Dear Stringreen: IMHO the subwoofers help to any audio system in many ways other than improve the low bass response.
Please read here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&27&4#27
Regards and enjoy the music.
Raul. |
Acoustic Science Corp (makers of Tube Traps) also recommends getting the subwoofer(s) up off of the floor (18" to 21") using their Subtrap.
My VMPS Larger Subwoofer is 21" off of the floor and it sounds much better with a tighter response. |
Dear Eldartford: Well your set up is very special. I'm refer to a more normal subwoofers set up.
Maybe my subwooferes could perform better at 40 inches above the floor but I can't do that.
My subject is that given a little more " space/height " to the subwoofers makes a remarkable difference in the quality sound reproduction of the whole audio system, at least that was/is what I'm experienced about with only 3 more inches ( total eight is 5" not 4" like I posted. Well 16" woofer-center from the floor. ).
Regards and enjoy the music.
Raul. |
Dear Rgordonpf: I think that you can/could achieve a very good quality sound improvement on your audio system with the addition of a second subwoofer connected in true stereo way.
Take a look/read to the link on my last post to Stringreen.
Regards and enjoy the music.
Raul. |
Dear Tbg: +++++ " I stopped suspending my speakers when I bought the 350 pound per side Duntech Sovereigns. " +++++
I think now you can do it again with your Acapella's !!!!
Regards and enjoy the music.
Raul. |
Raul, you are right given their lighter weight, but I have a pair of the Townsend speaker cradles coming. I have yet to hear them, but I am told they transform the La Campanellas. See: http://www.townshendaudio.net/index.php?option=com_content&task=view&id=67&Itemid=139 |
Great articles posted by Davehrab.
They explain it perfectly.
I lived with the REL Stadium II subwoofer in my system for 10 years and loved every minute of it but my main speakers are large floor standing units incorporating 12" paper cone woofers with NO crossovers.
The adjustments available for the REL allowed for beautiful integration but mainly because the main speakers were going down well to 40 Hz.
The only criticism I have with subwoofers (or any drivers that have adjustment available).....is the sheer TEMPTATION to fiddle.
On some music tracks, the bass is satisfyingly solid and deep, but on others there appears to be a distinct lack of it because in fact that was how the track was recorded, engineered and pressed.
But the sheer differences in the bass quality between records, tempts one to turn it UP for one record, and then turn it DOWN for others.
This eventually destroys the careful set-up procedures outlined in the articles attached by Davehrab.
A year ago I bought the Halcro DM58 monoblock amps which are able to drive my main speaker's woofers down to 28 Hz and I found the REL subwoofer was not going below this in my room anyway.
I now have no subwoofer and have removed the temptation to add or eliminate bass.
What the record has....I get. |
Dear Halcro: +++++ " Great articles posted by Davehrab. " +++++
I'm sorry, maybe I miss something: could you tell me where are those articles?, thank you in advance.
Regards and enjoy the music.
Raul. |
Dear friends: Two weeks ago the left channel Velodyne subwoofer ( in my system ) goes down ( till today I don't even have time to make the diagnosis to repair it. ) and till today it is in the same state.
Well, this trouble let me change some things in my system that were very interesting and learning about:
the first action that I take was to disconnect the subwoofer left signal and connected to the available right channel subwoofer ( left and right signals in the same subwoofer ) , this right channel subwoofer is placed in an almost " open " place/position with out any wall reinforcement ( this is its original position ). I don't change the crossover frequency not even the subwoofer output level, well it sounds but in " bad " way: the response was to strong, a little congested and with too many room resonances ( that before I never experience ), I set up with low output level but things were out of my satisfaction.
So I decided to change this right channel ( the one that is working, the other was down. ) subwoofer in the same position where was the left channel one ( down one ) that has a corner wall reinforcement, well all those " wrong " subwoofer bass response disappear and everything goes on " focus " with out reproduction trouble and with out any change on crossover frequency or output level.
How sounds this alone subwoofer against the normal two subwoofers arrangement?, well it sounds good ( very good ) but the two subwoofer ( true stereo fashion ) set up is really better and worth it.
Regards and enjoy the music.
Raul. |
Raul,
Davehrab posted 2 links when you first raised this issue.
Go back to first page of this Forum to click the links.
Here are two articles that you might find very interesting. They go a little beyond what is normally touched on here in the forum.
