Speakerplans.com Homepage
Forum Home Forum Home > General > Newbie Discussion
  New Posts New Posts RSS Feed - Double 10" Sealed Enclosure Advice please
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Double 10" Sealed Enclosure Advice please

 Post Reply Post Reply Page  <1234 12>
Author
Message
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 246
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 8:24am
Cheers guys i have tried winisd. I can enter a new speaker and write in all n the TS parameters all fine. And obviously i can read the volume of the box etc. 

But i dont actually know what im looking for with the outcome. Like the graph with the line on, i dont get what shape or where it should be at all.  And also 'tuning frequency hz' i have no idea what i should be setting that too?


Edited by Jack1991 - 14 April 2020 at 8:27am
Back to Top
JonB67 View Drop Down
Young Croc
Young Croc


Joined: 22 April 2016
Location: UK
Status: Offline
Points: 1092
Post Options Post Options   Thanks (0) Thanks(0)   Quote JonB67 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 9:06am
You need to balance the parameters to suit your needs

I'd suggest you just start changing the box volume and tuning frequency to see what happens to the graph. Move tuning 5 or 10hz and 10 litres at a time to start with. You'll soon see what's happening then you can dial it in to the hz! In my option its more important that you understand how the parameters  interact than you just get the result straight away.  You want a balance of a sensible box size with the port stopping the low frequencies rolling earlier than you need.

Obviously you want a flattish line, and you don't want it to drop off before it reaches your crossover point (Apw says tham reaches 120 so you need to be flat to there at least)


Back to Top
APW View Drop Down
Young Croc
Young Croc
Avatar

Joined: 13 November 2012
Location: New Romney Kent
Status: Offline
Points: 815
Post Options Post Options   Thanks (0) Thanks(0)   Quote APW Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 10:06am

At Jon said, you need to get the response as flat as possible in the band you are trying to reproduce, this is achieved by adjusting/balancing the box size and tuning, this in turn will dictate the port size. You can get into a situation where you get a very good response however itโ€™s not physically possible to fit the port inside the boxโ€ฆ Everything is a compromise!!

Peters screen grab looks good as he has the response flat down to 100HZ with the f3 at about 85Hz; this is achieved in a small box (21Ltr) with a sensibly sized port. The box size is very similar to my tops, however mine are tuned slightly lower (75Hz f3) and as Iโ€™m using a more efficient driver (98dB/w vs. 94dB/w) for every watt of power I put into the box I will get about twice the SPL out, a 3dB increase is double the sound energy.

BTW: 120Hz is the absolute highest you want to run the Thams, I x-over at about 100 - 110Hz. They will work higher than 120Hz but they donโ€™t sound so nice!!

Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 246
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 10:29am
Lovely cheers guys makes alot more sense now. I have been watching youtube videos on how to use winisd too (before posting this thread) but sometimes they go into too much detail. Where as you guys have explained just what im looking for so thanks for that ๐Ÿ™‚๐Ÿ‘๐Ÿผ

So now using the info youve all explained to me. As i was looking originally at making a sealed box can i use the same info but for sealed and see if i can get a good outcome? Down to 100hz.  Obviously i know i wont have a port to tune.  
Back to Top
Peter Jan View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 December 2008
Location: Belgium
Status: Offline
Points: 922
Post Options Post Options   Thanks (0) Thanks(0)   Quote Peter Jan Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 11:00am
That's what I did, I played around with volume and tuning and with a lowpass filter of 12dB/oct slope, because I guesstimated that "could" be the slope in the Pioneer amp and mainly to see what a crossover does to the respons and how you could go down to meet a Tham without compromise. Without this filter, you will see a bump in respons in the lower part, which may be not what you want, but all things have to be taken into account, not just cab size and port dimensions. You have to play around with all variables and see what it does to the respons and how you can shift it to where you want it to be. More or less flat respons is what you preferably aim for and whether the combo can properly "reach" your other components in frequency. In a closed box for example, this speaker does not go down low enough to reach a Tham. It rolls off too fast for any given cab size. Try simulating it and higher/lower cab size, you'll see the respons never ever gets in neighbourhood of let's say 100Hz ( and with crossover it only gets worse ) and also not with a somewhat flat respons.
I checked to have an as big port as possible to be able to get it in a relatively small box and ~8 cm diameter is good compromise size wise. The bigger diameter you start with, the longer the port needs to be for a given cab size and diameter or the port. Also, the smaller you make the cab, the longer a port gets for a certain tuning frequency and vice versa. Given this speaker/cab combo doesn't need to go down really low in frequency and the relatively low power that's gonna be put into it, the port does not need to be all that large in size to avoid "breathing" of "shuffing" of large amounts of air being pushed fast in en out of that port. You could go smaller in port size, but than the length is going to be short(isch) and that would lower the working of that port. I like to keep a port at least more or less as long as the diameter ( or longer ) to have it work properly as a resonator, because that's what a port is. A too short port is more a glorified airleak/hole than a resonator ;-)
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 246
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 11:15am
Perfect thanks again Peter Jan. This makes perfect sense now thankyou. I will have a play around today and see how i get on. I will try different drivers and sealed and ported to try and understand it more.

