“Real” bass vs. “Boom” — how do you know which?


I'm working on positioning a new pair of Ohm Walsh 100's in my listening room. I think I'm getting close to an optimal positioning with regard to soundstaging and imaging, but I'm less sure when it comes to tonal balance.

How can you tell if the bass you're hearing is “real bass” vs. ”boom“ from room interactions?

Oddly shaped room, around 12' x 15', wood floors, speakers placed asymmetrically (out of necessity) along long wall: both speakers are 20 inches from rear wall. Right speaker is 16 inches from right wall, left speaker is around 5 feet from left wall. Two pieces of soft furniture: day bed (listening position) opposite speakers, and lounge chair to left of left speaker. Windows on three of four walls, with soft blinds on them, although I've generally been more pleased with the sound with the shades up.

Thanks in advance!!
How to tell boom from bass: have a reference. You need to use the same disc each time and listen twice, once on a system whose bass is "known to be right" and again on your setup.

One thing you _can_ do without leaving the house, though, is play in mono and compare bass in left and right channels. With an asymmetrical setup like yours, you are bound to notice differences. Adjust speaker placement to minimize these.

When you compare by ear, make sure you do it from the final listening position.

A very good reference on speaker placement and some other things is Jim Smith's "Get Better Sound".


Wood floors can be tricky with the ports on the 100s located on the bottom. I've had Walsh 2s (older driver, same size) in rooms very similar in size and layout to yours in prior residences.

Try loosely plugging the ports on the bottom by rolling up a thin sheet of foam if you have it or even a pair of old socks (no-body will see them down there). This can help lighten things up a bit with the room acoustics if needed. You might try it with only the right speaker that is closer to the wall as well in that proximity to the wall could cause a relative boost on that side.

Also play with toe-out to point the tweet more towards your listening position perhaps to tilt up the timbre overall if needed. Try a little more toeout on the right speak that is close to the wall as well (similar to the big f-5 Ohms in the pic in my system).
Unless you are trained you probably need a Ratshack meter with some test tones and/or a program like EQ Room Wizard and a microphone + PC. The temptation is always to go for more bass than you should. However, you will hear more of the music if you get the bass right (even if it is not as impressive) because too much bass will mask higher frequencies such as the lower midrange and prevent you from maximizing the musical enjoyment.
SPL meter from R/S and Stereophile test disc with test tones will at least let you "see" what's happening with the bass, and give you an idea how "close" you are to ideal.
Consider purchasing "The Sheffield Drum and Track Disc," available from Acoustic Sounds and others. It is a reissue on cd of two noted direct-to-disk recordings from the early 1980's, containing extremely powerful, yet taut and accurate, drum set and electric bass passages. I have the original Track Record on vinyl (I haven't heard the Drum Record, which is also included on the cd), and I would say it is the best music-based bass evaluation and demo tool I have ever encountered.

The notes on my 1982 Track Record album feature a quote from Harry Pearson of "The Absolute Sound": "Absolutely the best sounding rock record ever made."

-- Al
you will hear more of the music if you get the bass right (even if it is not as impressive) because too much bass will mask higher frequencies such as the lower midrange and prevent you from maximizing the musical enjoyment.
Shadorne (System | Reviews | Threads | Answers)
Shadorne makes an excellent point. Boom always mucks up the midbass and midrange. When you get the bass right, you'll be amazed how realistic the midrange sounds. It should be balanced, natural and enjoyable. Are you doing any room treatment other than your furniture and drapes? If you aren't, I recommend searching the forums for suggestions. There's a lot of good info in there.

By the way, a great way to get a reference for how things should sound is to use headphones. Every audiophile should have a pair for this purpose. Best of luck on your quest! Mark
Listen to a pair of good headphone. Headphones are not perfect but compare to speaker and room interaction, they are much more accurate.
Headphones as a reference is a great idea!
Chesky has a sampler that includes bass tracks to hear if your getting good bass, you should clearly hear each note and pluck, if its too booming it will sound for the most part like "One note bass" a term used often in these circles.
Chadnliz got this one in my opinion. I have a cd of James Cottons "Deep in the Blues" on the Gitanes jazz productions/Verve label recorded in august 1995. Track ten is a solo bass instrumental by Charlie Haden called Ozark mountain railroad. You can hear every pluck and the vibrating of the strings and the stop and start of each note and every change in tone that note actually plays as it vibrates. No one note bass when played on a system that is getting it right and deep with no boom. I also like to use this CD for auditioning gear or speakers as it also features some very good Harmonica playing that is as hard as piano is to do properly and unfatiguing. Cheers
depends on the recording.
Yeah, its all "real", the question is how much is the right amount?