Read THIS and THIS
I've intergrated my 15 inch Velodyne sub to my NHT3.3 main speakers (which are -3db@ 23hz) by setting the sub crossover at 45hz just like the article says, and it works GREAT.
Easy, and quick reading ... soon the student will be the teacher.
Good Luck, Dave
Davehrab (Threads | Answers) |
I just moved to new digs in Scottsdale, Az. My stereo rig sounds so different here because of the room. The floors are French limestone blocks, 12 foot ceilings, the room is 14x30 with a totally glass wall on one side, and an open floor plan on the other. The bass is nearly non-existant and the echo is severe. ..sounds like 2 sub-woofers are in order to bolster the Vandersteen 5A's. |
Dear Halcro: Yes, I already read it.
What I want point in my last post is that ( at least in my system/room ) the wall subwoofer reinforcement position help to smooth the bass response against an " open " subwoofer position.
The other subject was to re-confirm that the use of subwoofers has to be in true stereo way.
I already point it out that IMHO the most important improvement that we can/could have adding a pair of true stereo way subwoofers is to lower the intermodulation distortion on the main spekaers, in this way you don't only have ( for the first time ) true undistorted low bass response ( that when you hear it for the first time it will be extremly hard to live with out it. ) but you clean up all the whole system frequency response: mid bass, midrange and high frequencies, that give to us several advantages : lower distortion response, lower coloration, higher accuracy response, better dynamics, improve over all the sounstage/imagin/focus, improve on inner detail perception, etc, etc that at the " end of the day " can(could take us nearer to the recording and nearer to the live event.
Regards and enjoy the music.
Raul. |
Dear Stringree: Well a not easy room. Adding two subwoofers in real stereo fashion will be help you in many ways but additional to that that room could need some kind of " treatment " trying to even its frequency response and kill those echoes.
Regards and enjoy the music.
Raul. |
Sorry Raul I am a bit late to respond, a while back you asked what I cross over my VMPS woofers at on the outboard cross-over and I believe I am at 135HZ as the midrange takes over a bit lower than that.
Since posting my original reply I added a HSU sub but only for HT and it is not tied into tube preamp, I just wanted to roll off woffers at 40hz to not worry about an expensive error just for watching a silly movie. |
Thanks Raul. Actually, I had a sound engineer come up. He did a frequency response check of the room which included reflections, and phasing. He suggested putting a soft island suspended from the ceiling the whole room through. Although the room is box-like, he suggested a very large oval shape. He also suggested accoutic floating soffets with indirect lighting, and some kind of treatment for those very large windows (not draperies or anything - they look great as is, but perhaps an accouticaly impenetrable window with 5 thicknesses of glass and a near vaccuum between them. This and other ideas sound good to me - the price is about 30,000 dollars. I suspect that I'll do it in stages. |
|
Hi Raul, how about a recent picture of your system? That picture is ancient. It must look quite different. I am sure many things have come and gone, along with equipment position, tweaks and room/fashion changes.
Thanks,
Bob |
Dear Bob: By coincide that was something that I already have in mind. Yes there are some changes: TT, tonearms,MM cartridges, speaker mods, Phonolne preamp up-grades, etc, etc.
Any way you can read through the " virtual system " about those changes.
Regards and enjoy the music.
Raul. |
I've struggled with the "two sub" question,though I currently have a REL Stentor reinforcing my Avalons(which have output below 30 hz,and are a sealed design).
My sub is positioned in the right/rear of room,not in corner,but not too far away (3from back x 2ft from side),and close to my right channel speaker.Very good blend!
I have called REL/Sumiko and was very interested in obtaining a second one,even though my own set-up does not call for it,on my own impressions,but have read SO much about the two sub option.
Sumiko adamantly stated my main speakers definitely did NOT require this second sub,since it's output was so good,and were against selling me one.
For a mfgr to recommend against selling "product" my radar told me that #1--here was a responsible company,and #2--my own impressions,which are often pretty good,should be adhered to.I am sticking with one sub...BUt my room is not large,at only 22.5 ftx 13 ft.
Go figure. |
Dear Sirspeedy: I wonder what happen with you and your mind. Almost two years ago everything was clear about ( after a lot of posts betwwen you and me reasoning about. ), here it is your agreement:
+++++ " Raul,as per your last thread,I finally DO get your point,which is valid.Best wishes!
