BP1503 t/S parameters
fs ...25.52Hz
Re ...3.9ohm
Qms ...4.46
Qes ...0.41
Sd ...737cm2
Vas ...92L
Xmax peak ...25.86mm
Le ...4.28mH
Nomimal power ...1000W
series resistance ... 0.2ohm
basic 18.56Hz tuned subwoofer
port inside diam. ...5.75inches
port area ...167.64cm2
port end correction ... 0.519
desired Physical Vb ...200L
Absorption, Qa ...20
Leakage, Ql ...15
Port, Qp ...140
Alpha, a ... 0.434
Vb ...212L
Fb ...18.56Hz
h ... 0.727
F3 ...17.37Hz
Response peak ...0
Peak at ...none
Port min diameter ...20.14cm
Port length ...61.58
Port 1. resonance ...249Hz
Vb + driver displacement + two large internal braces = 234L
INTERNAL dimensions are 38cm*77cm*80cm (W*D*H)
Flared ports
Parametric EQ
Unibox states that minimum port diameter is 20.14cm while my one was 5.75inch (14.6cm)
Anything seriously wrong or can you just ignore it?
thomas
How is this different to your as-15 subwoofer?
fs ...25.52Hz
Re ...3.9ohm
Qms ...4.46
Qes ...0.41
Sd ...737cm2
Vas ...92L
Xmax peak ...25.86mm
Le ...4.28mH
Nomimal power ...1000W
series resistance ... 0.2ohm
basic 18.56Hz tuned subwoofer
port inside diam. ...5.75inches
port area ...167.64cm2
port end correction ... 0.519
desired Physical Vb ...200L
Absorption, Qa ...20
Leakage, Ql ...15
Port, Qp ...140
Alpha, a ... 0.434
Vb ...212L
Fb ...18.56Hz
h ... 0.727
F3 ...17.37Hz
Response peak ...0
Peak at ...none
Port min diameter ...20.14cm
Port length ...61.58
Port 1. resonance ...249Hz
Vb + driver displacement + two large internal braces = 234L
INTERNAL dimensions are 38cm*77cm*80cm (W*D*H)
Flared ports
Parametric EQ
Unibox states that minimum port diameter is 20.14cm while my one was 5.75inch (14.6cm)
Anything seriously wrong or can you just ignore it?
thomas
How is this different to your as-15 subwoofer?
The design looks ok. I imagine Unibox's bigger port suggestion is to decrease the potential for port compression. Using a port with flares allows a smaller port to flow as much air as a larger one without compression. Using a smaller port means the box itself can be slightly smaller since the port takes up less space.
Ported designs somewhat forgiving, and can tolerate about a 10% 'fudge factor' before there's a major change in performance. I recommend building a prototype; so as to test the real world performance of the design before making serious investemt in finish grade materials. This though time and labor intensive, can save $$$ in the long run, particularly for the novice.
Ported designs somewhat forgiving, and can tolerate about a 10% 'fudge factor' before there's a major change in performance. I recommend building a prototype; so as to test the real world performance of the design before making serious investemt in finish grade materials. This though time and labor intensive, can save $$$ in the long run, particularly for the novice.
Yes certainly order the driver. Get the Lightning Audio flares, only if you can find PVC that has a 6.25" OD. Now the ID may vary depending on what you have available. So the final port length may need to be altered depending on what size pipe you're able to find. If you can't find PVC with a 6.25" OD, then don't order the Lightning Flares
Don't build the box in advance of having the driver; and until you know you can duplicate the port with flares, or know what size straight port you will be substituting if getting the flares isn't practical.
When deciding on the dimensions of your box, it's important to have the inside opening of the port approx 6" away from the back wall of the cabinet. Height, width, aren't critical, so they can be what you like, as long as the net interior volume is within the needed parameters, and the cabinet depth is be sufficient for 6" of clearance behind the port.
Once you have everything in hand, driver, port, etc, then I'll run LspCAD calculations from the final net internal volume you get. You can compare them to what you get with UniBox. They should be very close.
[Edited by ThomasW on 11-02-2001 at 10:41 PM]
Don't build the box in advance of having the driver; and until you know you can duplicate the port with flares, or know what size straight port you will be substituting if getting the flares isn't practical.
When deciding on the dimensions of your box, it's important to have the inside opening of the port approx 6" away from the back wall of the cabinet. Height, width, aren't critical, so they can be what you like, as long as the net interior volume is within the needed parameters, and the cabinet depth is be sufficient for 6" of clearance behind the port.
