It is currently Fri Mar 29, 2024 2:12 am


Learn something about sub enclosures from a Chevy pickup?

Speakers, amplifiers, headphones, multi-channel audio, reverb units, mixers, wiring, ...
  • Author
  • Message
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostMon Jun 19, 2017 8:16 pm

Aw C'MON DREW!!! I haven't heard anything out of you for months, now that I have just about settled on trying a ripole sub, you've gotta pull out the old Tuba HT again! :wink:

~S
"Life is just a dream, it is in death that we truly awaken!"
Offline

1961TC4ME

Member

  • Posts: 3144
  • Joined: Mon Feb 07, 2011 1:45 pm
  • Location: Lake Minnetonka, Minnesota

Re: Learn something about sub enclosures from a Chevy pickup

PostMon Jun 19, 2017 9:48 pm

Well, I did a bit of researching on the Tuba HT design this afternoon. There are quite a few variants out there being built, but there certainly seems to be some solid merit to this chamber within a box idea with openings in various places inside much like the windows being down idea allowing air from the driver to enter the cab so to speak and be amplified, but here for musical purposes. One thing I wondered as I drove along that day with the incredible wind shudder going on: Could someone driving beside me in the next lane also hear it? Due to its volume and intensity I'd think so and be surprised if they couldn't.

Drew, I know you recently had a long running post about your church sound system, I believe you built an HT, correct? If so what did you base the design on? Seems to be a lot of just throwing boxes of various designs together going on but most with decent results, at least that's what many of the builders are claiming.

I should also correct myself, I said earlier the huge wind shudder is annoying when driving along wanting to simply enjoy the outdoors with the windows down, but not at all annoying when it comes to pipe organs. :wink:

Marc
Offline

jkinkennon

Member

  • Posts: 1208
  • Joined: Thu May 07, 2009 9:43 am
  • Location: Vancouver, WA

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 20, 2017 10:37 am

The official Tuba HT design calls for a box that is essentially a 36" cube with the flexibility of dropping the width down to 24". The full width is supposedly the best -- I built one that was 32" wide. Lot's of output per watt with some EQ needed at the bottom end for a strong 16 Hz. Probably twice the output (3db) with half the power (250W).

The low profile version is a separate set of plans that can fit nicely in a 15"x18" corner but is 6' tall. For home use something like Rythmik Audio, Def Tech, or SRS will be stronger at 16 Hz though with less output across the entire bass range which is perfect in a residential room.
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 20, 2017 11:09 am

jkinkennon wrote:The official Tuba HT design calls for a box that is essentially a 36" cube with the flexibility of dropping the width down to 24". The full width is supposedly the best -- I built one that was 32" wide. Lot's of output per watt with some EQ needed at the bottom end for a strong 16 Hz. Probably twice the output (3db) with half the power (250W).

The low profile version is a separate set of plans that can fit nicely in a 15"x18" corner but is 6' tall. For home use something like Rythmik Audio, Def Tech, or SRS will be stronger at 16 Hz though with less output across the entire bass range which is perfect in a residential room.


Why do you think that? Is it because the Tuba HT needs more space, or is it just louder, or is it less 'musical'?

~S
"Life is just a dream, it is in death that we truly awaken!"
Offline

1961TC4ME

Member

  • Posts: 3144
  • Joined: Mon Feb 07, 2011 1:45 pm
  • Location: Lake Minnetonka, Minnesota

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 20, 2017 1:30 pm

scottherbert wrote:
jkinkennon wrote:The official Tuba HT design calls for a box that is essentially a 36" cube with the flexibility of dropping the width down to 24". The full width is supposedly the best -- I built one that was 32" wide. Lot's of output per watt with some EQ needed at the bottom end for a strong 16 Hz. Probably twice the output (3db) with half the power (250W).

The low profile version is a separate set of plans that can fit nicely in a 15"x18" corner but is 6' tall. For home use something like Rythmik Audio, Def Tech, or SRS will be stronger at 16 Hz though with less output across the entire bass range which is perfect in a residential room.


Why do you think that? Is it because the Tuba HT needs more space, or is it just louder, or is it less 'musical'?

~S


I was also always of the understanding from what I've read about sub box construction to avoid making them square, i.e. to avoid the exact same dimensions wide, high, deep. Maybe this doesn't apply (or isn't as much a factor) to an HT because of it's design?

Marc
Offline

jkinkennon

Member

  • Posts: 1208
  • Joined: Thu May 07, 2009 9:43 am
  • Location: Vancouver, WA

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 20, 2017 2:00 pm

scottherbert wrote:
jkinkennon wrote:The low profile version is a separate set of plans that can fit nicely in a 15"x18" corner but is 6' tall. For home use something like Rythmik Audio, Def Tech, or SRS will be stronger at 16 Hz though with less output across the entire bass range which is perfect in a residential room.


Why do you think that? Is it because the Tuba HT needs more space, or is it just louder, or is it less 'musical'?

