Hello,
I am rebuilding a vintage Hammond organ and am trying to decide on the best speaker compliment for the bass channel, or pedals section of the organ. The bass channel amplifier currently drives a ported 15" bass cabinet, but I would like to add a sub-woofer to capture the really low frequencies generated by the organ. All the sub woofer cabinets I've seen online are, I assume, intended mostly for car stereo use and are typically the same: a box with one or two port tubes with the face of the speaker visible behind the a grill. This is NOT what I am looking for. I know nothing about sub woofer cabinet design, but I have a small home theater system that has a sub woofer and I am continually impressed by its performance. The sub woofer small, maybe 12" high by 7" wide and perhaps 12" deep. There is an opening at the bottom on the front of this unit, which appears to be a port maybe 3" in diameter, but no speaker is visible, and the low-end out of this is astonishing and it is this design that I am looking for. I can only assume that the speaker is inside but perhaps NOT facing into this port. Maybe true sub woofer designs utilize what comes off the back of the speaker? I don't know, but I am looking for this type of design for use with a suitable 15"speaker. I also have a lo-pass filter which is selectable from 20Hz to 210 Hz and intend to use this to drive the sub woofer's amplifier. If anyone has any thoughts or designs on this type of sub woofer I would appreciate hearing from you.
Thank you,
Bruce
I am rebuilding a vintage Hammond organ and am trying to decide on the best speaker compliment for the bass channel, or pedals section of the organ. The bass channel amplifier currently drives a ported 15" bass cabinet, but I would like to add a sub-woofer to capture the really low frequencies generated by the organ. All the sub woofer cabinets I've seen online are, I assume, intended mostly for car stereo use and are typically the same: a box with one or two port tubes with the face of the speaker visible behind the a grill. This is NOT what I am looking for. I know nothing about sub woofer cabinet design, but I have a small home theater system that has a sub woofer and I am continually impressed by its performance. The sub woofer small, maybe 12" high by 7" wide and perhaps 12" deep. There is an opening at the bottom on the front of this unit, which appears to be a port maybe 3" in diameter, but no speaker is visible, and the low-end out of this is astonishing and it is this design that I am looking for. I can only assume that the speaker is inside but perhaps NOT facing into this port. Maybe true sub woofer designs utilize what comes off the back of the speaker? I don't know, but I am looking for this type of design for use with a suitable 15"speaker. I also have a lo-pass filter which is selectable from 20Hz to 210 Hz and intend to use this to drive the sub woofer's amplifier. If anyone has any thoughts or designs on this type of sub woofer I would appreciate hearing from you.
Thank you,
Bruce
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Hi there,
First up, I'd remove your e-mail address. Spammers can and will start trying to sell you watches, special tablets, or claim to be Nigerian princes that need your bank details.
I suspect that the home-theatre sub might not be as good as you think. To check, play around with a frequency generator and see how low it can really go. Be careful with the volume.
I tried this on a nice sub made by a highly-regarded manufacturer, and it stopped around 35Hz. Most HTIB systems will struggle to do 40Hz without it sounding like a bunch of harmonics. Yours might well be a rare exception, but I haven't heard/measured it, so can't tell you.
Anyway,
What's the current 15" cabinet? Is it loud enough?
What's your budget for this?
Do you have any amplifiers suitable?
How big do you want to build?
Chris
First up, I'd remove your e-mail address. Spammers can and will start trying to sell you watches, special tablets, or claim to be Nigerian princes that need your bank details.
I suspect that the home-theatre sub might not be as good as you think. To check, play around with a frequency generator and see how low it can really go. Be careful with the volume.
I tried this on a nice sub made by a highly-regarded manufacturer, and it stopped around 35Hz. Most HTIB systems will struggle to do 40Hz without it sounding like a bunch of harmonics. Yours might well be a rare exception, but I haven't heard/measured it, so can't tell you.
Anyway,
What's the current 15" cabinet? Is it loud enough?
What's your budget for this?