Speedy! " +++++, this was in 2005 in this thread.
Now, +++++ " For a mfgr to recommend against selling "product" my radar told me that #1--here was a responsible company .. " +++++
I'm sorry to disagree about on this subject but ( like I already posted somewhere in this thread ) IMHO that mfgr people does not nothing about improve the quality sound reproduction with the integration of two subwoofers in true stereo way, simple they don't have the precise know-how about, this ignorance IMHO is not a " responsible company " but ignorance, that's all.
Sirspeedy please re-read here ( and send to that mfgr people ):
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&27&4#27
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&158&4#158
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&4&4#4
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&176&4#176
If you and the Sumiko people can't understand what are on those links it is useless to follow talking about because both of you never had the opportunity to try the integration in your system of two subs in true stereo way but have argumentation against it: how could be that?, both of you continue with arguments with out facts!!!!.
Sirspeedy, maybe I could understand the Sumiko people ( because they are commercial oriented ) that sale the RELs that can't be integrated in true stereo fashion due that its crossover does not have a high pass filter but I can't understand to you ( with all respect ) that till today I think you are a wise and mature man.
Regards and enjoy the music.
Raul. |
Raul,in two years much can happen!...I changed my mind because, #1...I am very satisfied with my current(as of now) results,and #2...I have heard alot of superb set-ups since!!...The latest,being a Zanden/VTL/VAC/Brinkman/JM Labs Nova speaker driven "super system",in a large room.I liked the sound,like others present,but still have no reason to want more from my own low end performance,which I have greatly improved as of late....Also,my own group of audio friends(who have actually "heard" my set-up) are against the second sub,in "my" room!They've been in my room loads of times,so forgive me if I go with their recommendation.
"Til today I think you are a wise and mature man"...
Well sorry if you think otherwise!..Actually I can reverse the sentiment,as I would have thought that someone with your supposed experience would reserve judgement until something is actually "heard".In this case you are simply "assuming" something,based on theory.I choose my decisions on my actual aural experience.This is where we differ,I guess.
Best. |
Hi Raul, I look forward to seeing new pictures of your room. And I should take my own advice and update pictures of my own room. While not much has changed equipment wise, the room itself is a bit tidier. Also I will post a picture of the REW freq response. I have my room fairly well acoustically treated and have been able to obtain a good inroom response.
Bob |
Dear Sirspeedy: +++++ " but still have no reason to want more from my own low end performance... " +++++
this is almost the same that you posted in 2005 before you agree.
This sentence IMHO and with all respect to you tell me that you don't understand yet the whole means of the subwoofer goals to improve the quality reproduction of any system including the one that you just heard and yours.
Mark, you are the one that are loosing the quality improvement of the two subwoofer subject and it is ok for me.
Regards and enjoy the music.
Raul. |
Dear Bob: I like you need to do it.
+++++ " I have my room fairly well acoustically treated and have been able to obtain a good inroom response. " +++++
this is a critical subject and a very important link in the audio chain, good for you that already take care about: congratulations!.
Regards and enjoy the music.
Raul. |
Mark: I'm only try to help, I'm not a subwoofer distributor/dealer.
Raul. |
Raul,with all due respect I think you can use a bit more education,on the sub bass issue!
First of all,to flatly mention that two are automatically the way to go is just wrong!!...There are some circumstances to consider(crossover point),which I adhere to...before I make ANY changes in my system.
As to low bass,and the "need" for a sub...this is absolutely based on the "in room" performance of the main speakers.
A sub can be added for different reasons,and I will give you two...
Firstly,if the main speaker does not go "very low" in bass,then your theory is best,and one will "most likely" benefit from two subs....BTW,I have owned two BIG Infinity speaker systems,BOTH employing two multi driver sub cabinets,so I know about the bass issue in my room.
My current speakers,unlike yours are moved quite far out into my room,to maximize their amazing soundstage capabilities.I can do this because I have a dedicated room.However,one loses some bass impact(not frquency loss)due to the "particular" room loading issue.
I have useable output down to the mid to low thirty hz with this positioning,but the extreme bottom needs a bit of added heft.Not alot,and at very low frequencies!Most likely lower than you go in "your set-up"!From your pictures,you seem to have the main speaker far back,which affects stage depth.