Once you have everything in hand, driver, port, etc, then I'll run LspCAD calculations from the final net internal volume you get. You can compare them to what you get with UniBox. They should be very close.
[Edited by ThomasW on 11-02-2001 at 10:41 PM]
Here is a quote from a previous post:
"Making any changes in the design will result in a sub that doesn't perform up to the full potential of the HE15/BP1503"
I have a very different design. Is the as-15 is the only way to go to get the ultimate performance out of the driver? If so, then give me its physical Vb excluding driver displacement,bracing,damping,losses, etc. From this Vb I'll make a similar as-15 design-- the only difference is that it is simpler in the woodwork.
Or is the design I created with unibox is enough to get the ultimate performance out of the driver?
Say that unibox calculated your port length is 11". The front baffle of your designed subwoofer is 1.5 inches thick. The port is mounted through the hole you cut in the front baffle.
Should the port be cut and mounted in the subwoofer with a finalised length of 12.5"(plus the thickness of the front baffle) OR to a finalised length of 11"(ignoring the thickness of the front baffle)?
"Making any changes in the design will result in a sub that doesn't perform up to the full potential of the HE15/BP1503"
I have a very different design. Is the as-15 is the only way to go to get the ultimate performance out of the driver? If so, then give me its physical Vb excluding driver displacement,bracing,damping,losses, etc. From this Vb I'll make a similar as-15 design-- the only difference is that it is simpler in the woodwork.
Or is the design I created with unibox is enough to get the ultimate performance out of the driver?
Say that unibox calculated your port length is 11". The front baffle of your designed subwoofer is 1.5 inches thick. The port is mounted through the hole you cut in the front baffle.
Should the port be cut and mounted in the subwoofer with a finalised length of 12.5"(plus the thickness of the front baffle) OR to a finalised length of 11"(ignoring the thickness of the front baffle)?
Ok first let's not get too literal....
And second why has this conversation starting over again? You have a design and it's very similar to the AS-15.
The AS-15 was designed to obtain max performance from the smallest reasonable sized box, with no compromises. This goal was achieved.
I already answered the port behind the baffle question. Of course IF the ported is butted to the baffle, the hole in the baffle adds to the length of the port. This is common sense. However it's a better idea to have the port pass through the baffle. This way the baffle gives added support to the port.
The cabinet work for the AS-15 is part of the design to get the best performance. It's not that difficult. The cabinet MUST be sufficiently braced. If not, the driver is so powerful that serious wall flexing will result, and the performance will suffer.
Why? Well if the walls of the box are vibrating, then they are acting like the cone of a speaker, and the sound waves they generate will cancel those made by the woofer.
Also you need to understand I don't have hours and hours of time to walk you through every question you can think up regarding loudspeaker design. That's what books are for. If you want to build a close copy of the AS-15, I'll give you assistance.
And second why has this conversation starting over again? You have a design and it's very similar to the AS-15.
The AS-15 was designed to obtain max performance from the smallest reasonable sized box, with no compromises. This goal was achieved.
I already answered the port behind the baffle question. Of course IF the ported is butted to the baffle, the hole in the baffle adds to the length of the port. This is common sense. However it's a better idea to have the port pass through the baffle. This way the baffle gives added support to the port.
The cabinet work for the AS-15 is part of the design to get the best performance. It's not that difficult. The cabinet MUST be sufficiently braced. If not, the driver is so powerful that serious wall flexing will result, and the performance will suffer.
Why? Well if the walls of the box are vibrating, then they are acting like the cone of a speaker, and the sound waves they generate will cancel those made by the woofer.
Also you need to understand I don't have hours and hours of time to walk you through every question you can think up regarding loudspeaker design. That's what books are for. If you want to build a close copy of the AS-15, I'll give you assistance.
.... but you'd still need a hefty power supply to satisfy the current demands of a quality car audio amp, which are actually expensive, btw. http://www.jaycar.com.au offers a 40-amp [which is not enough] supply for AU$350. For that price, you could already buy a 200W or so plate amplifier 
My subwoofer will be used at home, so I have all the power I need..I dont care if the power supply is hefty or not, as long as the thing can power my sub properly
The car audio amps I see are 500W and only cost $150-$200US
I think I need to clarify some things...I need an amp that is preferably around 400watts(no less than 300). The cheapest way to get to this is by an car audio amp. The samson and qsc amps thomasw mentioned are around $350US!!My budget for the whole subwoofer is $600US ($1200AU) and the amp costs $350US!!!