I will post results when i think i have got it correct and get your feedback if thats ok. To make sure i have it correct before building.๐Ÿ™‚๐Ÿ‘๐Ÿผ
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 246
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 4:25pm
Vent diameter and length is what im now struggling with. 

Example:
Vent length is always minus numbers unless i make the diameter a ridiculous size like 15cm even then the vent length will be something like 1.9cm. Setting the vent length to 10cm makes its length -1.56cm which is obviously wrong. 

I feel like im missing something here again?
Back to Top
APW View Drop Down
Young Croc
Young Croc
Avatar

Joined: 13 November 2012
Location: New Romney Kent
Status: Offline
Points: 815
Post Options Post Options   Thanks (0) Thanks(0)   Quote APW Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 5:03pm
What size is your box and what tuning are you using?

The only way I can get the port length to go negative is by making the box about 4x to large i.e. 75-80 litres for a single driver that requires a 20ltr box, this seriously de-rates the power handling of the driver.


Edited by APW - 14 April 2020 at 5:07pm
Back to Top
Peter Jan View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 December 2008
Location: Belgium
Status: Offline
Points: 922
Post Options Post Options   Thanks (0) Thanks(0)   Quote Peter Jan Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 5:08pm
It's not wrong per sรฉ, the program does things on a pure mathematical level. A minus value makes just as much sense on a mathematical level as a positive on. Now for cabinets and a port length of course not so much...
It just means that you have chosen a too small diameter port to begin with, once you manually change to a bigger size ( as you did ), the values will make sense again.
Everything considerred, some values of cab size - port diameter - tuning frequency does not work out as desired with that speaker. You need to change a few things...
Back to Top
Peter Jan View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 December 2008
Location: Belgium
Status: Offline
Points: 922
Post Options Post Options   Thanks (0) Thanks(0)   Quote Peter Jan Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 5:11pm
Originally posted by APW APW wrote:

What size is your box and what tuning are you using?

The only way I can get the port length to go negative is by making the box about 4x to large i.e. 75-80 litres for a single driver that requires a 20ltr box, this seriously de-rates the power handling of the driver.


Like he said, probably a way too large box.
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 246
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 5:59pm
I have been trying to design it for 2x speakers. For 2x speakers i am getting a result for around 50L at 78hz with the port length being in the minus until i reach a diameter of around 15cm.

Am i better off designing it for 1 speaker, rather than trying to design it in winisd as 2x speakers.   But then when making the enclosure make 1 big box with 2x seperate chambers.


Edited by Jack1991 - 14 April 2020 at 6:21pm
Back to Top
Peter Jan View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 December 2008
Location: Belgium
Status: Offline
Points: 922
Post Options Post Options   Thanks (0) Thanks(0)   Quote Peter Jan Quote  Post ReplyReply Direct Link To This Post Posted: 14 April 2020 at 6:23pm
That makes sense... 2 speakers also means double cab volume and two of the same ports as the port for one speaker.
Back to Top
 Post Reply Post Reply Page  <1234 12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.096 seconds.