~S


My observation is based on having one of each, a Tuba HT (36x36x32) and a Rythmik Audio F15HP, in my living room at the same time. I was also able to compare the Tuba HT to an older conventional 15" ported sub in a small sanctuary. What I heard compared well with the published specs I've seen for both units. The Tuba HT has a massive power output with only 250W while the Rythmik Audio sub went down to 16 Hz without external equalization. Rythmik audio appears to believe that 600W is right to compensate for the servo losses -- that is if 600 watts is the right amount to produce 16 Hz while maintaining a reasonable safety factor for their massive driver, then some much smaller wattage will be used at higher frequencies.

The tradeoffs are what we should expect. A larger horn loaded sub is very efficient and tends to go really low by virtue or its size. A smaller unit needs internal equalization using conventional equalization or ideally a servo feedback loop in my opinion. The smaller subs can be designed to go as low as you like but with less output due to the loses in equalization. The vast majority of subs make no attempt to go to 16 Hz.

One could use a pair of the Rythmik Audio subs in a sanctuary and get results comparable to the Tuba HT without fiddling with external equalization. The cost difference would be significant of course. One could do the opposite and build a low profile Tuba HT for the living room but that would be overkill in my opinion.
Offline
User avatar

dw154515

Member

  • Posts: 439
  • Joined: Mon Nov 12, 2012 1:52 pm
  • Location: Indianapolis, IN

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 27, 2017 2:38 pm

1961TC4ME wrote:Well, I did a bit of researching on the Tuba HT design this afternoon. There are quite a few variants out there being built, but there certainly seems to be some solid merit to this chamber within a box idea with openings in various places inside much like the windows being down idea allowing air from the driver to enter the cab so to speak and be amplified, but here for musical purposes. One thing I wondered as I drove along that day with the incredible wind shudder going on: Could someone driving beside me in the next lane also hear it? Due to its volume and intensity I'd think so and be surprised if they couldn't.

Drew, I know you recently had a long running post about your church sound system, I believe you built an HT, correct? If so what did you base the design on? Seems to be a lot of just throwing boxes of various designs together going on but most with decent results, at least that's what many of the builders are claiming.

Marc


Yes, there are several variants out there but why change the winning formula if you don't have to. I did the original-spec 36x36x36 with the recommended Dayton Audio driver. The only the I varied slightly was some of the internal bracing. The build plans are extremely detailed but since they were just braces meant to reinforce the structure, I was a little more haphazard with those. Otherwise, I built it to spec. I cannot speak for the variations on the original, as I have not tried them. As I mentioned on my long thread, there is nothing more subjective than audio, and reading black and white text on the internet is most certainly no way of communicating something as subjective as "audio fidelity." So, be careful of what you read online. To quote my favorite composer, Gustav Mahler, "You most go and work in ones own way, neither depressed by failure, nor seduced by applause." You have to experiment for yourself in order to REALLY know if there are discernible differences in the designs or not.
Drew A. Worthen
Master of Music in Composition - Butler University
http://www.drewworthen.com
Director of Music & Website Admin - Greenwood UMC
http://www.greenwoodumc.org
Design Engineer - American Sound and Electronics - Indy
https://americansound.cc/
Offline
User avatar

dw154515

Member

  • Posts: 439
  • Joined: Mon Nov 12, 2012 1:52 pm
  • Location: Indianapolis, IN

Re: Learn something about sub enclosures from a Chevy pickup

PostTue Jun 27, 2017 2:44 pm

1961TC4ME wrote:I was also always of the understanding from what I've read about sub box construction to avoid making them square, i.e. to avoid the exact same dimensions wide, high, deep. Maybe this doesn't apply (or isn't as much a factor) to an HT because of it's design?

Marc


It doesn't matter in this design because internally, there is not one single parallel surface. Check out my build pictures here:

https://www.drewworthen.com/single-post/2016/06/07/Tuba-HT-by-Bill-Fitzmaurice
Drew A. Worthen
Master of Music in Composition - Butler University
http://www.drewworthen.com
Director of Music & Website Admin - Greenwood UMC
http://www.greenwoodumc.org
Design Engineer - American Sound and Electronics - Indy
https://americansound.cc/
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostWed Jun 28, 2017 11:09 am

Hey Drew, didn't you say that the Tuba HT wasn't much good over 32Hz?

~S
"Life is just a dream, it is in death that we truly awaken!"
Offline
User avatar

dw154515

Member

  • Posts: 439
  • Joined: Mon Nov 12, 2012 1:52 pm
  • Location: Indianapolis, IN

Re: Learn something about sub enclosures from a Chevy pickup

PostWed Jun 28, 2017 7:05 pm

scottherbert wrote:Hey Drew, didn't you say that the Tuba HT wasn't much good over 32Hz?

~S


Eh, that's not exactly it. It is certainly capable of going well above that, of course. It isn't exactly the most "articulate" or "musical" sounding thing - it isn't designed to be. It does one thing and one thing only... LOWS! So, while it is certainly CAPABLE of going much higher, you're likely going to set the crossover point somewhere around 75Hz, depending on your upper speakers if you're using only the TubaHT.

