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Title: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 06, 2018, 06:01:48 pm
Hi all,
I have a Sound 18 12' subwoofer on order and plan to build my own cabinet. The problem that I encountered is that I can't find the specs on it in order to plan a design. I contacted the company in Italy and got a response that it is not a regular production run but rather is a OEM product for another builder and therefore was unable to give the specs.  I know the program power is 600 watts and the peak is 1200 ($ohms) The tech said that all he could tell me that the Fs is between 50 and 55Hz. The model number is 12NW430Y. Any suggestions for an enclosure that could be used with this sub. Not much to go on but that is all I have right now. Thanks in advance.
David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 06, 2018, 06:39:49 pm
Without getting much more of the normal specifications, no, there really isn't much anyone can suggest.
Do you even know what commercial box this driver came out of? If so, something like that would be the most obvious answer.

If you're reasonably committed to this project and willing to spend a bit more time & money, you could measure enough of the TS parameters to be useful yourself. Here is one guide to how you can do it. (http://sound.whsites.net/tsp.htm)

Or, you can buy and learn to use This (https://www.parts-express.com/dayton-audio-dats-v2-computer-based-audio-component-test-system--390-806), though cost suggests that's only likely to be useful if you plan on doing a lot of speaker DIY.

HTH,
David.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: duane massey on March 07, 2018, 01:59:02 am
Or you could do it old school. Build a cabinet to the size you are are comfortable moving, and then experiment with the port(s) until you get it right. Yes, this is how we used to do it.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Chris Grimshaw on March 07, 2018, 04:25:05 am
Measuring T/S parameters is the way to do it. Happy to help once you've got those.

Chances are there's someone nearby that has the equipment to do it, even if they don't realise. I use a pair of guitar cables cut in half, a resistor, and a USB soundcard. Needs two matched inputs (ie, both XLR, or both 1/4" jack - some have one of each and the jack is often high-impedance, which will screw up your measurements).

Chris
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 05:25:57 am
Measuring T/S parameters is the way to do it. Happy to help once you've got those.

Chances are there's someone nearby that has the equipment to do it, even if they don't realise. I use a pair of guitar cables cut in half, a resistor, and a USB soundcard. Needs two matched inputs (ie, both XLR, or both 1/4" jack - some have one of each and the jack is often high-impedance, which will screw up your measurements).

Chris

Thank you very much. New to me so I  will ask around.
David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 05:29:59 am
Without getting much more of the normal specifications, no, there really isn't much anyone can suggest.
Do you even know what commercial box this driver came out of? If so, something like that would be the most obvious answer.

If you're reasonably committed to this project and willing to spend a bit more time & money, you could measure enough of the TS parameters to be useful yourself. Here is one guide to how you can do it. (http://sound.whsites.net/tsp.htm)

Or, you can buy and learn to use This (https://www.parts-express.com/dayton-audio-dats-v2-computer-based-audio-component-test-system--390-806), though cost suggests that's only likely to be useful if you plan on doing a lot of speaker DIY.

Thanks a lot. I don't plan on building any more at least not in the short term. I really have got to try and get the specs. I am buying he darn speaker- I should be entitled to the specs.
All the best
David

HTH,
David.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 05:33:35 am
Hi all,
I have a Sound 18 12' subwoofer on order and plan to build my own cabinet. The problem that I encountered is that I can't find the specs on it in order to plan a design. I contacted the company in Italy and got a response that it is not a regular production run but rather is a OEM product for another builder and therefore was unable to give the specs.  I know the program power is 600 watts and the peak is 1200 ($ohms) The tech said that all he could tell me that the Fs is between 50 and 55Hz. The model number is 12NW430Y. Any suggestions for an enclosure that could be used with this sub. Not much to go on but that is all I have right now. Thanks in advance.
David

Sorry-4 ohms
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 05:37:02 am
Or you could do it old school. Build a cabinet to the size you are are comfortable moving, and then experiment with the port(s) until you get it right. Yes, this is how we used to do it.
I am confident that with a little knowledge this could be a viable options- hadn't thought of that. Could you suggest a baseline design to start with if I were to go that way. Would using a sealed enclose be too risky without the specs?
Thanks,
David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Chris Grimshaw on March 07, 2018, 06:08:07 am
I am confident that with a little knowledge this could be a viable options- hadn't thought of that. Could you suggest a baseline design to start with if I were to go that way. Would using a sealed enclose be too risky without the specs?
Thanks,
David

Sealed enclosures are very tolerant to having random drivers dropped in there. They also don't provide much output for PA use.
A ported box is the next step up, more output but less tolerant to random drivers.
Horns are a further step in that direction. I wouldn't design a horn without carefully measuring the drivers that will be going in there.