Do you have any amplifiers suitable?
How big do you want to build?
Chris
Hi Chris,
Thanks for the advice. My email's been removed. I'm tired of Nigerian princesses and their games.
I understand your point about HT's sub woofer and will check it out with a sine wave generator, but it really is astounding and that's what I want for the organ's subwoofer. It's not like a bass cabinet that blasts the low end, but rather more subtle. I don't know how to explain it. The low end seems to float around the floor, and if I didn't know it was coming out of this small enclosure, I'd be hard-pressed to tell where it was coming from. Naturally, it handles the source from movies well, but even if I go to Pandora and get some true organ jazz going, the bottom end is beautiful. Go figure...
And looking down the throat of its port, all I see at the end is the corner of a transformer, so the speaker itself is offset somewhere, telling me that the design is pulling the frequencies off the speaker in some other fashion. Yes?
Currently, I have a 15" enclosure with a large, rectangular port at the bottom. It's loaded with an Eminence Legend CA154 speaker. I also have another 15" cabinet made by Kustom that was advertised as a sub woofer. Granted, both sound fine, it's just that I'm looking for that deep, low end like I have with the HT box, wherein it's hard to tell where it's coming from.
I'm using solid state amplifiers with, I believe, Mosfet technology. I know many of the audio folks prefer tube gear, but I am not interested in the heat or high voltages associated with them. And, correct me if I'm wrong, but I don't think raw wattage is the answer, as I've heard sub woofers that do a great job and are driven by 50-watt amps. If you have any suggestions or schematics for a suitable amplifier for this I'd be interested in seeing them. As for the speaker itself, I'm also open to suggestions. Does it need to be a 15" for decent response? Perhaps an 18", or maybe even a 12" or 10" in the right enclosure...? My budget would be between 300 to 500 for the speaker and enclosure. A bare wooden box would be fine as I will cover it with material to match the other gear, and install wheels, handle(s), and the jack plate. The bass enclosure I'll be using on stage is 20" high by 18" wide by 17" deep. I'd like to stick with dimensions close to this so I can place this one on top of the sub box.
I tried to send you a few pictures of my gear but don't see how to choose pics from my laptop...all I see is entering a URL address.
Hope this helps.
Thanks,
Bruce
Thanks for the advice. My email's been removed. I'm tired of Nigerian princesses and their games.
I understand your point about HT's sub woofer and will check it out with a sine wave generator, but it really is astounding and that's what I want for the organ's subwoofer. It's not like a bass cabinet that blasts the low end, but rather more subtle. I don't know how to explain it. The low end seems to float around the floor, and if I didn't know it was coming out of this small enclosure, I'd be hard-pressed to tell where it was coming from. Naturally, it handles the source from movies well, but even if I go to Pandora and get some true organ jazz going, the bottom end is beautiful. Go figure...
And looking down the throat of its port, all I see at the end is the corner of a transformer, so the speaker itself is offset somewhere, telling me that the design is pulling the frequencies off the speaker in some other fashion. Yes?
Currently, I have a 15" enclosure with a large, rectangular port at the bottom. It's loaded with an Eminence Legend CA154 speaker. I also have another 15" cabinet made by Kustom that was advertised as a sub woofer. Granted, both sound fine, it's just that I'm looking for that deep, low end like I have with the HT box, wherein it's hard to tell where it's coming from.
I'm using solid state amplifiers with, I believe, Mosfet technology. I know many of the audio folks prefer tube gear, but I am not interested in the heat or high voltages associated with them. And, correct me if I'm wrong, but I don't think raw wattage is the answer, as I've heard sub woofers that do a great job and are driven by 50-watt amps. If you have any suggestions or schematics for a suitable amplifier for this I'd be interested in seeing them. As for the speaker itself, I'm also open to suggestions. Does it need to be a 15" for decent response? Perhaps an 18", or maybe even a 12" or 10" in the right enclosure...? My budget would be between 300 to 500 for the speaker and enclosure. A bare wooden box would be fine as I will cover it with material to match the other gear, and install wheels, handle(s), and the jack plate. The bass enclosure I'll be using on stage is 20" high by 18" wide by 17" deep. I'd like to stick with dimensions close to this so I can place this one on top of the sub box.
