Speakerplans.com Homepage
Forum Home Forum Home > Plans > New Projects Forum
  New Posts New Posts RSS Feed - Lockdown Audio - A 12v 3way Small Rig Build
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Lockdown Audio - A 12v 3way Small Rig Build

 Post Reply Post Reply Page  <1 11121314>
Author
Message
 Rating: Topic Rating: 1 Votes, Average 5.00  Topic Search Topic Search  Topic Options Topic Options
smoore View Drop Down
Young Croc
Young Croc
Avatar

Joined: 30 March 2011
Location: N.Devon
Status: Offline
Points: 930
Post Options Post Options   Thanks (0) Thanks(0)   Quote smoore Quote  Post ReplyReply Direct Link To This Post Posted: 01 February 2022 at 8:58pm
The subs will couple like that just as well as they will couple with the mouths together, I'd bet there will be no audible difference. If anything I'd suggest the opposite and keep it like that. Subs stacked higher should gain more directional control down lower due to the 'mirror' image reflected from the floor, giving you more SPL than a low/wide stack would. Though in this instance it probably won't make much difference!
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 01 February 2022 at 9:32pm
Cool thanks for the info man. Its interesting stuff! Havent even had a chance to listen to it with the 4 subs yet, (wont be long now though) But still just enjoy reading up on speaker stuff and learning.
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 05 May 2022 at 8:40pm
Finally got to test it out all together and it was really good, had it on for about 8hrs of use, various genres of music and on max volume too and it pumps! Only needed it on around 1/2 - 2/3 volume though majority of the day was plenty. Battery used hardly anything too, i think ive got the gain settings pretty good now and the dsp is so good i love it!


My only gripe is the mids, nobody else could notice but i did myself. I feel like they arent going low enough to meet the thams. I am crossing them over at 100hz using LK-24. Same for the Thams.  Usong the dsp i isolated it so it was just the mids playing and it didnt sound quite right.

Straight away i wondered if i have used too much wadding inside the mids? Here is photos from the time i was building them of what i used and how much. It is this stuff on all 5 walls, it is not on the wall the speaker itself is mounted on. I have re-checked winisd now i understand it all a bit better and all seems fine. The mids are in a seperate enclosure each and both have a 4" port each.







Any help or advice would be great 🙂👍🏼



Edited by Jack1991 - 05 May 2022 at 8:43pm
Back to Top
infrasound View Drop Down
Old Croc
Old Croc


Joined: 13 May 2011
Location: Brizzle
Status: Offline
Points: 2259
Post Options Post Options   Thanks (0) Thanks(0)   Quote infrasound Quote  Post ReplyReply Direct Link To This Post Posted: 05 May 2022 at 9:43pm
Good thing is that you can remove the wadding and see if you prefer it without.

Although, the likely reason would be that you'll probably need to EQ in some extra weight 100-400hz with the mids to achieve a 'full sound'. Take a look into equal loudness contour and Harman curves to get an idea:


Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 05 May 2022 at 9:57pm
Yes it is good its easily removable. But yeh dont want to if its not necessary. You dont rekon the wadding is packing out the inside too much then and reducing the box tuning freqeuncy too much?

Cool cheers i will have a good read of them. Something i have never heard of before. 
Back to Top
infrasound View Drop Down
Old Croc
Old Croc


Joined: 13 May 2011
Location: Brizzle
Status: Offline
Points: 2259
Post Options Post Options   Thanks (0) Thanks(0)   Quote infrasound Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 12:00pm
I personally often end up with less. On the rear face, top face and one side face.

Maybe also worth blocking the port and adding more EQ to compensate. Avoids phase problems with crossover to THAMs and should clean up the midrange a little. They will use  slightly more power, but the real world effect on battery will be almost negligible IMO.

Also, I have found that Dacron works marginally better for me when I have AB'd against egg shell foam as you have. Would try the above options first before going down this route though.
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 12:20pm
Cool that sounds good ill give it a go. What do you reccomend to block the ports up with? Id like to do it temporary first just incase. Also yeh i have got dacron at home now too, recently got it for another project.

The software for the dsp on the EQ page looks like that in photo (photo off their website as im not home) Not sure if its possible without seeing measurements but do you have any suggestions for what to set the eq for the mids? Id like to learn how to measure it all & be able to test lots of things out, but i dont have the knowledge or space to do it.





