the OEM amp.

Thanks, good

[Dioniz]

Maybe you have found a solution for logic7 upgrade?