My original idea when doing the sub experimenting (an I idea I still might implement in this impending church project) is to incorporate two subs. The CSC Trio12 BIB is GREAT at 32Hz and above. I might use it as the sub for all of the 16' stops and leave the TubaHT to handle the 32-16Hz range (that is to say 32' stops) only. This is largely due to the articulation differences between the two sub designs. The TubaHT is a 15" driver, with a LONG horn to traverse, at very low frequencies. Therefore, you can't really expect a good articulation out of it. It will just give you a solid fundamental and a few overtones. But the CSC Trio12 BIB is an altogether different design. It's a resonator pipe-type of thing which has the 12" driver mounted in the bezel (face) like any other speaker cab, but utilizes the horn off the back side of the driver. This sub has a nice quick, responsive attack. I like that.

Sorry.... I kind of went on a tangent.....
Drew A. Worthen
Master of Music in Composition - Butler University
http://www.drewworthen.com
Director of Music & Website Admin - Greenwood UMC
http://www.greenwoodumc.org
Design Engineer - American Sound and Electronics - Indy
https://americansound.cc/
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostSat Jul 22, 2017 3:59 pm

Marc, I don't know how you are coming with your experiment, but I just remembered an article I read about a fellow who did a sub with a resonator. Called the "Teres Subwoofer", it used a fairly small box with two 12" woofers in a push/pull configuration, and a piece of 12" diameter plastic pipe out of the top as a resonator.

Come to think of it, I don't know for sure if this relates to your idea at all, but since there haven't been any posting on here for a while, I thought "why not?" :D

~S
"Life is just a dream, it is in death that we truly awaken!"
Offline

1961TC4ME

Member

  • Posts: 3144
  • Joined: Mon Feb 07, 2011 1:45 pm
  • Location: Lake Minnetonka, Minnesota

Re: Learn something about sub enclosures from a Chevy pickup

PostMon Jul 24, 2017 10:20 am

scottherbert wrote:Marc, I don't know how you are coming with your experiment, but I just remembered an article I read about a fellow who did a sub with a resonator. Called the "Teres Subwoofer", it used a fairly small box with two 12" woofers in a push/pull configuration, and a piece of 12" diameter plastic pipe out of the top as a resonator.

Come to think of it, I don't know for sure if this relates to your idea at all, but since there haven't been any posting on here for a while, I thought "why not?" :D

~S


Hi Scott,

Yeah, I've had one too many summer time projects going on as of late, and it also seems during the summer months that somebody always has your weekends planned for you if you know what I mean. I'm also an old car enthusiast and I've got a couple projects I'm tinkering with while it's warm out, whereas Hauptwerk related projects happen more during the cold months when I don't have much else to do.

Here's the Teres sub you reference >> http://www.teresaudio.com/haven/subs/subs.html

Interesting concept for sure, but not quite what I had in mind. I built a nice vented cabinet a few winters back to house a 15" driver that I never got around to using and I'm thinking perhaps that would be the candidate to use for this 'chambered' enclosure idea I have, we'll see once I get a few of the other projects out of the shop.

Marc
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostWed Jul 26, 2017 9:51 pm

I can only wonder if that tube would tend to 'tune' the bass to a particular note given its length, just as some subs are tuned to a certain frequency (which is the only note you hear from a car as it goes by!) :roll:

Perhaps this is why sealed subs are referred to as being more "musical"?

~S
"Life is just a dream, it is in death that we truly awaken!"
Offline

1961TC4ME

Member

  • Posts: 3144
  • Joined: Mon Feb 07, 2011 1:45 pm
  • Location: Lake Minnetonka, Minnesota

Re: Learn something about sub enclosures from a Chevy pickup

PostThu Jul 27, 2017 10:01 am

scottherbert wrote:I can only wonder if that tube would tend to 'tune' the bass to a particular note given its length, just as some subs are tuned to a certain frequency (which is the only note you hear from a car as it goes by!) :roll:

Perhaps this is why sealed subs are referred to as being more "musical"?

~S


I kind of wondered the same, if the tube diameter and / or length would exaggerate a certain range, but I suppose most subs are going to do that to some extent, some likely more than others, and the trick is having a nice flat response from top to bottom which if I understand things correctly, a sealed sub is better at achieving. Even in my weird driving my pickup with the back windows down experiment the pulsing really got exaggerated depending on how fast I was going, and I wonder if the same would apply to my idea depending on the movement of the driver at a given frequency. One thing for sure is I don't want a sub that booms and gets out of control at certain frequencies.

I guess only experimentation will answer that question.

Marc
Offline

scottherbert

Member

  • Posts: 466
  • Joined: Sun Jun 28, 2009 4:22 pm
  • Location: Southern Colorado, USA

Re: Learn something about sub enclosures from a Chevy pickup

PostThu Jul 27, 2017 11:56 am

Either that, or build a separate sub, w/ a separate tube, each tuned to each note of the scale. BRILLIANT!!!
:roll: O.K., I've been working too hard out in the sun today. :oops:

~S
"Life is just a dream, it is in death that we truly awaken!"
PreviousNext

Return to Amplification

Who is online

Users browsing this forum: No registered users and 3 guests