Connect 4 NuBox 310 on an HK 3480

[ckhNL]

Hi all fellow Nubert fans,

First of all: sorry for my english as I can't write good German

Just ordered 4 NuBox 310's to connect to a new to order Harman Kardon HK 3480 sterero receiver (2 on zone 1, 2 on zone 2). But as the salesperson in the HK shop told me that it was very dangerous to connect non 8 Ohm boxes to this receiver (and that I should buy 4x B&W DM-303's) I'm wondering what's the real truth. Is it really a problem, or shouldn't I worry?

In other words: how do these Nuberts perform when connected in 4 to an receiver? Will the blow up my stereo receiver? I hope some of you can help me! Best Regards and thanks in advance.

[K.Reisach]

Hi,

Yes, it was a problem, because if you put four 310er on that AMP, you will have two ohms!
That could kill the AMP!

Edit: Sorry for my very bad english...

Edit 2: Welcome here

[raw]

Welcome to the nuForum.

You could connect (for each channel two nuBox310) in series to get 8 ohms. But I heard that this kind of connection will make some kind of bass-damping worse... I don't know. Maybe some expert here will explain this issue.

A Harman/Kardon HK670 or 675 wouldn't have a problem with 2 ohms (a connection in parallel).

greetings
Denis

[K.Reisach]

You could connect (for each channel two nuBox310) in series to get 8 ohms.

Yes, but the volume would get lower......

A Harman/Kardon HK670 or 675 wouldn't have a problem with 2 ohms (a connection in parallel).

ckhNL don`t have such an AMP

bye, kevin

[ta]

It could work if the receiver has a terminal for two stereo speaker pairs.

Many ampliefiers can handle the 2 Ohms load ("low impedance capability"), which you have when you connect two 4 Ohm speakers parallelly to the amp.

Some can't handle the higher current flow and will be overloaded, which causes higher temperatures, a broken amp, or worse sound, especially at higher volumes. Perhaps protection mechanism will be activated which switches the device off.

Connecting two 8 Ohm speakers parallelly to an amp is far less critical, since this results in a 4 Ohm load which most amps can handle.

Unfortunately a NuBox 310 has 4 Ohms...

Refer to the manual of your receiver or ask the HK hotline if the receiver can handle the 2 Ohms load...



Ist "parallely" korrekt, ich denke schon, kommt mir nur komisch vor?!

[neuman356]

Since you've already ordered the speakers you might just as well give it a try. Though the 3480 is not to be known as an exceedingly powerfull and sturdy receiver, it might just work out fine as long as you don't crank up the volume too much. If the receiver can not handle the load, causing it to shut down, you'd probably be better off with true 8Ohm speakers,at which finding these nowadays is not really a task easy to accomplish.

[ta]

Hm...

Dutch Manual

Beide groepen kunnen ook tegelijk gebruikt
worden, mits de impedantie van elke groep 8
ohm of hoger is. Ook dan echter kan de impedantie
te laag worden, waarop de beveiliging
van de HK 3480 geactiveerd zal worden om de
versterker te beschermen tegen overbelasting.
Gebeurt dat regelmatig, kies dan slechts één
groep tegelijk, of sluit luidsprekers met een
hogere impedantie aan.
Page 5
[...]
Belangrijk! Wanneer twee stel luidsprekers op
de HK 3480 zijn aangesloten en beide stellen
worden ingeschakeld, mag de impedantie van elk
niet lager zijn dan 8 ohm.
[...]
Page 12

Source - Dutch Manual

German manual

Beträgt die Nominalimpedanz jedes angeschlossenen
Lautsprechers mindestens 8 ?, können Sie
alle vier Lautsprecher sogar gleichzeitig betreiben.
Prinzipiell gilt dies auch für Lautsprecher mit geringerer
Nennimpedanz (4 bis 8 ?). Beachten Sie bitte,
dass die tatsächliche Impedanz sich stark mit
der Signalfrequenz (und damit abhängig vom Musikmaterial)
verändert.Werden diese kritischen Frequenzen
häufig mit hohen Lautstärken abgespielt,
spricht eventuell die Schutzschaltung des HK 3480
an, um das Gerät vor Schaden zu bewahren. Sollte
dies häufiger passieren, sollten Sie lieber immer nur
ein Lautsprecherpaar oder nur Lautsprecher mit
höherer Nennimpedanz (8 ?) betreiben.
Page 5
[...]
WICHTIGER HINWEIS: Wenn Sie beide Lautsprecherpaare
am HK 3480 gleichzeitig mit hoher Lautstärke
betreiben wollen, darf die Nennimpedanz
pro Lautsprecher 8 ? nicht unterschreiten. Nutzen
Sie die Maximallautstärke nicht über längere Zeit
aus, darf die Boxenimpedanz auch niedriger liegen,
also zwischen 4 und 6 ?
[...]

Page 12

-->You can try it, but avoid higher volume levels. Nubert speakers are normally quite friendly to their amps.

As far as I understand, lower impedances are "forbidden" in the dutch manual; I don't know if you lose your Dutch warranty if you use 2x2 low impedance speakers at the same time.

[ckhNL]

@ta:

Thanks for your very clear and detailed answer. Funny also to see the difference between the german and dutch manual. Very funny...

So far as I understood I shouldn't have a problem as long as I don't use both groups at the same time and when switching for group to group (with the risk f having 2 groups on at the same time) I keep the volume low. Correct?

But why does Nubert (and other) then only have 4 Ohm, if all receivers require 8 Ohm at least? Isn't there another way to protect/improve my combination. Do I really need to send back the Nuberts if I want to be 100% sure? I hope not!

Best Regards

PS I'm just a starter that would like to have nice background music in two different rooms.
PPS I think it should be parallel, but parallely actually sound cooler

Editted: Thanks to the others too off course !!!