Most PA cabinets are ported.

If you add your location to your profile, someone around might be able to help you. If not, if you're happy to cover shipping to/from me, I'm happy to produce a full datasheet for your driver.

Chris
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 06:21:34 am
Sealed enclosures are very tolerant to having random drivers dropped in there. They also don't provide much output for PA use.
A ported box is the next step up, more output but less tolerant to random drivers.
Horns are a further step in that direction. I wouldn't design a horn without carefully measuring the drivers that will be going in there.

Most PA cabinets are ported.

If you add your location to your profile, someone around might be able to help you. If not, if you're happy to cover shipping to/from me, I'm happy to produce a full datasheet for your driver.

So you have or can get the full specs on this driver? (Sound 18  12NW430Y). I am going to contact the Music store where I ordered it an see if I can get the info. If not then I will certainly go that route. You can pm me the shipping cost in the meantime if I need to go that route.
Thanks,
david

Chris
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 08:00:04 am

Pm me with what you have to offer.
Thanks david
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Chris Grimshaw on March 07, 2018, 09:11:52 am
Pm me with what you have to offer.
Thanks david

Might as well write it up here in case anyone else wants it doing.

What I'll do is a couple of measurements of the driver, both free-air, one with mass added to the cone. Using REW, I can then get a set of the T/S parameters to you.
I don't have the equipment to do the Klippel testing for Xmax etc, but what I usually do is feed a sine wave into the driver and listen for when there's a slight knocking sound (NOT the sound of the coil hitting the backplate), which is distortion as the driver reaches its limits. I'll note the cone travel available from that test. NB - this isn't Xmax as such, since Xmax is often derived from the physical sizes of the voicecoil and magnetic gap. That definition is of limited use, though, as the suspension might lock up well before the motor goes non-linear. My test isn't particularly "official", but does give a good idea of what the driver can do.

If that all sounds good, put a Sheffield (UK) postcode into your shipping planner and see what it quotes you. For fairly obvious reasons, I'm not going to post my full address online.

If I start to get a huge influx of drivers I'll have to add a small charge, but for the odd one per year like this, I'm happy to help.

Chris
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 12:50:49 pm
Measuring T/S parameters is the way to do it. Happy to help once you've got those.

Chances are there's someone nearby that has the equipment to do it, even if they don't realise. I use a pair of guitar cables cut in half, a resistor, and a USB soundcard. Needs two matched inputs (ie, both XLR, or both 1/4" jack - some have one of each and the jack is often high-impedance, which will screw up your measurements).

Chris

I managed to track down the specs. Hopefully I can some suggestions for a relatively compact vented enclosure.
Thanks, David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 07, 2018, 12:53:18 pm
I managed to track down the specs. Hopefully I can some suggestions for a relatively compact vented enclosure.
Thanks, David

 
Fs 53 Hz
Re 2.6 Ohm
Sd 0,053 sq.mt. 
Qms 9,7
Qes 0,384
Qts 0,37
Vas 36 lt. 
Mms 93 gr. 
BL 19,7 Tm
Linear Xmax 8 mm 
Le (1kHz) 0,9 mH

Copied and pasted as given to me by the tech.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 07, 2018, 02:52:32 pm

Fs 53 Hz
Re 2.6 Ohm
Sd 0,053 sq.mt. 
Qms 9,7
Qes 0,384
Qts 0,37
Vas 36 lt. 
Mms 93 gr. 
BL 19,7 Tm
Linear Xmax 8 mm 
Le (1kHz) 0,9 mH

Copied and pasted as given to me by the tech.