So,the second point(one you MUST take into account before automatically telling someone to spend money on a second sub)is "how low do the main speakers go,in the room,and where does one need to crossover to a sub"?
Before I made any sub choice,I obtained the advice of Dave Wilson(I think he knows a bit about the subject),and maybe you don't know that bass frequencies below 60 hz are perceived as "omni directional",so if the "main" speakers go low enough,and one crosses over low enough(I crossover at 24 hz)then the issue of two subs comes down to a pretty irrelevant decision.
If one sub, set up with very good room loading/blend,and coming in very low,does the job,and if the main speaker has superb low bass output,the second sub is not a necessity.
Of course if one needs the sub to crossover in the upper bass,then two is the way to go.I believe your thoughts relate to a higher crossover point then I need.
I'm going with Dave Wilson on this one,not to mention that I am quite satisfied.
Best. |
Dear Sirspeedy: +++++ " and maybe you don't know that bass frequencies below 60 hz are perceived as "omni directional",so .... " ++++++
certainly that I know about.
Sirspeedy till you understand what means intermodulation distortion and harmonic distortion specially on non self-powered loudspeakers ( any ) we can't follow speaking about because you are talking only about low bass response that it is only one of several aplications of subwoofers and IMHO not the most important to improve the quality sound reproduction in any audio system.
+++++ " First of all,to flatly mention that two are automatically the way to go is just wrong... " +++++
this kind of statement has no single support ( real ) from your part.
I don't want to follow this " dialog " because your non know-how about only could confuse to other people and IMHO can't help to any one, I'm sorry not to have the right " education " here but I can't explain it in other educated way. Please don't bad feelings, I respect and you have my appreciation.
Regards and enjoy the music.
Raul. |
"I don't want to follow this dialog because your non know-how about only could confuse to other people"....Raul,you're lucky I have always liked you so much!
That is "exactly" how I feel about "your" input on the subject, as it relates to "my own situation".So we do agree on something!Let's agree to leave it at that.
BTW,to me,this is just friendly disagreement.
Best. |
BTW Raul,my mention of "education" had NOTHING to do with how I perceive your "formal" education.Just your knowledge of all things sub-bass related(we can "all" continuously learn).The business of "distortion" you mention has nothing to do with my application.....I think you are taking this a bit too seriously.
Best. |
Sirspeedy...I too am familiar with the idea that low frequencies are non-directional. Absolute BS! |
Eldartford,I guess you are more knowledgeable than Dave Wilson.I look forward to your future posts for enlightenment. |
Dear Sirspeedy: +++++ " Let's agree to leave it at that. " +++++
and then you posted again!.
+++++ " The business of "distortion" you mention has nothing to do with my application... " +++++
I assume that you are hearing to your Ascent speakers. Well that " business of distortion " IMHO has to do with any home audio aplication but headphones.
That " business " distortions " is the most important subject ( quality improvement ) when we integrate subwoofers in our audio system.
It is obvious that you don't understand the whole concept and that's why you are showing your ignorance about but like you posted: +++++ " we can "all" continuously learn " +++++
I always said and posted that I learn every single day on audio topics even from what you already posted on this subject, why don't you try to do the same?:
""" there is no worst unable to hear person that the one that don't want to hear. """""
Regards and enjoy the music.
Raul. |
Sirspeedy...I have no idea who Dave Wilson might be, and can only speculate as to why he might promote this myth which is only too easy to disprove simply by listening. |
Eladtford ---you are not viable to me,mainly because you seem to "want" to be a contrarian,without knowing the subject matter,and I don't think you know what you are talking about.LOW frequencies...NOT the midbass that Maggie 1.6's produce!I won't respond to you again,unless you seem plausible about a subject you are not "assuming" things about,without true first hand experience!Sorry,I don't want to be rude.Let's leave it there,if you can?
Raul,...NOW you are "intentionally" being insulting!!
None of my responses to you were meant in the way you apparently took them....It was YOU who decided to take a particular comment made by me,about my not feeling I needed two subs,and you basically went "ballistic" over that,and started with the insults about my understanding of the subject!..You accused me of lying because TWO years ago I felt differently about the subject.Well,two years ago I didn't like red wine,and NOW love it!
