Subwoofer meshes well with 2-channel?

I just introduced a Velodyne Optimum-8 (~$1,000 online) sub into my 2-channel system with phenomenal results! I've paired it with my NHT Classic Threes and was able to easily and quickly seamlessly integrate it in. I'm running the NHT's to their full extent (they are -3d @ 45hz) and have the Velodyne connected via the speaker-level inputs with the crossover set at 40hz. Wonderful addition and I wonder how I ever lived without it!

Wow, that got pretty technical for my limited knowledge of subwoofers and sound waves!

So, the gist of what was being said is that there is no dis-advantage to going with a 2 way speaker (or a 2.5 or 3 way, but not something with a huge MTM design) and adding a sub. In fact, it may be superior, and a whole lot more versatile (not wrestling with a 250lb speaker with 5 drivers et cetera). If done right, it will add weight to the music, especially when the music needs weight, such as in orchestral passages. Sound about right?

I've tried the 85Hz filters from ACI and they clearly degraded the high frequencies

I had the same result. I couldn't get the ACI filters to work at all in my system.

bob reynolds; Dude, best response i think i have ever read, bar none. not saying i agree with sub part, but the rest definently dude!

I've tried the 85Hz filters from ACI and they clearly degraded the high frequencies. A noticeable loss of detail and air. They helped in other areas such as relieving the amp from having to reproduce the lower frequencies. I guess it would depend on how resolving your system is as to whether or not you would notice it. I sent them back. You could always try them and then either keep or return them as ACI has a good return policy and provides excellent service.

Johnc5 - Of course, you'll have to reintegrate your sub(s) if you have any after installing the filters.

No degradation detected at all. As a matter of fact, high-passing my mains (two 6" woofs each running uninhibited otherwise) cleaned up the sound dramatically. The only "negative" was a -3db in volume, which, for me, wasn't a negative since I have a volume control on my pre - I just turn it up a little higher now. (This does not use more amp power.) I started with the 65Hz filters when I had only one sub but ended up with the 85Hz filters once I got a second sub. Best $35(?) I ever spent in audio.

Rockadanny
Did the ACI filters degrade the sound? I have some 65 hz passive filters from ACI but have been reluctant to use them.

Dawg, I high-passed my mains (connected passive filter in-line at amp from pre connection) with 85Hz filters from ACI (they have balanced and unbalanced) and adjusted my two ACI Titan (powered) subs to fill in the LFs. Works fantastic! Easy to do with Radio Shack SPL meter (cheap) and test tone CD. Very full, balanced sound to 20Hz. And two energize my room better than one.

Dawg, If your sub "virtually disappears" you are not home yet. You should never be able to localize a sub(s). Usually, this means it is rolling off too high. Variable phase is great if you don't have many placement options. Mr. Reynolds has most of the rest of it right. (Hi Bob)

I must add that it Is a shame because I like them both very much,speakers and subs, but just cannot use hi-level connection in my setup. I am thinking to replace the subs for months now, but I can't get over that.

Ok, I made a statement few years ago and they all thought I was crazy. Now that at least one person shares my experiece with sub-phase problem I will repeat what I said then:
My main speakers are full range, VA Mahlers which are porter, and my subs are two rels, a stentor III and a stadium III. For months i tried to figur it out but i dont think i have any doubts now. By setting the speakers as large and augument them with the subs at 22hz and below, When I did that with the subs' phase set to 0 cancelled the speakers below 25hz while increasethe output above that frequency. For istance, when the phase is set to 180, there is a normal boost below 25hz and a decrease of output above that. I alway thought it was a phase interaction between the mains and the subs. Note that if you ask Sumiko which sub to add to the VA they will strongly suggest the stentor. Go figure...

The key is integration. For 2 channel I do not like using a crossover for the mains, but rather rolling the sub (or subs--which is much better) in at a low frequency (35 to 30 hz). Phase must be right which is easily calculated by the distance of the subs to the listener and the speakers to the listener (thus the subs must be the same distance or closer for best results). Continually variable phase is a big help.

We developed the sub-PARC to give the ultimate sub integration experience. Obviously, I'm biased here, but it is what we designed this beast for--and it is a beast. The amplifier took forever to get right because most amps just can't handle the demands of the LFE channel and still have the finess for a good 2 channel system. It also has parametrics which makes integration much better and gets rid of the issue of muddying up the sound.

