Genelec 8020D - Weak bass in right speaker

[åäö]

Hi!

I purchased a set of Genelec 8020D speakers three days ago. Yesterday, I noticed that the right speaker lacks punch in the lower frequencies. This issue wasn't apparent when I first bought them or immediately after setting them up at home, but it has become obvious now.

To troubleshoot the problem, I have tried the following:

• Checked the sensitivity setting and dip switches.
• Swapped the XLR cables so that the left speaker plays the right channel and the right speaker plays the left channel. The problem persists with the right speaker.
• Visually inspected both circuit boards and did not see any issues when comparing them closely.
• Visually inspected and measured the resistance in all four drivers. The readings were the same between the right and left speaker. I can re-measure the readings if needed.
• Exchanged the circuit boards between the speakers, so the right speaker got the left one's board and vice versa. The right speaker still lacks low-end frequencies.

Based on this, I suspect the problem lies with the driver in the right speaker. Initially, I thought the issue might be with a capacitor on the board. Before I start looking for a replacement driver, I wanted to see if there are any other tests or checks that I could perform.

Any help is greatly appreciated!

 

[kemmler3D]

Hi!

I purchased a set of Genelec 8020D speakers three days ago. Yesterday, I noticed that the right speaker lacks punch in the lower frequencies. This issue wasn't apparent when I first bought them or immediately after setting them up at home, but it has become obvious now.

To troubleshoot the problem, I have tried the following:

• Checked the sensitivity setting and dip switches.
• Swapped the XLR cables so that the left speaker plays the right channel and the right speaker plays the left channel. The problem persists with the right speaker.
• Visually inspected both circuit boards and did not see any issues when comparing them closely.
• Visually inspected and measured the resistance in all four drivers. The readings were the same between the right and left speaker. I can re-measure the readings if needed.
• Exchanged the circuit boards between the speakers, so the right speaker got the left one's board and vice versa. The right speaker still lacks low-end frequencies.

Based on this, I suspect the problem lies with the driver in the right speaker. Initially, I thought the issue might be with a capacitor on the board. Before I start looking for a replacement driver, I wanted to see if there are any other tests or checks that I could perform.

Any help is greatly appreciated!

Welcome to ASR! Sounds like you've been pretty thorough here, but a couple obvious checks to do:

-Did you run frequency sweeps with REW or something similar to measure the extent of the discrepancy?
-Did you move the speakers into a different room, or move them around the room, to make sure it's not a room mode causing the dip in low frequencies?

Did you buy the speakers new or used? Genelec has pretty good warranty coverage.

 

[DVDdoug]

Is your room & speaker placement symmetrical?

​

 

[wwenze]

Final test / First test: Swap the left and right speaker physically

 

[åäö]

Welcome to ASR! Sounds like you've been pretty thorough here, but a couple obvious checks to do:

-Did you run frequency sweeps with REW or something similar to measure the extent of the discrepancy?
-Did you move the speakers into a different room, or move them around the room, to make sure it's not a room mode causing the dip in low frequencies?

Did you buy the speakers new or used? Genelec has pretty good warranty coverage.

Thank you! I unfortunately don't have equipment to measure the speakers and in-room response of them. I have only used them in one room, the fault in the right speaker is so obvious I haven't moved them to another room. I did swap them completely as suggested here but the fault remains. The speaker sounds almost anemic compared to the other one.

I bougt them used and didn't get a receipt. The lady who sold them said she will look for it and send it if she found it. The speaker belonged to her organization where they hadn't been much used according to her. They do have some scuffs in the paint but given the built-in protection and the good reputation of Genelec speakers I went for it. It seems they are from late 2018.

Is your room & speaker placement symmetrical?

Not completely, I have a window on one side. I listen to them in nearfield where the fault remains with the speaker when switching them, so it's safe to assume it's not due to the room.

Final test / First test: Swap the left and right speaker physically

Did this now and the fault remains with the speaker. When listening normallly it can be hard to hear what exactly is going on, but even then it's clear something is lacking. Switching playback back and forth it's very obvious.

 

[wwenze]

I unfortunately don't have equipment to measure the speakers and in-room response of them

You have a phone. Just download a spectrum app, and then use equalizerAPO to adjust the speakers until they sound the same. You don't need a calibrated mic for this.

If your faulty speaker has an empty part in the frequency response it will be obvious.

