Interesting ....
I'm about to build a Sub as well and also considering a 10" , But could go 8" or 12" depending on where the design leads me. I have a old Meridian 505 Mono Power amp (160 W at 8 ohms) and a NAD THX218 (225Wpc , 780W bridged mono) that I'm going to audition for the role, and probably use a Behringer cx2310 crossover to do the low pass magic.
qguy states that he dosen't "want to go the PR route" ...
Why not ???
I was seriousely considering the PR as a way of opening up the speed and dynamics of the driver without the huffing and puffing of the port.
I'm looking at the Dayton and Peerless as well. Seas also has a good looking couple of options. Although not specifically "Subwoofers" I like the idea of a lighter cone for speed.
The Seas Options in 10" (They also have 8" versions of the items below)
PASSIVE RADIATORS
Seas SP26R (H9946) 10" Passive Radiator @ 88 US $
Seas SP25R (H9902) 10" Poly Cone Passive Radiator @ 47 US $
DRIVERS
SEAS Prestige CA26RFX (H1305) 10" Coated Paper Cone @ 150 US $
SEAS Prestige L26RFX/P (H1209) 10" Aluminum Cone @ 165 US $
I will build a reinforced cabinet out of the Baltic Birch I used to bulid my Fostex 108EZ BIBS.
Scaramoucheii
I'm about to build a Sub as well and also considering a 10" , But could go 8" or 12" depending on where the design leads me. I have a old Meridian 505 Mono Power amp (160 W at 8 ohms) and a NAD THX218 (225Wpc , 780W bridged mono) that I'm going to audition for the role, and probably use a Behringer cx2310 crossover to do the low pass magic.
qguy states that he dosen't "want to go the PR route" ...
Why not ???
I was seriousely considering the PR as a way of opening up the speed and dynamics of the driver without the huffing and puffing of the port.
I'm looking at the Dayton and Peerless as well. Seas also has a good looking couple of options. Although not specifically "Subwoofers" I like the idea of a lighter cone for speed.
The Seas Options in 10" (They also have 8" versions of the items below)
PASSIVE RADIATORS
Seas SP26R (H9946) 10" Passive Radiator @ 88 US $
Seas SP25R (H9902) 10" Poly Cone Passive Radiator @ 47 US $
DRIVERS
SEAS Prestige CA26RFX (H1305) 10" Coated Paper Cone @ 150 US $
SEAS Prestige L26RFX/P (H1209) 10" Aluminum Cone @ 165 US $
I will build a reinforced cabinet out of the Baltic Birch I used to bulid my Fostex 108EZ BIBS.
Scaramoucheii
Ok ... ?
So your saying a Passive Radiator design is a Bass Reflex and, that the 2 have the same characteristics ?
My primary original question was to qguy, as to why he didn't want to go the Passive Radiator route ! SPL ?
I have been doing some extensive listing at my friends house over the past 3 years and his SACD setup of 4 x Classe Omega amps and 4 x Wilson Alexandria X2's is astounding in what I refer to as "speed and dynamics" in the area below 300 hz. The Alexandria X2's are a front ported enclosure with a 13" and 15" in the bass cabinet.
Perhaps describing the sound, on 600 K system, of the upright bass strings vibrating so deeply and clearly, the sound of the bass pedal striking the drum skin shouldn't be described as fast and dynamic ..... but that's how it sounds .... !
What I would like to do is create that large warm tight bass to reinforce the bottom end of my Fostex 108ez Bib's for about 1,000 bucks. I don't have the 600,000 to spend on the Omegas and Alexandrias .....
Scaramoucheii
So your saying a Passive Radiator design is a Bass Reflex and, that the 2 have the same characteristics ?
My primary original question was to qguy, as to why he didn't want to go the Passive Radiator route ! SPL ?
I have been doing some extensive listing at my friends house over the past 3 years and his SACD setup of 4 x Classe Omega amps and 4 x Wilson Alexandria X2's is astounding in what I refer to as "speed and dynamics" in the area below 300 hz. The Alexandria X2's are a front ported enclosure with a 13" and 15" in the bass cabinet.
Perhaps describing the sound, on 600 K system, of the upright bass strings vibrating so deeply and clearly, the sound of the bass pedal striking the drum skin shouldn't be described as fast and dynamic ..... but that's how it sounds .... !
What I would like to do is create that large warm tight bass to reinforce the bottom end of my Fostex 108ez Bib's for about 1,000 bucks. I don't have the 600,000 to spend on the Omegas and Alexandrias .....
Scaramoucheii
After much playing in WINISD and contemplating ....