There are many car audio amps around the same power that retail for $200US-a good saving
can anyone suggest good sounding, powerful, amplifiers (plate or professional - but not car) that has 300W+ power, that retails for less than $300US, that can power my low efficient BP1503 sub?
[Edited by pkgum on 11-04-2001 at 02:22 AM]
The car audio amps I see are 500W and only cost $150-$200US
I think I need to clarify some things...I need an amp that is preferably around 400watts(no less than 300). The cheapest way to get to this is by an car audio amp. The samson and qsc amps thomasw mentioned are around $350US!!My budget for the whole subwoofer is $600US ($1200AU) and the amp costs $350US!!!
There are many car audio amps around the same power that retail for $200US-a good saving
can anyone suggest good sounding, powerful, amplifiers (plate or professional - but not car) that has 300W+ power, that retails for less than $300US, that can power my low efficient BP1503 sub?
[Edited by pkgum on 11-04-2001 at 02:22 AM]
That's the thing with car amps -- assuming a quality and cheap one is available, for it to perform to its full potential with little distortion, the AC-DC power supply would have to be hefty in terms of ampere rating. Such power supplies are quite expensive thus negating the concept of "cheap" amplifier in the first place
AFAIK, http://www.jaycar.com.au is the only one with a 350W @ 4ohms amp for AU$429. I haven't seen anything more powerful than that one which is locally available. Perhaps guitar shops have some more powerful amps (just make sure the amp can reach -3dB at 5Hz or 10Hz). If you're handy with a soldering iron, you could build your own amps -- http://www.sound.au.com
If only the subwoofer you're planning to order (the BP1503?) had dual voice-coils, the Electronics Australia Pro3 stereo power amp would be enough for your needs. I'm not sure though if the same amp is bridgeable, I never had to bridge mine.
Edit:
Also, I seem to remember that it was Silicon Chip magazine which published a 500W amp. Maybe a local library still has a copy of the issue. Dick Smith Electronics used to sell kits of the 500W amps. They were on clearance sale last year for only AU$100.00 each!! I couldn't forgive myself for missing the sale
Isaac
[Edited by f4ier on 11-04-2001 at 03:09 AM]
AFAIK, http://www.jaycar.com.au is the only one with a 350W @ 4ohms amp for AU$429. I haven't seen anything more powerful than that one which is locally available. Perhaps guitar shops have some more powerful amps (just make sure the amp can reach -3dB at 5Hz or 10Hz). If you're handy with a soldering iron, you could build your own amps -- http://www.sound.au.com
If only the subwoofer you're planning to order (the BP1503?) had dual voice-coils, the Electronics Australia Pro3 stereo power amp would be enough for your needs. I'm not sure though if the same amp is bridgeable, I never had to bridge mine.
Edit:
Also, I seem to remember that it was Silicon Chip magazine which published a 500W amp. Maybe a local library still has a copy of the issue. Dick Smith Electronics used to sell kits of the 500W amps. They were on clearance sale last year for only AU$100.00 each!! I couldn't forgive myself for missing the sale
Isaac
[Edited by f4ier on 11-04-2001 at 03:09 AM]
gum
No don't mess around trying to use a car amp.
The BPD-1503 has a single nominally 4 ohm VC. So any amp that is stable driving a 4 ohm load, and delivers 500+ watts will be fine. It can be a monoblock or stereo amp strapped in to mono, doesn't matter
Start by looking at the pro sound shops in your area for used gear. Crest, Crown, Ashely, Rane, etc, are companies that make excellent gear, and the stuff is built like a tank. I don't know if there are local AU companies that make amps like these, but if there are then certainly consider their products as well.
A dedicated sub amp doesn't need to deliver super clean power. Primarily it just needs to deliver alot of stable power.
Also understand that many of the lower cost pro amps are fan cooled. So if you're bothered by the constant sound of a fan running then buyer beware.
No don't mess around trying to use a car amp.
