Foam Bungs With Kef R500's

[Cap1]

I have a pair of Kef R500 speakers which are 15 inches away from the rear wall of my lounge however the bass is very uncontrolled and dominates the sound. Over the weekend, I placed the full foam bungs into both of the rear ports on each speaker whereupon the bass now appears much tighter and controlled whilst none of the speaker qualities appear to have been compromised. I did initially try using just the half bung however found results improved considerably by using a full bung. I just wondered if anyone has any experiences in using foam bungs in such a way and what your findings were? Also, does anyone have an idea of the minimum distance these speakers should ideally be away from rear walls to allow them to be 'bung' free?

 

[tyhjaarpa]

I have my R500's less than 20 inches from wall and they sound good without the foams. It really depends on your room and do you use some kind of room corrections. I myself use my receivers room correction and I also have my R500's sitting on isolation platforms I build for them using Auralex platfoam. I found that those platforms increased clarity a lot, but this also is a room specific thing, on some room they might benefit from and in some not. I plan to use the foams when I have change to buy sub to go with my R500's as I wont need to bass extension from R500's by then.

After all it is you who listens to your R500's and what ever sounds the best for you is your right decision. R500 is great speaker to listen, I have enjoyed mine and will do for a while.

 

[Cap1]

I have my R500's less than 20 inches from wall and they sound good without the foams. It really depends on your room and do you use some kind of room corrections. I myself use my receivers room correction and I also have my R500's sitting on isolation platforms I build for them using Auralex platfoam. I found that those platforms increased clarity a lot, but this also is a room specific thing, on some room they might benefit from and in some not. I plan to use the foams when I have change to buy sub to go with my R500's as I wont need to bass extension from R500's by then.

After all it is you who listens to your R500's and what ever sounds the best for you is your right decision. R500 is great speaker to listen, I have enjoyed mine and will do for a while.

Thanks for your response. Over the weekend, I removed the foam bungs from the upper ports leaving the lower ports fully bunged only and I must say, this has tamed the errant bass notes and still allows the full benefits of the Kef's to shine through. More so infact, than when fully bunged. I do not use room correction however my speakers are sitting on granite plinths.

 

[markw]

I've got a pair of DCM CX-21's that are rear ported and put out quite a bit of bass. They did not come with bungs but a pair of tightly rolled and balled up socks works pretty well. ...seriously.

[edit] Oops.. I they are 21's not 31's.

 

[Cap1]

I have heard socks work well! Particularly black ones . Happily Kef provide the foam bungs so no need for socks! I did call Kef who assure me that 'bunging' the rear ports does not harm the speakers but does indeed help with unwanted bass/boom. Just bunging the lower ports has proved to be the best option for my set up.

 

[tyhjaarpa]

I have heard socks work well! Particularly black ones . Happily Kef provide the foam bungs so no need for socks! I did call Kef who assure me that 'bunging' the rear ports does not harm the speakers but does indeed help with unwanted bass/boom. Just bunging the lower ports has proved to be the best option for my set up.

Well I doubt they would provide those foams in first place if they damaged the speakers any ways. Every room is different and every one prefers different sound so trying is best way to go. You could also try to half block the ports. If I remember correctly those foams were in 2 parts so you could remove the center and make the port smaller.

 

[Cap1]

Well I doubt they would provide those foams in first place if they damaged the speakers any ways. Every room is different and every one prefers different sound so trying is best way to go. You could also try to half block the ports. If I remember correctly those foams were in 2 parts so you could remove the center and make the port smaller.

I did try the half bungs in all 4 ports however without much success. The full bungs in the 2 lower ports seem to have solved the problem.

 

[tyhjaarpa]

I did try the half bungs in all 4 ports however without much success. The full bungs in the 2 lower ports seem to have solved the problem.

Well most important thing is that you found a solution that makes you happy! Hopefully you will enjoy your R500's for a long time.

 

[Cap1]

Well most important thing is that you found a solution that makes you happy! Hopefully you will enjoy your R500's for a long time.

Thank you and yes I think I will. The R500's are a superb all round speaker that IMO, compete with those twice their price! If I had paid £2,500 them instead of £1,500, I would be as equally pleased with them!