I tried to send you a few pictures of my gear but don't see how to choose pics from my laptop...all I see is entering a URL address.
Hope this helps.
Thanks,
Bruce
Hi bnelson218,
Post #3: "... tried to send you a few pictures of my gear but don't see how to choose pics from my laptop..."
When posting a reply scroll down to Attach Files, and click on Manage Attachments. The Manage Attachments window will open, and you can Browse to files on your computer. Pick the one you want to share, and click Upload. Note the file types and sizes listed towards the bottom of the Manage Attachments window in the Attachement Key table.
It would be nice to get name and number of your HT subwoofer, from your description I would guess it is an active (internally amplified) BP4 (4th order band pass) design.
Regards,
Post #3: "... tried to send you a few pictures of my gear but don't see how to choose pics from my laptop..."
When posting a reply scroll down to Attach Files, and click on Manage Attachments. The Manage Attachments window will open, and you can Browse to files on your computer. Pick the one you want to share, and click Upload. Note the file types and sizes listed towards the bottom of the Manage Attachments window in the Attachement Key table.
It would be nice to get name and number of your HT subwoofer, from your description I would guess it is an active (internally amplified) BP4 (4th order band pass) design.
Regards,
Hi Bruce, if its an organ and you want to improve the bottom end your talking 10-20hZ, most ported or reflex enclosures cough out at below 30hZ and are unsuitable for your application, IMOP you almost certainly need a largish sealed enclosure to get anything useful at your foot pedal frequencies!
Regards,
Roger
Regards,
Roger
Hi,
Your AV sub is a sealed bandpass optimised for a 80Hz AV x/o.
It may contain some active bass boost for the low end.
Its advantage over sealed is more output at the top end,
where the port acts acts a a low pass filter and SPL boost.
Disadvantages are its a one trick pony, designed for
a specific x/o frequency, which you have to know in
advance, and they are difficult to get the design right.
rgds, sreten.
Your AV sub is a sealed bandpass optimised for a 80Hz AV x/o.
It may contain some active bass boost for the low end.
Its advantage over sealed is more output at the top end,
where the port acts acts a a low pass filter and SPL boost.
Disadvantages are its a one trick pony, designed for
a specific x/o frequency, which you have to know in
advance, and they are difficult to get the design right.
rgds, sreten.
Pictures of my existing gear and home theater sub box
Here are some pictures. The first is the ported box with an Eminence Legend CA154 15" installed. It does a good job but is rather boomy (word?).
The second is the Kustom sub woofer which sounds much better than the first one, but still does not give the output I am looking for. Granted, I haven't yet assembled what will ultimately comprise the "sub woofer" channel, which will entail tapping the bass signal, sending it to a lo-pass filter, and then to an appropriate amp.
The 3rd and 4th shots are of my little home theater's sub box that just sounds so good. Even if I bring up Pandora and get some good Jimmy Smith jazz organ going, this little box puts out exactly what I am looking for. The 3rd shot is the box itself, while the 4th is down the throat where you'll notice you don't see the speaker, which leads me to believe it is mounted elsewhere and this port pulls frequencies off other aspects of the speaker, such as the rear?
Here are some pictures. The first is the ported box with an Eminence Legend CA154 15" installed. It does a good job but is rather boomy (word?).
The second is the Kustom sub woofer which sounds much better than the first one, but still does not give the output I am looking for. Granted, I haven't yet assembled what will ultimately comprise the "sub woofer" channel, which will entail tapping the bass signal, sending it to a lo-pass filter, and then to an appropriate amp.
