The tiny sub, big bass paradox

[h3idrun]

Hey guys, 

After joining this forum yesterday to thank Rikki for the Skram plans I built this time last year I'm very happy to see its pretty active still, so I thought I'd throw my next project into the mix. 

The goal: a portable sub to go with my small monitors that live in my car and get pulled out while camping, at the beach or on job sites.

The restrictions: small size, low power (I know, bass needs to be big, this is an issue haha)

The gear: Currently the monitors have 2x CDT 6.5" coaxials per side in a sealed box, these will be upgraded eventually but sound fine for my current needs. They run from the head unit in my Prius, I have speakon connectors in my glovebox to extend them beyond the car.

I have 6x Exodus Anarchy (4x 4ohm and 2x 8ohm), also a peerless XXLS 10, would prefer not to buy new drivers. 

My Prius has the back seats removed and a flat platform built to carry my tools or camping gear or whatever so the only free space is where the centre console should be, or the rear seat footwells (which is where the monitors currently live)

I would love to run the sub off the remaining 2 head unit channels but I also have a few small 2 channel amps laying around if I really need more power. 

Volume doesn't need to be crazy, it's usually not much over conversation volume but a little headroom would be nice, I usually listen to bass music so lows are important, deep dubstep, dnb, sometimes psy trance or Techno etc. 

Am I crazy? Is it even possible? Who knows 🤷‍♂️

[h3idrun]

This is the space I have to work with, il get measurements when I'm home in a few days, I don't currently have the car with me

[SME]

I don't know if the size and/or dimensions work, but this looks like the design you want:

https://www.avsforum.com/threads/reed-exodus-anarchy-25hz-tapped-horn.1238398/

Edit to add: A caveat is that it requires a high-order (DSP) crossover.  You really need the crossover to cut the output above 80-100 Hz or else it won't sound very good.

[h3idrun]

1 hour ago, SME said:

I don't know if the size and/or dimensions work, but this looks like the design you want:

https://www.avsforum.com/threads/reed-exodus-anarchy-25hz-tapped-horn.1238398/

Edit to add: A caveat is that it requires a high-order (DSP) crossover.  You really need the crossover to cut the output above 80-100 Hz or else it won't sound very good.

Sounds perfect from the title! Il have a read tonight

I have an Alpine CDA9887 head unit so should be able to manage a reasonable crossover on that

[klipsch]

I have had 2 of these for about 8 years now. I drive them with a used emotiva small 2 channel amp. 

The cabinets are not small in height or depth, but the width is very manageable.

They produce excellent quality bass at SPL levels that  are more than enough for the 13'x15'x9' small office they are in. 

[h3idrun]

After much deliberation and reading many threads I'm starting to think that rebuilding the 2 monitors to include better low end extension is a better idea than a separate sub.

Even that tapped horn design is too big to fit in the car as well as the 2 monitors unfortunately, but if I have 2 larger boxes rather than 3 smaller ones it might package nicer.

Next step is to do some modelling and figure out what alignment to do, sealed, ported, bandpass? 1 or 2x anarchy per box? Etc etc

[Ukko Kari]

Before adding a subwoofer, if you add baffle size with foldable / detachable wings and top / bottom panels you will increase forward directivity which is useful. Of course, this comes with the caveat that it will make the monitors heavier, not to mention easier to tip over if the wind whips up. This moves the baffle step frequency lower, and may require a bit of tailoring with eq. Wings could be made from dollar store / craft store foam poster boards or 1" xps foam board, assuming you do some rudimentary bracing.

Considering you are using a car for transport and are short on space a pair of larger boxes instead of 3+ boxes may make more sense. Perhaps a pair of decent commercial passive speakers like the Behringer B215XL. Cheap, relatively robust.

https://www.musiciansfriend.com/pro-audio/behringer-b215xl-15-1000w-passive-pa-speaker/580026000000000?rNtt=passive speaker&index=2

 

[h3idrun]

On 1/3/2021 at 3:44 PM, Ukko Kari said:

Before adding a subwoofer, if you add baffle size with foldable / detachable wings and top / bottom panels you will increase forward directivity which is useful. Of course, this comes with the caveat that it will make the monitors heavier, not to mention easier to tip over if the wind whips up. This moves the baffle step frequency lower, and may require a bit of tailoring with eq. Wings could be made from dollar store / craft store foam poster boards or 1" xps foam board, assuming you do some rudimentary bracing.

Considering you are using a car for transport and are short on space a pair of larger boxes instead of 3+ boxes may make more sense. Perhaps a pair of decent commercial passive speakers like the Behringer B215XL. Cheap, relatively robust.

https://www.musiciansfriend.com/pro-audio/behringer-b215xl-15-1000w-passive-pa-speaker/580026000000000?rNtt=passive speaker&index=2

 

I have a few Martin Audio W3 passive 15s that I could use if I want to go that loud. This system is aimed at smaller speakers, for quieter/closer listening with more emphasis on low end extension.

I will experiment with larger folding baffles though, thanks!