Rives Sub-PARC

I use dual subs (Dynaudio 12 inch) to augment my Dynaudio Temptations. I don't high pass the signal going to the Temps. I just add some low end 'filler' with the subs. It provides a much more realistic sound to things like kick drums, for example. The best way I can describe it is that it adds a 'fullness' to the trailing part of the notes. Without the subs, although the bass is good, the notes die too quickly to be realistic.

It is sooo much better with the subs, even though they are only augmenters (I LPF the signal to the subs at 40Hz).

To clarify, the Velodyne SMS will work with any sub you choose: a low group delay, high distortion model like Stanwal's REL or a lower distortion, higher group delay model like the SVS that Bob has recommended from time to time. Further, you can choose to use the SMS' internal x-over to filter the mains or run them full range per Stanwal's philosophy. Or, you can choose to try both approaches and see which sounds (and measures) better. I did so and choose to actively filter the mains at a higher point. However, my subs were chosen primarily for their small cabinet size (rather than optimizing performance) so I don't want to suggest that active filtering of the mains is generally a better approach, just that it worked better in my system.

Marty

Dawg,

For $600 you can understand the bass shortcomings of your current speakers with a Velodyne SMS-1 sub controller (X-over, room analyzer, PEq). First, just use the analyzer portion of the SMS (no sub) to analyze your speakers in your room below 200hz. This will conclusively demonstrate that you want a subwoofer - just predicting here, but confident from my own experience.

As to Stanwal's philosophy vs. Bob Reynold's philosophy, home theater experience is not Bob's reference point here. His position is based on data from performance tests, Stanwal's on his listening experience and that of some reviewers. My own experience is too limited for me to dismiss either opinion, but I am personally more comfortable with Bob's approach. I have researched the numbers that Bob linked to and intend to audition those models that perform well. Unfortunately, i am just starting this effort...so no conclusions, yet.

Thus far, I can only ofer a few observations followed by one bit of speculation:

1) "Tight" bass seems to be a function of a spec called "Group Delay" (this is not gospel and is subject to some debate). Sealed boxes tend to minize this spec.

2) Loudspeaker distortion in the deep bass is orders of magnitude higher than elsewhere in your system. In subwoofers, a large driver in a large, vented cabinet tends to minimize distortion.

3) JL subs (very expensive) and SVS subs (less expensive to much less expensive, depending on model) both perform very well on both tests, the JL's show higher distortion but lower group delay, the SVS vice versa (per the link Bob has provided).

My observation:

The Velodyne SMS-1 will (with some work) allow smooth low frequency response below 30hz in a decent room as well as seamless integration with a variety (probably not all) of main speakers. The X-over and PEq in combination with the visual aid of room analysis are very effective tools for dialing in a seamles match.

Marty

PS - FWIW, the SVS Ultra 13 (app $2500 per pair) offer a combo of Group Delay and distortion specs that are hard to beat at any price. The less expensive SVS ($1100/pair) aren't far behind, particularly if you believe that extremely controlled Group Delay performance is not important.

My advice, as always, is in direct contradiction to Bobs, which must be derived from home theater practice. I use 2 REL Stadium subs with either Spendor SP-1s or S 100s which are full range speakers. Being full range does not imply a 20 to 20k Hz response. It refers to a speaker that is capable of reproducing music by itself. I cross mine over at 22 Hz and do not high pass. The subs are not noticeable , they add weight to the sound but you do not "hear" them. They provide a noticeable increase in the realism of the sound. A good sub will, as Alvin Gold recently pointed out in his review of the Eclipse TD 725, " if crossed over with care, without high pass filtering the satellites( i.e. around 30 Hz for floorstanders and 40-60 for more compact designs) integrates unusually well, seamlessly adding color and scale as well as bass extension." Bob does not know of the advantages of this approach because he has never tried it, I wish he would post his own system so we could see where he is getting the ideas he espouses with such certitude. Anyone who has ever run his main signal through a crossover can tell you that it degrades it. REL recommends setting up their subs as I suggested, I arrived at this approach independently almost 30 years ago when I was selling Audio Pro subs.

>I hadn't really given it much thought before, but will a sub work well with a 2-channel system (when reproducing music)

Yes.

>or does it just muddy things up? I have full-range speakers (Tyler Linbrook Sig's) that go down to 30hz or so, and have 2 7" Seas drivers.

A couple of 7" drivers or an 8" driver are OK for upper bass (80+ Hz) but lack the excursion to play lower frequencies cleanly. Most significant is that using such drivers as mid-bass units screws up your midrange through IM distortion when you ask them to reproduce real bass at the same time.

