These days it is simple and relatively cheap to get extension down to the teens with "adequate" headroom in a domestic sized room. Easily done with 1 or two vented cabs. It is just as easy to extend down to the very bottom to the limits of your electronics with sealed or IB subs. There isn't anything difficult or mysterious about it. It doesn't have to cost that much. It's amazing the amount of hearsay and myth still surrounding low bass reproduction. Most of it seems to come from people who have little to no experience with it.
I hear what you're saying, but different frequencies will excite different things in one's dwelling - my front door rattles below a certain Hz, for example, despite seemingly being solid wood (!), and I know what I'm listening too must be deep if it is doing it. Likewise, some tracks set other things off despite not sounding bass heavy, so I think there must be some deep fundamentals below the dominant elements of the track. My point is that just feeling one's seat move is a different experience to wondering if something's going to break in the house - I know which is more entertaining in my world, even if it does create some distractions till you've identified the culprit and stopped it rattling lol, and it is probably more realistic in terms of earthquakes / explosions / etc.!
Last edited:
Good words from one of the benefactors of the audio world.
So, aside from ignoble reasons, what are the realms of legitimate adult striving for audio improvement? Or at least for each DIY person?
For me, it would be clarity/cleanliness and sound quality delivered to my seat.
Clarity is key in the planar/ESL forum. But you'd have to search a lot of sub-woofer forum posts to find help with those topics since half the posts are belly-button-watching how to tweak a sim and rarely a measurement of distortion or ringing or much that's innovative. Also, pity there's no room acoustics forum.
B.
Keeping THD low in the passband is usually quite high on my list when considering an alignment, as is delta GD across the passband. which will be high for any alignment that features "ringing". And of course getting the best results starts with a good sim. Not all of us here are interested in just raw SPL, though that could be fun at times
.One of the benefits of a substantial multi-driver sealed system in-home, designed for single-digit-Hz reproduction at movie Reference level, is that distortion is very low on music playback at any 'normal' (i.e. not hearing-damaging) levels.
This is because the drivers are barely moving to create the required levels for music - as has already been touched on, music usually does not have that much extremely low bass, therefore does not require as much air to be shifted as during a bass-heavy movie.
If one wants to take it a step further, one can also design the setup for said drivers to be a PPSL arrangement, although I accept there is discussion around whether the changes induced by such an arrangement are beneficial and also noticeable. (Full disclosure - I am a convert
)Another benefit is that one can scatter boxes round a room (assuming no WAF issues
) and time/phase align them to remove/reduce any issues created by the room.Apart from cost/space/amplification requirements/WAF considerations, I don't see any downsides to a well-designed, properly calibrated, multi-driver, single-digit-Hz-capable system.
Last edited:
No, please no. 7hz @ 140db would be life changing in a way where your liver is taking the place of your left lung.
I remember a guy who was doing SPL competition at the wrong frequency (poor SPL results)... somewhere in the 32-35hz region, 148db. Was really
Much more than any 155-160db i ''heard'' in higher frequencies.
But, hey, what do i know? Maybe 7hz is completely harmless at high SPL. I just don't want to guinea pig it
I have a club in the not to far distance from my home town that does some cabaret/culture blabla things plus DJ'ing. One wall of the room consists of
32 x 15 inch closed drivers in concrete cabinets.
Wall of Bass | Lambda Labs
25600Watts from Powersoft modules will produce a bass wave through the room that is captured by the bass trap at the other side to avoid the only possible room mode. No top-down resonance, no left - right mode, and the back -front mode is cancelled by the trap. Think the specification of that system was 7 Hz flat at 140dB. With smoke in the air you can see the trembling of the air. I am not aware of any casualities or injuries so far.
Queasy effects of low frequencies
In one of my room configurations, I had a pair of long throw 18 inch drivers (fs of 16 hz) in an PPSL open baffle (long path for the rear wave to cancel the front wave). I was also listening to them in the near field - ~ 5 feet away and I was likely sitting in a room node (because moving the subwoofer back ended this effect). But I had really good bass response to low frequencies (below 20 hz, I am pretty sure).
CDs with really low bass content could shake my inter organs and made me feel queasy. The effect is similar to that feeling when an airplane suddenly drops in flight. The effects stays with you for a little while.
My plan is put these long throw 18 inch drivers in tapped horns (well tapped pipes really), which should allow me to have bass response down to 10 hz.
My neighbor, who does sound professionally cautioned me against this for the reason of causing the nausea.
We shall see.