I had a quick google for the driver and the pic I found looked a lot like the 12NW530. Those specs are virtually the same as the 530, which is a slight problem. Normally, when you make a 4 ohm version of a driver, both Re and BL reduce, but on those specs BL has stayed exactly the same as the 8 ohm version. That in turn means it couldn't have the same Qes. I suspect a careless cut'n'paste job at play, to be honest.

So, if it really is just a 4R version of the 530, something around 30l tuned to 55Hz for the small end of what's reasonable, up to 50l tuned to 45Hz at the lower/deeper end of the scale. The larger & lower you go, the less power it takes to reach Xmax so that affects how loud you can get while maintaining sound quality.

The pic below shows predicted output (for the 530 version as I already had those spec's entered in WinISD) for the above 2 setups, the 50l in green and the 30 in blue. Green takes 350W to reach Xmax and blue 550. That's just over continuous and just under program respectively.

One 12.7cm dia vent will be enough to keep vent airspeed to about 30ms-1 in either case, for the big box it needs to be 28.1cm long, and for the small box 32.5cm.

Excursion & Xmax have been calculated assuming 24dB Butterworth HPF's in each case, at 39Hz for the bigger box and 45Hz for the smaller.

HTH,
David.

Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 08, 2018, 01:32:28 pm
I had a quick google for the driver and the pic I found looked a lot like the 12NW530. Those specs are virtually the same as the 530, which is a slight problem. Normally, when you make a 4 ohm version of a driver, both Re and BL reduce, but on those specs BL has stayed exactly the same as the 8 ohm version. That in turn means it couldn't have the same Qes. I suspect a careless cut'n'paste job at play, to be honest.

So, if it really is just a 4R version of the 530, something around 30l tuned to 55Hz for the small end of what's reasonable, up to 50l tuned to 45Hz at the lower/deeper end of the scale. The larger & lower you go, the less power it takes to reach Xmax so that affects how loud you can get while maintaining sound quality.

The pic below shows predicted output (for the 530 version as I already had those spec's entered in WinISD) for the above 2 setups, the 50l in green and the 30 in blue. Green takes 350W to reach Xmax and blue 550. That's just over continuous and just under program respectively.

One 12.7cm dia vent will be enough to keep vent airspeed to about 30ms-1 in either case, for the big box it needs to be 28.1cm long, and for the small box 32.5cm.

Excursion & Xmax have been calculated assuming 24dB Butterworth HPF's in each case, at 39Hz for the bigger box and 45Hz for the smaller.

HTH,
David.

Thank you so much.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 06:00:50 am
I had a quick google for the driver and the pic I found looked a lot like the 12NW530. Those specs are virtually the same as the 530, which is a slight problem. Normally, when you make a 4 ohm version of a driver, both Re and BL reduce, but on those specs BL has stayed exactly the same as the 8 ohm version. That in turn means it couldn't have the same Qes. I suspect a careless cut'n'paste job at play, to be honest.

So, if it really is just a 4R version of the 530, something around 30l tuned to 55Hz for the small end of what's reasonable, up to 50l tuned to 45Hz at the lower/deeper end of the scale. The larger & lower you go, the less power it takes to reach Xmax so that affects how loud you can get while maintaining sound quality.

The pic below shows predicted output (for the 530 version as I already had those spec's entered in WinISD) for the above 2 setups, the 50l in green and the 30 in blue. Green takes 350W to reach Xmax and blue 550. That's just over continuous and just under program respectively.

One 12.7cm dia vent will be enough to keep vent airspeed to about 30ms-1 in either case, for the big box it needs to be 28.1cm long, and for the small box 32.5cm.

Excursion & Xmax have been calculated assuming 24dB Butterworth HPF's in each case, at 39Hz for the bigger box and 45Hz for the smaller.

HTH,
David.