The 3rd and 4th shots are of my little home theater's sub box that just sounds so good. Even if I bring up Pandora and get some good Jimmy Smith jazz organ going, this little box puts out exactly what I am looking for. The 3rd shot is the box itself, while the 4th is down the throat where you'll notice you don't see the speaker, which leads me to believe it is mounted elsewhere and this port pulls frequencies off other aspects of the speaker, such as the rear?
Attachments
Hi Sreten,
I've got a frequency chart that shows pipe organ and synth frequencies starting at 27Hz, so I think a box that can be responsive down to 20Hz would be great. Being a little light on this type of electronic theory, what tailoring should an amplifier have to work down in the 20 to, say, 200Hz range?
I've got a frequency chart that shows pipe organ and synth frequencies starting at 27Hz, so I think a box that can be responsive down to 20Hz would be great. Being a little light on this type of electronic theory, what tailoring should an amplifier have to work down in the 20 to, say, 200Hz range?
Hi Roger,
Thanks for the info. I think my ideal setup would be an enclosure roughly 22" wide by 22" deep by, maybe 10" high with a 15" or perhaps an 18" inside, facing down, and the necessary port(s) taking the freqs off the back...? And I say this because it'd be nice to be able to place my regular bass enclosure on top of the sub enclosure.
Thanks for the info. I think my ideal setup would be an enclosure roughly 22" wide by 22" deep by, maybe 10" high with a 15" or perhaps an 18" inside, facing down, and the necessary port(s) taking the freqs off the back...? And I say this because it'd be nice to be able to place my regular bass enclosure on top of the sub enclosure.
It's a worthwhile thought, too. Hammond numbers their frequencies but not in Hertz, and I don't know if doing so was their own process or if the numbers actually correspond by some formula to Hertz. For instance, all the Cs available from the tone generator are numbered 1, 13, 25, 37, 49, 61, 73, and 85.
Flat to ~30 Hz at sufficient SPL @ the LP once room gain is factored in, which is what the OP needs?
Regardless, for stage duty where room gain is virtually nil down low without a huge false wall baffle, it will take a pretty powerful sub system to properly handle the bottom octave and to get it will require around a 26 Hz tuning, so that once the high pass is factored in, it will be flat to ~32 Hz.
GM
12" Eminence Lab 12C 4th order bandpass
Hi.
The most interesting driver for a 4th order bandpass, this having a sealed compartment with a reflex compartment being a speaker with 2 enclosures, is the 12" Eminence Lab 12C.
I'm going to explain why and giving you a list of other interesting drivers that as another example will fall in or out of the equation e.g. net vol., price, range, having in mind that a big speaker might also have a smaller port and a smaller speaker with a very long port also makes the total volume bigger.
EMINENCE LAB 12 C, VC = 34.10 L, FAC = 49.86 Hz, VAC = 26.94 L
Range: -3 dB 32 - 78 Hz
Meaning sealed enclosure VC, reflex enclosure VAC and tuning FAC.
Port for BR (reflex) as below.
Port: Diam. 10.16cm/4" -- Length. 28.6cm/11.26"
Eminence Lab 12C High Power 12" Subwoofer Speaker Driver 4 Ohm
http://www.eminence.com/pdf/LAB_12C_cab.pdf
http://www.eminence.com/pdf/LAB_12C.pdf
(the trade offs in order to change from the driver above you may have to build a bigger enclosure have to pay more or having worse or better range in frequency)
I would personally go with a rubber surround driver.
This gives a net estimate of aproxim. 60L= 2.12ft³ if not counting with internals (divisions/ports/drivers) what then is much less for the bandpass enclosure.
Hi.
The most interesting driver for a 4th order bandpass, this having a sealed compartment with a reflex compartment being a speaker with 2 enclosures, is the 12" Eminence Lab 12C.
I'm going to explain why and giving you a list of other interesting drivers that as another example will fall in or out of the equation e.g. net vol., price, range, having in mind that a big speaker might also have a smaller port and a smaller speaker with a very long port also makes the total volume bigger.