Edited by Jack1991 - 06 May 2022 at 12:20pm
Back to Top
fatfreddiescat View Drop Down
Young Croc
Young Croc
Avatar

Joined: 15 October 2010
Location: N.E.Wales
Status: Offline
Points: 957
Post Options Post Options   Thanks (0) Thanks(0)   Quote fatfreddiescat Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 2:22pm
Really need to check the acoustic response of the xover area to make sure their in phase either side of it and working as expected, also the top box will likley want some baffle step compensation as will be transitioning from 4pi to 2pi loading ish.
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Offline
Points: 10703
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 4:36pm
I just skipped back a bunch but couldn’t see anywhere that you showed your WinISD plots / settings, or the cabinet dimensions for your mids. Can you share those?

You might find that the time of flight around the cabinet for your port’s output is arriving out of time with the same pass band from the front of the driver. If you have the cabinet dimensions, then you can calculate the time offset. A port’s output is anti phase to the diaphragm regardless - a polarity inversion and extra time delay is basically a principle of cardioid subwoofer setups for cancellation at the rear.

If you have that the wrong way round physically, the cancellation might be happening at the front instead. Hard to tell even stood at the rear of the mid box, because the directivity of the diaphragm output means you won’t hear the upper region anyway.

Also, did you account for port end correction in the model?

I can’t remember if it’s enabled in WinISD by default, but a port’s length generally needs to be adjusted from what the simple models say to achieve the desired tuning. The amount of end correction changes based on port dimensions and shape. Some software such as Tolvan Basta! has a check box to calculate a length correction factor, but even then there’s often some fudging needed based on measurements.

The reason I ask is that you may find the box is currently tuned too low. A friend did that recently on an 8” coaxial box - calculated the port to 67Hz but ended up under 50Hz which was so far in the roll off that it sounded thin. It’s easily done.

Adding lots of stuffing will make the box appear bigger acoustically at some frequencies too, so it might be making the problem worse.
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 8:24pm
Fatfreddiescat:
Ah ok i see thanks man. As for the baffle step compensation that is something i havent heard of before so will get reading up on that to try understand it.


toastyghost:
Oh yeh only just noticed myself too i didnt post my winisd results. I will get them now from my laptop and share them on a seperate post. For the mids I have 2 seperate chambers, volume of each chamber is  23L  1x round port per chamber 10cm wide by 11.5cm long. Tuned to 73.50hz.

Im not quite sure what you mean on the second paragraph its a bit out of my depth of knowledge. And also as far as i know i didnt account for port end correction, something i havent heard of before either. Thats good to know about the stuffing too, i do feel as if it sounds a bit too stuffed, although as a newbie im not 100% sure, it just sounds a bit 'softer'.

I remember when i was learning winisd to make the mids, I assumed and was told that it was right to make the tuning freqeuncy as low as it goes with as flat a line, as i would be crossing over at around 100hz anyway so anything below wouldnt be used through the mids.

I should have also said previously too, when i took out just 2 thams, the mids and tops a couple years ago, before i had the dsp, so i was only using the amplifiers built in crossovers, and no delay etc. I didnt notice the mids sounding not quite right. To me then it all sounded perfect. So wether i have just got a better ear for it now, or something i am setting wrong in the dsp isnt quite right maybe, im not sure.


On the DSP i have only set delay and the crossovers.

Delay:
Mids and Tops delayed by 5.9ms, as i worked out tham horn length to that.

Crossovers all LK 24 
Thams 20hz - 100hz
Mids 100hz - 2000hz
Tops 2000hz - 20,000hz




Edited by Jack1991 - 06 May 2022 at 8:30pm
Back to Top
Jack1991 View Drop Down
Registered User
Registered User


Joined: 05 February 2020
Status: Offline
Points: 406
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jack1991 Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 8:37pm








If there is any other particular bits on winisd i should post let me know and ill get them 🙂👍🏼






Edited by Jack1991 - 06 May 2022 at 8:45pm
Back to Top
Bams View Drop Down
Young Croc
Young Croc


Joined: 08 April 2009
Status: Offline
Points: 553
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bams Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2022 at 9:30pm
In my experience non-discerning listeners tend to “forget” the major impact of a decent mid-section and therefore also will say something sounds gold faster than when you are listening critical. Therefore.. trust only your own ears.
Back to Top
 Post Reply Post Reply Page  <1 11121314>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.05
Copyright ©2001-2022 Web Wiz Ltd.

This page was generated in 0.111 seconds.