You turn almost any response I make into some stupid assault on my knowledge of subject matter,AND you have NOT ever heard my system....ALL my audio friends have heard it,and are set "against" a second sub!!!They happen to be as knowledgeable/experienced as you,but now I am beginning to think alot less of you,due to your "original" instigation,and ongoing negative comments.
I have always defended you when others attacked you for "what I felt was only enthusiasm",but now I am beginning to change my mind a little....This has got to be one of the dumbest conversations(not "you",the actual conversation) I've had on Audiogon,in a long time!!
Is your ego so big that you simply must insinuate yourself into something just to keep your supposed reputation in tact,because I prefer a one sub set-up in my room(which you have never even heard).I stated that there are times when one might not need two subs....Do you actually think that the ONLY way to go is two?...Do you understand the main speakers "room loading" as well as overall low frequency performance greatly affects this?....Are you afraid other regular posters will think less of you,if a subject does not go your way?...What is the BIG DEAL??........OK,I give up!...You can be right!Every situation where a sub is needed should be dealt with by adding two!!...Happy?..
|
Hi Raul, I just added an in room freq response from the Room EQ Wizard. This response with subs and mains, includes only the room acoustic treatment and the Marchand Bassis EQ for the sealed woofers. No other EQ. I will take some new pictures of my room this weekend (hopefully) and update the room pictures at that time.
Raul, do you have a response of your room that I can see?
Bob |
Dear Sirspeedy: +++++ " NOW you are "intentionally" being insulting!! " +++++
I'm sorry that you thing that because was not my intention, Mark if you tell me ( on any subject ) that I have ignorance about I don't take it like an insult because maybe in that " virtual " subject I'm ignorant ( I don't have know-how about. How could you say non know-how? for me is ignorance and for you? ): no big deal. +++++ " .....I think you are taking this a bit too seriously. " +++++: your post.
Sirspeedy, the whole subwoofer subject IMHO has nothing to do about: +++++ " AND you have NOT ever heard my system....ALL my audio friends have heard it,and are set "against" a second sub!!! " +++++, it is not what your friends think, you or me: it is a stand alone subject.
+++++ " actually think that the ONLY way to go is two?..." +++++
no, not only but the best way and some times three or four ( and here yes depending on room ).
+++++ " as well as overall low frequency performance greatly affects this?...." +++++, you still are talking about only one subwoofer " goal " you are not taking the whole " view ", why? I can't understand it because like I alredy told you you are a wise and mature person.
+++++ " ...Are you afraid other regular posters will think less of you,if a subject does not go your way?..." +++++
cf course not, like you already told and I agree " we are learning ".
Mark, this is not a friendly fight to see which one win, the main point here is that no one loose and every body win some way or other.
I'm follow answering your posts because you follow posting it but I already told you:
+++++ " you are the one that are loosing the quality improvement of the two subwoofer subject and it is ok for me. " +++++, and is true if you agree or loose that opportunity or what ever that facts can/could not affect me.
Regards and enjoy the music.
Raul. |
Dear Sirspeedy and Rauliruegas,
On this subject, I would like to offer my opinion.
First of all, this thread has become a grenade tossing exercise, and from two people whose words in these rooms I greatly respect. Pardon me in advance if I don't have a great knowledge of intermodulation distortion and harmonic distortion, however, I do have a good set of ears being a life-long non-professional musician and a professional editor who mixes his own audio for air on a major TV network. I am your common "joe". And I am like 80 percent of us here: what I don't know in engineering and theory I make up for in listening with my head and my heart.
I have a great 2 channel system....Krell amp, Adcom GFP 750 pre-amp flowing into a pair of Dunlavy SC3's. They are great speakers: very revealing, time and phase coherant, and have a very small sweet spot. They have plenty of slam, but are rated at only around 40HZ at the low end (the top? forget about it, just glorious). Anyway, I wanted to round out the low end an extra 10 or 15 hertz. So, I bought a Von Schweikert VS-1 subwoofer, and stuck it just left of center. Now I hear this wonderful bass presence, increased slam, and an overall heft that is not too overbearing, but just enough to make me smile. I set the crossover on my sub at around 40K to let my Dunlavy's handle everything that they do best and let my sub do the rest. One sub, an extra 15 hz in the low end, and I am happy as a clam.
Sirspeedy, your explanations and experiences are very well written and understandable. Thanks for your info.
Raul, your knowledge of this hobby is at a level way above me, but I sure respect and appreciate it, always have, always will.
