Sub or Not??
I've a pair of floor standing speakers which claims to have a frequency response of 22Hz - 20Khz. It has built in Class D powered bass drivers.
I largely listen to 80s-90s Bollywood songs which are poorly recorded. Question is, in such situation, whether a high quality subwoofer like Rythmik G25HP makes any difference in getting some extra bass energy from music ( I don't use it for movies, btw ) ? Or should I get something like MiniDSP DDRC-24/SHD/SHD Studio ( & no SUB ) and boost the lower frequencies since the floorstanders are capable of producing it anyway. Also the larger question is, for music that too a poorly recorded one, do we really need a sub?
Btw, here's the speaker spec if that helps to suggest a solution.
Full range:
Horn loaded labyrinth: 2.2m ( 7" – 4") length
Full range driver: Custom designed
7 inch paper cone w/whizzer
Foam surround
Voice coil dia.: 32mm
Sensitivity: 99 db/w/m at 1khz, or mean averaged from 200hz to 2khz
Bass:
Sealed Isobaric chamber: 50 lit. volume.
Bass drivers: Custom designed; 4 units per enclosure
7.5 inch paper cone
Rubber surround
Voice coil dia: 25 mm
Sensitivity ( of each driver ): 91 db/w/m
Bass module amplification: one monobloc per enclosure
Hypex UCD digital amp
Max. output: 400 wpc @ 8 ohms.
Level Control
Continuously variable active crossover filter controls
System:
Loudspeaker sensitivity: 100 db/w/m.
Nominal impedance: 8 ohms.
Frequency response: 22 Hz to 20 Khz.
Minimum amplification power: 2 wpc
If you have sufficient bass from your speakers then the main reason to add (a) sub(s) is to smooth in-room response. You can position the sub(s) to moderate nulls in the bass response caused by room dimensions and your seating position. If the bass response is flat enough, clean enough, and low enough at the main listening position (MLP) then you probably do not need a sub. If there are large dips in the frequency response then subs can help with that.
FWIWFM - Don
Old, old, post on why I have subs follows.
I use subs, and have for decades, for all the usual reasons:
- Very (perhaps extremely) few "large" speakers actually play well below 40 Hz let alone 20 Hz. They distort heavily when presented with large bass signals (which most are -- see Fletcher-Munson) and driving them down low robs headroom for higher frequencies and causes distortion well above the fundamental signal frequency (harmonic and nasty intermodulation). Subs typically enable the mains to operate with much lower distortion.
- Very rare is the room setup such that the best place for stereo imaging and soundfield is the best place for the subs (or deep bass drivers) to counter room modes and such. Having independent subs provides placement options to smooth the in-room response. It is almost impossible to counter a null without subs (typically must move the MLP or change the room's dimensions though there are purpose-built panels that can also work). This is one of the things that led me to subs despite having quite capable mains.
- Powered subs offload the main amplifiers of the need to provide deep bass energy, providing more headroom and cleaner sound from the amplifiers.
- Music (let alone action movies) often contains deep bass content even if it is not real obvious. Kick drums, tympani, organ, sure, but also piano hammer strikes, plucked strings, beat patterns from instruments playing together, etc. May not really notice when they are there but usually obvious when they are taken away. Having subs fill in the bottom octave or three can make a difference.
- Purpose-built subs can provide high output cleanly at relatively low cost. The amplifiers and drivers need only cover a fairly limited frequency range so have fewer constraints upon them than woofers in a full-range system.
I do prefer main speakers with fairly deep bass and always have. Crossovers are not brick walls so a fair amount of energy still comes from the mains an octave below the crossover frequency. Higher-order crossovers allow you to reduce the overlap, but I still like having the capability. I have never really understood the idea of running "passive" bi-amping as implemented by an AVR (sending full-range signals to multiple channels and letting the speaker's crossovers separate frequency bands -- wastes amplifier headroom and seems to me of little benefit). Nor do I agree with the "plus" setting putting subs and mains in parallel; again, my idea has always been to isolate the two for the reasons above.
My first sub was a DIY design using an Infinity IRS woofer with my own control box to provide the crossover and a servo circuit using the second voice coil of the woofer. I had a Hafler DH-220 around so also incorporated a circuit to bridge it for use as a subwoofer amp. It worked well and the -3 dB point was ~16 Hz. I now run four small (F12) Rythmik subs using a similar (but updated) servo design with my Revel Salon2's and am happy with the result.
FWIWFM/IME/IMO/my 0.000001 cent (microcent) - Don
Stereo subs:
I have gone back and forth on stereo subs over many years (since ~1979/1980 when I built my first sub) and ultimately decided it is not worth it. It limits placement and correction options, almost no stereo content exits at sub frequencies (remember a wavelength is >11 feet at 100 Hz, >22 feet at 50 Hz, just how much stereo separation can there be in a normal listening situation?), and the end result was always much better when I ran the subs mono and placed them optimally for best in-room bass response. If your crossover is so high and/or filter roll-off so low that your subs intrude into the lower midrange you might appreciate stereo but I have always rolled off well below the point at which I could localize the subs. For years I ran stereo subs but many tests blind and otherwise convinced me stereo subs are just an unnecessary hassle that actually reduced my system's performance and sound.
