Benchmark AHB2 Review (Updated Measurements)

[JP]

The low level pop, or click noise from the speakers, when activating the power off button on my bridged ABH2s, is gone! I was experiencing the same noise as some others in this thread.

I moved my amps today, closer to each speaker, and replaced the 12 ft Bluejeans 10 GA cables with 4 ft versions of the same. The real difference was installing speakON connectors, replacing locking bannana's at the amp end. The slight pop, I call it a click sound from the tweeter/mid, is gone. I still hear the relays in the amp a second or two after hitting the button, when the lights go out, but that's it.

There were 6 other people in this thread by my count reporting a similar noise on power down. Might be interesting to know if they are using the bannana or speakON connections.

I’m using speakon - have never touched the binding post connectors.

 

[EdW]

Agree. Any speaker with a load that difficult was designed by an incompetent.

The PC response here is that it is a ’feature’.
My view - a feature we could all do without.
edit: typo

 

[EdW]

The low level pop, or click noise from the speakers, when activating the power off button on my bridged ABH2s, is gone! I was experiencing the same noise as some others in this thread.

I moved my amps today, closer to each speaker, and replaced the 12 ft Bluejeans 10 GA cables with 4 ft versions of the same. The real difference was installing speakON connectors, replacing locking bannana's at the amp end. The slight pop, I call it a click sound from the tweeter/mid, is gone. I still hear the relays in the amp a second or two after hitting the button, when the lights go out, but that's it.

There were 6 other people in this thread by my count reporting a similar noise on power down. Might be interesting to know if they are using the bannana or speakON connections.

This is very strange! Did you also change the input to a fully balanced configuration from, say, a single ended RCA to XLRM connector. That change might be expected to cause a noise at switch on or off.

 

[denydog]

@EdW
No change there. I've been using balanced XLR on the input since day one. Though they are longer now.

@JP
Just to clarify, do you hear power off noise or not?

 

[USER]

There were 6 other people in this thread by my count reporting a similar noise on power down. Might be interesting to know if they are using the bannana or speakON connections.

I too have only used speakon. Small pop on power down. Not a big deal.

 

[EdW]

@EdW
No change there. I've been using balanced XLR on the input since day one. Though they are longer now.

@JP
Just to clarify, do you hear power off noise or not?

I didn’t think that you would’ve changed the input feed without mentioning it but I had to ask the dumb question!

 

[denydog]

I too have only used speakon. Small pop on power down. Not a big deal.

Well, that goes against my experience. Thought I was on to something.
Now it's a mystery as to why mine stopped making the click sound.

No, wasn't a big.deal to me either. Very minor.

 

[elvisizer]

Speakon here too, no pops.

 

[JP]

@EdW
No change there. I've been using balanced XLR on the input since day one. Though they are longer now.

@JP
Just to clarify, do you hear power off noise or not?

Tick when mute activates. If I power cycle a handful of times it’ll happen when it disengages as well, and a bit louder.

 

[mikethep]

Pop/click when using non-locking bananas at both ends and what seems to be the same pop/click now when using Speakon and locking bananas. XLR between HPA4 and AHB2 with both types of cable.

 

[denydog]

Thanks for the replies.
Doesn't seem to be any correlation between the clicks and differing output connections so far.

 

[DonH56]

Aren't the speakON and binding post connectors wired in parallel? I do not see how choice of output connectors would affect the turn-on/off pops.

 

[denydog]

I do not see how choice of output connectors would affect the turn-on/off pops.

Me either. But it seems to have done just that in my case. Might be something else.

 

[yanm]

I had a small pop at turn off with banana connector. I changed to speakon yesterday, the pop is still there.

There is not really a reason for the connector type to have an influence on the presence of the pop or not. Changing the cable might, as it has more influence on the inductance than the connector. Still, it should be minimal.

 

[amirm]

Didn't realize I had not post the pop measurements. Just added it to the review:

 

[Chester]

Now it's a mystery as to why mine stopped making the click sound.

Did you change anything else at the same time? Location, other components etc?

 

[denydog]

Did you change anything else at the same time? Location, other components etc?

As mentioned earlier, I moved the amps inside, and next to the speakers (from a rack just to the right, of the right speaker), and used shorter 4' cables of the same type, except speakON connection instead of bannana's. Previous speaker cables were 12'.

Also swapped in approximately 14' balanced input cables from the shorter 4 footer's. All cables were the same standard Bluejeans Cable types. The lengths and speakON connectors were the only changes, besides the location change. I put the amps on short 4" black glass computer monitor stands. Nice that the amps are so small and light. Perfect fit.

My thinking that the speakON connection change had something to do with the click noise going away was just a wild guess. I've never read of this being addressed by people hearing a click, so just thought I'd ask about other's experience with noise and connection method. But doesn't appear to be any consistency.

EDIT: I guess a next step would be to hook up the previous speaker cables with the amps in their current position, to see if the click returns. Easy enough to do.

 

[EdW]

As mentioned earlier, I moved the amps inside, and next to the speakers (from a rack just to the right, of the right speaker), and used shorter 4' cables of the same type, except speakON connection instead of bannana's. Previous speaker cables were 12'.

Also swapped in approximately 14' balanced input cables from the shorter 4 footer's. All cables were the same standard Bluejeans Cable types. The lengths and speakON connectors were the only changes, besides the location change. I put the amps on short 4" black glass computer monitor stands. Nice that the amps are so small and light. Perfect fit.

My thinking that the speakON connection change had something to do with the click noise going away was just a wild guess. I've never read of this being addressed by people hearing a click, so just thought I'd ask about other's experience with noise and connection method. But doesn't appear to be any consistency.

EDIT: I guess a next step would be to hook up the previous speaker cables with the amps in their current position, to see if the click returns. Easy enough to do.

If you have access to a good oscilloscope it should be very easy to scope the magnitude of the problem by repeating @amirm test for startup.
Failing that a multimeter across the speaker terminals to check that the amplifier has no dc offset should give you piece of mind that the amplifier is OK and that you are unlikely to damage your speakers

 

[Chester]

Yes as you say, not a big deal. I’m just intrigued now as it appears to be something that comes and goes depending on individual setups.

 

[walt99]

Not sure how your amps are turned on/off but are the amps being turned on/off before your preamp or whatever the input is?
I have mine controlled from the trigger input (3 of them) and have never heard any pops, I have had multiple processors controlling them and never an issue.
I would suspect possibly the input preamp is what is causing the pops.