I'm pretty much decided on the SEAS Prestige L26RFX/P (H1209) . 10" Aluminium Cone, In a 98 cu ft box with a 4.5" x 1 inch x 9.8" deep vent. This gives a flat response down to 36 hz and to 25 hz @ -3db. So I guess a little bit like a fonken cabinet. with the same style of internal braceing.
The box will be quite large, (And heavy with the bracing, and I'm planning on a stereo pair, but ..... Should give impressive Low and Sub bass
I currently have a input filter on my ST-70 which is driving the Fostex BIB's, at about 25 hz, (This is an old Van Alstine tweak for the ST70 ) but once I finish the pair of subwoofers I will raise that up to about 200 hz. And use the active crossover to power the NAD Sub Amp from 200 hz down to start with. This will eliminate all the low end load from the Fostex BIB's and the ST70 output transformers,
The Seas will be about 4 db less sensetive than the 108ez BIB's but not going to be a problem with the NAD 218 and an active crossover with a gain control has +/- 6db of gain.
Scaramoucheii
I'm pretty much decided on the SEAS Prestige L26RFX/P (H1209) . 10" Aluminium Cone, In a 98 cu ft box with a 4.5" x 1 inch x 9.8" deep vent. This gives a flat response down to 36 hz and to 25 hz @ -3db. So I guess a little bit like a fonken cabinet. with the same style of internal braceing.
The box will be quite large, (And heavy with the bracing, and I'm planning on a stereo pair, but ..... Should give impressive Low and Sub bass
I currently have a input filter on my ST-70 which is driving the Fostex BIB's, at about 25 hz, (This is an old Van Alstine tweak for the ST70 ) but once I finish the pair of subwoofers I will raise that up to about 200 hz. And use the active crossover to power the NAD Sub Amp from 200 hz down to start with. This will eliminate all the low end load from the Fostex BIB's and the ST70 output transformers,
The Seas will be about 4 db less sensetive than the 108ez BIB's but not going to be a problem with the NAD 218 and an active crossover with a gain control has +/- 6db of gain.
Scaramoucheii
IMO, a 10" woofer in a 1.5 ft^3 *sealed* box is foolishness. To be any good, the efficiency would have to be terrible. Go with a larger box, or a smaller woofer, a port or a passive radiator. I had exactly what you describe in my system for many years, and the improvement in low end was dramatic when I went with a smaller woofer in the same size box. Obviously it all depends on the parameters and I'm making a very general statement here, but ultimately the laws of physics don't smile on large woofers in small sealed boxes, especially with the drivers currently on the market.
I wrote earlier and just noticed that I stated 98 cu feet, That should be 98 Liters, 3.5 cu ft.
Conrad Hoffman wrote
That was WAY back at the begining of the thread from gguy and we haven't heard from him since.
I did design a Sealed box in WinISD and the best sealed performance was in a 55 L box (1.9) cu feet. I may still goo that route.
My primary design goal here is quick transient response time, as I will be crossing this over quite high ( 120 - 200 hz) and using it exclusively for music. So it will be required to do a little bit of upper bass as well as the Sub duties. Having looked at the extended performance below 40 hz of the vented 98 L box I'm leaning that way.
I will be making 2 Carboard Mockups next week (1 x 55 l , 1 x 98 L ) to finalize my decision as the room does have space installation restrictions.
Any final thoughts on the differance between a 55 L sealed box Verses a 98 L vented box for a music only application ? I do have the suitable power available to drive this to max excursion so no problems there, and I will build 2 as the crossover frequency will be high enough to be able to image the upper bass, so SPL I wouldn't consider a factor ! What I do like about the vented box is the flat response all teh way down to 36 hz, but I,m just a bit concerned that the vent may not sound as "musical"
Regards
Scaramoucheii
Conrad Hoffman wrote
That was WAY back at the begining of the thread from gguy and we haven't heard from him since.
I did design a Sealed box in WinISD and the best sealed performance was in a 55 L box (1.9) cu feet. I may still goo that route.
My primary design goal here is quick transient response time, as I will be crossing this over quite high ( 120 - 200 hz) and using it exclusively for music. So it will be required to do a little bit of upper bass as well as the Sub duties. Having looked at the extended performance below 40 hz of the vented 98 L box I'm leaning that way.
I will be making 2 Carboard Mockups next week (1 x 55 l , 1 x 98 L ) to finalize my decision as the room does have space installation restrictions.
