4ohm Center in a 8 ohm system.

E

Earendil

Audiophyte
Hi, can anyone tell me if integrating a Polk L400 center (replacing a Polk R400), will cause any significant issues to equipment. Also, will it affect listening quality that the L400 is capable of producing? (I hope that made sense).
 
F

fmw

Audioholic Ninja
Hi, can anyone tell me if integrating a Polk L400 center (replacing a Polk R400), will cause any significant issues to equipment. Also, will it affect listening quality that the L400 is capable of producing? (I hope that made sense).
Using a different kind of speaker for center will change the sound of whatever comes through the center. Is that good or bad? Your call, not mine.

4 ohm impedance? That doesn't matter as long as the amplifier is comfortable with that nominal impedance. You didn't ID the amplifier. Using a lower impedance causes increased current at every volume level. Increased current causes increased heat. Perhaps an issue and perhaps not depending on the equipment. Not much help I understand but you need to find out how well your amplifier deals with a 4 ohm load. Otherwise people are just guessing.
 
everettT

everettT

Audioholic Spartan
Hi, can anyone tell me if integrating a Polk L400 center (replacing a Polk R400), will cause any significant issues to equipment. Also, will it affect listening quality that the L400 is capable of producing? (I hope that made sense).
Impedance is not constant across the frequency range and as long as your AVR has sufficient amplification to drive a 4 ohm speaker, it shouldn't be a problem. The voicing should be very comparable between the two models
 
D

dlaloum

Full Audioholic
Yep, as others have stated - the thing to look at is whatever amp or AVR is driving the center channel.

Driving a 4 ohm speaker requires substantially more current than driving an 8ohm one...

For my AVR, I found that driving 3 x 4 ohm speakers was too hard for it - the soundstage and midrange got muddled - sounded like rubbish.

Putting L&R onto external amps, and leaving the center channel on the AVR, cleaned things up and it all sounded good at that point... which demonstrated to me that the individual channel amps could handle the 4 ohm speakers, but the power supply could not provide enough current to drive them all... with only a single 4 ohm speaker and the L&R removed completely - the AVR handled it just fine.

Your case is different - as it still has to provide power for the 8ohm L & R in addition to the 4 ohm center - so we need to know what you are powering it with!! It is likely to come down to the size of the transformer and the amount of capacitance in the power supply - stuff that is not normally described in the specs.

More examples... my old Integra DTR70.4 AVR could handle my 4ohm speakers without major issues - my current Integra DRX 3.4 cannot (as described above)... the old 70.4 weighed around 50lb/25kg the new 3.4 weighs around 10kg... and most of the weight difference was in the massive transformer the old model had.
 
Kingnoob

Kingnoob

Audioholic Samurai
Hi, can anyone tell me if integrating a Polk L400 center (replacing a Polk R400), will cause any significant issues to equipment. Also, will it affect listening quality that the L400 is capable of producing? (I hope that made sense).
What avr are you using without that information it’s a long shot …
 
G

Golfx

Senior Audioholic
I had a Polk L400 it is very favorably reviewed here on audioholics. It sounded wonderful BTW. Two thoughts: 1. If your AVR is newer and robust it should handle a 4 ohm center mixed in with the 8ohm speakers. 2. Because the l400 has bi-amp/bi-wire speaker connections you could actually use an 2 channel external amp and use say the left channel for the bass connection and the right channel for the tweeter connection. That is what I wound up doing and it worked fine. You can find reasonable two channel amps at Crutchfield who will give you setup tech support and allow you return it if it doesn‘t work out to your liking.
 
mtrycrafts

mtrycrafts

Seriously, I have no life.
Been a number of days since you responded. ;)
No one has mentioned that you should rerun your level matching of your speakers.
 
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