The BPD-1503 has a single nominally 4 ohm VC. So any amp that is stable driving a 4 ohm load, and delivers 500+ watts will be fine. It can be a monoblock or stereo amp strapped in to mono, doesn't matter
Start by looking at the pro sound shops in your area for used gear. Crest, Crown, Ashely, Rane, etc, are companies that make excellent gear, and the stuff is built like a tank. I don't know if there are local AU companies that make amps like these, but if there are then certainly consider their products as well.
A dedicated sub amp doesn't need to deliver super clean power. Primarily it just needs to deliver alot of stable power.
Also understand that many of the lower cost pro amps are fan cooled. So if you're bothered by the constant sound of a fan running then buyer beware.
Ive found some good bargains below:
http://www.onlinestagegear.com/pages-PA/PT1600.html
(It has two nice meters on it-too bad the thing doesnt use those cool Light power meters that light up to the rhythm of the music)
Heres the second bargain:
http://shop.store.yahoo.com/etronicsnet/flepa1.html
Heres another amp:
http://www.millionbuy.com/pylpt2000.html
(It also has 2 nice meters on it-the same brand as the first bargain)
Are these a good powerful amps?
Which is the best one to buy?
NOTE: I find the Crest, Carver, Ashley, etc amps to be too expensive. They cost $450 - 650US. Thats nearly all of my budget! My budget for a power amp is $150-250US. $250US is already too much.
http://www.onlinestagegear.com/pages-PA/PT1600.html
(It has two nice meters on it-too bad the thing doesnt use those cool Light power meters that light up to the rhythm of the music)
Heres the second bargain:
http://shop.store.yahoo.com/etronicsnet/flepa1.html
Heres another amp:
http://www.millionbuy.com/pylpt2000.html
(It also has 2 nice meters on it-the same brand as the first bargain)
Are these a good powerful amps?
Which is the best one to buy?
NOTE: I find the Crest, Carver, Ashley, etc amps to be too expensive. They cost $450 - 650US. Thats nearly all of my budget! My budget for a power amp is $150-250US. $250US is already too much.
I'm not sure of the reputation of those online stores you have mentioned, but if they check out ok, the Fleco amp looks better.
But... the difference between the 350W plate amp I mentioned above and Fleco amp is only 2dB at the most. Then again, there's the issue of headroom (I'm not helping, am I ) Personally, I wouldn't go through all that trouble in ordering the amp online. Moreover, if the thing suddenly stops working (Murphy's law?), think of the hassle in returning and chasing up warranty... overseas service even!
I still think the EA Pro3 stereo power amp is the best deal if you're handy with a soldering iron. Ask someone like Rob Evans at EA -- the Pro3 designer, I think -- or someone at Jaycar how the Pro3 could be safely bridged. If not, the 350W plate amp is the second-best thing
Isaac
But... the difference between the 350W plate amp I mentioned above and Fleco amp is only 2dB at the most. Then again, there's the issue of headroom (I'm not helping, am I
) Personally, I wouldn't go through all that trouble in ordering the amp online. Moreover, if the thing suddenly stops working (Murphy's law?), think of the hassle in returning and chasing up warranty... overseas service even!I still think the EA Pro3 stereo power amp is the best deal if you're handy with a soldering iron. Ask someone like Rob Evans at EA -- the Pro3 designer, I think -- or someone at Jaycar how the Pro3 could be safely bridged. If not, the 350W plate amp is the second-best thing
Isaac
I dont know how to solder an amp..so the EA is out of the question...
I would have bought the jaycar if the frequency response wasn't 20Hz-160Hz. This is absolutley pathetic...My sub sub is destined to reach into the 18Hz area..even 16Hz..and the jaycar can only go to 20Hz
The power amps Ive mention go down to 10Hz +/-3Db
I would have bought the jaycar if the frequency response wasn't 20Hz-160Hz. This is absolutley pathetic...My sub sub is destined to reach into the 18Hz area..even 16Hz..and the jaycar can only go to 20Hz
The power amps Ive mention go down to 10Hz +/-3Db
You'll want to be careful with the so called 'DJ' amps. Pyle, Pyramid, Speco, GemStar, etc. They inflate the output rating frequently listing peak power instead of RMS.
The Fidek units are ok, they do have a fairly loud fan.
The only reason I mentioned Crown, Crest, and Ashley, is that often those amps can be found used. And they're usually a good buy, given the very high build quality
The Fidek units are ok, they do have a fairly loud fan.
The only reason I mentioned Crown, Crest, and Ashley, is that often those amps can be found used. And they're usually a good buy, given the very high build quality
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