Boomy bass issue

hi all

I got some great advice on here a while back about getting a NDS XS2 or Nova ultimately going for the streamer linked to my existing Supernait mk1 and PMC Twenty.24’s. In the lounge that holds my kit including av gear I had a nicely balanced sound that whilst didn’t plumb the depths in terms of bass it was tight. Sometimes I engaged the BK electronics sub if I felt the need for more lower end. Recently we have refurbed the lounge and whilst we haven’t changed the layout of the room, speaker placement etc. I am now faced with loads of bottom end that didn’t exist before so definitely don’t need a sub! But the new found bass is very boomy at the extremes and so muddies the upper bass and lower mid. How do I sort this out?

For extra info. The speakers are about 2.5m apart, 2m clear of side walls and .5 clear of rear wall. One side wall is an expanse of large patio doors which were previously covered by slatted blinds but now aren’t. The electronics were on a Glass AV rack with spikes. Very heavy well built Stands Unique kit. That has been replaced by a really lovely oak av cabinet made by Audinni, 2 metres wide with moveable oak shelves. The cabinet is on castors rather than spikes as it is really handy to access when needed plus we didn’t want to have spikes on new floor. Having said that the speakers are sat on spikes onto coins at the moment as they were previously. So I don’t think the speakers have not really changed. The floor is covered largely by a rug as before. But the cabinet is very different being enclosed and on castors. Could the issue be one of isolation? If so, what would folk recommend trying? Having spent a lot of money on the lounge I don’t want to spend a lot on resolving this ideally but any thoughts greatly appreciated.


Before spending money I would do a few low or no-cost things.
I would try using a throw over the rack to see if that makes a difference to find out if it makes a difference and the issue is connected to the rack.
Moving the speakers slightly, sometimes a couple of cms can make a surprising difference. Adjusting toe in could also make a difference. Experiment and keep a written record of what the spacing between walls and each other is, so you can easily go back to the best sounding.

Sorry to read this.

Relative to the position of the speakers, has your listening position changed at all?

I’m no accoustics expert but wonder if the slatted blinds were helping and now aren’t although I’d not have expected bass to be affected much. Has your listening position changed from an ‘destructive’ location to a ‘contructive’ one vis-a-vis bass sound wave frequency??

A picture would help.

Sounds like part of the problem could be the first reflection off the patio doors if they are glass.

I agree with paulbysea, as it’s a “before and after” issue then it’s surely related to the changes you’ve implemented as you not only don’t need the sub now but the speakers are now overly-bassy. Could the new cabinet be moved at all and the blinds go back on? If so try experimenting. If it’s a case of “nope, gotta stay as is” then my suggestion would be to firstly put something like cushion stuffing in the speaker ports which I’ve used successfully in the past to reduce bass boom and is to my ears better than foam. Secondly, you could try swapping out the brass rods between the connector pairs and replacing with 1mm copper wire which might make a difference? Both these mods are obviously reversible and cheap if you get no gains.

Thanks for the responses. Seating position is the same. The speakers are not rear ported do plugs wouldn’t work and I wouldn’t want to mess with the transitional line output. I have played with speaker positioning and can do a bit more but I’m inclined to think it’s room related. So either lack of blinds or more probably the new oak cabinet on castors. We do have new electric blinds do I’ll check them closed - should have tried that already :blush:. I’ve got speakers toed in but could try straight on :thinking:. Any cheap way of isolating the amp and steamer? Could that be the issue? Cheers

I concur.

“One side wall is an expanse of large patio doors which were previously covered by slatted blinds but now aren’t.”

And, castors not spikes? Quelle horreur!

If blinds over the windows and changing speaker positions don’t help at all, then the top candidate must be the new cabinet - as other say - particularly if the speakers point at it or your floor is lively.

The cabinet might itself by making some noise when excited, even if you don’t consciously notice, or it could just be a non-ideal support for the solid-state boxes - microphony is usually very low on the list of things to worry about IMHO, but it does exist.

If you put the electronics on the floor (on the rug or on a chopping block from the kitchen) or your old rack, while keeping the cabinet in situ, does the bass boom stay exactly the same?

