Just want to point out that the usual raison d’etre for line arrays in a home is to use pistons with much longer combined size than the wavelengths of the frequency they are reproducing.
Please, buy as many subs as you can afford, but you are going to have a very tough time creating a line array that is 56’ long.
My only point is that yes, I love line arrays, but I’d have a tough time imagining that I’d get the same benefits for the same reason with an array of subs against a wall in my house. Of course, more IS better. 😂
If you are willing and able to put in multiple subs, SWARM may be a better value overall. In my modest home, one sub is my absolute limit.
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BTW, I really am straying into solutions. I am not saying you can't get good without a high pass filter, but rather, I find it a lot easier to get there.
In this sense, I'm 100% with Richard Vandersteen. :)
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So the question is...If the high pass method makes the speaker sound so much better, wouldn't every speaker manufacturer use this superior method?
@gdaddy1
Well.... funny you should mention this, because they DO! Look at it this way. Every multi-way speaker incorporates high and low pass filters in their crossover. Adding a subwoofer is no different in my mind than increasing the number of drivers in a box.
It is precisely because I approach adding a subwoofer as a speaker maker that I always consider a high pass filter as part of the process.
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@james633
I find it silly when people chase bigger and bigger speakers at sky high prices for better bass, but refuse to try an actively passed sub system.
Too many speaker buyers take the speaker specs far too literally and think that knowing the -3dB point of a speaker in an anechoic chamber will be close to what happens in their room. From their perspective, if you want more bass you need a speaker with a lower -3dB point.
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Using my ears (crazy isn’t it?) I concluded that if your main speakers produce good bass down to 50hz why restrict them? Why? Because it sounded better, fuller, more glorious. Plugging ports and making a sealed cabinet restricts cone movement. Makes the main speaker sound thin and anemic.
@audioquest4life
I think what you are missing from the original thesis is that how a speaker performs once placed in a room is very different from the measurements. Sometimes in good ways sometimes in terrible ways.
Your experiences are going to be very room dependent. In your room and with your speakers plugging those ports may sound "thin and anemic" which in another situation might sound less boomy and better balanced. I’ve heard from one A’goner that they found the perfect balance by plugging 1 speaker but not the other.
Nowhere do I universally suggest you should plug all main speakers, but that if you are adding a subwoofer it may be a good option to make it easier to integrate a subwoofer. What matters is the in-room bass response and which option causes fewer headaches to deal with in equalizing the entire system.
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Except with horns. The cabinet/horn does the heavy lifting, not the driver - very neat.
Well, I meant to talk about the enclosure, not how a driver is loaded out the front. I hope most people understood I was specifically comparing acoustic suspension to ported enclosures and not trying to extend that to horns as well.
I thought that would have been clear since I was clearing up the efficiency of ported speakers myth. Sorry for any confusion.
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@sfgak
Without wading in too much to solutions, the THX standard of 4th order low pass, 4th order high pass at 80 Hz is really convenient.
Keep things in mind though, the goal is 4th order response includes the speaker response, and that we do in fact use assymetrical crossovers in speaker building all the time. 2nd HP and 3rd LP is very common for 2-way speakers. The point is, if all you can do is add a cap to your amp to create a 1st order HP filter, it’s worth it.
At the end of the day though, you can't get to a 4th order electro-acosutic response unless you actually measure your starting and end point.
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@gdaddy1 I have to believe your experience, but I also wish you had measurements to show us what was happening at the same time.
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Almost 100% of the time, newcomers will set the crossover too high and the gain (volume level) too low. This will result in a sound that is fatter, boomier and improperly integrated with the main speakers. The secret is to realize the [subwoofer] crossover needs to be lower than the main speaker’s output [emphasis added] at which point the gain can be significantly higher resulting in very flat, natural and extended deep bass.
@gdaddy1 That’s correct, but there is a key phrase here which is not in any conflict with what I’m saying:
The secret is to realize the [subwoofer] crossover needs to be lower than the main speaker’s output
Yes, exactly. And at no point am I advocating otherwise. This is why I’m consistently advocating for a high pass filter. If you are using a subwoofer strictly to fill below the main speaker output, then that’s as high as you can go. I’ve also suggested plugging ported speakers for the same reason. It raises the -3dB frequency allowing the sub to do more work while meshing smoothly with the mains.
What I thought I was pretty clear about is that raising the -3dB point of the main speakers to ~ 80Hz and using the subwoofer to take over at least 2 octaves at the bottom is a lot better than leaving the main speakers alone, and using the subwoofer only between 20 and 30-40 Hz.