Just a "common Joe" here, throwing in my 2 cents.
Raise the faders on the pre-amp, it's another sunny day inside!! Cheers! |
Dear Judsauce: Thank you for your contribution, was/is a pleasure.
regards and enjoy the music.
Raul. |
Dear Bobb: Thank you for the notice.
Soon, I will have it and try to put on the virtual system.
Regards and enjoy the music.
Raul. |
Raul,since you claim not to understand my implementation of only one sub, as stated by you... "you still are talking about "only" one sub woofer goal,you are not taking the whole "view",why? I can't understand it"...I will give it one "last" attempt.....This is it...Because my MAIN speaker has superb output at "very low frequencies",AND I am ONLY using my sub to crossover at "24 hz"!!So,In MY ROOM,and with the particular "room loading" of the main speaker with "this" sub a second,third or whatever sub would be "overkill" to me,and those who have "heard" my system agree. I would rather put my money elsewhere!
It is NOT a "stand alone subject",but dependant on the room,main speaker's low bass,how low one crosses over "the main speaker" to the sub,not to mention that I am totally happy as is!AND I "think" I am pretty critical.
I really hope you follow my logic,as it pertains to me.It might not be your way of viewing the subject,but makes sense to me,and BTW I also greatly respect my friends who were responsible for introducing the hobby to me many years ago...I am done discussing my own taste and approach,and hope you are happy with your own choices.
Best. |
Judsauce thanks for lowering the testosterone.Btw,how do you know how happy clams are? -:) |
Raul,Sorry...I forgot to ask you a final question about "your" set-up.Could you please tell me at what frequency your main speaker crosses over to your subs at?Just curious.
Best....Btw, I hope this post is not repeated,as I had to keyboard it twice. |
Dear Sirspeedy: I'm croosing at 48Hz ( high pass ) where the manufacturer specs low bass ADS speaker response is: -3db at 22Hz and -5db at 18Hz.
Regards and enjoy the music.
Raul. |
Sirspeedy...Do my three subwoofer systems,(for the front channels) each having a 12" and a 15" driver qualify me as having some first hand experience with subwoofers?
Upon further consideration I realize that a single subwoofer may be appropriate if your source is vinyl. Because of problems with vertical groove modulation it is common for LF signal to be blended to mono, which is horizontal groove modulation.
Have a nice day.
. |
Eldatford,thanks for the info...to answer your question..."NO"...Not if you believe frequencies below 55-60 hz are "not" omnidirectional!But I have not heard your set-ups,so I know little about you,other than sarcasm.
Best to you anyway,as this should all be in fun! |
Eldatford,please disregard my last post,except the "last" sentence.You certainly have the right to voice an opinion,and I am sorry for being so defensive.Now I am "done" with all this sub business,and will do some needed listening.-:)
Best. |
|
Dear Sirspeedy: I love you man ! and that's why ( I take my time for this. ) I give you next some high-lights that different people ( including me ) posted on this thread on the subject ( two subwoofers/IMD/HD ):
this one was an answer to what you posted:
Dear Sirspeedy: +++++ " if the main speakers can support a certain low frequency,before rolling off,it will be best to bring in the sub at just under this point. " +++++
Well this is one approach that mainly goes to have a lower bass response: it is the REL approach and other subwoofer manufacturers but not all of them.
My approach is different from yours, mine goes to obtain ( first place ) a better quality performance in my main speakers and in second place to achieve a better quality bass performance that could goes lower too.
I use two subwoofers in true stereo way to achieve those targets, the first one ( that you can't achieve with your approach. ) is obtained lowering the Intermodulation Distortion ( main speakers ), this means to stop to ask to the woofers ( main speakers ) the simultaneous reproduction of frequencies between 20Hz and 200HZ or higher( if yours goes flat to 30Hz then you still have some distorted response at 20Hz that makes higher the IMD subject/problem ), this means ( again ) that we have to choose a crossover frequency higher than what the main woofers are handled : in my case 60 Hz and in Eldartford 80Hz.
In this manner the main woofers will be free/less stressed of the low bass reproduction working from 60Hz-80Hz up and lowering ( cleaning in deep ) the IMD: this fact makes a huge improvement ( in any speaker including yours ) in the quality sound reproduction of the main speakers ( it is not matters what you think about or what I think about, lowering the IMD always improves the quality performance of " that " driver, physics laws. ).