If it sounds just the same, then the cabinet itself is probably the issue. Try blue-tac under the shelves?

If it sounds much better with the boxes on your old rack, even if you turn it up a bit, I’d suggest isolation platforms (probably Supernait first at a guess) on the new cabinet may well help. Try the chopping blocks by all means, or try a free trial of a not-ridiculously-priced professional version.

If none of that has any useful effect, then you might try ameliorating the effect without trying to find the source. I have just added Isoacoustics Gaias to my B&W 804s and wooden floor, and the improvement in bass control is to my ear pretty marked - they won’t be going back. However, if it all sounded bass-light before your recent changes, this can’t be the first thing to try.

1 Like

Thanks all. I blushed whilst writing the word castors but it was one of those compromises we have to make some times. The lounge was an eyesore with previous open AV table so new cabinet looks great but in order to be able to move it, get behind etc we went for castors as the thing is 2m wide and .5 deep/height. Anyway, closing blinds/curtains does improved things slightly but not totally. I think isolating the amp could be worth trying. I’ve got a marble slab under the t\t on top of the cabinet which has given me a few thoughts. Firstly, I have an lp of one of the offending albums as well as digital copy. I’ll compare both to see if the isolation on the t/t helped it all. If it does I could look to try the amp on it and see if that helps at all. Also, try it outside of the cabinet again on the slab. I can’t change the castors or cabinet so need to find a way to tighten up some how. Interestingly, lots of albums actually sound good with the extra bass so I wonder if it’s certain low frequencies that cause the boom rather than all bass :thinking:. I won’t get chance until tomorrow now realistically but will report back. Anyone, used Auralex isolation products or sound deck damping feet?

You may find that what suits a turntable may not suit an amp and vice versa - which turntable?

Otherwise, I look forward to hearing how it goes.

What’s the ‘new floor’?

Any furniture / bookshelf / etc changes?

This also could be very significant. Can you try a blanket or better still a quilt hanging makeshift in front of the glass to see if any improvement?

I tried a curtain across the patio door yes. It did help somewhat but hasn’t solved it completely. Apart from the new cabinet one bookcase has moved from speaker wall to seating wall.

Try moving your speakers out a wee bit n try ur toein …good :wink:

I had to move one of my speakers due to some work being done in the house a couple of days ago. I moved the speaker back to what I thought was the right position by eye and the system sounded slightly off. Partly prompted by this thread yesterday afternoon I got out the tape measure and discovered it was 1.5cm out of position and toe-in was slightly out, less than 5mm wrong on one side measuring from the back of the speaker to the wall. Making these small changes resulted in a definite SQ improvement. My advice is to play with positioning for a bit longer and hopefully, you will find the sweet spot soon.

Try REW software, use the simulator function to model your room and speakers to find the issues, if you are keen you can get a Umik 1 mic and measure the room using your system.
Changing the listening position can significantly effect the bass response from your listening position. REW can give a clear picture of what is happening taking out the guess work before you start moving anything about. It’s also quite fun and educational

1 Like

Hi again, some really useful stuff above. So I have played around this morning with good results. Although, we don’t have slatted blinds in place we can put the electric roller blind down and or close the curtains. Doing so makes a small but noticeable improvement. I’m my own mind I had expected glass to have brightened the sound rather than thicken it so hadn’t considered that.
I then removed the supernait from the shelf and placed it on top on a marble slab used by the turntable normally. That made a bigger difference. I now have more bass than before but controlled. I then measured the speakers from rear wall, cabinet, each other, new and realised there were slight differences e.g. one closer to the rear wall, one closer to me. I sorted that out and played with toeing in/out. They sound best with just a bit of toe in but less than before.
Now the issue is, I can’t keep the amp on top and the marble won’t fit on the shelf. So what would folk suggest to add to the shelf to get that extra isolation?
Final thing for me is to get the SN serviced which is now overdue.


How much clearance have you got? Would raising the SN by 5cm be a problem? How about a bit more?

1 Like

I have potential for 10cm at a push :thinking: