i am going to make a subwoofer with this driver: http://www.maplin.co.uk/Products/Mo...ID=030723195021919&moduleno=20900&modulelist=
i know this driver is not hifi, and i do not want any driver suggestions.
i put the driver specs into winisd beta, and got these curves. yellow is sealed, green is vented. i prefer the yellow curve, but i am going to make test boxes of both to see what they sound like.
my question is about stuffing. what does stuffing do? should i stuff my sub?
i know this driver is not hifi, and i do not want any driver suggestions.
i put the driver specs into winisd beta, and got these curves. yellow is sealed, green is vented. i prefer the yellow curve, but i am going to make test boxes of both to see what they sound like.
my question is about stuffing. what does stuffing do? should i stuff my sub?
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Matttcattt said:i am going to make a subwoofer with this driver: http://www.maplin.co.uk/Products/Mo...ID=030723195021919&moduleno=20900&modulelist=
i know this driver is not hifi, and i do not want any driver suggestions.
Well, you are going to get driver info.
The Eminence Beta 15 does not have an extended core or a Faraday ring. That means that in a vented box, as the frequency approching Fb, the cone travels all the way in or out to the end of it's travel. This phenomenon is called "suck-out". At the frequencies near Fb, it essentially shears off half the waveform.
Eminence does make models with extended cores.
Another source for Eminence products in the UK is www.bkelec.com Checkout the prices on the entire Eminence line, Beta included.
Matttcattt said:
You're going to build test boxes of 700l and 1100l? I like your style, but you might have problems getting both you and your boxes in the same room at once!
Stuffing is used to damp the interior of the box, increase the apparent volume, and absorb troublesome wavelengths. In sealed boxes it is generally important to get the stuffing right, and this is done through listening and tweeking.. In vented boxes, stuffing is generally less in volume, and as a general rule, fixed to the cabinet sides to avoid blocking the airflow to the ports.
Check out the Eminence Delta 15LF, (make sure it's LF), at www.bkelec.com
Bigger magnet, has extended core so that "suck-out" problem doesn't happen in the deep bass, takes more power, and costs £53, including VAT. You can build a box of 13 cu ft that has an F3 of 30 Hz.
A better deal all around.
Bigger magnet, has extended core so that "suck-out" problem doesn't happen in the deep bass, takes more power, and costs £53, including VAT. You can build a box of 13 cu ft that has an F3 of 30 Hz.
A better deal all around.
Re: Re: Sub woofer questions
i meant that i dont want other drivers suggested to me.
so i have to have a sealed box?
700l isnt that big... ...only about 0.9m cubed... ...thats pretty big actually... ...i hadnt though about how big it would be...
any suggestions for stuffing i should try? having to have a sealed box narrows the choises down i suppose...
thanks for the replies.
kelticwizard said:
i meant that i dont want other drivers suggested to me.
so i have to have a sealed box?
pinkmouse said:
You're going to build test boxes of 700l and 1100l? I like your style, but you might have problems getting both you and your boxes in the same room at once!
Stuffing is used to damp the interior of the box, increase the apparent volume, and absorb troublesome wavelengths. In sealed boxes it is generally important to get the stuffing right, and this is done through listening and tweeking.. In vented boxes, stuffing is generally less in volume, and as a general rule, fixed to the cabinet sides to avoid blocking the airflow to the ports.
700l isnt that big... ...only about 0.9m cubed... ...thats pretty big actually... ...i hadnt though about how big it would be...
any suggestions for stuffing i should try? having to have a sealed box narrows the choises down i suppose...
thanks for the replies.
Matttcattt said:any more info kelticwizard? does not having an extended cone mean i can only have a sealed box?
the size of the box does not really matter. i dont want to go below 300l as i want the sub to play low bass, and im not really bothered by effeciency.i agree that 700l is a bit much though...
Matttcattt:
If you don't have a extended core, a sealed box is more advisable. The ported will have high distortion at the deep bass end.
The Eminence Delta 15LF has an extended core, the Beta 15 does not.
Even a 15 incher will have trouble putting out super high output at 30 Hz in a sealed box. The ported box will have a higher maximum SPL at it's rated power. I would suggest the ported for more output. However, you can go sealed as an option.
