Todd Nunley
CarAudio.com Newbie
Well, yes and no.
I would say that most of all of you car audio guys (I include myself) are interest in all aspects of audio, including home audio, home theatre, etc.
I've done a lot of it over the years. Multi-amp 12 speaker car systems, home system with huge subs in cabinets, 250 lbs of amps crossover, pre-amp in a rack powering the whole thing. Skirting the fine line of the lease breaker and divorce maker in my audio obsession. But doing this for over 40 years and having built a lot of cabinets for subs. Some good sounding ones, some not so good; I've never been satisfied. I could never achieve what I considered a smooth linear response from one with low distortion. Not that I'm one of those nutty audiophiles that must have tube amps and gold plated everything. Give me a break. I'm one of the guys that buys a non-working amp because it's cheap and fixes it myself.
But I just finished a subwoofer install that I'm damn satisifed with. It isn't perfect, but it checks a lot of the boxes I could never check before. This install is an infinite baffle subwoofer in my home.
This type I've never attempted because I've never had the right space to install one. Now I do and it took a while to get here. So, if you can sit still for a little background how this happened, I'll take another sip of coffee and tell you.
We purchased this house in 2016; in a beautful country setting away from the city. It has an attached garage really isn't a basement, but at a lower level than the rest of the house. In 2018 my parents had a mishap; their house caught on fire. They returned from the grocery store to see smoke and flames coming out of the windows. It was clear the time had come they need to live with one of their children. Since I owned a large house and had extra room, they moved in with us. We decided to convert the garage to an apartment for them. So they moved in and lived out the rest of their lives with us. They were happy and felt they were still independent and did what they wanted. (Funny, as they were completely dependant on us). They were both in their 80s, and their health was quickly declining and after a few years both mom and dad passed away. I was then left with this large room with a small attached kitchen to do something with. At first I considered renting it out for some passive income. But then I decided against it. I really treasure the peace and quiet of the country setting we live in. I then realized it is a perfect space for home audio system. It isolated from the main part of the house so there won't be shouts of "Turn it down please!" from the wife. But what is really unique about this arrangement is that behind the back wall is actually the crawl space for the rest of the house with about 5" of headroom. It is not open to the elements so it makes it ideal to install an infinite baffle subwoofer. The rule of thumb is you want a sub with a Qes of at least .7 or higher. This way it will preform well in "free air", without an enclosure. It happends a relative inexpensive SKAR SR18 sub had a Qes of .76 That's good for me be since it was only $127 (told you I was cheap). So I built a wooden frame from 2x6 boards measuring 24"x24". Doubled up a 1/2" plywood to make the baffle for it. Then cut a matching hole in the dry wall of the room, plus cut out 2 studs in the wall and screwed the 2x6 frame to it. I added a couple 2x4s across the back of the frame to add rigidity to the whole thing. Powering this thing is a ancient Peavey CS400 amp. One I purchased non-working many years ago with a bad main filters. I went through it and replaced all the electrolytic caps and it was back from the dead. Its far from a hi-fi amp. These were designed to power stack of speakers at high output levels continously. The design is more of a 'brute force' one with a bank TO3 bi-polar output transistors per channel. Ancient, made in 1980; but this thing will drive the load all the way down to 5Hz. My source is an Onkyo receiver using the subwoofer output. So how does it sound?