"Beyond the Missouri Sky" by Haden and MEthany is another recording that represents a special challenge. If the bass playing on this one comes in clear and defined throughout (no "one note" stuff), you are probably in the right ballpark.

BTW this recording NEVER sounded completely satisfying on my system with any speaks until the recent move to the Arc SP16 TUBE PRE-AMP. Now: Bingo!!! So there is more to really good bass than just speakers and room acoustics for sure!
As you might know the same speakers driven by a different amp can affect the bass like you wouldn't believe. Oh, and lets not forget the source because it also impacts (pun intended)the bass and or quality,thereof.
Consider purchasing "The Sheffield Drum and Track Disc,"

Good suggestion - you can also get this on XRCD from Japan (they used the original master tapes which were made at the same time as they made the Direct-to-disc masters). The nice thing is that the first two tracks offer different examples of tuned drums. This way you can have a feel for where you system sits dynamically and how "tight" your bass is. Of course it would help to hear these tracks on a SOTA system to train yourself how it sounds.

Other tracks are, as suggested above, Chesky's Rebecca Pigeon "Spanish Harlem" with its nicely spaced bass lines - listen to see that all bass notes are of equally loudness (very useful for checking the critical 50 to 80 Hz range).

Other great drum tracks are: George Benson "Weekend in LA" Live "On Broadway" with Harvey Mason on drums. Also Keb'Mo's albums seem to have well recorded drums (unusually they have preserved the drum kit dynamic range on many of his tracks whereas typical rock/pop will crush drums with compresion/limiters). Another (but slightly bass heavy) great sounding CD is Dave Grusin "Hommage to Duke" - listen for balance in the bass riffs.

I'd also recommend funk music due to the heavy importance of drums and bass in this type music. Nils Landgren Funk Unit playing "Da Fonk" is a great one for the bass - very articulate. On the pop music side Peter Gabriels "Sledgehammer" has great bass which can be overpowering if you get it wrong but can sound "goldilocks just right" if you get your bass acoustics adjusted well.

If you get the bass right you will also find there is more depth to the soundstage - perhaps because you hear the lower midrange better and the "ambience" on the recording comes through.

When you listen to music and something sticks out ( say a particular bass note) then you have to ask yourself if it was intended or is a result of an incorrect setup. Usually recording engineers are msuicians and they try to keep everything in balance...

Nevertheless it takes a while to adjust to get used to "real" bass which can be subtle and understated. I
"As you might know the same speakers driven by a different amp can affect the bass like you wouldn't believe."

Yes indeed. for the larger OHMs in particular, that increasingly means a higher current, higher efficiency amp that mostly doubles rated power output from 8 to 4 and even 2 ohms.

So in summary, here is the recipe for the larger OHMs in order of importance IMHO:

1) speaks fit/tuned to room
2) high current amp
3) good quality source and pre-amp

Great stash of suggestions, folks. I'm on it. Actually I'm out sick today with a stomach flu (blech) so maybe I'll have a little time to mess with this today (if I can stand up, that is....)
Two possibilities -- listen or measure.

Listen; you must already have recordings with reasonable bass information (<200 Hz). Select a few with what you believe to be the cleanest bass (electric or acoustic bass, low end piano or organ, synthesizer, etc.) and listen at a high/average level. Pay attention to how well different instruments are defined and whether or not there is a dominant tone, regardless of instrument. The "boom" that some have mentioned will often occur around 60 Hz and jump out at you. I'm not a fan of using drum recordings since the bass drum will have one note pitch so will not offer the differentiation I look for.