 

[MaxwellsEq]

Put the speakers next to eachother, away from walls and furniture. Then run a sweep* in stereo several times whilst moving your head left and right of an imaginary line between the two.

* Don't use music. You can either download REW and play a sweep or find some on Tidal or Spotify.

 

[Reed]

Are the little switches in the back of the speakers set the same? Make sure they are.

 

[kemmler3D]

Are the little switches in the back of the speakers set the same? Make sure they are.

+100 GOOD POINT.

 

[åäö]

You have a phone. Just download a spectrum app, and then use equalizerAPO to adjust the speakers until they sound the same. You don't need a calibrated mic for this.

If your faulty speaker has an empty part in the frequency response it will be obvious.

Gave it a go with REW and as you said the results are obvious. Yellow line is the right speaker. I measured both speakers in the middle of my room one by one to try and get as good results as possible with the equipment I have.

I think I have found a replacement driver to order, that one has the extra designation "CN" at the end of the part number. Hopefully all the 8020s share the same driver. I'm also gonna switch the circuit board once again and measure, just for peace of mind.

https://imgur.com/PAENiGu

Put the speakers next to eachother, away from walls and furniture. Then run a sweep* in stereo several times whilst moving your head left and right of an imaginary line between the two.

* Don't use music. You can either download REW and play a sweep or find some on Tidal or Spotify.

Did the testing with sweeps from REW and the weak low end can be heard then as well.

Are the little switches in the back of the speakers set the same? Make sure they are.

Yes, exactly the same.

 

[AnalogSteph]

If it's not the electronics, the most likely things I can think of would be a woofer that's physically stuck or some sort of leak (e.g. loose surround). Since you have to get to the woofer anyway, you might as well give it a push and a through physical inspection then.

 

[Frank2]

Did you check the bass reflex ports at the back? Since these speakers are used, maybe someone put or dropped something in one of these ports?

 

[åäö]

If it's not the electronics, the most likely things I can think of would be a woofer that's physically stuck or some sort of leak (e.g. loose surround). Since you have to get to the woofer anyway, you might as well give it a push and a through physical inspection then.

I did check the woofer visually though it's difficult to see much as the basket covers a lot. I'm gonna try and switch just the woofer between the units and see what happens and give it a good push.

It's strange that both the resistance is the same across the woofers as well as there's no indication that something is wrong with it visually. And the woofer does play, it just misses the depper punch and bass.

Did you check the bass reflex ports at the back? Since these speakers are used, maybe someone put or dropped something in one of these ports?

Yes, both the reflex ports are entirely clean. They were a bit dusty and I did as you have a suspicion someone might had pushed something down there.

 

[tmtomh]

I did check the woofer visually though it's difficult to see much as the basket covers a lot. I'm gonna try and switch just the woofer between the units and see what happens and give it a good push.

It's strange that both the resistance is the same across the woofers as well as there's no indication that something is wrong with it visually. And the woofer does play, it just misses the depper punch and bass.

Yes, both the reflex ports are entirely clean. They were a bit dusty and I did as you have a suspicion someone might had pushed something down there.

At this point, switching just the woofers between the two speakers seems like the way to go - that should tell you definitively.

The only other thought I have - and this is admittedly a long shot - is that one or more of the rear switches is dirty and not actually set to what it seems like it's set to. Might be worth it to spray some DeOxit or contact cleaner in the switches, turn each one to Off and On several times, and then fire it up once more and try again.

 

[åäö]

At this point, switching just the woofers between the two speakers seems like the way to go - that should tell you definitively.

The only other thought I have - and this is admittedly a long shot - is that one or more of the rear switches is dirty and not actually set to what it seems like it's set to. Might be worth it to spray some DeOxit or contact cleaner in the switches, turn each one to Off and On several times, and then fire it up once more and try again.

I swapped the speakers, and the problem moved to the other speaker, confirmed by listening and measuring again. Something is definitly wrong with the driver. I inspected it thoroughly, and both drivers look identical. I also tried disconnecting the tweeter and played the woofer in the open without the aluminum casing, but didn't see or hear anything strange. When I turned the volume up really high, I could hear a slight rattle in the driver, as if it was hitting something inside, but this doesn't happen at normal playing levels.

I checked with the Genelec store, and a replacement LF driver will cost roughly $80. I requested an order for one yesterday.

Big thanks for all the help and suggestions!