Well, what I encountered was unexpected. It's not loud. Its very subtle. At first I didn't really hear it at all, and thought it wasn't working. But then it really seem that suddenly my smallish left and right speakers had this amazing smooth, low end extension. There is no way these old 2 ways speakers sound that good. I got up and felt the cone of the sub, yes, it was moving, but barely. I took a couple steps back and realized that even at this low volume level it was kicking out some phenomenal lows. Even with almost no preceivable cone movement. Yes, an 18" woofer, the cone is large and has a lot of mass and moves a lot of air. Fs for this sub is 21Hz. So if a little volume is good, more volume is better right? Here is where I ran into problems. It is the mechancal coupling of the sub to the baffle, which is the wall. The wall is made of some POOR material for this purpose. 2x4 studs and dry wall. When you turn the volume up loud enough you start hitting the resonate frequencies of the wall. You get buzzes and rattles that are pretty distracting. I had it cranked to the point there was big cone movement in the sub, and the entire wall was heaving with the cone movement. Not good. How do I fix this? Well, there are some damping material I could try but the real issue is the wall itself. It just makes a poor baffle. But for now, what I had acheived was good enough to focus on the good and not the bad. There is little to no distortion (boomyness). This is inherent to some degree in most box enclosure subwoofer designs. The output is smooth and natural sounding. Also, it is better at reproducing super low sound (30Hz and lower) than any sub I've ever heard. I'm hearing things I've never heard before in recordings I've listened to dozens of times. Especially in things like live recording and old classic Jazz recording. Sounds like someone brushing against the mic stand producing a very low level low frequency "bump" noise. This sub does not "come on strong" as far as producing a driving beat. Music that lives in the 60-100Hz range; and that is bad. I love the driving drums and bass guitar of bands like Steely Dan. And to turn it up to get that kind of bass out of it, it will "hit the wall" so to speak and produce that unpleasant rattling noise in the walls. That is another thing, it is not LOUD. More volume does not really produce that preportional output you expect. That is a big benefit of a subwoofer in a box, and that higher output especially from ported enclosure. So after scratching my head over this for a minute, I went to my storage building and dug out a huge 15" ported sub I built probably 20 years ago, and disconnected the infinite baffle sub and connected the ported box sub. I always considered that to be a good sounding ported sub but after a few minutes of listening to it, I disconnected it and reconnected the infinite baffle sub. The ported sub was twice as loud as the infinite baffle sub, but had so much more distortion, and lacked the smoothness I was enjoying, it just wasn't as pleasant to listen to. It can produce that driving bass from drums and bass guitar I love but man, suddenly it was lacking something I couldn't do without.
So have I finally cracked the subwoofer code? For sure it is not perfect, and I'm sure my execution of it could be better. But in many respects it is the best sounding sub I've built so far. Later I may suppliment it with a box enclosed subwoofer to add those hard driving beat I like. But for now I'm listening to it at relatively low levels and enjoying it very much.
-Cheers
I would say that most of all of you car audio guys (I include myself) are interest in all aspects of audio, including home audio, home theatre, etc.
I've done a lot of it over the years. Multi-amp 12 speaker car systems, home system with huge subs in cabinets, 250 lbs of amps crossover, pre-amp in a rack powering the whole thing. Skirting the fine line of the lease breaker and divorce maker in my audio obsession. But doing this for over 40 years and having built a lot of cabinets for subs. Some good sounding ones, some not so good; I've never been satisfied. I could never achieve what I considered a smooth linear response from one with low distortion. Not that I'm one of those nutty audiophiles that must have tube amps and gold plated everything. Give me a break. I'm one of the guys that buys a non-working amp because it's cheap and fixes it myself.
But I just finished a subwoofer install that I'm damn satisifed with. It isn't perfect, but it checks a lot of the boxes I could never check before. This install is an infinite baffle subwoofer in my home.
This type I've never attempted because I've never had the right space to install one. Now I do and it took a while to get here. So, if you can sit still for a little background how this happened, I'll take another sip of coffee and tell you.