Measure; while the RS meter may not be a precision instrument, you are looking for differences, not absolute values, so it should work fine. Mount the meter on a tri-pod at your listening position and make notes of the values shown for a test disc such as the bass response segment from one of the Stereophile discs. First set loudness to your normal listening level, then note the dB for the 1K tone. Next write down the dB level for each frequency from 40 to 200 Hz. Any peak tones will be obvious. The goal is to achieve the smoothest bass response possible - the least total dB variation from the 1K baseline when adding up all base frequency measurements. I've used this method to fine tune speaker position with good success.
All these suggestions and no one has yet pointed out the only true way you can know - you must be intimately familiar with the real thing (i.e. acoustic instruments in a real space). This takes some time and effort. You should attend some classical and unamplified jazz concerts and listen to the low end - how it blooms into the recording space, its natural timbres, etc. Once you have done this enough, you can more easily tell what is "boom" and what is natural. Taking studio recordings and other test discs and/or making measurements simply cannot determine this. Sorry, this is not the easy answer you may be looking for but it IS the only real way to accomplish this(and it applies to the entire frequency spectrum too, not just the bass).
I'm not a fan of using drum recordings since the bass drum will have one note pitch so will not offer the differentiation I look for.

Good point (although drum sounds are much more complex in their sound compared to typical instruments that follow harmonic rules). Drums do let you check the "transient" response - as this can be just as much of a problem in the bass as frequency response (although the two are tightly related because a high Q resonance of an underdamped speaker will create a broad frequency response hump as well as additional cycles of the woofer after the music has stopped, and although this broad hump can look mild when viewed with the eye it is actually very easily audible)

The key with drums is to listen for their own timbre (after the hit) and then the room echo (from the recording location) as well as your own listening room. If you can't hear this clearly (you don't hear the space around the drums) then you may have masking from an underdamped bass response... either from your speaklers or ringing from room modes.

Masking works upwards: Basically low frequencies wipe out your ability to hear higher frequencies - so if they last too long (resonance) or if they are overly loud then you'll miss stuff off the recording - simply put you won't hear it.

This is why warm resonant sound can pretty much fix a bad recording...it just lathers everything in resonance and hides imperfections that you might normally notice.
Hey Rebbe,

Lots of good thing recommended here to try.

Bottom line is you need a frame of reference for what good bass is. Listening live (to a well produced performance) and listening on good headphones if you have them, where room acoustics are taken out of the equation, are two good ones.

Once you have the frame of reference, then you can try the various tweaks as needed to attempt to match it. Tehre is no way to take the acoustics of your room out of the equation though. In the the end you have to tweak your system to your room to simulate what you hear elsewhere.

Believ me, once you get all this worked out with those 100's, you'll know it and be a happy dweller in bass heaven!
a test cd will help you solve this problem.
a test cd will help you solve this problem."

I say, are you still living in the ice age?

Try this instead; http://www.hometheatershack.com/roomeq/

If you want to know if you have boomy bass just take a look at your waterfall plots. Dont forget to have a hanky handy, to cry into when you see what your room/system response really is.
If you want to know if you have boomy bass just take a look at your waterfall plots!

You can see an example of a waterfall on my virtual system. It is simple to do but I suspect most "plug 'n play" folks (who consider a major upgrade to be changing an interconnect or a speaker cable) would find this approach daunting. "Nerds Only" applies! ;-)
some fine thoughts above. you already know how the sound of your favorite musics bass sounds by now i'm sure. the master speaker setup will position your speakers in your room with the bass response right. if you have not done this you should do so it just takes a little time but believe me this will get your bass sounding like you know it should. along with all other frequencys you're speakers will couple into the room for the best sound response air and bloom. test sounds and frequency readings are not music and can miss lead you on what truly can be had using music instead to position your speakers. do a search and and you can read up more about the master setup. best of luck mike
Hi Shadorne, I agree that you appear to be a nerd when using meaurements. But one appears to be a fool if not using measurements. Because a fool denies knowledge and truth.

And audiophiles are fooling themselves if they believe that freq response and waterfall etc are not indicative of exactly what you are hearing and that changing these parameters is proufoundly and easily heard. That a good inroom response is important and is significancant to help us understand what we are hearing.

You do not need to be an audiophile, trained ear, musician to tune your system. We are indeed looking for just that, a good inroom response and one without ringing (including the speakers) and low freq modal problems. This is something that can be measured. All this technology can do is assist you in getting the most from your speakers and system. What more can you ask for?

How you get there and if you want to get there is your own concern regarding this issue. But there is no denying its importance. You are course free to explore all manner of speakers and amps and TTs etc but one of the fundemental goals remains the same.