The second advantage on this approach is that now the low bass frequency response not only goes down through the subwoofers but with a better quality bass performance due that those bass frequencies will be reproduced for " drivers /amplifiers " that were designed specific for those kind of bass frequencies. " +++++
+++++ " Where the subs can help us ? :
Intermodulation Distortions ( harmonic distortions ): Almost any three ways speaker ( all two ways/one way ) has it's crossover frecuency ( low driver ) between 150Hz and 450Hz. I can assume that any of ours speakers system goes down flat ( at least ) between 60Hz to 20Hz.
What does that means ?, well that a single driver has to reproduce frecuencies/harmonics from 20Hz/60Hz to 150Hz/450Hz. With that kind of frecuency range here exist a great intermodulation distortions that put it's " color " on the sound reproduction.
You have to imagine that that single woofer/driver has to reproduce, at the same " time ", a 30Hz frecuency along a 350Hz frecuency: here is where exist that IM that gives heavy distortions in what we hear ( there is no perfect driver: moving coil, electrostatic, ribbon, etc.. The speaker designers has to choose the best " trade offs ", but the distortions are there. ): less clarity, less resolution, less precision, less natural balance, less pitch, les, less, less......., and this is what we are really hearing: LESS MUSIC.
What happen when that low driver is free from those frecuencies ? ( main speakers: monitors or full range, it does not matters. My main speakers are flat to 22Hz and only 5db +.- at 18Hz and I have benefits with the subwoofers integration to my system ), below 60Hz ( this is the crossover frecuency that we find the best point to start to blend a subwoofer. Mines are at around this 60Hz frecuency: 78Hz,yours ( I think ) will be around that frecuency. ):
SUDDENLY the " lights are on ", your music/audio " life " its born: the mid bass is clean, the midrange is clean, the highs are clean: high resolution every where ( the distortions are almost gone ), and now you can really hear for the first time the MUSIC through your home stereo audio system: what a pleasure!!!!!. " +++++
Mark the second subwoofer is not to obtain more bass but to even and smooth the room bass response:
08-02-05: Skushino
After adding a second sub to my system, there was smoother bass response. Again, this isn't about louder or stronger bass, in fact, I was seeking lower, smoother bass. Ironic that the path to this goal was accomplished by adding a sub! My girlfriend is a great listener and concurred that bass was better quality. Since I returned the second sub (on loan from my neighbor), I miss the performance " +++++
this quote comes from a in deep research made by Harman International Group:
+++++ " Using very large numbers of subwoofers would result in
cancellation of room modes. For practical numbers of
subwoofers, there appears to be no obvious correlation.
Two subwoofers, at opposing
wall midpoints, performs very nearly as well as four at the
midpoints and gives a much better LF factor
Can a sufficiently large number of
subwoofers cancel out all room
modes?
Theoretically yes
With 5000 subwoofers, modal variation is virtually
eliminated. !!!! " +++++
+++++ " I don't know at which frecuency you are cutting your REL. But, for example, if the crossover is at 27-30Hz and if the low pass filter is of second to fourth order then your REL is reproducing frecuencies as high like 80-100Hz that are interfering with the same frecuency range of your main speakers " +++++
this quote comes from a friend ( Agon ) that send to me for this thread. The research/investigation or whatever were made by: Audio Perfectionist Journal and Vandersteen:
+++++ " Suppose I told you that you could add two
components to your system that would reduce
intermodulation distortion in the midrange by a
factor of two or more, dramatically improve the
resolution of midrange and high frequency detail,
double or triple the dynamic range capability of
your system without changing your existing
amplifier or speakers and improve imaging more
than you can imagine. You would probably be
interested, right? But wait, theres more.
These same components would allow the
amplifier to maintain tighter control over the
speakers in the mid-bass and lower midrange.
They could extend bass response to infrasonic frequencies
while lowering bass distortion and
improving the systems ability to accurately convey
the rhythm and pace of music. And these
same components could virtually eliminate the
uneven response at lower frequencies caused by
room standing waves.
Does all that sound too good to be true?
Are you concerned about the possible cost of all
this improvement? If all this is so easily achievable,
are you wondering why youve never heard
about it before?
Let me assure you that all these sonic
improvements can be yours and Ive been conservative
in my estimates of the level of audible
improvement youll get.