David,
Forgive me if this is too simplistic, but I am very new to this and want a small sub to compliment a pair of tops in order to do some light DJ work. Could I have your, or anyone else's opinion, on the following enclosure. All measurements are in inches. L-17, W-16.5 and H-20.5. The vent on the bottom measures 2.5 by16.5 and has a shelf that is 13 inches deep. I wish I knew more about this topic, but that is why I am here seeking advice.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 06:45:38 am
David,
Forgive me if this is too simplistic, but I am very new to this and want a small sub to compliment a pair of tops in order to do some light DJ work. Could I have your, or anyone else's opinion, on the following enclosure. All measurements are in inches. L-17, W-16.5 and H-20.5. The vent on the bottom measures 2.5 by16.5 and has a shelf that is 13 inches deep. I wish I knew more about this topic, but that is why I am here seeking advice.


Here are the specs on the speaker again so that other people may have a look at it also.

Fs 53 Hz
Re 2.6 Ohm
Sd 0,053 sq.mt. 
Qms 9,7
Qes 0,384
Qts 0,37
Vas 36 lt. 
Mms 93 gr. 
BL 19,7 Tm
Linear Xmax 8 mm 
Le (1kHz) 0,9 mH

Copied and pasted as given to me by the tech.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Chris Grimshaw on March 10, 2018, 08:54:15 am
Looks reasonable. What does the simulation look like?

For what it's worth, bracing can be particularly effective when you join opposite panels. In subwoofer use, the forces acting on the panels will try to blow the cabinet up like a balloon, so physically connecting the opposite panels strengthens against that very well.

Chris
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 10, 2018, 10:01:30 am
David,
Forgive me if this is too simplistic, but I am very new to this and want a small sub to compliment a pair of tops in order to do some light DJ work. Could I have your, or anyone else's opinion, on the following enclosure. All measurements are in inches. L-17, W-16.5 and H-20.5. The vent on the bottom measures 2.5 by16.5 and has a shelf that is 13 inches deep. I wish I knew more about this topic, but that is why I am here seeking advice.

It's approximately 59.5l net internal volume which should leave it tuned to about 45Hz.
That's actually not too bad at all for your driver.

However, the bigger question raised is what you mean by "light DJ work" please?
One 12" sub on its own will not produce enough bass to keep up with most of what I understand DJ'ing to be about, so you may very well still end up disappointed even if you build a box that gets the best out of this driver.

What size audiences will you be playing to, and what main PA speakers will you be using? Those 2 factiods should help narrow down what you might actually need, in case it doesn't match what you've bought.

That said, here's the predicted plot for your driver in the fEarful box. It will take around 340W to reach Xmax; at this power level vent airspeed is very good at 16.5ms-1. A 39Hz Butt24 HPF is again needed.

Cheers,
David.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 10:26:38 am
Looks reasonable. What does the simulation look like?

For what it's worth, bracing can be particularly effective when you join opposite panels. In subwoofer use, the forces acting on the panels will try to blow the cabinet up like a balloon, so physically connecting the opposite panels strengthens against that very well.

Chris

Will do. Thanks.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 10:32:08 am
It's approximately 59.5l net internal volume which should leave it tuned to about 45Hz.
That's actually not too bad at all for your driver.

However, the bigger question raised is what you mean by "light DJ work" please?
One 12" sub on its own will not produce enough bass to keep up with most of what I understand DJ'ing to be about, so you may very well still end up disappointed even if you build a box that gets the best out of this driver.

What size audiences will you be playing to, and what main PA speakers will you be using? Those 2 factiods should help narrow down what you might actually need, in case it doesn't match what you've bought.

That said, here's the predicted plot for your driver in the fEarful box. It will take around 340W to reach Xmax; at this power level vent airspeed is very good at 16.5ms-1. A 39Hz Butt24 HPF is again needed.

Cheers,
David.
150 people-no hiphop just country ,rock and roll and some pop

Tops will be EV ZLX12p or the like
How can I tune to 50hz or is the diff not even worth worrying about?
Thanks,David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 10, 2018, 12:35:49 pm
150 people-no hiphop just country ,rock and roll and some pop

Tops will be EV ZLX12p or the like
How can I tune to 50hz or is the diff not even worth worrying about?
Thanks,David

One 12" bass bin will absolutely not keep up with 2 12" mains if you really want it to have some impact, I'd want one 15 or preferably 18 per 12" as a starting point.

