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Subwoofer equalizer recommendation
Could anybody here recommend me an equalizer for my powered sub? I do not wish to spend more than $200. I cannot find one with in/out speaker terminals. Thank you.
JRA
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You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
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1 Attachment(s)
Quote:
Originally Posted by N. Abstentia
You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
The real question you should be asking is why you DON'T have a parametric EQ for your sub in your system yet.
The subwoofer can be as expensive, and top quality as money can buy. It won't change the fact that a rooms acoustics will affect the frequency response by as much as +/- 20 dB (NOT an exaggeration). Every room will have modes and nodes that affect the response below 200 Hz or so. You wouldn't own a speaker that had a frequency response +/- 6 dB, why accept far worse than that for a subwoofer?
By not addressing the in room acoustics with a parametric equalizer, your bass response is the weak link in your system. The most popular Parametric EQ here is the Behringer Feedback Destroyer (BFD), for about $100. At that price, you can't afford NOT to have one. You're either setting the sub volume too high, or too low depending whether you adjust to a peak or dip in the response at the reference frequencie. Or you're somewhere in the middle and your room gives you crappy response.
The EQ isn't destructive to the audio frequencies when used properly, and even if abused, it's doubtful you'd be able to hear any distortion at frequencies below 80Hz - a lot of high-end subs got away with 10% THD for years.
Here's a chart of my early trials with equalization. I use to own the PW-2200 before I upgraded to my current 15" sealed unit. My room is a bit odd shaped, and I dont' have many placement option for a 15" sub...I've seen worse response charts than mine, however. The blue is before Parametric Equalization, the pink after:
Room treatments only help so much. My 2" foam (auralex, sonotec) made almost no difference at all below 200 Hz, where foam really becomes useless. The rigid fiberglass bass traps I made work about 5 times better than the foam below 200 Hz, and even that only knocked a few dB's off the peaks and valleys. It'd have to use a ton of bass traps to kill this mess.
So I EQ the rest. It is easily the best $100 I've spent on my system.
(edit: a note on the graph - I've since learned my Galaxay Audio SPL meter underscores the FR below 32 Hz or so...it's down about -5 dB by 18 Hz, so that bottom end is tilted up higher...still, it's a lot more accurate than my Radio Shack meter).
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Quote:
Originally Posted by N. Abstentia
You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
I cannot believe that you wrote this! Ghetto peice?? LOL It is ghetto thinking that you can do without a sub EQ when using a sub in any room. I have never understood how people could just admire someone equipment, and not pay one bit of attention to the room that it sits in.
Harumph!:rolleyes5:
Hey, Kex type dude, how and where did you get the graph? I would like to do one of those for my rooms
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Sir T,
http://www.hometheatershack.com/bfdguide/#004
I'm not on my home PC or I'd just send you the file, but you can download it fromt this excellent BFD guide webpage...(you now need to register to a forum, but oh well).
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Quote:
Originally Posted by kexodusc
Thank you much National Minister of Pertanent Information.
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Kexo,
Thanks for the link. I had it saved somewhere before (probably the last time someone posted on this topic), but lost it. This time I printed it out, a whoping 28 pages, but worth it.
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Quote:
Originally Posted by N. Abstentia
You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
My sub/room creates this huge leap around 55-65, almost a gain of 12dbs compared to other avg frequnecy frequency. It is pretty annoying. EQ may alter sound quality but it's just lower frequency. If I had over $1200 to upfgrade my gear, I dont wish to spend it on a musical sub.
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Hey kexodusc, what is the lowest frequency that I can set to adjust FROM, not to.
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With parametric EQ's you can dial into any frequency - I know 20Hz is possible on the BFD, I'm sure you could widen the band to go lower or maybe even dial in lower.
The BFD is usually recommended for cutting frequencies (like most parametric EQ's for bass), but boosting "can" be done if you're very careful. If your seated in a spot where the room is naturally causing cancellations, all the boosting will do is eat up amp power.
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Quote:
Originally Posted by jrhymeammo
Could anybody here recommend me an equalizer for my powered sub? I do not wish to spend more than $200. I cannot find one with in/out speaker terminals. Thank you.
Hmmm. Sub doesn't have line inputs? That will probably be a tall order in that most EQs are not intended to be connected directly with speakers.
