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      01-12-2022, 06:27 AM   #1
SimonO
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Hifi 676 with L7 Woofers

Hi all,

Is there any reason why I cannot upgrade my Hifi woofers to L7 units? I am planning on installing an XD600/6 at the same time. I understand there are differences in resistance, but not sure if this would cause any negative affects.

Hifi units are 40W and 2Ohm, L7 are 70W and 4Ohm.

My last E92 had the entry level 6-speaker system. I did the Alpine upgrade complimented with L7 woofers and was reasonably pleased.

Thanks

Last edited by SimonO; 01-12-2022 at 06:41 AM..
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      01-12-2022, 10:22 AM   #2
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Quote:
Originally Posted by SimonO View Post
Hi all,

Is there any reason why I cannot upgrade my Hifi woofers to L7 units? I am planning on installing an XD600/6 at the same time. I understand there are differences in resistance, but not sure if this would cause any negative affects.

Hifi units are 40W and 2Ohm, L7 are 70W and 4Ohm.

My last E92 had the entry level 6-speaker system. I did the Alpine upgrade complimented with L7 woofers and was reasonably pleased.

Thanks

This will depend on the amplifier and if it can handle the lower impedance load.... Many amplifiers are not stable at 2 Ohms, capacitors can be non linear causing extra distortion, etc... With that said speakers tend to have different impedances and are not erally a flat 2ohm load. Amplifiers are often designed with some margin so it "might" work.

Some amplifiers might not handle the lower resistance so running the low resistance speaker could damage the amplifier. At higher powers the 2Ohm speaker could damage the amplifier.

It is always "safe" to use a higher impedance speaker on an amp (although it may reduce the achievable power) going with lower resistance doesn't always end well.

You can always try it or see if others have but it could damage the amplifier and might not sound very good.

-Rich
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      01-12-2022, 11:55 AM   #3
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The Logic 7 speakers are 4 ohm .
I have a Jl 600/6 and I ran the stock Hi Fi speakers a few days and
they did not blow . They did not sound all that good though they did
have more output. Don't know about the Logic 7 underseats but
the Hi Fi under seats suck. If the Logic 7 subs are like the Hi Fi 's I wouldn't
be rushing out to get them .

Also that spec they use for power is bogus . Because there spec is at 10 percent
distortion. At 1 percent distortion the the same under seats are at 55 watts at 1 percent
distortion which is still a high distortion spec compared to any decent aftermarket amp.

https://www.e90post.com/forums/showthread.php?t=1144129
chip specs link are in the above thread.

The spec on the Hi Fi system is 25 watts doors and 40 watts floor but it's at that same
bogus 10 percent distortion. This is why is falls apart whenever you turn the volume up.
The doors will sound better with amplification but the floors with stock Hi Fi speakers are
not moved that much forward.

Last edited by ctuna; 01-12-2022 at 12:06 PM..
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      01-12-2022, 12:04 PM   #4
rbryantaz
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Quote:
Originally Posted by ctuna View Post
The Logic 7 speakers are 4 ohm .
I have a Jl 600/6 and I ran the stock Hi Fi speakers a few days and
they did not blow . They did not sound all that good though they did
have more output. Don't know about the Logic 7 underseats but
the Hi Fi under seats suck.
Sorry I misread it which was the 4ohm vs 2ohm.

I agree that 10% distortion is a fake spec. 1% is probably reasonable and is the general definition of what is not considered clipping but getting 0.1% is much better....

The 4ohm speakers will not hurt the amplifiers but they might not have enough power to drive them to the full SPL(sound pressure level)/volume.

It will take twice as much power to drive a 4ohm speaker to the same volume (assuming that it has the same sensitivity which is a whole other topic).

At any rate it is safe to use the higher ohm speakers but if your amplifiers don't provide enough power then you could end up clipping and damaging the speakers rather than the amplifier which is likely.

For normal listening it should work fine but I would be careful pushing it to high SPLs to avoid clipping.

-Rich
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      01-12-2022, 02:17 PM   #5
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Thank you guys.

Perhaps I bought the L7 woofers in haste then. If I just upgrade the standard Hifi amp to JL 600/6 will I be happy, or will there be a want/need to upgrade the Hifi speakers too? Some people have suggested that just the amp will disrupt the balance?
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      01-12-2022, 03:44 PM   #6
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How much is a JL 600/6 amp worth? I can't see why you would go that route when the Match 7BMW wouldn't be much more? Which is simple plug-and-play, best bang-for-buck option for the HiFi. With DSP, you can tune it exactly to your liking

I contemplated replacing speakers, but now I don't think I will.

Last edited by TiAgAu; 01-12-2022 at 04:10 PM..
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      01-12-2022, 04:16 PM   #7
SimonO
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Quote:
Originally Posted by GovernUrMental View Post
How much is a JL 600/6 amp worth? I can't see why you would go that route when the Match 7BMW wouldn't be much more? Which is simple plug-and-play, best bang-for-buck option for the HiFi. With DSP, you can tune it exactly to your liking

I contemplated replacing speakers, but now I don't think I will.
I would be getting it for approximately half the price, but to honest I had no knowledge of the Match 7BMW. I may just put this on hold and do some more research. Thanks!
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      01-12-2022, 05:38 PM   #8
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I have a JL 600/6 with Morels and Jehnerts there nothing wrong with this
system but if I was doing it now I would go for one of the DSP Amp's
with not less than 50 watts a channel . Audiotec Fisher is where I would look
first. 86dsp , BMW7 although there are lot more devices like this now..
I think the Audio tec fisher products have better dsp and it is more supported.

half price is pretty compelling.

Stock speakers are crap although they will sound better with an amp they
are not close to aftermarket speakers.
the guy in the following link did a budjet dsp/amp upgrade looks
like the best I have seen in awhile .
https://www.e90post.com/forums/showthread.php?t=1887014

Last edited by ctuna; 01-12-2022 at 06:14 PM..
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