Tuning higher (by shortening the vent) tends to push the response up into a hump, which can sound unnatural due to it causing "ringing" around the tuning frequency - I've not experienced an example of it myself, only read a little about it, so can't predict how obnoxious it would be in any given case. Reducing box volume can mitigate this though - that would take you back towards the kind of smaller box I modelled earlier. Obviously, both raising tuning and reducing internal volume both cost you in terms of less LF extension.

Herewith the fEarful box with ports shortened to 20cm only in yellow (HPF increases to 42Hz, Power to 390W) and a 45l box tuned to 50Hz again wtih 42Hz HPF and power at 440W in violet.

Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Ivan Beaver on March 10, 2018, 02:55:12 pm
Looks reasonable. What does the simulation look like?

For what it's worth, bracing can be particularly effective when you join opposite panels. In subwoofer use, the forces acting on the panels will try to blow the cabinet up like a balloon, so physically connecting the opposite panels strengthens against that very well.

Chris
I always tried to tie the sides together, and the top and bottom together-with both of those braces tied together.

Bracing is KEY to getting a good sub cabinet.  Yes it is more trouble, and the cabinet gets heavier, but the results are far better.

I also like to put braces on individual panels as well so that the individual panel cannot flex.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 04:16:47 pm
One 12" bass bin will absolutely not keep up with 2 12" mains if you really want it to have some impact, I'd want one 15 or preferably 18 per 12" as a starting point.

Tuning higher (by shortening the vent) tends to push the response up into a hump, which can sound unnatural due to it causing "ringing" around the tuning frequency - I've not experienced an example of it myself, only read a little about it, so can't predict how obnoxious it would be in any given case. Reducing box volume can mitigate this though - that would take you back towards the kind of smaller box I modelled earlier. Obviously, both raising tuning and reducing internal volume both cost you in terms of less LF extension.

Herewith the fEarful box with ports shortened to 20cm only in yellow (HPF increases to 42Hz, Power to 390W) and a 45l box tuned to 50Hz again wtih 42Hz HPF and power at 440W in violet.

Thanks again.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 10, 2018, 04:19:02 pm
I always tried to tie the sides together, and the top and bottom together-with both of those braces tied together.

Bracing is KEY to getting a good sub cabinet.  Yes it is more trouble, and the cabinet gets heavier, but the results are far better.

I also like to put braces on individual panels as well so that the individual panel cannot flex.

Will certainly bear this in mind.
Thanks Ivan.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 10, 2018, 05:24:32 pm
150 people-no hiphop just country ,rock and roll and some pop

Tops will be EV ZLX12p or the like
One 12" bass bin will absolutely not keep up with 2 12" mains if you really want it to have some impact, I'd want one 15 or preferably 18 per 12" as a starting point.


Further to this, there's a forum member called Dennis Wiggins who has some experience using small 12" subs for (I think) the kind of usage you have in mind - here are a couple of threads in which he mentions his setup.

http://forums.prosoundweb.com/index.php?topic=164414.0 (http://forums.prosoundweb.com/index.php?topic=164414.0)
http://forums.prosoundweb.com/index.php?topic=165126.10 (http://forums.prosoundweb.com/index.php?topic=165126.10)

You may want to PM him for some direct experience of this size of sub, rather than trusting me.

NB, your driver appears more capable than the ones likely to be in the subs Dennis uses, so you may not need quite as many of them.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 12, 2018, 01:06:25 pm
Looks reasonable. What does the simulation look like?

For what it's worth, bracing can be particularly effective when you join opposite panels. In subwoofer use, the forces acting on the panels will try to blow the cabinet up like a balloon, so physically connecting the opposite panels strengthens against that very well.

Chris

Hi Chris,
Forgive me but I have no way of doing a simulation on the driver/enclosure design. Can you enlighten me a little here.
Cheers,
David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 12, 2018, 03:13:12 pm
One 12" bass bin will absolutely not keep up with 2 12" mains if you really want it to have some impact, I'd want one 15 or preferably 18 per 12" as a starting point.