 

[Cap1]

Just by way of an update, the lumpy uncontrolled bass has now gone, as have the foam bungs!

I have bypassed the internal linking plates of the Kef's by asking the nice people at my local Audio T to make me up 4 single 5 inch jumper leads out of NACA5 that have the Naim plugs on one end with the bare wire ends 'tinned' at the other. In essence I now have all for connections being directly driven by my amp which has made a quite unbelievable improvement. Arguably the best £45 I have ever spent! A very cheap, simply yet fantastic upgrade.

 

[Vampa]

Just by way of an update, the lumpy uncontrolled bass has now gone, as have the foam bungs!

I have bypassed the internal linking plates of the Kef's by asking the nice people at my local Audio T to make me up 4 single 5 inch jumper leads out of NACA5 that have the Naim plugs on one end with the bare wire ends 'tinned' at the other. In essence I now have all for connections being directly driven by my amp which has made a quite unbelievable improvement. Arguably the best £45 I have ever spent! A very cheap, simply yet fantastic upgrade.

Ey Cap1, thanks for updating.
I also have the r500s and have as well found the bass sometimes loose and boomy. Have the outer bungs in the rear bottom port.
From your last post I understand you have bi-wired the r500s, is that correct? If not, could you please develop what you have done? I have my r500s bi-wired as well and though improved, have not totally solved the problem.
Thanks!

 

[Cap1]

Hi....My Kefs are not bi wired. As you will see from the photo, I connect to the HF and use the jumper leads to go from the HF to the LF which seems to work perfectly. (If you do this, remember to disconnect the internal linking plates first!) I have had to move my speakers closer to the wall since my last post (8 inches) and because of this, I have the outer rings of the bungs in both ports of each speaker which works fine for me. If speakers are spiked directly into the floor through carpet, such can encourage bass boom. I have my Kefs sitting on granite chopping boards (spikes retained with spike shoes) which also helped. Make sure you speakers are not 'toed in' too much and are at least 6 feet apart from each other. Not sure what source, amplification, speaker cable and interconnects you are using? With the Kefs, you will certainly require an amp with a decent grip on the bass and speaker cable that is not on the 'warm' side?

 

[Steve81]

I plan to use the foams when I have change to buy sub to go with my R500's as I wont need to bass extension from R500's by then.

That's how I run things as it improves the integration between the towers and sub a bit in my setup (smoother response with fewer cancellations).

 

[tyhjaarpa]

Just by way of an update, the lumpy uncontrolled bass has now gone, as have the foam bungs!

I have bypassed the internal linking plates of the Kef's by asking the nice people at my local Audio T to make me up 4 single 5 inch jumper leads out of NACA5 that have the Naim plugs on one end with the bare wire ends 'tinned' at the other. In essence I now have all for connections being directly driven by my amp which has made a quite unbelievable improvement. Arguably the best £45 I have ever spent! A very cheap, simply yet fantastic upgrade.

Could you specify what kind of improvements you found out by this update?

 

[Vampa]

Clear, many thanks Cap1! I do not quite understand yet why the jumper leads make a difference over the internal links, but if it works for you, then great. I have the kefs bi-wired.

I have the outer bungs in the rear bottom ports only, so will try placing them in the upper ones too. Will try the granite board as well, as I have the spike shoes directly on the floor (wood).

My amp is a moon 340i and have as well the chord hugo dac (just have digital music). Both are really good, so do not think the problem is there.

 

[PENG]

Clear, many thanks Cap1! I do not quite understand yet why the jumper leads make a difference over the internal links, but if it works for you, then great. I have the kefs bi-wired.

I have the outer bungs in the rear bottom ports only, so will try placing them in the upper ones too. Will try the granite board as well, as I have the spike shoes directly on the floor (wood).

My amp is a moon 340i and have as well the chord hugo dac (just have digital music). Both are really good, so do not think the problem is there.

One possibility is that the internal links in his speakers are not making good contacts, they should, but you never know. It can be confirmed with an expensive ohmmeter capable of high current and measuring micro ohms. A good ohmmeter/multimeter that can measure accurate to say 0.1 ohm may do the job but I prefer one that can measure low resistance with higher current capability.