How long does this port need to be?

[cameron paterson]

So I got my amp yesterday and these things are insane directly behind your couch. I can feel extreme amounts of chest slam and raw bass! I am very happy with these. I have them playing 45hz to 200hz. Voices are more profound as well but not boomy. I had a question... if I ordered 2 more of these and used them on their sides for stands for my 1099's, up front, and keep the 2 I have now behind my couches is it going to ruin the sound because they're so far apart? Thanks for your help TLS Guy! They sound awesome!

 

[TLS Guy]

Glad it worked out. I doubt it will ruin the sound at those frequencies and might smooth the room response.

 

[cameron paterson]

Thanks! Cool I will probably try a couple more in the near future!

 

[Eng-399]

The sub your using was launched at my GTG meet that was posted in Avsforum. Matt mtg90 designed that box for and Erich had a cnc company make the cuts so he could sell the flat pack. I use the DatsV2 to prove the tune of box after running the numbers through winisd. I have two of these drivers like but I built a custom box to fit my space for mbm In Our family room. That box is not tuned for 63 hz or what was posted. Run the dats on it. Here’s the original box at my house that Erich sells before DIYSG even sold them.

Shadyj was at my gtg to that writes for this forum and heard them that day to.


Sent from my iPhone using Tapatalk

 

[TLS Guy]

The sub your using was launched at my GTG meet that was posted in Avsforum. Matt mtg90 designed that box for and Erich had a cnc company make the cuts so he could sell the flat pack. I use the DatsV2 to prove the tune of box after running the numbers through winisd. I have two of these drivers like but I built a custom box to fit my space for mbm In Our family room. That box is not tuned for 63 hz or what was posted. Run the dats on it. Here’s the original box at my house that Erich sells before DIYSG even sold them.

Shadyj was at my gtg to that writes for this forum and heard them that day to.


Sent from my iPhone using Tapatalk

It was not tuned to 63 Hz. Read the post. It was however optimally tuned for the cabinet and driver.

 

[cameron paterson]

So where is the opitmal tuning? Where you had me do a 7.3 inch port for my boxes? Where is mine tuned at?

 

[TLS Guy]

So where is the opitmal tuning? Where you had me do a 7.3 inch port for my boxes? Where is mine tuned at?

So go to post 11 and open up the pdf. of your sub model. Now near the top you will see Fb. That is the box tuning frequency. As stated before that number is NOT how low the sub plays. If you look at the impedance curve, you will see the answer to your question as well. The tuning frequency is indicated by the null between the two peaks of impedance. That is right at 38 Hz. Now look at F3 which is the 3 db down point.

Now look at the first response graph and see where F6 is. You will see there is good output maintained to the mid forties. In fact the 6 db point is right on 45 Hz.

Because the driver is low Q it allows for an extended bass alignment, where the initial response fall off is a little less steep than usual.

This is what you wanted and optimal for your driver. This driver is a good driver, but is highly sensitive and therefore will not play really low. But you wanted a so called mid sub and that is what you got. One that is ideal to cross in the mid forties. So that is where the 6 db down point is and should be for your application.

By your post 41 it sounds as if it delivered as advertised and then some.

 

[cameron paterson]

Thanks TLSGuy! It all makes sense now! And I lowered my lpf to 120hz. Integrates with my sub and fronts much better now! Cant believe the kick in the chest with ac/dc and def leppard or any other rock/metal! Is 50hz a good subsonic filter for these guys? Or should I try 55hz?

 

[TLS Guy]

Thanks TLSGuy! It all makes sense now! And I lowered my lpf to 120hz. Integrates with my sub and fronts much better now! Cant believe the kick in the chest with ac/dc and def leppard or any other rock/metal! Is 50hz a good subsonic filter for these guys? Or should I try 55hz?

Glad you are happy. I don't think they need a subsonic filter. I think 120 Hz is fine for the top and. Then set the high pass between these mid bass units and your sub at 45 HZ LR second order, and the low pass to your sub at 45 Hz LR fourth order, that should give you a very good transition.

Those mid bass units will be 18 db down by 22.5 Hz so no need for a subsonic filter.

 

[cameron paterson]

Ok I will tinker with everything you said and see what I like the best. Thank you.