I use an inexpensive third octave Behringer unit with the subs in my HT system that would fit your budget, but only has line level input/outputs.
rw
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To correct common room anomalies
Quote:
Originally Posted by N. Abstentia
You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
I use a third octave EQ on the subs in my HT system due to a nasty suckout at 100 hz and to provide a subtle lift at the bottom. The room really is too small to use the gaggle of bass traps found in the larger space where my audio system lives.
I wouldn't use EQ, however, full range on the 'stats in that system.
rw
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How do you have your system connected right now? I'm a bit confused because I don't recall the PW-2200 having any speaker level inputs, and the RSX-972 is an AV receiver with its own bass management and line level sub outs. Don't know why you'd want an EQ with speaker level inputs/outputs. For one thing, I don't know of any that fit that description.
If you can attach a subwoofer to a line level output, then the Behringer Feedback Destroyer is a great bargain -- easy to find for less than $120, lots of people use this model with their systems, and has 12 parametric filters per channel (more than you'll ever use). Keep in mind though that the BFD does introduce audible colorations into the signal path. These colorations are insignificant in the low frequencies, which coupled with the low price is why the BFD is a popular choice among home theater owners. But, they do affect the highs and mids, so if you need to attach this to a setup that uses the subwoofer's line level high pass filter (the PW-2200 cuts off at 80 Hz), then the BFD might not work well.
Quote:
Originally Posted by N. Absentia
You've got a nice list of equipment there....why would you want to add a 'ghetto' piece like an EQ....to a subwoofer no less?
Like the others, I'm a bit surprised by this quote, considering your level of knowledge and how well you've done with your own system! All I can say is if you think your system sounds good right now, you'll be in for a huge shock at how much better it sounds after you equalize the subwoofer. With the BFD available on Musician's Friend for $100, this is an insane bargain for the sound quality improvement that it makes.
BTW, my before and after curve with the BFD is shown below. Equalizing the sub eliminated the boomy peaks that my room was creating, and my in-room bass response is now within 2 db all the way down to 25 Hz.
http://members.aol.com/sfwooch/myhomepage/subtest.gif
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Quote:
Originally Posted by Woochifer
Like the others, I'm a bit surprised by this quote, considering your level of knowledge and how well you've done with your own system! All I can say is if you think your system sounds good right now, you'll be in for a huge shock at how much better it sounds after you equalize the subwoofer. With the BFD available on Musician's Friend for $100, this is an insane bargain for the sound quality improvement that it makes.
hehe he seems to have disapeared all of a sudden. I was quite shocked to be honest.
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Quote:
Originally Posted by Woochifer
How do you have your system connected right now? I'm a bit confused because I don't recall the PW-2200 having any speaker level inputs, and the RSX-972 is an AV receiver with its own bass management and line level sub outs. Don't know why you'd want an EQ with speaker level inputs/outputs. For one thing, I don't know of any that fit that description.
If you can attach a subwoofer to a line level output, then the Behringer Feedback Destroyer is a great bargain -- easy to find for less than $120, lots of people use this model with their systems, and has 12 parametric filters per channel (more than you'll ever use). Keep in mind though that the BFD does introduce audible colorations into the signal path. These colorations are insignificant in the low frequencies, which coupled with the low price is why the BFD is a popular choice among home theater owners. But, they do affect the highs and mids, so if you need to attach this to a setup that uses the subwoofer's line level high pass filter (the PW-2200 cuts off at 80 Hz), then the BFD might not work well.
http://members.aol.com/sfwooch/myhomepage/subtest.gif
Nice curve you got their.
My Rotel is in a box tucked away
Unfortunately, using sub-out and line-out is not an option. I'm using my tube integrated which does not have output stages. My Rotel is in a box tucked away, maybe I should sell it after having a technician clean the unit.
I have my speakers connected from sub's speaker high pass output. I believe my PW2200 is the first one they made, since it doesnt have a version number.
That's too bad, I was getting excited about controlling my lower frequency.
Thanks for all the help though.
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So I ran a sweep test with my setup. Obviously my 6.5" woofers are not capable of playing below 50hz. I thought by using speaker in/out on back of my sub would eliminate sending lower frequency(80hz and below) to my main speakers. Come to think of it, I dont know crap about subwoofer.
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EQing a sub was the biggest topic last year, but I can't recall anyone talking about it anymore. What gives?
