25 hz, 20 hz, or lower, how low do I need to go?

Posted by: Lizard King

25 hz, 20 hz, or lower, how low do I need to go? - 01/31/07 10:28 PM


As I ponder on to which sub I will want to use, I need to ask all of you some questions.

I an an audiophile and music is my number one criteria. I see myself listening to CD (stereo), audio feeds from my PC, FM stereo, Movie soundtracks and broadcats via the Cable HD tuner and PS2 game console.

Music is what matters most followed by movies in that order. With this already stated and my listening area being 10 ft W x 13.5 ft L x 7 ft H. (part of a larger room), should I be concerned about going down to and lower than 20 HZ? Classic rock is my favorite genre (Pink Floyd is my favorite band) and i do like to listen to some classical music, esp. orchestral.

I am thinking about the LFM-1 as it looks like a good fit for my room. The HSU VTF-2 Mk3 is larger and go go deeper (costs more) to 18hz.

Most music IMHO cannot go down to 30 HZ. I say most not all as Pink Floyd, and some orchestral may get down to 25 HZ on occasion. I want the sub to sound musical, not boomy.

My choices appear to be the LFM-2, HSU VTF-2 MK2, or the LFM-1.

I will watch movies off a great DVD player so is 25 HZ good enough or should I go for a sub that can reach 18hz? For my music, is 25 hz low enough or do I need to go lower?

I welcome all your opinions.

Posted by: bestbang4thebuck

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 02/01/07 07:43 AM

My general thoughts on the ‘how low do I need to go’ issue:

It is my understanding that on the majority of commercially available music recordings a low-frequency roll-off has been introduced. Strictly speaking, you would not need the ability to reproduce below 20Hz, or even 25Hz, unless you are concerned about the following:

- You listen to music in which, for the sake of adding a room or vehicle ‘shake’ factor, the artist/mixer has added a lower octave that has been synthesized or artificially added based on existing fundamental frequencies in the music. Depending on the style of music, the amplitude of these enhancements can be fairly large. Unless you’ve heard this as part of a particular recording somewhere else, you wouldn’t miss them.

- You listen to music ‘recorded live’ in a large venue with very low frequency reverberations that have, in a rare instance, not been rolled-off. These frequencies are very low amplitude but add to the sense of realism rather than being strictly a part of the music being performed.

- Most feature film mixes rarely contain information below 40Hz. Occasionally a feature film mix will have both musical and effects low frequencies occurring simultaneously. If one of those frequencies is a musical 55Hz and another is an effect of frequencies warbling around 40Hz and these two sources happen to be of roughly equal amplitude, significant sideband frequencies are going to be created at the sums and differences of 55Hz and 40Hz. One of those would be 15Hz. I’m not advocating buying a subwoofer good to 10Hz or something like that, but if there is still some output, albeit 3dB to 12dB down, into the frequency teens, a portion of the lower sideband will be heard as the two higher fundamental frequencies mix. In this case the amount of the lower sideband that you would hear is determined not just by the point at which your subwoofer’s low end is rated, but also how fast lower frequencies effectively roll off below that point.

A related matter: does your listening environment significantly suppress or exaggerate very low frequencies? Saving a bit on the particular subwoofer model and spending the difference on acoustic room treatment may be better than just buying a lower-going sub.

In any case, if within your budget, you might spend just a bit more to gain lower frequencies, it is probably worth it. If you have to spend two, three, or four times as much to go from 25Hz to 18Hz or 20Hz down to 15Hz, unless you have the extra money to spend without sweating and it is very, very important to you, that much extra money may not be worth it.
Posted by: Videodrome

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 02/01/07 11:39 AM

To piggyback on some of the comments bestbang4thebuck made (and speaking as a fellow LFM-1 owner), the number of recordings -- and even beyond that, the types of music -- that have much musical information at or around 20Hz is somewhat rare. Organ peddle notes are one of the first examples that come to mind, and a sub or speaker system that can delve into these nether regions can really help you feel the pressure wave. But in terms of 90% of what I listen to, the LFM-1 goes plenty deep. This includes all sortsd of music as well as big explosions and other effects on movie soundtracks.

IMHO, how the sub interacts with your room will really drive how musical/natural it sounds and, more importantly, how it does or does not integrate seamlessly with your mains.

As bb4tb mentioned, room treatments can help. Beyond that, a product like the Velodyne SMS-1 or Behringer Feedback Destroyer can help optimize the LFM-1 (or any other sub that matter) to your room. I have yet to buy one, but plan to in the next month. From what I've heard, it takes a sub like the LFM-1, Hsu, etc. from good to great.
Posted by: gonk

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 02/02/07 03:18 AM

This is a common question, and for good reason. Much like speaker preferences often come down to personal taste, I see bass extension as a personal choice.

What I've liked about my LFM-1 as much as the way it can provide strong low-frequency punch on movies is the way that it blends in with my main speakers for music - the LFM-1 contributes to the music, but doesn't advertise its presence. I've heard subs that don't achieve this with music. (Think something along the lines of: "Hey, look at me - I'm a subwoofer! I like this song, but I'd rather have an action movie right now. Bump! Bump! Bump!"). Any sub requires some calibration to integrate with your other speakers, but that goes without saying...

Part of the is also room acoustics. My SVS 25-31PCi was pretty boomy with music in our old house (to the point that I had the mains crossed over at 40Hz so that the sub didn't get asked to do much with music). That boominess stil existed in our current house, but it wasn't as severe. I didn't get the LFM-1 until after we moved, but it integrated smoothly from the get-go. My SMS-1 did refine the sound (most noticeably on movies, where the sub gets more work to do), but since my room acoustics were in decent shape to begin with it isn't as significant as it could have been in a different space.
Posted by: Lizard King

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 02/02/07 06:08 AM

Thanks Gonk. Seems to me that there is no need to be concerned about getting all the way down to, and lower than 20 HZ.
Posted by: Lizard King

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 02/06/07 07:21 PM

Well I am going with the HSU VTF-2 Mk2. This is a great deal, A terrific sub that I got on sale.

Due to the size of my room, the 8 inch sub is best, 12 inch is too large so the 10 inch makes the best choice.
Posted by: FAUguy

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 05/29/07 04:02 AM

I love my LFM-I Plus that I've had for almost a year. It blends in well with my B&W DM603 speakers, and should also blend well with my 804S speakers that are on their way.

Since the 804S speaker has more bass and goes lower than my 603, I might need to readjust the sub once they are installed.

The newest version of the sub, the LFM-1 EX, only goes 2HZ lower than the LFM-1 Plus. I don't see why Outlaw needed a new version.
Posted by: gonk

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 05/29/07 07:26 AM

Well, technically, it goes 2Hz or 3Hz lower (depending on whether or not the port is plugged) and 3dB louder.
Posted by: psyprof1

Re: 25 hz, 20 hz, or lower, how low do I need to go? - 05/29/07 08:13 PM

Does anybody use the LFM-1 (Plus or not) with the Magneplanar 1.6QR, listening primarily to music? Some Maggie reviews have suggested that they are hard to match with subwoofers.