Below is the Eminence Delta 15LF and the Eminence Beta 15 in two identical boxes. I checked the eminence website and found that the Beta 15 is just 1 dB more sensitive than the Delta 15LF, (even though it is listed as 2 dB), so the chart is off by one dB. big deal
.As you can see, these two give virtually identical performance in a 13 fT³, (that's 368 liters in Metricspeak
), box tuned to 30 Hz. How low did you want the sub to go?
kelticwizard said:
Matttcattt:
If you don't have a extended core, a sealed box is more advisable. The ported will have high distortion at the deep bass end.
The Eminence Delta 15LF has an extended core, the Beta 15 does not.
Even a 15 incher will have trouble putting out super high output at 30 Hz in a sealed box. The ported box will have a higher maximum SPL at it's rated power. I would suggest the ported for more output. However, you can go sealed as an option.
Below is the Eminence Delta 15LF and the Eminence Beta 15 in two identical boxes. I checked the eminence website and found that the Beta 15 is just 1 dB more sensitive than the Delta 15LF, (even though it is listed as 2 dB), so the chart is off by one dB. big deal
As you can see, these two give virtually identical performance in a 13 fT³, (that's 368 liters in Metricspeak
i must have looked at the graph wrong, ported looks much prefereable.
im not really sure how low i would like it to go. i was told before that 20Hz at -3db is very good, but im not sure about how loud -3db is
looking at winisd beta, the optimised curve with 1108.8l volume looks good to me, but 1000l is huge. the curve is ok (i think so anyway) down to about 600l. what do you think?
Matttcattt:
Both are ported in the chart. Only ported systems have Fb. You cannot tune a sealed box, except by making the box bigger or smaller.
I made the chart to show that both the Beta 15 and the Delta 15LF are pretty much the same, except the Delta 15LF is a better made driver and works in ported boxes better.
Both are ported in the chart. Only ported systems have Fb. You cannot tune a sealed box, except by making the box bigger or smaller.
I made the chart to show that both the Beta 15 and the Delta 15LF are pretty much the same, except the Delta 15LF is a better made driver and works in ported boxes better.
Matttcattt:
Unless you are getting some kind of discount from Maplin's, the Delta 15LF is only £53 including VAT at www.bkelec.com , which is only £3 more than the Maplin's link for the Beta 15.
That is why I mentioned the Delta 15LF when you made it clear you didn't want any recommendations. I figured it was okay to mention another driver if it is the same price, LOL.
Anyway, I'll let you make your own shopping decisions. Obviously I don't know all the facts of your situation.
If you don't mind my asking, where do you plan to put this? From the volumes you mentioned for the enclosure, I almost think you are putting this into a large unused closet. I did that once, by the way.
Unless you are getting some kind of discount from Maplin's, the Delta 15LF is only £53 including VAT at www.bkelec.com , which is only £3 more than the Maplin's link for the Beta 15.
That is why I mentioned the Delta 15LF when you made it clear you didn't want any recommendations. I figured it was okay to mention another driver if it is the same price, LOL.
Anyway, I'll let you make your own shopping decisions. Obviously I don't know all the facts of your situation.
If you don't mind my asking, where do you plan to put this? From the volumes you mentioned for the enclosure, I almost think you are putting this into a large unused closet. I did that once, by the way.
kelticwizard said:Matttcattt:
Unless you are getting some kind of discount from Maplin's, the Delta 15LF is only £53 including VAT at www.bkelec.com , which is only £3 more than the Maplin's link for the Beta 15.
That is why I mentioned the Delta 15LF when you made it clear you didn't want any recommendations. I figured it was okay to mention another driver if it is the same price, LOL.
Anyway, I'll let you make your own shopping decisions. Obviously I don't know all the facts of your situation.
If you don't mind my asking, where do you plan to put this? From the volumes you mentioned for the enclosure, I almost think you are putting this into a large unused closet. I did that once, by the way.
i want to/need to buy everthing from maplin as i do not have any way to pay online.
i was thinking the floor, with my other speakers.
Yes, online ordering can be a problem. That explains a lot.