It's just lower frequency so the tonal quality isnt that significant. I still don't see why everyone uses it. Since I purchase a preamp( still no amp) the idea of SubEQ has been popping inside of my head again.
Any afterthoughts on this?
Thanks
JRA
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Quote:
Originally Posted by jrhymeammo
It's just lower frequency so the tonal quality isnt that significant. I still don't see why everyone uses it. Since I purchase a preamp( still no amp) the idea of SubEQ has been popping inside of my head again.
I would disagree that tonal quality isn't significant. Maybe you've either never heard a good sub, or never heard a bad sub and are taking good sound for granted?
EQ'ing, IMO can produce far more benefit to sound quality than even an upgrade in pre-amp or amplifier. And it certainly doesn't cost nearly as much. It's nice to see more subs are coming with it integrated (though not very well). Someday, every sub should have it built in. It's a necessary function for a sub.
Everybody's room plays a role in preventing the sub from playing like it would in an anechoic chamber, the results are large peaks and booms that force you to do 1 of 2 things when setting the levels and integrating with your mains:
1) set the sub to the loudest frequency bands, in which case a great deal of bass could be 20-30 dB lower in volume, or
2) set the bass to a lower level, in which case you have a large peak across another band that is incredibly distracting, as it drowns out and overpowers the rest of the music. This why a lot of people find their subs boomy, poor for music, and can locate them directionally. They're not set up right!
Bass is important, especially subwoofer bass which accounts for around 2 octaves when best implemented. That's no area to go short on. A good sub, well integrated of quality equal to your main speakers will deliver better, more musical bass than woofers can for a variety of reasons. Most people never take it that far.
I always use speakers as a comparison. You wouldn't own a speaker with a frequency response of +/- 18 dB. Why do you allow that for your subwoofer?
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Good Post Kex, and Oops..
Quote:
Originally Posted by jrhymeammo
I still don't see why everyone uses it.
JRA
I meant to type "I still dont see why everyone's NOT using it"
Sorry about that... completely different than the way it was intended(I do it all the time).
I dont think it's possible for anyone to own a sub that will produce flat (3+/- dBs from 20-100hz) frequency response, not matter what the spec states.
I wanted to revive this thread for my purpose and others without an equalizer for subs. Is there an alternitive to Behringer FBD since last year for around $200?
Thanks
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Quote:
Originally Posted by jrhymeammo
I wanted to revive this thread for my purpose and others without an equalizer for subs. Is there an alternitive to Behringer FBD since last year for around $200?
Thanks
I'm not aware of all the eq solutions that exist out there, but the BFD is still arguably the most cost effective unit. Most other PEQ's I've seen run at $300-$600 and by all accounts units on the low end of that scale aren't as flexible as the BFD, some are said to introduce some noise in the signal. The BFD, if used properly, keeps that to a minimum, and there's lots of free tools available (including a downloadable auto room eq wizard.)
Parts Express sells the latest BFD for $99. You can buy a used one cheaper, but at that price it's hard to beat.
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Quote:
Originally Posted by jrhymeammo
It's just lower frequency so the tonal quality isnt that significant.
I will also have to disagree. Getting the first couple of octaves right can help make a system disappear. In my main music system, I achieved that with careful placement of the speakers and a forest of bass traps.
Quote:
Originally Posted by jrhymeammo
I still don't see why everyone uses it. Since I purchase a preamp( still no amp) the idea of SubEQ has been popping inside of my head again.
Well, I purchased a Behringer EQ for the powered subs in the HT, but no longer use it. Why? It's in a different room now where the issues are above the range of the sub. I tried it full range, but don't like the sonic compromise. So it sits on the shelf.
rw
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Quote:
Originally Posted by jrhymeammo
Good Post Kex, and Oops..
I meant to type "I still dont see why everyone's NOT using it"
Sorry about that... completely different than the way it was intended(I do it all the time).
I dont think it's possible for anyone to own a sub that will produce flat (3+/- dBs from 20-100hz) frequency response, not matter what the spec states.
I wanted to revive this thread for my purpose and others without an equalizer for subs. Is there an alternitive to Behringer FBD since last year for around $200?
Thanks
And I'm glad you did jr. Kex has offered me a lot of advice for my redundant and stupid questions about my subwoofer situation. Had I dug a bit more I would've found this thread and saved everybody from answering the same questions over and over again.