Retsel
In one of my room configurations, I had a pair of long throw 18 inch drivers (fs of 16 hz) in an PPSL open baffle (long path for the rear wave to cancel the front wave). I was also listening to them in the near field - ~ 5 feet away and I was likely sitting in a room node (because moving the subwoofer back ended this effect). But I had really good bass response to low frequencies (below 20 hz, I am pretty sure).
CDs with really low bass content could shake my inter organs and made me feel queasy. The effect is similar to that feeling when an airplane suddenly drops in flight. The effects stays with you for a little while.
My plan is put these long throw 18 inch drivers in tapped horns (well tapped pipes really), which should allow me to have bass response down to 10 hz.
My neighbor, who does sound professionally cautioned me against this for the reason of causing the nausea.
We shall see.
Retsel
Just a question in your otherwise wise post. Is there good evidence to believe distortion is low in such drivers at low loudness?
I've never been able to hunt down the answer myself. For sure, you can over-drive a driver and see distortion skyrocket.
But with a mic on REW in my room, as I lower the level, measured distortion rises as the other crap in the measurement set-up* become more prominent in the THD display.
Anybody know?
B.
*And my Class G Kenwood Basic amp might have terrible distortion at whisper levels. Folks interested in the Amp Camp Amp which claims no crossover distortion take note.
although I can't see why it would work better than a 6th order reflex, running a beat - throwaway Karlson tuned like Exemplar does and loaded with an Altec 416Z (qts IIRC ~0.23) had good sound quality. I used some boost around tuning. Perhaps relatively low moving mass is a good thing. I don't understand why there would be a benefit from the front chamber at these frequencies. Good theater organ CDs were nice and I only used a mono setup with maybe 20 watts from a cheap JC Penny receiver into K15 on the bottom and a vintage Knight 12 coax in a K12. Maybe a 6th order reflex with an Altec would sound similar (?)
the mod is simple - just mount two 3" right angle pvc elbow or "street el" (with one flange ) on a board over the stock
K15 Karlson port. Apply some boost around tuning (~30Hz)
the mod is simple - just mount two 3" right angle pvc elbow or "street el" (with one flange ) on a board over the stock
K15 Karlson port. Apply some boost around tuning (~30Hz)
Last edited:
Sub-Woofer Lower Frequency Bound
The primary "imperfection" is system orientation in respect to where the signal comes from; i.e., "music-oriented-system" vs. "movie-oriented-system". The terms are not mutual exclusive, as the signals to both may be accompanied by a video signal and contain, a musical signal, voice signals, and Foley derived and other signals not coming from musical instruments. So, the distinction leads to all sorts of specious arguments concerning audio systems placement in these categories. The primary limit on sub-woofer low frequency response, is your audio system's monetary budget limit that has been conditioned by your listening preferences. For example, if you are a serious pipe organ buff, then you may want your system to pass 8 Hz cleanly. With this sort of system in place, when you watch Jurassic Park or Listen to the 1812 Overture nothing will be left behind here as well. WHG
Is it real? Should we target something different regarding that hard-to-reach first octave (and below) with music-oriented-system and movie-oriented-system (HT) ?
In a perfect world, i'd say no.
Any true Hi-Fi system should be able to reproduce with fidelity any sound, including the explosion of a planet (!) even though sound waves are not travelling through space and even though our neighbors are not always enjoying infrabass as we might do...
But, it's not a perfect world, is it...
So, what about -3 db (F3) @ 25hz for music and F3 @ 15hz for movies, can we settle for that once and for all ?
After many years of careful observations, i think there is some very important music content starting from about 27-28hz. Missing that would be a shame. In fact, most of the older recordings are in fact lacking of the first octave in general. They need a boost in that region. I'm a big fan of EQ boosting around 30hz (high Q, though) to get more ''meat'' around the bones of most recordings, especially the very thin and anorexic stuff from the 80's (darn CD re-mastering of this era....)
Anyway... What do you think?
Should we be more ambitious, regarding music oriented system? F3 @ 20hz or even less ?
Or, on the contrary, you can deal with less of that first octave and be very happy with it ?
The primary "imperfection" is system orientation in respect to where the signal comes from; i.e., "music-oriented-system" vs. "movie-oriented-system". The terms are not mutual exclusive, as the signals to both may be accompanied by a video signal and contain, a musical signal, voice signals, and Foley derived and other signals not coming from musical instruments. So, the distinction leads to all sorts of specious arguments concerning audio systems placement in these categories. The primary limit on sub-woofer low frequency response, is your audio system's monetary budget limit that has been conditioned by your listening preferences. For example, if you are a serious pipe organ buff, then you may want your system to pass 8 Hz cleanly. With this sort of system in place, when you watch Jurassic Park or Listen to the 1812 Overture nothing will be left behind here as well. WHG
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.