18" Ported Subwoofer Build, Advice on best driver.

[stevef22]

Hello! Im a new builder so the plan is a simple build inspired by BTS Ported Single Sub box

Inspiration Box here 72X28X17
https://shop.gsgad.com/collections/behind-the-screen-bts-subwoofers

I would like to make something similar. However no grooves and interlocking peices. Just woodglue and straight cuts.

I know I want to use LaVoce 18" Speaker here.


But I see 4 models. What model of 18" sub do I need for this box? Any advice for building my own box?

This is for home audio, 2 ch listening to music. Electronic, drum and bass.



Thank you

 

[DVDdoug]

Get some speaker design software. WinISD is FREE.

Plug-in the Thiele-Small parameters for each woofer and see what box volume it recommends for each. It will also show the predicted frequency response, and you can virtually-try different box sizes and sealed and ported designs.

 

[stevef22]

Get some speaker design software. WinISD is FREE.

Plug-in the Thiele-Small parameters for each woofer and see what box volume it recommends for each. It will also show the predicted frequency response, and you can virtually-try different box sizes and sealed and ported designs.

Thank you! I didnt know about this. Much appreciated.

 

[Aijan]

But I see 4 models. What model of 18" sub do I need for this box?

Of the 4 models, the best one is SAF184.03 if you don't mind the weight from the ferrite motor. That model has a strong motor, the lowest Fs, and the most excursion.

 

[stevef22]

Of the 4 models, the best one is SAF184.03 if you don't mind the weight from the ferrite motor. That model has a strong motor, the lowest Fs, and the most excursion.

Thank you! This is what I needed. Much apprecaited.

 

[voodooless]

Just note that these woofers are 8 Ohm, which is typical for Pro audio. For home audio subs, 4 Ohm impedance is more typical, because usually amps offer more power at lower impedance.

There are other options at PartsExpress, like:

Dayton Audio UMII18-22 Ultimax II 18" DVC Subwoofer 2 Ohm Per Coil

Dayton Audio UMII18-22 18" Ultimax II DVC Subwoofer Introducing the Dayton Audio UMII18-22 Ultimax II 18" carbon fiber cone subwoofer driver - a true powerhouse, engineered to deliver more of everything you loved about the original Ultimax drivers. This cutting-edge subwoofer is the product of...

www.parts-express.com

Dayton Audio RSS460HO-4 18" Reference Series HO Subwoofer 4 ohm

The Dayton Audio Reference Series subwoofers take the quality and performance of the much acclaimed RS line into the subwoofer realm. As with the rest of the Reference Series, the main focus of these subwoofers is ultra-low-distortion. Second, third, and intemodulation distortion are kept...

www.parts-express.com

Why ported? With those large woofers and home audio, closed is probably a viable option. Especially with the two above.

 

[Palmspar]

Agree with @voodooless it are pro audio drivers the fs is 30hz what is high for a home audio subwoofer driver, the dayton looks better with fs18.8hz.
Sealed is also better in my opinion, use 3 Diy subs with Scan-Speak drivers low fs 17/18hz with Hypex FA plate amps

 

[Aijan]

While pro audio drivers may have a relatively high Fs and less excursion compared to models like the Dayton Audio Ultimax, their high efficiency and stronger motors often allow them to achieve impressive sound levels in significantly smaller enclosure volumes and with less amplifier power. Also, they deliver a killer mid-bass punch that's hard to match.

 

[voodooless]

high efficiency and stronger motors often allow them to achieve impressive sound levels in significantly smaller enclosure volumes and with less amplifier power.

That is partially correct. However SD and Xmax are still king for subwoofer duty, and power is cheap. PA subs still need significant volume to operate significantly, and most of the efficiency is gained in the mid-bass.

Also, they deliver a killer mid-bass punch that's hard to match.

Which is true, but given that home subs usually are used only below 80 Hz, you won’t hear any of that anyway.

Having said all of this, you can probably make an excellent sub out of either driver. They just have different strengths and weaknesses. If you want to enjoy the magical midbass, then possibly the setup would be changed to accommodate for this; you would need at least two subs, near to the main speakers so they can blend in well.

So to really see what is needed, some more information is probably a good idea:
- what speakers should the sub integrate with?
- are you planning on multiple?
- how low do you expect them to go?
- hou loud to you want them to go?
- how big is the room?

 

[stevef22]

- what speakers should the sub integrate with?
R700 with McIntosh 250WPC amp. WIIM ULTRA
- are you planning on multiple?
YES, TWO FOR SURE
- how low do you expect them to go?
18HZ
- hou loud to you want them to go?
PISS OFF NEIGHBORS, TIMETRAVEL
- how big is the room?
BIG, OPEN - approx 14ft wide, 15ft ceilings (average), 24ft long


Room Walkthrough
https://youtu.be/EgG56ixn1AE?si=9OJXdjJboN252JoB



I want to put the subs in the corner of room where the chairs are, but I will perform the room crawl method to find best spot.


PS. I have heart set on a

Crown XTi 2002 Power Amplifier 2 x 800W at 4 Ohms, So a sub box pair that would work with this would be good. ​

after watching Toids Video Link Here





This is the reason for the
Inspiration Box here 72X28X17
https://shop.gsgad.com/collections/behind-the-screen-bts-subwoofers


I listen to electronica, house, techno etc.


Thanks for your help

 

[voodooless]

Okay, so with corner subs, 80 Hz is the highest they should go, so no mid-bass needed. 18 Hz from a 30 Hz fs PA woofer is a bit of a stretch, and with a reflex enclosure the ports will be quite long. I think in this case, the Dayton woofers will suit you better. Some simulation should shed some more light on that, though.