Any final thoughts on the differance between a 55 L sealed box Verses a 98 L vented box for a music only application ? I do have the suitable power available to drive this to max excursion so no problems there, and I will build 2 as the crossover frequency will be high enough to be able to image the upper bass, so SPL I wouldn't consider a factor ! What I do like about the vented box is the flat response all teh way down to 36 hz, but I,m just a bit concerned that the vent may not sound as "musical"
Regards
Scaramoucheii
I'm a numbers guy and always like what I can calculate with a vent. Unfortunately, the best sounding systems I've built have all been sealed, so without knowing much of anything else, I'd go sealed. FWIW, I typically go a bit high on Q, closer to 0.9 than 0.7 or 0.5 like most people. I prefer non-rectangular boxes. They probably don't sound better because of any special internal reflection properties, but because they tend to be more rigid.
Hey Conrad
Thanks for the insight.
I agree with you because the numbers keep telling me vented box, but I just can't commit to it. So I think I will try and build a slightly oversized sealed box, perhaps about 60 L and just use the brute force of the amp and room gain to bring the SPL back up.
You mentioned that you would use a Q of 0.9 rather than 0.7 or 0.5 ! Can you elaborate on that ?
I also like the slightly non rectangular box shape for 2 reasons,
1; can be more creative in the design shape for astechics and can fit into the room overall design and style.
2; Box stiffness as you state.
And using a smaller (than vented) sealed box I can fit the box into a better position in the room.
Alot of people here and elsewhere in high end audio get STUCK on numbers and magic ratios forgetting about the real world issues. For example I was just reading a thread from a guy trying to modify his amp input filter to go up to 100K because he thinks that there is data on SACD's up there that will affect his systems sound ! Maybe it will but the powerstage of the amp won't reproduce it and if it did the speakers won't transduce it, and if they did his ears wouldn't hear it ... But 100k is an impressive number !!!
Here is the PDF document link from SEAS from the Madisound website, and the data in text. if anybody cares or would like to add a comment on the Vented Sealed debate.
http://www.madisound.com/catalog/PDF/seas/H1209.pdf
Outside diameter 269mm
Cut out 232.2mm
Depth 107.5mm
Nominal Impedance 8 Ohms
Recom. frequency range 20-1000 Hz
Short term max. power 300 W
Long term max. power 125 W
Sensitivity (1W/1m) 87 dB
Voice Coil Diameter 51 mm
Voice coil height 20 mm
Air gap height 6.0 mm
Linear coil travel (p-p) 14.0 mm
Max. coil travel (p-p) 35 mm
Magnet weight 3.0 Kg
Total weight 4.05 Kg
Voice coil resistance 6.3 Ohms
Voice coil inductance 1.48 mH
Force factor 10.7 N/A
Free air resonance 20 Hz
Moving mass 58 g
Suspension compliance 1.1 mm/N
Suspension mech. resistance 3.18 Ns/m
Effective piston area 330 sq. cm
Vas 166 Liters
QMS 2.30
QES 0.40
QTS 0.34
Thanks for the insight.
I agree with you because the numbers keep telling me vented box, but I just can't commit to it. So I think I will try and build a slightly oversized sealed box, perhaps about 60 L and just use the brute force of the amp and room gain to bring the SPL back up.
You mentioned that you would use a Q of 0.9 rather than 0.7 or 0.5 ! Can you elaborate on that ?
I also like the slightly non rectangular box shape for 2 reasons,
1; can be more creative in the design shape for astechics and can fit into the room overall design and style.
2; Box stiffness as you state.
And using a smaller (than vented) sealed box I can fit the box into a better position in the room.
Alot of people here and elsewhere in high end audio get STUCK on numbers and magic ratios forgetting about the real world issues. For example I was just reading a thread from a guy trying to modify his amp input filter to go up to 100K because he thinks that there is data on SACD's up there that will affect his systems sound ! Maybe it will but the powerstage of the amp won't reproduce it and if it did the speakers won't transduce it, and if they did his ears wouldn't hear it ... But 100k is an impressive number !!!