I just wish these vBB's had better search engines.
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Quote:
Originally Posted by Rich-n-Texas
And I'm glad you did jr. Kex has offered me a lot of advice for my redundant and stupid questions about my subwoofer situation. Had I dug a bit more I would've found this thread and saved everybody from answering the same questions over and over again.
I just wish these vBB's had better search engines.
I shouldn't take much credit, if you look back 3 years ago or so I was of the opinion subs should only be used for home theater and never for music, that crossovers should be as low as you could set them (mine was 40 Hz) and didn't really know too much about room acoustics and their impact on bass beyond the fact there'd be "peaks and dips" in the response. I learned a lot from people like Woochifer, Sir Terrence, Dr. Greene etc on this stuff.
Just glad I could share what I've learned, some of those folks are no longer with us here.
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Equalizing my sub might just become an end of summer project now.
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Quote:
Originally Posted by E-Stat
...So it sits on the shelf.
rw
For sale??? :ihih:
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Quote:
Originally Posted by E-Stat
I will also have to disagree. Getting the first couple of octaves right can help make a system disappear. In my main music system, I achieved that with careful placement of the speakers and a forest of bass traps.
rw
Well I miss wrote, but I think you knew that.
Without any first hand experience, I would like to speculate this.
I think subs would sound better without EQ, IF bass traps and other acoustic treament can control it. I still imagine that adding EQ will colour lower sound, but probably isnt that big of deal.
If traps sound becomes a huge WAF, then EQ should be on top of the list for everyone who are annoyed with substantial peaks?
My REL T-3 is significantly better than PW-2200 I had. But of course, I never got to try T-3 in my last apartment as well as PW-2200 in my new place.
What I would like to ask is:
Have you tried using your EQ in your main system without traps? If so, what did you know like about it. I have to think EQzer would allow you to fine tune your room response a little easier than carefully treating your room. I just dont see how anyone could make such precise placement that will work better than an EQ. I believe it's possible to achieve... but I just can't believe how you did it. If added coloration was the reason why you chose traps over an EQ, then I can't argue with you. Again, I dont have any experience with this.
Would you care to discuss this a little?
Thanks to all the replies I received to this point.
Peace
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Quote:
Originally Posted by jrhymeammo
Without any first hand experience, I would like to speculate this.
I think subs would sound better without EQ, IF bass traps and other acoustic treament can control it. I still imagine that adding EQ will colour lower sound, but probably isnt that big of deal.
You can trap your room until the cows come home, but I would suggest it would make the sound far too dead for music, would cost a small fortune, and still wouldn't solve all the problems. Unless you've got a monster sized room 20 X 30 or something, then it can get a bit easier towards the sweet spot. Most homes probably don't have that. Even then, you're still going to have large, uneven responses throughout the room (if you live in an oval or something you might get away with it). Physics sucks.
Likewise, an EQ only approach might be good at one listening position, but all bets are off the further way you more.
Traps can definitely help. I definitely had to use less drastic adjustments and notice more even respone from 3 of 4 seating areas after I put mine up. The less filters, and the less aggressive the filters, the better for sure!
Everyone always equates EQ's with sound coloration. When we use the BFD, we're typically applying only a few cuts - maybe 3 or 4 tops (some would say that's too much) and maybe, if you're good, one boost of moderate amounts. The fewer, the better. We aren't boosting and cutting throughout. The processing is in an area of the spectrum that our ears are more forgiving with so we can get away with it. I also believe a lot of the noise artifacts simply are beyond the abilty of a subwoofer to reveal, especially harmonics higher in frequency.
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Agreed, but I think I will try it first before making further statements. Hopefully before this year is over.
Your statement about limited effective areas/seating is what I had in mind.
I'm glad Feanor talked me into getting a preamp/amp instead of simpler integrated amps.
Thanks Kex,
JRA
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I think many of you have valid points but I always suggest EQ be a last resort and approached with conviction. NO EQ is better than bad EQ. As touched on, lowering humps is acceptable but raising dips in frequency is not generally suggested. E Stat has a good point too. Speaker and subwoofer placement should be the first plan of attack and EQ should be a last resort if all techniques fail like panel placement. Many people think that buying more equipment is always the solution without ever learning about room acoustics, room modes, room setup, seating distances, speaker placement, etc. If you have mastered these fore mentioned topics, then you probably do not need to post a question on a forum as to what EQ device is the best for the money.