Tuning higher (by shortening the vent) tends to push the response up into a hump, which can sound unnatural due to it causing "ringing" around the tuning frequency - I've not experienced an example of it myself, only read a little about it, so can't predict how obnoxious it would be in any given case. Reducing box volume can mitigate this though - that would take you back towards the kind of smaller box I modelled earlier. Obviously, both raising tuning and reducing internal volume both cost you in terms of less LF extension.

Herewith the fEarful box with ports shortened to 20cm only in yellow (HPF increases to 42Hz, Power to 390W) and a 45l box tuned to 50Hz again wtih 42Hz HPF and power at 440W in violet.

Is there a schematic drawing of a sub box(es) that you are suggesting?I really want to try to have a box design that is similar to the one I posted-for ease of construction. My thoughts on this sub is that I just want to augment the low end a bit and take some of the lower-
end strain off the mains-nothing earthshaking, just a little more punch.
Thanks
David
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 12, 2018, 03:42:05 pm
Is there a schematic drawing of a sub box(es) that you are suggesting?I really want to try to have a box design that is similar to the one I posted-for ease of construction. My thoughts on this sub is that I just want to augment the low end a bit and take some of the lower-end strain off the mains-nothing earthshaking, just a little more punch.
Thanks
David

I've started one, but haven't finished adding in the dimensions yet.
Externally it's 400mm wide, 430mm deep and 470mm tall, assuming construction from 15mm ply.

Here's the partial, I should get time to add the dimensions in tomorrow or perhaps Wednesday.
(It's one mm per pixel if you want to get an idea of the rest yourself.)

You should also know that calculating exact port lengths has a bit of art to it, not just science. The "standard" calculations all assume the rear end of the port is in free air, i.e. not built in against a box wall. Doing the latter makes the port appear as if it's longer than it really is and the extent of this virtual extension is subject to a bit of approximation. Therefore it's always recommended that a prototype is built, the actual tuning frequency measured and the port length adjusted if necessary before committing to a final build.

Meanwhile, those who know might also comment if they think my proposed bracing is in the right ballpark or not?
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 12, 2018, 03:48:48 pm
Hi Chris,
Forgive me but I have no way of doing a simulation on the driver/enclosure design. Can you enlighten me a little here.
Cheers,
David

Dowload WinISD (https://www.facebook.com/WinISD/) and/or Hornresp (http://www.hornresp.net/), read up on the respective helpfiles and perhaps some other online sources (This one (https://forum.speakerplans.com/guide-to-winisd-pro-and-hornresp_topic1314.html) is reasonably decent, though not entirely up to date), enter your driver data and welcome to hours of potentially frustrating fun  ;).
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: David Morison on March 14, 2018, 04:56:34 pm
Is there a schematic drawing of a sub box(es) that you are suggesting?I really want to try to have a box design that is similar to the one I posted-for ease of construction. My thoughts on this sub is that I just want to augment the low end a bit and take some of the lower-end strain off the mains-nothing earthshaking, just a little more punch.
Thanks
David

As promised, now with numbers  :)
Double checked a few details and the final box can be a tiny fraction smaller without reducing the internal volume, it's now 450mm tall rather than 470.

Good luck,
David.

PS: I haven't given dimensions for how far back to place the handles on the sides - you're best to build the box without them, load the driver and grille then balance it on a thin strip of material to find the real CG and centre the handles there. Just be careful you don't put them too far forward else you may find they foul the driver.
Title: Re: Sub design for a 18 Sound 12" subwoofer
Post by: Dave Jackman on March 14, 2018, 06:19:19 pm
As promised, now with numbers  :)
Double checked a few details and the final box can be a tiny fraction smaller without reducing the internal volume, it's now 450mm tall rather than 470.

Good luck,
David.

PS: I haven't given dimensions for how far back to place the handles on the sides - you're best to build the box without them, load the driver and grille then balance it on a thin strip of material to find the real CG and centre the handles there. Just be careful you don't put them too far forward else you may find they foul the driver.

Thank-you so much for all your help. This looks like a great design for my needs. The driver should arrive soon and I will get to the build.
Cheers,
David