You need at least a 3-way speaker (a sub woofer counts) to get acceptable mid-range performance if you're going to listen at reasonable levels and not restrict your musical choices (witness "audiophile" speakers that do a fine job on small ensembles but fall apart on orchestral works at subjectively realistic levels).

>If this the case, is there a particular reason that huge speakers are common, vs. a smaller speaker and subwoofer combo?

Many sub-woofers are bad, built for maximum output instead of accurate response. Most consumer speakers are built with ports to get more bass extension but this makes them harder to integrate with sub-woofers due to the inherent phase shifts and problems with excursion skyrocketing below the port tune. Most sub-woofers don't address the integration problem. So lots of sub + main speaker pairings are outright bad and there's understandable audiophile prejudice against them.

Among other things, separate sub-woofers allow you to position the units for much better interaction with room resonances and so that you don't have the quarter-wave reflection dip from room boundaries within neither the main speakers nor sub-woofers' pass band.

Avoid the problems and you literally can't do as well with a single enclosure speaker system.

Greetings
Mr Cambell is offering you fine advice.
what should also be explained is the Vandersteen 2WQ is unique in that you can run them with the optional Vandersteen 5A Battery Bias Hi pass.
These allows your main amp to dramatically lower its distortion improving clarity and transparency of your whole system.
There are 3 8 inch woofers in a sealed enclosure
the quality of bass these offer is unriveled by anything I have found for 2 CH music.Most people ask the question why did my mid range improve?
Best John Rutan

Dwag you're looking for a sub that will go to 20hz clean. If you purchase a sub that only goes to 30hz @-3db you really don't gain a lot other then a little better control of the bass
Bass should not be heard but felt in the center of your chest for a two channel system

Sdcampell I have a great respect for vandy and have always been intrigued by their offerings for the past 20 years
I didn't mean to offend you in any way but I just think his speakers go to low and eliminate only but a few of the deepest reproducing subs out there

Vandys seem to work best with vandy speakersIMHO

Thank you for the suggestions.

I was thinking of a sub mainly from the standpoint of getting a more realistic "full" sound when reproducing full orchestral passages at higher volumes. These do go down pretty low, and I am not sure I need something that goes "lower" than 30hz, but something that moves more air may create more realism. For example, the speakers I could upgrade to (Tyler D1's) don't go lower, but they move more air (larger cabinets and 4 drivers vs. 2 on my LSS) which is why I thought that perhaps I could get the soundstage I am looking for out of the full-range D2 and still add a sub for realistic low-end.

I have tons of room tuning baffles around, so I bet I can limit any weird interactions. Just putting some panels in the corners really tightened up the bass.

I haven't looked into subs, but I assume they have built-in crossovers? Just plug the RCA/XLR's in from the Main 2 outs on my preamp?

I don't need a sub to replicate rock or hip-hop music. I just want my system to do a good job re-creating a double bass, for example.

Apache1 may be correct about the Vandy 2wQ's in your system, but let me add two points that I should have stated in my initial post.
1. A pair of subs is much preferable to a single sub. Having two subs reduces or largely cancels out room nodes that may reduce the audible bass response.
2. The low frequency response you actually achieve in your listening room is going to depend to a significant degree on the acoustics of the room itself. Many people who add subs to their systems often find that "fine-tuning" the room (with furniture placement, sound treatment, etc.) is necessary.

What I can add about the 2wQ's is that I often play organ recordings and my 2wQ's reproduce frequencies into the low 20-Hz range. They also do a good job with low-frequency sound effects, although they lack the "slam" and dynamic headroom of some of the best subs (such as Velodyne, BagEnd, etc.).

30hz is low if that is at -3db
You will need a sub that is gonna reach 20hz or lower at -db to see a real significant improvement. That will mean no HT subs. Quality subs like bags end or rels bigger subs
The vandy mentioned is a good sub but not sure if it will get the job done with your setup

Many current subwoofers work VERY well with a 2-channel system. One of the advantages to using subs is that they relieve the drivers in the main speakers from having to reproduce the very low frequencies. Many listeners find that their systems not only reproduce low frequency sounds better, but that mid-range clarity and transient response are improved as well. One of the better subwoofers that integrates very well with a 2-channel system used mainly for music is the Vandersteen 2wQ. I have two of them in my system, and they virtually disappear into the music. You should obviously look at as many subs as possible that fit into your budget, but I do urge you to listen to the Vandy 2Wq's.