Reflex or horn?

How would i go about simulating a cabinet like this? Can it be done in HornResp? It houses 2 x 15" and is intended to play 60-250hz.

Thanks in advance :)

Edited by Thomas Hosker - 24 March 2015 at 6:12pm

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Marjan i feel guilty keep asking you to help me!! LOL

Can it be simmed in HornResp? Does the tight V angle not give any horn characteristics? No Gains?

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I built a pair of very similar cabs a fair few years back. The influence of the V baffle is subtle but noticeable. You get a bit of gain in the upper bass region and also a bit of a bandpass effect.

The problem with simulation of them is that the 'horn' is quite small compared with the size of the driver so it doesn't really fit the simplifications that programs that Hornresp use.

The way I see it there are a few main advantages. Firstly the cabinet is much stiffer and there will be less panel and chamber resonances due to the triangulation. The next one is that it effectively combines the output of both drivers into a single, larger radiating area which probably helps couple the drivers to the air in the outside world. The third one is not an acoustic one but just that it reduces the front area of the cabinet so you can stack more in the same space!

That V is too wide to act as a bandpass in the intended usage region.

Marjan Milosevic
MM-Acoustics
www.mm-acoustics.com
https://www.facebook.com/pages/MM-Acoustics/608901282527713

on a v plate reflex, there are small gains but with every gain there is a negative, I have found you all ways get a dip in response, some time out of the playable region, some times in the playable region... changing the degree of the v changes were the dip is.... The dip is normally higher in the frequency range...

https://www.elements-audio.com

You need to consider the compression ratio on the midrange horn. Your design as-is has a ratio of about 3.5:1 (Sd to throat) which is quite high. Higher compression will give higher efficiency, however you need a driver with a very stiff cone and a phase plug to reduce the throat area sufficiently. There is also the risk of introducing distortions due to the high air pressures. Personally I probably wouldn't go higher than 2-2.5:1. You may also need to consider things like path length differences from different parts of the cone to the throat and using a phase plug to equalise them.

Regarding the 2x15", personally I would just simulate as a reflex to get the port tuning and then determine whether the V has any desired or undesired effects with a prototype cab. You are unlikely to to get accurate results from a simulation. I really liked my 2x15" V-baffle cabs. I got the tuning a bit on the high side (nearly 50Hz) so they couldn't really be called subs but they had a really nice kick to them.

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Thomas Hosker Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493	Post Options Post Reply Quote Thomas Hosker Report Post Thanks(0) Quote Reply Topic: Reflex or horn? Posted: 24 March 2015 at 6:11pm
	How would i go about simulating a cabinet like this? Can it be done in HornResp? It houses 2 x 15" and is intended to play 60-250hz. Thanks in advance :) Edited by Thomas Hosker - 24 March 2015 at 6:12pm
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MarjanM Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 10 February 2005 Location: Macedonia Status: Offline Points: 7816	Post Options Post Reply Quote MarjanM Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 6:22pm
	Reflex
	Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713

Thomas Hosker Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493	Post Options Post Reply Quote Thomas Hosker Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 6:31pm
	Marjan i feel guilty keep asking you to help me!! LOL Can it be simmed in HornResp? Does the tight V angle not give any horn characteristics? No Gains?
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mobiele eenheid Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 15 August 2004 Location: Netherlands Status: Offline Points: 1568	Post Options Post Reply Quote mobiele eenheid Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 6:48pm
	It's a port assisted horn, simple as that. Kinda reminds me of this This one (the size of a Cubo 15), will sound good up to 225 Hz. Best regards Edited by mobiele eenheid - 24 March 2015 at 6:51pm

ceharden Members Profile Send Private Message Find Members Posts Add to Buddy List The 10,000 Points Club Joined: 05 June 2005 Location: Southampton Status: Offline Points: 11776	Post Options Post Reply Quote ceharden Report Post Thanks(1) Quote Reply Posted: 24 March 2015 at 7:33pm
	I built a pair of very similar cabs a fair few years back. The influence of the V baffle is subtle but noticeable. You get a bit of gain in the upper bass region and also a bit of a bandpass effect. The problem with simulation of them is that the 'horn' is quite small compared with the size of the driver so it doesn't really fit the simplifications that programs that Hornresp use. The way I see it there are a few main advantages. Firstly the cabinet is much stiffer and there will be less panel and chamber resonances due to the triangulation. The next one is that it effectively combines the output of both drivers into a single, larger radiating area which probably helps couple the drivers to the air in the outside world. The third one is not an acoustic one but just that it reduces the front area of the cabinet so you can stack more in the same space!

Thomas Hosker Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493	Post Options Post Reply Quote Thomas Hosker Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 7:41pm
	Ive got to admit i do like the cubo kick. i heard one a few weeks back with some cubo 18s and it was pretty nice. Cheers Chris, you much help as always. I seem to be on a V-baffle mission at the moment! LOL So im safe to sim in hornresp as a basic conical horn with 2 drivers and ports?
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MarjanM Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 10 February 2005 Location: Macedonia Status: Offline Points: 7816	Post Options Post Reply Quote MarjanM Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 8:29pm
	That V is too wide to act as a bandpass in the intended usage region.
	Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713

MarjanM Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 10 February 2005 Location: Macedonia Status: Offline Points: 7816	Post Options Post Reply Quote MarjanM Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 8:31pm
	Also if you simulate it as a horn, where exactly the horn starts?
	Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713

bee Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 14 June 2011 Location: Middlesex Status: Offline Points: 4553	Post Options Post Reply Quote bee Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 9:01pm
	on a v plate reflex, there are small gains but with every gain there is a negative, I have found you all ways get a dip in response, some time out of the playable region, some times in the playable region... changing the degree of the v changes were the dip is.... The dip is normally higher in the frequency range...
	https://www.elements-audio.com

Thomas Hosker Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493	Post Options Post Reply Quote Thomas Hosker Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 10:59pm
	The throat looks way to small on the 10" horn? Comments..?
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ceharden Members Profile Send Private Message Find Members Posts Add to Buddy List The 10,000 Points Club Joined: 05 June 2005 Location: Southampton Status: Offline Points: 11776	Post Options Post Reply Quote ceharden Report Post Thanks(0) Quote Reply Posted: 24 March 2015 at 11:47pm
	You need to consider the compression ratio on the midrange horn. Your design as-is has a ratio of about 3.5:1 (Sd to throat) which is quite high. Higher compression will give higher efficiency, however you need a driver with a very stiff cone and a phase plug to reduce the throat area sufficiently. There is also the risk of introducing distortions due to the high air pressures. Personally I probably wouldn't go higher than 2-2.5:1. You may also need to consider things like path length differences from different parts of the cone to the throat and using a phase plug to equalise them. Regarding the 2x15", personally I would just simulate as a reflex to get the port tuning and then determine whether the V has any desired or undesired effects with a prototype cab. You are unlikely to to get accurate results from a simulation. I really liked my 2x15" V-baffle cabs. I got the tuning a bit on the high side (nearly 50Hz) so they couldn't really be called subs but they had a really nice kick to them.

Thomas Hosker Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493	Post Options Post Reply Quote Thomas Hosker Report Post Thanks(0) Quote Reply Posted: 25 March 2015 at 7:20pm
	What area would you recommend i start with Chris? Around 200cm2? I was intending to do a phase ring and bung. I guess horn resp was just to give me a rough idea what to expect and a starting point. Ill run with what ive got on the 2 x 15" and just tweak the ports in WinISD.
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