When properly integrated with the system,
subwoofers blend seamlessly with the main
speakers and dont make their presence known.
But thats a very hard sell to the average consumer
and selling is the name of the audio game.
Subwoofers are supposed to add bass, right?
After their initial forays into the market,
few manufacturers continue to try to make subwoofers
that accurately represent music. Why try
to educate consumers when its easier to just give
them what they think they want? Boom!
Subwoofer makers soon learned what
dealers had already figured out: if they cant hear
it woof they wont buy it. Manufacturers started
to build subwoofers with high-Q alignments and
vents in order to provide more slam. Dealers
started to set up their demonstrations for maximum
thump, and maximized sales figures.
Awareness of the basic concepts of specialized
bass reproducers faded or was suppressed.
Home theater exacerbated this situation.
People today expect a subwoofer to rattle their
fillings and the exaggerated bass that most subwoofers
deliver is incompatible with accurate
music reproduction.
But there is more to bass than boombass
is the foundation of all music. And there is more
to subwoofers than bass. They reproduce bass frequencies
to be sure, but bass extension is possibly
the least of the sonic benefits offered by good
powered subwoofers.
Why Good Subwoofers Improve Sound
In order to provide the benefits mentioned
at the beginning of this article, subwoofers must
utilize a dedicated bass amplifier, and the main
amplifier and speakers must be high-pass filtered
using a passive, first-order device.
A high-pass filter does just what you
would expect: it allows frequencies above the cutoff
point to pass, and blocks frequencies below
that cut-off point. " +++++
this is another quote on the subject:
+++++ " - There is no single external / stand alone amplifier that can work or do a better job than a low bass dedicated amplifier like the one that comes with a powered subwoofer:
think that this dedicated bass amplifier was designed/tailored to match every single woofer parameter: impedance, frecuency response range, damping, power, distortion, etc, etc,...
- It is not only this dedicated amplifier what makes this subwoofer approach/technology ideal to handle the low bass octaves.
The driver/woofer is designed/tailored too for that specific frecuency range.
There is no passive FRS ( full range speaker ), at any price with any amplifier, that could beat a self powered subwoofers in that frecuency range. When you have and hear the subs on your system you never can live again with out those subwoofers.
Here we have to remember other important issue: the best subwoofers are SERVO CONTROLLED, this characteristic give to the subwoofer a heavy advantage over a FRS about the low distortion that a well designed subwoofer had against a higher distortions on any FRS.
- With a subwoofer we not only gain with a lowest harmonic distortion but with a lowest intermodulation distortion too. This means better quality sound reproduction.
- Other advantage is that with the integration of two subwoofers in a true stereo fashion to a full range speakers system: the main ( s ) amplifier will be free of those high power consumtion low bass frecuency range: this means too, better quality music sound reproduction. No exception.
- Other advantage with the subs integration is that facilitate the integration of our mains speakers to the room.
Do you think that your FRS audio system sounds great? Wait till you do the subwoofers integration: you will be on music heaven !!!!!!!! Nothing less. Try it. " +++++
Please read carefully, I only want ( I would that ) that you understand the whole subject concept, if you want to aplicate or not is a totally different subject.
Regards and enjoy the music.
Raul.
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Rauliruegas...I basicly agree with your argument. But please note that I do not cross over at 80 Hz (as you state). After many frustrating years of trying to find the "right" X/O frequency I have realized that there is no one right frequency, even for a particular system. It depends on the music. I have therefore chosen an electronic crossover where the frequency is easily adjusted with the twist of a knob.
Where the music has little LF content, I push the X/O down to 40 Hzm or so. My Maggies are fine at 40 Hz. Where the music has a great deal of LF content (typically organ) I push the X/O up as high as 200+ Hz. I can do this because my subwoofer systems include a 12" NHT woofer that is used up to 800 Hz in their systems, so my SW systems are not band-limited on the high end. (They actually go up to about 400 Hz without audible distress). 80 Hz is just where I am set before these music-sensitive adjustments.
Another feature of my system that I think is good is the placement of the subwoofers as a line array (if 2 drivers make a line) behind the Maggies so that all the sound originates from the same place and with planar dispersion characteristics.
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For further aggravations See,
http://www.ultraaudio.com/twbas/twbas_20080401.htm |