Here is the PDF document link from SEAS from the Madisound website, and the data in text. if anybody cares or would like to add a comment on the Vented Sealed debate.
http://www.madisound.com/catalog/PDF/seas/H1209.pdf
Outside diameter 269mm
Cut out 232.2mm
Depth 107.5mm
Nominal Impedance 8 Ohms
Recom. frequency range 20-1000 Hz
Short term max. power 300 W
Long term max. power 125 W
Sensitivity (1W/1m) 87 dB
Voice Coil Diameter 51 mm
Voice coil height 20 mm
Air gap height 6.0 mm
Linear coil travel (p-p) 14.0 mm
Max. coil travel (p-p) 35 mm
Magnet weight 3.0 Kg
Total weight 4.05 Kg
Voice coil resistance 6.3 Ohms
Voice coil inductance 1.48 mH
Force factor 10.7 N/A
Free air resonance 20 Hz
Moving mass 58 g
Suspension compliance 1.1 mm/N
Suspension mech. resistance 3.18 Ns/m
Effective piston area 330 sq. cm
Vas 166 Liters
QMS 2.30
QES 0.40
QTS 0.34
This is a guess, but sealed systems tend to roll off over a wide frequency range, whereas vented systems tend to be flat, then fall off a cliff. I think the slow rolloff of a sealed system is interpreted by the ear as bass-shy. When I bump up the Q I get a small bass bump in the response. You get a little more impact, and the ear is fooled into thinking the response has been tilted back to normal. It might be best to build a rolled off sealed system with good transient response (Q-.577 or so), then use active equalization to bring the response back to flat. Marchand makes a box for just that purpose. I was on the verge of buying the kit, but never managed to get the order placed. IMO, you always get a lot for your money with them, though I'm sure others make similar eq boxes.
FWIW, I used to run some heavy duty Audio Concepts 10" woofers (AC10?) in medium sealed boxes. They'd go loud, and the sound was good as far as it went, but there wasn't any real bass. When the surrounds finally failed, I replaced them with some surplus 8" poly woofers and readjusted the crossover. It won't go as loud, but the response is flatter and musically much more satisfying.
One other note- I don't know how good the specs are on that woofer. I've found too many fs numbers that are optimistic. Just for fun, pretend your woofers end up with the same Q numbers, but an fs of 27 Hz. Run your numbers again and note how bad the 60-80 Hz response becomes. I *always* measure the drivers I'm going to use.
FWIW, I used to run some heavy duty Audio Concepts 10" woofers (AC10?) in medium sealed boxes. They'd go loud, and the sound was good as far as it went, but there wasn't any real bass. When the surrounds finally failed, I replaced them with some surplus 8" poly woofers and readjusted the crossover. It won't go as loud, but the response is flatter and musically much more satisfying.
One other note- I don't know how good the specs are on that woofer. I've found too many fs numbers that are optimistic. Just for fun, pretend your woofers end up with the same Q numbers, but an fs of 27 Hz. Run your numbers again and note how bad the 60-80 Hz response becomes. I *always* measure the drivers I'm going to use.
Hey Conrad
You mention
It might be best to build a rolled off sealed system with good transient response (Q-.577 or so)
Using WinISD their number in the "Box" tab of the design is labled as Qtc, Which I cannot find referenced anyhwere ????
The Q you are talking about I assume to be Total Q (Qts) ?
Using WinISD I can get the Qtc to 0.9 by specifying a box volume of 1 cu ft .... Which seems a very very small volume .......
Using a volume of 2.1 cu ft (60 L) I get a Qtc of 0.66 and a nice looking graph ...
Anybody out there understand what WinISD is refering to with the Qtc ?
You mention
and
It might be best to build a rolled off sealed system with good transient response (Q-.577 or so)
Using WinISD their number in the "Box" tab of the design is labled as Qtc, Which I cannot find referenced anyhwere ????
The Q you are talking about I assume to be Total Q (Qts) ?
Using WinISD I can get the Qtc to 0.9 by specifying a box volume of 1 cu ft .... Which seems a very very small volume .......
Using a volume of 2.1 cu ft (60 L) I get a Qtc of 0.66 and a nice looking graph ...
Anybody out there understand what WinISD is refering to with the Qtc ?
To said a long times with many understandings but LOL don't know qtc or qts. ok u rn't good English.
before we talk together again,i think it's good if we drink together.guys see the topic that qguy said about sealed box.i think he did not want a big box. okay guys with a good design. i agree sealed or vented box can go with the music. i ever heard the sealed or vented sub and they did adjust the respond for lower.it's good for all. so that if qguy want a sealed box. he can go with it. R u..uuu ok?
/TW"That was WAY back at the begining of the thread from gguy and we haven't heard from him since."
Just reading and learning here as I already posted my requirements I am just all ears..
All responses are appreciated
so would an 8 inch subwoofer be a better option in 1.6 cu sealed box ? or should I stay with the 10 inchers from Dayton ?
Just reading and learning here as I already posted my requirements I am just all ears..
All responses are appreciated
so would an 8 inch subwoofer be a better option in 1.6 cu sealed box ? or should I stay with the 10 inchers from Dayton ?
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