Gotcha, and I say it would be terrible because most times tuning at a particular frequency for a ported box means that frequency and the frequencies around it are played louder and anything below that frequency would cause the subwoofer to bottom out. Bass below 40hz is not all uncommon in music so you would have constant problems. Tuning above 40hz not to mention 60hz is almost exclusively for SPL competitions in ported boxes, but as you stated I guess this does not apply to a bandpass enclosure.
So to sum this up, a bandpass gives you more flexibility with your subwoofer than a ported or sealed box, while adding into the complexity and at times size of the enclosure, right?
I can't seem to understand what is the reasoning behind all of this, to me it seems like you can get equal or better results with a properly tuned ported box or a sealed box with much less hassle.
edit
Behavior for the Bandpass vs. the BR. As you can see from post #18 by Mike you also benefit from the acoustic roll-off that is so important to crossover at sub-low frequencies to the mains.
Behavior for the Bandpass vs. the BR. As you can see from post #18 by Mike you also benefit from the acoustic roll-off that is so important to crossover at sub-low frequencies to the mains.
Last edited:
The sub is still excursion limited in a 4th order. A BP can be more efficient than BR or sealed, at the cost of enclosure size. You don't need electrical filtering which is a huge advantage in some apps.
You seem to want to repeat that they're pointless while ignoring that there are reasons to use them that have been pointed out.
You seem to want to repeat that they're pointless while ignoring that there are reasons to use them that have been pointed out.
A lot of newbies come here just to voice their opinions and learn nothing...
Before you talk, please do your home work.
Now now, don't be going around talking me down on my threads, so what if I am a newbie?? Why don't you correct me and show me where I made the mistake, instead of demeaning me and acting like you are some hot Sh**
By the way the bandpass enclosure description you added was actually insightful and taught me something.
But other than that I don't feel that I am mistaken about my take on the ported enclosure, correct me if i'm wrong.
"Before you talk, please do your homework"
What? I am learning from forums and articles online, in my opinion that is doing your homework, besides what is with the perpetual attitude on this site, that people should know everything about audio. WTH is the point of a forum if all of us here are super duper professionals? Is it not the forums intentions to teach newbies, to allow people to absorb information that otherwise would have been unavailable?
Sure I could have taken years of college and classes, read a room full of books, only to gain some knowledge that I may or may not ever use.
I understand you are an audio fanatic and enjoy this forum, but I am in no way ruining it or trolling.
My questions are genuine albeit slightly unintelligent and simple, choosing to reply to a thread is your option, some people would consider my questions stupid and pointless, other would be delighted to point me in the right direction, because some day long ago there were other people that helped them learn what they know now.
I learn from what resources I can and in turn teach and comment on peoples threads about things that I am well past in the learning process (like not much on this particular site LOL) because I understand that someone dedicated their time to help me with my questions so I pass the good deed along to someone else who needs it.
If we were to start deleting all the threads that had any slightly uneducated questions, this forum would have much less traffic and people like me would have never even joined.
I had questions about bandpass enclosure and why people built them and what application did they use it for. Sure there maybe people hear that find that below them, does NOT mean that there aren't others wondering the same things.
In my opinion I DO NOT need to go to years of college or read a million books on bandpass enclosures because I may never even build one in my life, but in order for me to find out if it is even worth my attention I needed someone to explain the advantages of a bandpass. Perhaps if there was some that I found worthwhile with bandpass, I would have the books already ordered.
Basically you are saying is I should spend a ton of my valuable time to research and study something that I will most likely not be interested in at all, when I could simply ask a forum, see if there is anything to it that intrigues me and then go from there. 🙄
Edit: Inductor edited his post so this seems out of context lol
Last edited:
Thank you for the reply, and no after several replies on this thread I don't think they are pointless anymore, I just haven't found any reasonable applications that would work for me so far. The point of this thread was for me to find out whether there was something to it that I was missing (and there was) to see if I may be interested in designing one(i'm not, not yet anyway). Since the explanations so far do not warrant me building one, to me it is pointless, but to other the bandpass could be just what they needed.
A properly designed bandpass will smooth out the system response. On my PA system the main speakers are -3db at 75 hz and fall like a rock below that, my EV18B subs which are a band pass design put that 75hz-40hz back. (don't care below 40 because there is no music there in what I mix). This reduces the strain on my main amplifier so the music it is re enforcing (75hz-20k) has the head room needed (no compression) to sound great.
Play with WinISD, pick a small 4" speaker with an FS around 100hz and try to design a ported or sealed box that will have frequency curve of a band pass. Then you will know why people like them.
Play with WinISD, pick a small 4" speaker with an FS around 100hz and try to design a ported or sealed box that will have frequency curve of a band pass. Then you will know why people like them.
Thank you for the reply. Things seem to make sense a lot more now. I personally listen to some music that drops to the 20's in hz. I will mess with WInisd when I get a chance and see exactly which improvements are made with various designs
I corrected my post in the mean time as you can see. There's nothing incorrect about it after the edit.
