Eh hem!...Subwoofers... What do ya know?
I am reading the JL Audio article on sub integration. I'll be responding to it shortly. Honestly it's a bit of a mess, but I agree with their main points. As much as I like how well their room correction works, I find this article attempting to make things a lot harder to understand than really necessary. It's trying to scare you out of trying. But their main point, that adding a sub is like adding a driver to a speaker design, is spot on, and exactly what I've said before. Like they'd loose any money. :) |
Hi @dpac996 So, if I understand correctly, you want to take an amplifier’s output as the input to the subwoofer, correct? And that this output would be shared beteen your main speaker and the subwoofer's input? If not, disregard all of this. :) Now, onto theory and experience! Measurements show that while the effect of an average speaker load on a solid state amplifier is small, it isn’t zero. If you look at the Stereophile simulated speaker load, https://www.stereophile.com/content/real-life-measurements-page-2 they estimate a minimum impedance in the bass of around 6 Ohms, while my experience says this is often in the 3 Ohm or less. So, take a moderately solid integrated, like the Luxman 509, whose deviation from flat based on that load is here: https://www.stereophile.com/content/luxman-l-509x-integrated-amplifier-measurements The effect of the simulated speaker is very slight, honestly, around +- 0.1 dB. So lets say that at 3 Ohms that’s twice as much, +- 0.2 dB. My experience has shown that this is sometimes audible, making speakers seem more demanding of an amplifier. For this reason, if you can take the signal from the preamp instead, which will have a flat impedance presented to it, you can avoid any such issues. In other words, while I understand the math of output impedance, speaker impedance, voltage and current, my experience says that around 3 Ohms is enough to demonstrate a difference among a lot of amplifiers. I wouldn’t want to use that as a reference voltage for that reason. PS - I own a Luxman 507ux myself. Very happy with it, but when I set up my sub, I’ll be taking the signal from the pre out. :) Best, E |
Everytime i hear a rig with a sub for 2 channel, i can HEAR the subwoofer, its not a balanced / natural tone to my ears. And this is the problem for me, who bats for team sub. Most subwoofers are not integrated well. When they are, they are magic, when not, they call attention to themselves. When speakers and subs are done correctly with moderate room treatment and EQ they all disappear. The benefit of the sub seems to improve the performance of everything, not just percussion and movies, and extend the dynamic range apparently to infinity. So, what to advise a music lover who just wants good sound? That is the question. Get a big enough speaker, and you end up with the same issues. Get naive or poor room EQ, with poor room acoustics, and you end up with a frankenspeaker effect. |
This may sound like a dumb question but since the sub has three drivers firing in different directions does this create the effect of multiple subs ? It does give you more bass than a single 8" driver would otherwise, but it’s not like having separate subs individually placed. The direction they are pointing in is kind of irrelevant assuming they can all breathe. Using three 8" subs you get the surface area of around a 12" sub, maybe a little less. The direction they are pointing in probably has more to do with aesthetic choices. The reason for using multiple separate subs is to try to equalize room modes. The situation where you have big peaks and valleys in the bass response. I notice it has no built in EQ. You absolutely want to use an EQ with a sub. It will make integration a lot easier. So will bass traps if you find you have big nulls. |
it puzzles me why individuals buy speakers with poor bass response Let’s convert the word "poor" and say "deep." The smaller the speaker, the less likely you are to run into room mode problems, not to mention matching the decor (yes, this is important) and finding the ideal place for them. Pretend physical size is not an issue. Say you have a 6" cube speaker that is flat 16Hz to 30kHz in a test chamber, with infinite dynamic range. That could be a terrible sounding speaker in a lot of rooms. Speakers that measure anechoically to a -3dB point at around 40-60 Hz may end up being a lot better balanced in a room. So the purist, who eschews equalization, if having to choose the best balanced speakers in his room, may end up with a speaker with limited bass. I’m going to argue, again, that a lot of issues people attribute to subwoofers and ported speakers have less to do with speed and distortion and a lot more to do with how many dragons they wake in the depths. If money is no object, build an acoustically ideal listening room with giant speakers. If you don’t really care about boutique DAC’s and preamps, then a pre or integrated with DSP room correction is going to be your drug of choice. In the middle of this are a variety of interesting opportunities:
So, to answer the question, it makes perfect sense to me why audiophiles would choose speakers with limited bass response. Getting deep high output bass is complicated, and expensive, and for a lot of music lovers not in their field of expertise. A high quality two way is often their sweet spot. |
2 subs are better in that you have more power, and more driver pushing air. So absolute terms, sure, you can increase output by 3 dB with lower distortion. But if you place the subs symmetrically, I would imagine that you end up reinforcing the same mode and anti-modes. Maybe some one has a better idea? As far as I know, you place the first sub as well as you can, and then place the second sub so that it fills in any nulls. Is this not how the cool kids do it today? |
Are 2 subs better? Honestly a lot of this is an economic problem. Not just expense of the sub, but the room. Can you afford / do you have the space to locate each sub ideally? If so, then yes. If not, a good compromise is room acoustics, 1 sub placed as well as you can plus an EQ. In my own situation, I really really don't want to be moving a sub 6" 12 times to compare and measure. I have about 2 locations where this 100lb beast can go, and I'm going to put it there and EQ it and call it done. :) |
What are your opinions on subwoofers? Hard to integrate well. Glorious when done right. What did you learn and how did you learn it? That’s a really good question. I started off with an M&K satellite/subwoofer system. Bought into the hype, used a passive 2nd order crossover (yeah, enormous toroids) and a couple of different RTAs to attempt to get the two to play well. Honestly they never did. The best I was able to do was use a little room math to damp the peaks. The rest of my answer is a little long, but the short version: I integrate subs as if I’m building a speaker. Here’s the long answer: The V1B subwoofer eventually fell apart and I parted it out on Ebay, sold the S-1Bs. Years later I was in San Francisco and got into upgrading speakers, and that led, very rapidly to learning speaker analysis and making my own. Now mind you, I have some professional background in analog and I was lucky enough to audit classes at Georgia Tech when I was too young for the math. Point is, I didn’t just jump into speaker design from zero. One thing that changed a lot in my favor was the availability of cheap test and simulation tools. DATS, OminiMic and XSim made everything I wanted to do a lot easier, but none of them were useful without having a background already. The other thing that was new was miniDSP having a number of affordable and very high feature active crossovers. Even with this background I made a couple of choices that really made everything a lot easier:
Had I not done that, I would have made plenty of mistakes in analyzing the mid-bass response, or gotten overwhelmed with the quasi-anechoic requirements of a 3-way (this is short-hand, please don’t jump on this sentence). Anyway, after this I returned to wanting a sub. Based on reviews including those at: data-bass.com I went with a Hsu. They were out of the model I wanted, but for a couple of hundred I could get the next larger unit. What arrived was the size of a small refrigerator, and me in a small apartment!! Hahahaha. Anyway, I tried a number of ways to integrate the sub, bought a pair of GIK Acoustic soffit traps, and the miniDSP HD balanced. What finally worked for me was this: Treat the sub exactly as if I was adding a 3rd driver to my speakers. Which meant measuring the acoustic distance, putting in the response of the satellites and subwoofer into XSim, phase/time matching them and then using OmniMic to simulate EQ’s. Pant flapping glorious. |