The last difficult situation is that most people do not have the equipment necessary to properly measure room acoustics and frequency response. It takes equipment that has a very high sample rate. Most DDS and FFT time window systems that are affordable have a resolution that is greater than or equal to 100Hz resolution (usually 1\3 octave spectral averaging solutions). Q measurements can rise and fall within even 0.5 dB so reliably measuring these frequency changes just is not in the average persons capabilities.
I do not mean to burst anyone bubble. It just is the reality of current technology and without adequate research, you could really be chasing your tail and throwing lots of money at a solution that is not achievable without professional help.
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Quote:
Originally Posted by Sir Terrence the Terrible
Thank you much National Minister of Pertanent Information.
Oh my, let us all bow down to one of the AR masters. Did you just come out of hibernation to grace us with your wisdom T......lol good to see you again old friend.
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Quote:
Originally Posted by recoveryone
Oh my, let us all bow down to one of the AR masters. Did you just come out of hibernation to grace us with your wisdom T......lol good to see you again old friend.
Note the date of Sir T's post.
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Quote:
Originally Posted by jrhymeammo
What I would like to ask is:
Have you tried using your EQ in your main system without traps? If so, what did you know like about it. I have to think EQzer would allow you to fine tune your room response a little easier than carefully treating your room. I just dont see how anyone could make such precise placement that will work better than an EQ. I believe it's possible to achieve... but I just can't believe how you did it. If added coloration was the reason why you chose traps over an EQ, then I can't argue with you. Again, I dont have any experience with this.
Would you care to discuss this a little?
Thanks to all the replies I received to this point.
Peace
Personally, the best setups I've heard incorporate a combination of placement, calibration, room treatments, and EQ. In my room, I use acoustic panels, but they are more for blunting front and side wall reflections. As of now, I don't have any bass traps installed and only use a parametric EQ. The reason is the WAF (the homemade bass traps look like arse) and the cost for commercial bass traps.
From my experience, I can tell you that equalization alone made a dramatic improvement in my sub's in-room performance. The subwoofer's tonal characteristics varied dramatically depending on where I placed it within my room, but no matter what location I picked, I measured at least two very large frequency peaks. While room treatments can reduce the magnitude of these wave interactions, treatments alone cannot eliminate them in a typical room. As Kex said, physics sucks.
EQ by itself is an imperfect solution for any number of reasons (only works at one seated position, introduces delay, etc.), but I think that in conjunction with proper placement and calibration, EQing can significantly improve the performance for just about any subwoofer in a typical room. In going with treatments and EQ, it's not an either/or proposition. Both approaches by themselves are preferable to doing nothing (sure no EQ is preferable to bad EQ, but properly applied EQ can be much preferable to no EQ depending on your room acoustics). And ideally you'd want to get your placement, calibration, and room treatments optimized before using the EQ to fine tune the larger problems that cannot otherwise be corrected.
Quote:
Originally Posted by westcott
The last difficult situation is that most people do not have the equipment necessary to properly measure room acoustics and frequency response. It takes equipment that has a very high sample rate. Most DDS and FFT time window systems that are affordable have a resolution that is greater than or equal to 100Hz resolution (usually 1\3 octave spectral averaging solutions). Q measurements can rise and fall within even 0.5 dB so reliably measuring these frequency changes just is not in the average persons capabilities.
People familiar with the Room EQ Wizard would probably disagree with this statement. All that application requires is a PC with a sound card and a Radio Shack SPL meter (the mic calibration file is built into the application) along with some rudimentary RCA cabling and 1/4" jack adapters. And it's an open source freeware application. The application includes an automatic calibration function that identifies the best attenuation settings (both center frequency and bandwidth) for a parametric EQ, and it can be used to measure the frequency and time response.
For purposes of subwoofer equalization, you don't need measurements that are reliable to within 0.5 db, and just plotting the frequency response with test tones and a $40 Radio Shack SPL meter will give you enough data points since the EQ filters used with a subwoofer will rarely need anything beyond a 1/12 octave bandwidth. This is not a full spectrum measurement, so the kind of precision you're talking about is not necessary here.