What kind of amplifier will be driving these? Since they are in the 95+ dB range, they will play much louder than a hifi sub, so you need less power. But I was just wondering what you planned to drive them with and with how much power.
Just because the Betas take 350 watts and the Deltas take 500, doesn't mean you necessarily have to give them that, of course.
What kind of amplifier will be driving these? Since they are in the 95+ dB range, they will play much louder than a hifi sub, so you need less power. But I was just wondering what you planned to drive them with and with how much power.
Just because the Betas take 350 watts and the Deltas take 500, doesn't mean you necessarily have to give them that, of course.
I think if you are going to build a sealed box, one is as good as the other for your purposes. If you are going to go ported, the Delta has that big, big advantage of not having to worry about "suck-out" near resonance.
One tiny warning. The bass you get from the Delta in a 13 Ft³ might not be the cleanest bass in the world. Let me explain.
Back in 1971, Neville Thiele published a monumental paper that analyzed the ported box. Before that, most engineers used Sealed boxes because they did not know what kind of response they were going to get. If you see the term "Thiele-Small" parameters, that's the guy.
He took over a dozen examples of ported boxes with different Qts ratings for the drivers, etc, and called them "alignments". He gave a list of acceptable "alignments", and pointed out the ones which gave too much distortion. Drivers with a Qts over 0.38 give increasing amounts of distortion if the box volume is over Vas, which this is.
The "alignment" for this ported box is the last "alignment" Thiele put on his list. After this, the distortion gets too high. In other words, this setup will give some distortion in the bass, but that distortion will be acceptably low according to the fellow who is considered the pioneer in the ported box field.
Although I would not have chosen a speaker with this high a Qts to make a ported box, we must do with what we financially can afford at the moment. This speaker is available to you at a good price, and the "alignment" is on Thiele's list of acceptable "alignments".
You can get a smoother bass sound from a sealed box, but in my opinion, the cutoffs are too high. A 6½ inch speaker can go down to 50 Hz. If all you want is 50 Hz, why buy a 15 inch speaker?
When you bought this 15 incher, knowing it was a PA speaker such as a band would use and not a hi fi speaker, I assumed that you meant to say, "I want a good, tough bottom on my music that comes through real loud, and I am not worried about pleasing super high end standards. I want it built according to good principles, though."
I believe you will get that using the Delta 15LF in a 13 Ft³ box.
Of course, building a 13 Ft³ is quite an undertaking. I hope you have access to a good workshop, or are willing to have a lumber yard cut the pieces for you.
One tiny warning. The bass you get from the Delta in a 13 Ft³ might not be the cleanest bass in the world. Let me explain.
Back in 1971, Neville Thiele published a monumental paper that analyzed the ported box. Before that, most engineers used Sealed boxes because they did not know what kind of response they were going to get. If you see the term "Thiele-Small" parameters, that's the guy.
He took over a dozen examples of ported boxes with different Qts ratings for the drivers, etc, and called them "alignments". He gave a list of acceptable "alignments", and pointed out the ones which gave too much distortion. Drivers with a Qts over 0.38 give increasing amounts of distortion if the box volume is over Vas, which this is.
The "alignment" for this ported box is the last "alignment" Thiele put on his list. After this, the distortion gets too high. In other words, this setup will give some distortion in the bass, but that distortion will be acceptably low according to the fellow who is considered the pioneer in the ported box field.
Although I would not have chosen a speaker with this high a Qts to make a ported box, we must do with what we financially can afford at the moment. This speaker is available to you at a good price, and the "alignment" is on Thiele's list of acceptable "alignments".
You can get a smoother bass sound from a sealed box, but in my opinion, the cutoffs are too high. A 6½ inch speaker can go down to 50 Hz. If all you want is 50 Hz, why buy a 15 inch speaker?
When you bought this 15 incher, knowing it was a PA speaker such as a band would use and not a hi fi speaker, I assumed that you meant to say, "I want a good, tough bottom on my music that comes through real loud, and I am not worried about pleasing super high end standards. I want it built according to good principles, though."
I believe you will get that using the Delta 15LF in a 13 Ft³ box.
Of course, building a 13 Ft³ is quite an undertaking. I hope you have access to a good workshop, or are willing to have a lumber yard cut the pieces for you.
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