Behringer HA4400 help and advice

[RyboUK]

Hey.
First post from me on this forum. Hi everyone.

I recently obtained a Behringer Powerplay HA4400 headphone distribution unit.

A promising bit of kit for my small set up.
Has 4 channels fed by a main in. One aux in per channel. And 3 headphone outputs per channel. Great potential for tracking and feed different fx or a separate mix via the aux.

Looking at the manual I found the attached paragraph re impedance. But confused by the 100ohms output impedance. Seems a limiting factor.
100ohms min seems quite high as a lot of studio headphones have modest impedances. And if the outputs are in parallel (as I assume they are) this only gets worse the more headphones you plug in per channel ie. 3 sets of 32 ohm have a net impedance of ~11 ohms.

I'm checking with Behringer to see if the min output of 100ohms is per channel. Or total - which would be worse.

Anyone have any advice they can give on this. Might be missing something. Im basing my knowledge on impedance matching between guitar/audio amps and speakers so I may be way off track!

 

[bouldersoundguy]

I'm pretty sure 100 Ω is per channel. I agree, that's not great. The newer HA4700 specifies a minimum of 8 Ω per channel, which is much better. Note that it says 8 Ω in the text, but the spec chart says 8 kΩ, which I doubt is correct. The HA8000 has 100 Ω in the text and 100 kΩ in the chart. I've put two headphones on one channel of the HA4700 with no trouble. It seems likely that the 100 Ω minimum rating was one of the reasons they revised that product.

 

[RyboUK]

Thanks bouldersoundguy

For info - I received the following response from Behringer which I find confusing still - implies the jacks aren't in parallel, as they suggest simply summing the impedance...

"This will be 100Ohms per channel and not for the whole of the device, please also note this will only apply in the instance you are connecting multiple headphones at once.

For instance if you are connecting two sets of headphones to the headphone outs on channel one there overall impedance must be 100Ohms or above so using two sets of headphones rated at 50 Ohms is ok, or in the instance you wish to use 3 sets of headphones you could have 2 rated at 50Ohms and one at 25Ohms."

So it is 100ohms per channel.
But only applies when you connect more than one set of phones - so using a single set of (eg) 32ohms is fine. And for connecting multiple sets, they suggest summing the impedances.
Not 100% sold on this advice. Wish they would submit a systems diagram or schematic with their products.

I was given the unit - so I am happy to run the risk and follow what they say. If it fails Ill look into a second hand 4600 as I like the concept/features of the unit.

 

[CoolCat]

We have had a Behringer headphone amp (Pro8) here for years and its a great unit, many many hours, years on it.
Pro-8 for like $29 back then.... used... but Behringer has some products "utility" that are decent.

It says if you are going to get crazy with adding a bunch of headphones add a Y and box too.

The "minimum 100ohms" seems weird.....the Sen HD280 64ohm the Sony 7506 63ohm are two of the most popular HR headphones, imo, both under 100 ohm.?

Section 3- Maybe this is from a newer version?

 

[RyboUK]

Thanks @CoolCat - the 4700 manual makes more sense than the response from Behringer!

I would assume the advice for the HA8000 unit is read across to the 4400 as they above have output impedances of 100ohm. To utilise 3 outputs, and keep the 100ohm min, you'd need 3 sets @ 300ohm?? I've seem some cans at 250ohm but 300ohm??

I actually received a second hand 4700 unit in the post this morning. I think having 8ohm min is more workable in my home set up. I can work with my standard headphones which are all around 16-32ohm. Maybe a slight mismatch, but not as much with the 4400 or 8000.

Good units though. I think aux will be great for adding monitoring fx from hardware units, not added to the signal for recording. EQ on the 4700 is a bonus too.