Do you want to spend thousands of dollars on a high-end brand sub just for incremental improvements or do you want the end result to be a glorious sounding system? That’s the difference and why I advocate the way I do.
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I agree with @avanti1960 except in one technical nitpick:
The efficiency of a driver in a cabinet is determined by the driver, not the box. Sealed and ported cabinets will have the exact same efficiency if they use the same driver. The difference is the -3 dB location will shift down for a ported cabinet. Also, the optimally flat solution for a sealed cabinet can be much smaller than for the optimally flat ported solution.
I recently made a sealed center channel, and using sealed cabinets reduced the volume by about half, and raised the -3 dB point a little, but since I was going to crossover at 80 Hz, the -3 dB point of 45 vs. 60 Hz was moot.
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@clio09 - Using a high crossover point to fix a low frequency bump is sound. I've done the same while making internal crossovers. It avoids extra EQ components.
My recommendation is usually to ask users to plug any ports for kind of the same reasons. It makes integration a little easier.
@tomic601 Don't use a laser scanner to prove what you can easily see in distortion.
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You will never find tight punchy bass by setting a crossover high near 80hz or higher and then having to lower the volume to remove boominess. Like stepping on the brakes trying to go faster. That’s completely backwards and is NOT what a subwoofer was designed to do.
Ahem, well, that was addressed really early on, but this is conflating a number of issues. I specifically mentioned that peaks had to be dealt with, often by EQ or EQ + bass traps. Remove them and you can raise the subwoofer level, no problem. That’s a completely different issue than the crossover frequency.
Same for using SWARM. I'd still recommend 80 Hz as an excellent starting point. Certainly better than 40 Hz.
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@tomic601 Large, well made subs are efficient and have excellent pistonic motion in their intended frequency range and will deliver higher dynamic range.
Anyone who doubts this should just look at distortion specs for any 6-8" woofer and compare it to an excellent 15" driver. The distortion measurements don’t lie. Big is better and more accurate.
The room though, that's what will befoul any sub.
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I want to highlight something I fear may be missed. I wrote this at the top of my original post:
I want to talk about the impression that subs are fast or slow compared to planar or line sources.
So this thread is about all the things that go wrong when adding a sub and how most audiophiles attribute this to the mass of the cone. That a 15" sub has too much inertia to be accurate, and is therefore slow. This thread is very much focused on what is perceived, which is poor bass, and how different that is from the actual root cause.
That is, I wanted to center listener perceptions instead of the physics, which are clear that big subwoofer drivers are the way to go, if only you didn't have a room you had to put them in.
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There are some things that go wrong if you don’t high pass your mains too. Distortion and dynamic range are usually off, not to mention many times we EQ the sub but not the mains.
All drivers suffer from higher distortion at the lowest octaves they reproduce. Subwoofers do as well but at 2 octaves lower. So by leaving in the mains you are leaving that distortion in place. Next is dynamic range. Again, higher dynamic range, lower frequency and subs are absolutely going to win. You’ll end up with your mains producing significant distortion (harmonic and compression) levels you could have avoided by using a high pass filter.
I’m not sure that I know exactly which of these issues is why high passed main speakers sound so much better to me, but I suspect the answer is in one of these issues.
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@gdaddy1 I’ve had my subs tuned to produce from 16Hz to 80 Hz. It was glorious with music. There was no reason to limit the output, BUT...
the frequency response was absolutely smooth without peaks and tilted downwards. About 1.25 to 1.5 dB/octave.
Overall, I know your approach is a popular one, but I disagree with it based on experience, and talking to audiophiles who have actually made the changes. The approach you are taking is have the sub do the least possible. I say, have it do the most, up to 80 Hz possible, and have the mains do the least. It's OK that we disagree, but I wanted to acknowledge your position so I could talk to it. Thank you.
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While high pass filtering is a Plus option, with an abundance of speaker amplifier power the filtering is noticeably less desirable.
Honestly disagree. There are measurements showing that less bass = less IM distortion from main speakers, and many attribute this reduced IM/doppler distortion to some of the benefits possible. I’m not sure how much of that matters, but I can say, conclusively, that the high pass filters absolutely make the main speakers sound better.
Also, as an aside, Monitor Audio recently produced a high tech speaker, not sure if it was a prototype, with woofers facing each other, so you listen at 90 degrees to their motion, and I’m convinced this is an attempt at solving that particular problem.
From a power/efficiency point of view, you are right, no reason to high pass or use active crossovers in a home environment, but if you ask me if it sounds better, I am completely convinced it does.
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I have had good success with 8" and 10" drivers and have no desire to go larger than that.