EMINENCE LAB 12 C, VC = 34.10 L, FAC = 49.86 Hz, VAC = 26.94 L
Range: -3 dB 32 - 78 Hz
Meaning sealed enclosure VC, reflex enclosure VAC and tuning FAC.
Port for BR (reflex) as below.
Port: Diam. 10.16cm/4" -- Length. 28.6cm/11.26"
Eminence Lab 12C High Power 12" Subwoofer Speaker Driver 4 Ohm
http://www.eminence.com/pdf/LAB_12C_cab.pdf
http://www.eminence.com/pdf/LAB_12C.pdf
(the trade offs in order to change from the driver above you may have to build a bigger enclosure have to pay more or having worse or better range in frequency)
I would personally go with a rubber surround driver.
Attachments
Other driver options as analysis for better or worse with this member request (not in order).
Construction note: always leave some space between back of port and the inside (interior) of the baffle.
SCANSPEAK 26W/4558T00, VC = 23.40 L, FAC = 47.22 Hz, VAC = 18.77 L
Range: -3 dB 30 - 74 Hz
Port: Diam. 10.16 cm/4" -- Length. 50.35 cm
ScanSpeak Discovery 26W/4558T 10" Subwoofer
Look at the bigger net enclosure and small port here and a nice price. High sensitivity (mounted) almost 94dB/2.83V/m:
PEERLESS SLS12 830669 v2012, VC = 65.70 L, FAC = 53.83 Hz, VAC = 43.91 L.
Port: Diam. 10.16cm/4" -- Length. 11.45 cm
Range: -3 dB 34 - 86 Hz
Peerless 830669 12" Paper Cone SLS Subwoofer
Here the very prized Seas L26ROY 10" Subwoofer - D1001-04 - 4 ohm
SEAS L26ROY, VC = 20.80 L, FAC = 50.08 Hz, VAC = 16.79 L.
Port: Diam. 10.16cm/4" -- Length. 50 cm/19.68"
Range: -3 dB 32 - 78 Hz
SCANSPEAK 32W/4878T00, VC = 51.60 L, FAC = 40.30 Hz, VAC = 41.31 L.
Port: Diam. 10.16cm/4" -- Length. 35.26 cm
Range: -3 dB 26 - 63 Hz
(have note of the range of this driver in a 4th order bandpass. And also the price calls for the high quality)
Scan-Speak 32W/4878T Revelator 13" Sub
Construction note: always leave some space between back of port and the inside (interior) of the baffle.
SCANSPEAK 26W/4558T00, VC = 23.40 L, FAC = 47.22 Hz, VAC = 18.77 L
Range: -3 dB 30 - 74 Hz
Port: Diam. 10.16 cm/4" -- Length. 50.35 cm
ScanSpeak Discovery 26W/4558T 10" Subwoofer
Look at the bigger net enclosure and small port here and a nice price. High sensitivity (mounted) almost 94dB/2.83V/m:
PEERLESS SLS12 830669 v2012, VC = 65.70 L, FAC = 53.83 Hz, VAC = 43.91 L.
Port: Diam. 10.16cm/4" -- Length. 11.45 cm
Range: -3 dB 34 - 86 Hz
Peerless 830669 12" Paper Cone SLS Subwoofer
Here the very prized Seas L26ROY 10" Subwoofer - D1001-04 - 4 ohm
SEAS L26ROY, VC = 20.80 L, FAC = 50.08 Hz, VAC = 16.79 L.
Port: Diam. 10.16cm/4" -- Length. 50 cm/19.68"
Range: -3 dB 32 - 78 Hz
SCANSPEAK 32W/4878T00, VC = 51.60 L, FAC = 40.30 Hz, VAC = 41.31 L.
Port: Diam. 10.16cm/4" -- Length. 35.26 cm
Range: -3 dB 26 - 63 Hz
(have note of the range of this driver in a 4th order bandpass. And also the price calls for the high quality)
Scan-Speak 32W/4878T Revelator 13" Sub
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