Occasional bass "boom" ...update...powerline added...gosh

Something you generous and knowledgeable chaps may have some insight on.

On some recordings with more significant bass I get the occasional bass note cone through really strong, verging on unsettling.

95% of the time it’s all good. I certainly don’t think things are bass heavy. Or maybe just a tiny bit. Not enough to worry about as I like that apart from these occasional booms.

An example is Brandi Carlisle…The Story. When the bass notes in the verse kick in they really kick in and almost dominate.

My best guess is its my room rather than anything inherent in the system. Or quite possibly the SF Nova2 are a little large for the space.

Can’t change them really as I really like them and Mrs Mensab would flip… they are my 4th speakers in 4 months and amazing in nearly all respects.
My pmc standmounts I added a sub to as there was not enough bass. The Novas are so much easier to listen to than the Sopra 2s they replaced.
Any startling solutions I haven’t considered. I have some room treatment in place. Gaia feet under the speakers. Its a hard floor and a fairly long but narrow room 8 x 3 and the speakers are firing across the 3.0m. No choice there.


I must ask - Why…???

1 Like

Run a frequency sweep and check if it’s certain frequencies. You will hear it, but for a basic check of which frequencies it is, even a simple phone app is helpful. Most likely it will be a few specific ones. Meaning that it’s room modes. You can improve them by changing placing of speakers and, even more importantly, listening position. However, you will most likely not be able to do away with them completely

1 Like

Well I started small in December with a sonus connect (as i had sonus around the house) and some Dynaudio Emit.
Then I went Atom, then Nova. And justified an upgrade to PMC 26 22i with Rel.
Then I saw a deal on the Sopra2s whilst on a weekend break and brought them home. Impulse buy.
Then i changed to boxes as per current set up. Wasnt bonding at all with the Sopras and demoed alternatives. Fact 12, 2625i and the Novas.
I appreaciate I’ve been impulsive, but really quite staggered how things are sounding now. I do research and take advice. This forum is a powerful wallet emptier. I did not appreciate how powerful a drug this would be. And yes, I made some expensive mistakes.

Thank you. I’ll try that. The Roon parametric might be useful.
To an extent its reassuring for someone to say you cant have it all.

1 Like

45 - 55 Hz is the boom zone.

If the room is fairly regularly shaped, the room mode calculator will help:

If you do DSP on your own, it is fine to flatten bumps, but don’t try to fill in dips, at this easily overloads speakers and amps.

With Roon, you can use a measurement microphone and get filters made professionally:

room issue

Naim releases the Naim Equaliser which allows you to turn down the nasty frequencies tomorrow.

1 Like

Yeah, certain room dimensions cause certain frequencies to create standing waves. It’s a function of wave length and room dimension. As the wave length is fairly large for low frequencies, there is little you can do except making the room larger. Though moving the listening position out of the peak can help, as can speaker position changes

Passive bass traps, despite the name, do nothing for these frequencies (they would need to be huge). Active bass traps are expensive.

With digital sources, DSP adjustment is the best bet

Really? Interesting.

Thank you.

No :slight_smile: But some brands include Dirac room correction in their preamps, e.g. NAD and others

I think you need to slow the changes down, then stop.

Perhaps a visit to a good dealer might help you… :thinking:


1 Like

I’m done.
This is a very minor niggle. After all we are always looking for the small things that can make a difference. Keeps things interesting.


Hi K, you have to keep real about what a 250 is able to drive speaker wise. We are not talking playing music, but drive and control. In my view PMC Fact 12s need no less than a 500 DR to open up and with good bass control. I appreciate that is not your current choice of speaker.
Try and enter your room dimensions into The Amroc room mode calculator, if as you measured 40-45 Hz is your problem ( and double checked with Amroc ), you will beyond optimising your set up need some heavy absorption I suspect. Alternatively you could always turn your Sub off :+1:t3: The good old saying ‘ You can have your cake……’ rules in mysterious ways in the World of hifi and musical replay also, when as in most cases the room is the limiting factor. Been there…… :face_with_head_bandage: Good luck Peter

Thank you. To clarify I am not running a sub at present.
Aside from this rare “glitch” I’m overjoyed with the sound.
The limitations (relatively of course) of the 250 were a factor in not going with the Fact 12s. Mainly though the Novas had the sound in my head. Something as a guitarist, I’m all too familiar in trying to achieve.
I am obviously not tempted by a 300DR.
Although it would be cheaper than moving house :thinking:

1 Like


Beyond system set up optimisation and every aspect there of, your mode can be treated if within the confines of what is domestically acceptable. :wink: ATB Peter

1 Like