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oops the thread is almost a year apart lol
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Quote:
Originally Posted by Woochifer
The reason is the WAF (the homemade bass traps look like arse) ...
Hmmm. I guess it depends upon whose arse to which you refer. Say, Kristanna Loken's fine example as seen in T3 where she approaches the chick in the Lexus convertible? ;)
Seriously, they don't have to look bad. Although my listening room is one of two WAF free zones in my house (the other being the garage), I wanted an attractive living space myself. I did have to barter with my wife to make all the socks though! Unfortunately, we couldn't find enough gray spandex so one of the four traps in each of the back corners is black.
http://home.cablelynx.com/~rhw/audio/traps_left.jpg
http://home.cablelynx.com/~rhw/audio/traps_right.jpg
Quote:
Originally Posted by Woochifer
For purposes of subwoofer equalization, you don't need measurements that are reliable to within 0.5 db, and just plotting the frequency response with test tones and a $40 Radio Shack SPL meter will give you enough data points since the EQ filters used with a subwoofer will rarely need anything beyond a 1/12 octave bandwidth. This is not a full spectrum measurement, so the kind of precision you're talking about is not necessary here.
Agreed, but not limited to subwoofer placement either. I used a SP test CD, RS SPL meter and calibration curves to fine tune the placement of my 'stats, room treatments, and couches for the smoothest response in the bottom three octaves.
rw
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You have to work with what you have but Q resonances are there and do peak in areas way beyond the ability to measure them with typical hardware. Just because you have never heard of these issues does not mean they do not exist.
I think you need to read the attached pdf and if you do not want to read the whole thing, skip down to page 17, 18, and 19 to understand what I am referrning to.
Q resonances affect timbre and pitch, depending on the frequency range and in the case of subwoofers, timbre is the major problem.
Dr. Floyd Toole - Audio Science
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Quote:
Originally Posted by E-Stat
Hmmm. I guess it depends upon whose arse to which you refer. Say, Kristanna Loken's fine example as seen in T3 where she approaches the chick in the Lexus convertible? ;)
Seriously, they don't have to look bad. Although my listening room is one of two WAF free zones in my house (the other being the garage), I wanted an attractive living space myself. I did have to barter with my wife to make all the socks though! Unfortunately, we couldn't find enough gray spandex so one of the four traps in each of the back corners is black
Okay, I take it back (those DIY traps in your pics do not look like the kind of arse I was thinking of -- very nice! :ciappa: )! I should have phrased it differently. DIY traps would look like arse if I tried building them myself!
Quote:
Originally Posted by westcott
You have to work with what you have but Q resonances are there and do peak in areas way beyond the ability to measure them with typical hardware. Just because you have never heard of these issues does not mean they do not exist.
I think you need to read the attached pdf and if you do not want to read the whole thing, skip down to page 17, 18, and 19 to understand what I am referrning to.
Q resonances affect timbre and pitch, depending on the frequency range and in the case of subwoofers, timbre is the major problem.
Thanks for clarifying. I did not realize that you were referring to the time domain, which I do know that EQs can distort.
But, within this context, if the Q resonances are beyond the ability of end users to measure, then are you suggesting that EQs be avoided altogether, even if their corrections to the frequency domain are easy to measure and hear?
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Quote:
Originally Posted by westcott
You have to work with what you have but Q resonances are there and do peak in areas way beyond the ability to measure them with typical hardware. Just because you have never heard of these issues does not mean they do not exist.
I think you need to read the attached pdf and if you do not want to read the whole thing, skip down to page 17, 18, and 19 to understand what I am referrning to.
Q resonances affect timbre and pitch, depending on the frequency range and in the case of subwoofers, timbre is the major problem.
Figures Toole would work his way into this conversation.
You're only considering the "Q-resonances". What about non-Q resonances?
Toole's point was NOT that low-Q resonances are more important for subwoofers than high-Q resonaces. In fact, Toole even states in his paper that at low frequencies, all bets are off on the audibility of the thresholds of resonances (think Fletcher-Munson). When we factor in the human ear's sensitivity to frequencies in that range, it's just the opposite. The issue isn't the Q-factor, high or low, for frequencies below 100 Hz especially, but rather the relativity intensity of these resonances compared to the reference level.