In many rooms that may very well be ideal. While I could argue you'd get more out of a larger sub, there are dragons in the depths and not messing with success is a good principle to live by.
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@phusis I don't think we can entirely stop talking aobut potential solutions, whether that be my preferences, SWARM or a horn loaded woofer, because ultimately they all prove the idea that large drivers aren't fast is simply not the real problem.
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@audiokinesis is not wrong, but the SWARM solution, like adding EQ, and traps, is probably NOT what audiophiles expect when they first think of adding a sub.
SWARM and other approaches prove however that the issue is not the size of the sub but the room /sub/speaker integration. 15" subs don’t sound bad because they are 15". They sound bad because most have no idea how much they’ll need to make them sound good.
The idea that large drivers have excess stored energy which they can’t get rid of fast enough is bunk. That, and that alone, is my point. Which set of challenges audiophiles decide are best for them is for another thread.
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Anyone that has used a sub without a highpass is doing it wrong
I don’t think it’s IMPOSSIBLE.... but very difficult to do this by ear or based on published specs or measurements. You must figure out what your main speaker is doing in room. I repeat, in room speakers are entirely different creatures. It’s like you go to the store, get a sweet puppy which tries to eat your eyeballs as soon as you get it home.
IF you have a DSP based system, and only do the subwoofer, you often end up wiht very complicated EQ at the transition area, so, practically speaking, yeah it's nigh impossible.
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PS - IMHO, bass should not be "fast." It should be glorious. That is, it shouldn’t sound like you are listening to a bullet traversing the air, nor should it feel like a hammer in your chest.
Excellent bass should be clear like air or water and evidence itself only by the scale and dynamic range of the music being played and seemingly come out of nowhere and ignores the physical size of the room.
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@deep_333 - Sorry, got distracted by an ad that told me I could cure diabetes with baking soda, so this is how I know that everything on Youtube is real.
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@koestner
There are online calculators for this, and IF the speaker is actually 8 Ohms at the crossover frequency you'd need ~ 250uF.
A much smaller value would be needed to do this before the amp, which is ideal.
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I guess my point is, I wanted to focus on all the problems which makes audiophiles call subs slow to point out how much has to be right.
In the service of that, I have no problem with users having very positive experiences with one approach or another (including SWARM) but would like to see more discussions about SWARM taken to their own threads. "How I solved all my bass problems with SWARM" would be a good title for a thread someone else starts I think.
I think audiophiles are 100% correct when they say adding a sub to a great sounding pair of speakers ruined the sound, but usually WRONG about why it went bad. That's what this thread is about.
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@phusis No one wants peaks or nulls, but IMHO and experience, peaks are worse. Of course, mathematically we can compute power differences for each, but peaks are bad because they tend to force the listener to keep the overall subwoofer level excessively low. OTOH, I’ve never seen a real system where the nulls were so pronounced that they forced an excess in sub volume. Maybe I got lucky.
In my experience, clipping the peaks and then raising the subwoofer level is 2/3rds of the battle.
The purpose of this thread was to discuss the myth of subwoofer speed, not any particular technology, and it invariably happens that SWARM fanboys show up and turn the thread into "WHY DON"T YOU HAVE SWARM" and take the discussion far afield from it’s intended point.
So, sure, any tech which evens out the peaks and nulls and correctly meshes the response of the subs to the mains is good, including SWARM, but this thread is about dispelling myths that you can’t add a sub to a "fast" speaker, not pushing any particular solution.
The sense of a subwoofer being bloated, or peaky or slow can be addressed with a single subwoofer or swarm. The problem is the finesse involved which first time subwoofer owners may be completely unprepared for.
Installing 1 subwoofer correctly is a big deal and a lot more work than most audiophiles want to do. Tripling the number of speakers (from 2 to 6) for SWARM is also a big deal for many. Failing to do either well is what makes for slow, mushy or overbearing sub experience.
Either of these approaches can dispell the myth that big cone subs are slow and unable to keep up with "fast" planar speakers. OTOH, lets be realistic that audiophiles are also unprepared for the work they’ll have to do in many cases to be done.
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Hey @bjesien
I beleive you. The issue with subs, always, is integration. It is hard without measuremengs and nearly impossible with them. I applaud Vandersteen's use of high pass filters, but recognize how hard the rest of it can be before you get good results.
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@bjesien : Because it sounds so much better. In almost all cases when users have a high pass filter they are astonished at how much better their main speakers sound passed high vs. passed low.
The naive (without actual experience) is that you paid megabucks for your main speakers, so they should be much better than your sub which costs 1/5th or less.
The reality is, almost always, that your main speakers perform so much better when relieved of more bass.
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