We purchased this house in 2016; in a beautful country setting away from the city. It has an attached garage really isn't a basement, but at a lower level than the rest of the house. In 2018 my parents had a mishap; their house caught on fire. They returned from the grocery store to see smoke and flames coming out of the windows. It was clear the time had come they need to live with one of their children. Since I owned a large house and had extra room, they moved in with us. We decided to convert the garage to an apartment for them. So they moved in and lived out the rest of their lives with us. They were happy and felt they were still independent and did what they wanted. (Funny, as they were completely dependant on us). They were both in their 80s, and their health was quickly declining and after a few years both mom and dad passed away. I was then left with this large room with a small attached kitchen to do something with. At first I considered renting it out for some passive income. But then I decided against it. I really treasure the peace and quiet of the country setting we live in. I then realized it is a perfect space for home audio system. It isolated from the main part of the house so there won't be shouts of "Turn it down please!" from the wife. But what is really unique about this arrangement is that behind the back wall is actually the crawl space for the rest of the house with about 5" of headroom. It is not open to the elements so it makes it ideal to install an infinite baffle subwoofer. The rule of thumb is you want a sub with a Qes of at least .7 or higher. This way it will preform well in "free air", without an enclosure. It happends a relative inexpensive SKAR SR18 sub had a Qes of .76 That's good for me be since it was only $127 (told you I was cheap). So I built a wooden frame from 2x6 boards measuring 24"x24". Doubled up a 1/2" plywood to make the baffle for it. Then cut a matching hole in the dry wall of the room, plus cut out 2 studs in the wall and screwed the 2x6 frame to it. I added a couple 2x4s across the back of the frame to add rigidity to the whole thing. Powering this thing is a ancient Peavey CS400 amp. One I purchased non-working many years ago with a bad main filters. I went through it and replaced all the electrolytic caps and it was back from the dead. Its far from a hi-fi amp. These were designed to power stack of speakers at high output levels continously. The design is more of a 'brute force' one with a bank TO3 bi-polar output transistors per channel. Ancient, made in 1980; but this thing will drive the load all the way down to 5Hz. My source is an Onkyo receiver using the subwoofer output. So how does it sound?
Well, what I encountered was unexpected. It's not loud. Its very subtle. At first I didn't really hear it at all, and thought it wasn't working. But then it really seem that suddenly my smallish left and right speakers had this amazing smooth, low end extension. There is no way these old 2 ways speakers sound that good. I got up and felt the cone of the sub, yes, it was moving, but barely. I took a couple steps back and realized that even at this low volume level it was kicking out some phenomenal lows. Even with almost no preceivable cone movement. Yes, an 18" woofer, the cone is large and has a lot of mass and moves a lot of air. Fs for this sub is 21Hz. So if a little volume is good, more volume is better right? Here is where I ran into problems. It is the mechancal coupling of the sub to the baffle, which is the wall. The wall is made of some POOR material for this purpose. 2x4 studs and dry wall. When you turn the volume up loud enough you start hitting the resonate frequencies of the wall. You get buzzes and rattles that are pretty distracting. I had it cranked to the point there was big cone movement in the sub, and the entire wall was heaving with the cone movement. Not good. How do I fix this? Well, there are some damping material I could try but the real issue is the wall itself. It just makes a poor baffle. But for now, what I had acheived was good enough to focus on the good and not the bad. There is little to no distortion (boomyness). This is inherent to some degree in most box enclosure subwoofer designs. The output is smooth and natural sounding. Also, it is better at reproducing super low sound (30Hz and lower) than any sub I've ever heard. I'm hearing things I've never heard before in recordings I've listened to dozens of times. Especially in things like live recording and old classic Jazz recording. Sounds like someone brushing against the mic stand producing a very low level low frequency "bump" noise. This sub does not "come on strong" as far as producing a driving beat. Music that lives in the 60-100Hz range; and that is bad. I love the driving drums and bass guitar of bands like Steely Dan. And to turn it up to get that kind of bass out of it, it will "hit the wall" so to speak and produce that unpleasant rattling noise in the walls. That is another thing, it is not LOUD. More volume does not really produce that preportional output you expect. That is a big benefit of a subwoofer in a box, and that higher output especially from ported enclosure. So after scratching my head over this for a minute, I went to my storage building and dug out a huge 15" ported sub I built probably 20 years ago, and disconnected the infinite baffle sub and connected the ported box sub. I always considered that to be a good sounding ported sub but after a few minutes of listening to it, I disconnected it and reconnected the infinite baffle sub. The ported sub was twice as loud as the infinite baffle sub, but had so much more distortion, and lacked the smoothness I was enjoying, it just wasn't as pleasant to listen to. It can produce that driving bass from drums and bass guitar I love but man, suddenly it was lacking something I couldn't do without.
So have I finally cracked the subwoofer code? For sure it is not perfect, and I'm sure my execution of it could be better. But in many respects it is the best sounding sub I've built so far. Later I may suppliment it with a box enclosed subwoofer to add those hard driving beat I like. But for now I'm listening to it at relatively low levels and enjoying it very much.
-Cheers
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