Small resonances of various Q of course exist in the lower octaves. I don't think Wooch or anyone else is denying EQ'ing won't solve a small, low-Q peak of 0.25 dB with a Radio Shack SPL meter and BFD. We may argue the magnitude of impact on the sound quality, timbre, and pitch a low-Q resonce has when one considers the human ear's senstivity to frequencies below 200 Hz.
I have yet to see any rational argument that supports not using an EQ to deal with low, medium, or high Q resonances of larger sound pressure levels (say +6 to +9, even +12) that are present (and there are some nasty, strong low-q resonances quite often), inevitably after room treatment and proper speaker placement in most homes, and which are quite easily captured by sine wave test tones in 1/6 octave increments, and sweeps on conventional equipment.
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Quote:
Originally Posted by jrhymeammo
I think subs would sound better without EQ, IF bass traps and other acoustic treament can control it.
Agreed.
Quote:
Originally Posted by jrhymeammo
Have you tried using your EQ in your main system without traps?
Oh yes.
Quote:
Originally Posted by jrhymeammo
If so, what did you know like about it.
First of all, my main system uses full range electrostats, so I cannot selectively use it only with sub(s) like I have done in my HT. Where do I start? Added false brightness. Soundstage gets narrower and shallower. Resolution suffers. The sense of musical delicacy, detail, and effortlessness I've spent years to achieve goes out the window in one swell foop.
Quote:
Originally Posted by jrhymeammo
I have to think EQzer would allow you to fine tune your room response a little easier than carefully treating your room. I just dont see how anyone could make such precise placement that will work better than an EQ.
Perhaps. Remember skeptic / Soundmind? He once said that it takes him two years to get his system adjusted with his three EQs. I spent the better part of a day running about two dozen trials varying position of speakers, traps, and listening couches. I get 30-200 Hz +/- 1.5 db with a 2 db peak at 25 hz. The result sounds neutral enough to me without butchering the signal.
I purchased my current EQ (a Behringer unit) specifically for my HT subs. The room in my previous house had a huge 100 hz suckout and a 160 hz peak that I wanted to fix. Limited to subs, I think they work very well.
rw
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Dr. Toole's paper clearly states at the bottom of page 18, that I refered to earlier, that
........... "at very low frequencies, the long wavelengths and periods allow ringing to be heard as an extension to bass sounds - boom."
The conventional method of specifiying frequencies is useless..... and 0.5dB variances can clearly be heard at all frequency levels (high or low) equally. Once again, at the bottom of page 18.
I point these things out so that others can view things from both sides of the fence. Whether you agree or disagree with Dr. Toole, it still points out that many experts in the field suggest EQ be used with prudence and that its affects are far more wide ranging than most people are aware of.
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Originally Posted by westcott
I point these things out so that others can view things from both sides of the fence. Whether you agree or disagree with Dr. Toole, it still points out that many experts in the field suggest EQ be used with prudence and that its affects are far more wide ranging than most people are aware of.
I don't disagree with him at all, and I agree with your recommending using EQ's with caution - good advice. Though nobody here is suggesting anyone go trigger happy with an EQ.
I could be off, but your earlier you seem to take what he wrote about the total spectrum, in specific reference to loudspeakers and conventional FR testing methods in and applying it to subwoofer equalization in a very specific, low frequency range. It's a bit trickier than that.
I can quote him too (p.17):
"High-, medium- and low-Q resonances shown at the detection thresholds, below which the resonances cease to be audible. It depends on what you are listening to. The locations of the illustrative peaks on the frequency scale are arbitrary. The audibility is similar at all frequencies except, perhaps, at very low frequencies."
We are less sensitive to low frequencies. Much less.
What you've said about EQ'ing is good advice - use it after you get all your other affairs in order. All I'm trying to point out is that while we can't achieve perfection, using an EQ to eliminate the remaining, really bad problems, can still get us closer to the goal.
RE: the time domain - this is where my comfort level drops significantly, except that I do know if you're experiencing problems with FR because of room acoustics, you're undoubtedly experiencing problems with the time domain as well. The risk, I suppose is that you'll make it even worse. In practice, we find that you're improving the FR at a greater "rate" than you're further worsening the phase/time interference, which should result in a net benefit. Of course this probably isn't always the case, and that's where listening comes in. If you apply a filter and it sounds bad, don't use it.
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