That is of course if you as an audiophile believe that freq response and ringing are important. And that indeed these can be measured

What happens if the measurements look good but things still don't sound right? No two people hear exactly the same, do they?

Also, I know you can measure frequency response, but how do you measure imaging accuracy and soundstage?

You can baseline accurately on measurements certainly, but you still might have to tweak from there to get things to sound best to you. Measurements are still a partial solution at best.

Plus, you have to know what you are doing to some extent in order to get the right measurements and know how to interpret them. This is not a trivial thing for many who are not technically oriented and just want to enjoy the music.

In that case, if you have the money, it might be worth it to pay someone to do it for you.
Can you hear the *individual pitch* of bass notes? That may not be all there is to it, but it certainly is a very important and good way of knowing if your bass vs boom is good.

My suggestion is to play a few recordings with bass, and get very familiar with them. Jazz piano trios are great because there are only 3 instruments, i.e., it's easier to hear or follow the bass. Then make a change to your speaker and/or room set-up. You probably will know quite quickly if there is an improvement. If not, stop and try a different change to your set-up. If things do sound better after the first change, stop and become very familiar with the sound of these recordings again; then you can move on to making another set-up change. Go through this process until you feel satisfied (which may be never : -)

Caveat: the above way of tuning may take you a long time; and a lot of patience that you may not have. It has proven to be the most effective way of guaranteed improvement (without back tracking and getting confused) over time for me, however. One more thing: I suggest you get a notebook and keep track very specifically of the changes you make; and what you hear when you make the changes. BE SURE you keep track (again, VERY specifically) with what your reference set-up is as you go along...small things sometimes make a big difference...just unplugging your video, microwave, etc will result in different sound from your stereo, for example. This will help you document improvement over time, and will allow you to go back to a previous reference to check it again if you wish. Good luck!
Three things improved bass in my system making it more articulate (shorter) and dynamic - new interconnects, new amp and vibrapods under speakers. My old amp had boomy, woolly bass that covered most of the midrange. It got better after replacing power supply cap and much better with my new class D amp. Vibrapods made bass short and even ("musical" would be the right word) by eliminating floor resonances that spikes (placed on coins) failed to do. It is difficult to say how it should sound since concerts have own, often bad, acoustics. Headphones as reference might be good but some of them are bass heavy while the others (like my Sennheisers) are bass light.

Vibrapods at $6 a piece are the cheapest (and the greatest) improvement in my system. They come in 5 different weight ranges. It will be different for the two front ones and the back once - use scale to find exact load.
I like the Vibrapod idea if needed as a last resort in your case Rebbi in that you have wood floors and I am assuming not a solid concrete foundation.

With my 100s, in the 12X12 room located in teh basement with concrete foundation and thin carpet and padding, with speaks a good 3 feet out from rear wall, bass is full, defined and tight.

Same speakers in 12X12 room on ground level, a typical wood foundation with tile floors and speaks only 12 inches or so from rear wall due to WAF, bass is a good bit fatter and needs to be tamed.

This is the case in that room with both my OHM 100s and tiny but fairly wide range Dynaudio monitors, so I partially plug the ports with a pair of old socks with both when in that room
Kinjanki said, "Three things improved bass in my system making it more articulate (shorter) and dynamic - new interconnects, new amp and vibrapods under speakers. My old amp had boomy, woolly bass that covered"

Thats great that you got rid of bad sounding equipment but it did nothing to your room.

"Thats great that you got rid of bad sounding equipment but it did nothing to your room."

Bob - that's true but the room, as we all know, is the most expensive part of any audio system. At least I stopped floor from resonating (and it was a cheap fix).
" the room, as we all know, is the most expensive part of any audio system"

Also not everybody has dedicated listening rooms that can be tweaked to the max so sometimes there are real limits with what can be done to the room in actual practice.
agree with samhar and others... spl meter and test cd. even still you just may find you prefer a bass hump or roll off in certain range. flat response does not appeal to many listeners truth be told. corners are always bass problem areas so..treat seriously

As the original poster, I want to again thank all of you for this priceless advice. Some family illness and a houseguest occupying the room where my system is located will prevent me from testing your suggestions for awhile, but I'm sure they'll be helpful when I get to messing with the system again.