(It's just your obnoxious approach criticizing everything and waiting for others to correct you, that is not very friendly, but hey that's why we are all different...) 🙂
Can you name an enclosure that reduces second and third harmonic distortion *besides* a bandpass box?
Lol I hear ya, but I wasn't criticizing everything. Like stated in my first post I did some reading and research online and came to the conclusions in my numbered list. In fact because of peoples replies here I was able to learn and correct the misconceptions I was initially lead to believe. In my research I initially found very little benefit to a bandpass enclosure, so I was confused on why people even bothered with bandpass. 😕
I wasn't aware that a bandpass enclosure can reduce harmonic distortion until now. I logically assumed the additional ports would only add to the distortion.
Hopefully will start ordering my gear soon. I want a much more powerful lower extension in my living room than what I currently have (Klipsch RW12D)
I was spoiled by my newly installed 12w7 in the car. I will be doing a whole lot more research before I order and build an enclosure for my application.
Why rush into a project to be unsatisfied later? I guess I could experiment with lots of various enclosures, but experimenting with various woofers would be too costly or too much of a hassle.
SOO I have to do my research to the fullest extent that way I don't feel like I should have designed it differently later on.
I wanted opinions and facts on the bandpass, I got that now, and find that for my application and skill level the bandpass is not the optimum enclosure. Now it is a toss up between sealed and ported boxes. I love the way the sealed box sounds in my car but something like 90% of the home theater subwoofers are ported so I have much more to learn.
Regardless of which enclosure you end up preferring, you need to start modeling small-signal responses now. All this time spent posting and not simulating is time you could have spent actually learning, even if you may never build one---thats part of learning; not everything you learn will be useful but if you pick up something along the way that benefits you it's all worth it. Your time is not more valuable than ours, so even if you have to spend YEARS to find out you don't even like something, well that's part of life and learning experiences. No one is exempt from that. You're also extremely confused about the level of knowledge books will give you. You probably think that we're asking you to read 3inch thick books on bandpass enclosures. Hardly. Books give you insight on low-frequency reproduction in a scientific way that you can further expand on if you wish. I'd be willing to bet that 70-80% of the people here that are answering your questions have picked up some kind of audio engineering book at some point in their life. After all, it is why we're doing the answering and not the asking. 😉
Now download WinISD, and not a single other post until you learn the basics!! 🙂
Now download WinISD, and not a single other post until you learn the basics!! 🙂
I can't seem to understand what is the reasoning behind all of this, to me it seems like you can get equal or better results with a properly tuned ported box or a sealed box with much less hassle.
Yes, I was of that opinion too for many years. One of the first bandpass subwoofers I bought was the JBL SB-5. I think it was sometime in the early 90s. I bought it to complement the Control 5.
Sadly, I wasn't impressed. Other bandpass subs followed. All were disappointing. However, this is not true for all BP subs. The Bose Acoustimass 5 was hugely successful.
I have a pair of 10" subs for many years and I've never been able to get them to sound right. I tried sealed and ported with different volumes and tuning. Simply no definition in the midbass.
A couple of years ago, out of curiosity, I decided to test them with a BP design. Astonishing, they performed fantastically. There's definition in the midbass. Even excellent transients. The kind of sound you get with very expensive drivers.
I believe this is due to the way a BP design loads the driver. In a sealed or ported box, the front of the woofer radiates into the open whereas in a BP, the front and back of the cone are both enclosed in a box. Because of this loading, the woofer is less dependent on the motor and suspension. That may explain the superior cone control and possibly less distortion.
I don't have any scientific proof, just an educated guess. Nonetheless, I will continue to test BP. I like to think of it as an alternative to Servo Controlled Subs.
Your proof may not be scientific, but it is empirical! 🙂
You're basically confirming what RonE said about the freedom to tailor the response of a BP enclosure. The particular combination of sealed volume along with the tuned acoustic filter in front of it definitely exercises a great amount of control on the woofer's cone, which is easily visible on the excursion plot in any modeling program worth a penny. Reduce cone movement, and you simulatneously reduce distortion components because it is directly dependent on the amplitude of the cone's motion. Not only that, the ported section acting as an acoustic filter, rolls off the "highs" including said distortions, reducing them even further. Without distortions present in the signal, the upper bass frequencies (if tuned to allow them through the acoustic filter) come out largely as pure fundamentals, without the extra artifacts that are difficult to reduce with direct-radiator systems such as sealed or vented bass-reflex unless you have state-of-the-art drivers. Keep up the good work, look forward to more success stories about your systems.
I do not have access to WINISD until I get my computer fixed so I am learning what I can't without the hands on approach.
Also that's true my time may not be more valuable then yours and no one here is required to answer my questions if they don't have the time or don't want to.
All this time I spent posting stuff is time spent well because I am learning new things while I am pinned in a situation where I can't actually start on the project just yet.
I just don't understand, what's the problem with asking questions? You can always unsubscribe from the thread if you have found it to be tedious.
no need to fix your computer, you can run WinISD online without installing a program to investigate Frequency Response
LinearTeam
You can ask any questions you want, as I can reply to any thread I want. No one is forcing me to reply, but no one is stopping me either. 😀
- Status
- Not open for further replies.