 

[stevef22]

Okay, so with corner subs, 80 Hz is the highest they should go, so no mid-bass needed. 18 Hz from a 30 Hz fs PA woofer is a bit of a stretch, and with a reflex enclosure the ports will be quite long. I think in this case, the Dayton woofers will suit you better. Some simulation should shed some more light on that, though.

Thanks for your reply! Pardon my ignorance, buy why should corner placed subs only go up to 80Hz? Im a big fan of strong mid bass. The subs may be moved out into the room as well.

 

[Doodski]

why should corner placed subs only go up to 80Hz?

Because they will sound very boomy and exaggerated.

 

[stevef22]

Because they will sound very boomy and exaggerated.

Ok, Thank you!

 

[voodooless]

Because they will sound very boomy and exaggerated.

Well, that may be helped with EQ. The main reason is actually because you will be able to locate them above 89 or so Hz. If you want to cross higher, they need to be close to the mains.

 

[stevef22]

Well, that may be helped with EQ. The main reason is actually because you will be able to locate them above 89 or so Hz. If you want to cross higher, they need to be close to the mains.

Ok that being said. I will move closer to mains. What speaker do you recommend? Thank you


Polk R700

Frequency Response

38-38k Hz

 

[voodooless]

So, I did some quick sims.. First off, that enclosure you posted is about 500L. That is rather big for these woofers, but it could be made to work if you really wanted. The LaVoce is certainly the most uncomfortable in this arrangement because it will have a low shelf tuning with a little bump in the response. This can be mitigated with EQ for sure, or lower tuning, but that will eat into your power budget a bit.

All in 500L, the red one is the UM in a closed box, and the blue one is reflex (16 Hz tuning). Either works pretty well. The LaVoce is the green one with still impressive bandwidth.

So, when it comes to max output, I modeled the 800W at 4R amp, meaning that the LaVoce only gets about 540W (same voltage):

Here, things are really close for the ported enclosures. Only above 80 or so Hz does the LaVoce give significantly more output. The ported UM had a bit more bandwidth down low and also lower group delay, making it probably sound smoother. But the room will dominate this part, so who knows... This comes more into view if you look at what happens if you have more than 800W available:

Now it's clear that the LaVoce has way more output in the mid-bass. But it also shows the typical reflex droop, which is quite large because of the large difference between fs and enclosure tuning. At 800W though, nothing to worry about. The big advantage of such massive boxes is that for low tuning, you don't even need that long of a port, making it less of an issue with port noises.

At 110 dB at 20 Hz, the closed box version of the UM is still very capable, though. I'm sure the Polk will not keep up with that amount of bass! And that's just a single box

So, this is just one example of what can be done with these particular woofers in that kind of enclosure. There might be way more to explore! If you want some more inspiration, have a look at https://data-bass.com/

 

[Ciobi69]

Try the BMS 18n862 expensive but it’s a killer driver

 

[stevef22]

So, I did some quick sims.. First off, that enclosure you posted is about 500L. That is rather big for these woofers, but it could be made to work if you really wanted. The LaVoce is certainly the most uncomfortable in this arrangement because it will have a low shelf tuning with a little bump in the response. This can be mitigated with EQ for sure, or lower tuning, but that will eat into your power budget a bit.

View attachment 430200

All in 500L, the red one is the UM in a closed box, and the blue one is reflex (16 Hz tuning). Either works pretty well. The LaVoce is the green one with still impressive bandwidth.

So, when it comes to max output, I modeled the 800W at 4R amp, meaning that the LaVoce only gets about 540W (same voltage):
View attachment 430201
Here, things are really close for the ported enclosures. Only above 80 or so Hz does the LaVoce give significantly more output. The ported UM had a bit more bandwidth down low and also lower group delay, making it probably sound smoother. But the room will dominate this part, so who knows... This comes more into view if you look at what happens if you have more than 800W available:
View attachment 430202
Now it's clear that the LaVoce has way more output in the mid-bass. But it also shows the typical reflex droop, which is quite large because of the large difference between fs and enclosure tuning. At 800W though, nothing to worry about. The big advantage of such massive boxes is that for low tuning, you don't even need that long of a port, making it less of an issue with port noises.

At 110 dB at 20 Hz, the closed box version of the UM is still very capable, though. I'm sure the Polk will not keep up with that amount of bass! And that's just a single box

So, this is just one example of what can be done with these particular woofers in that kind of enclosure. There might be way more to explore! If you want some more inspiration, have a look at https://data-bass.com/

Very interesting! "But the room will dominate this part, so who knows... This comes more into view if you look at what happens if you have more than 800W available:" Can you expand on this a little bit?

I like the blue line. Whatever that speaker is. Im sure the LaVoce is the green line.

Apologies for being so new at this. Im learning.

Does this sound crazy to you? The reason I wanted the LaVoce speaker is because I like the way it looks. Meaning, it doesnt have a thick rubber surround like many high excursion speakers do. If you know a speaker that looks like the LaVoce but behaves like high excursion UMII18 that would be the one for me. And also 4Ohm.


Thanks for your help along this journey, you will be proud of me when I post pictures of my build. : ) Very greatfull for your help.

 

[stevef22]

Try the BMS 18n862 expensive but it’s a killer driver

You got to be from out of USA. I cant find it for sale here.

Just the spec page here

Overview

bmsspeakers.com