Switching From 8's to 10's

[Bobbytwonames 5,000+ posts]

I'm going to switch out my 4 VFL 8's to 4 VFL 10's in the same box. How much will my peak frequency change? My peak frequency is 31 hz. right now with the 8's. I will also be changing amps. I'm going to take out the 3,500 watt smp and put in a 5K amp. My box is 3.9 cubes net tuned to 33 hz. That will be tight for 4 tens.

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[ThxOne Premium Member]

That's less than a cube per sub. 2.5" VC... I think near 50hz.

 

[Bobbytwonames 5,000+ posts]

That's less than a cube per sub. 2.5" VC... I think near 50hz.

I'm thinking about 35 - 37 hz. max.

 

[ThxOne Premium Member]

I'm thinking about 35 - 37 hz. max.

What is the optimal airspace for the 10's?

 

[Bobbytwonames 5,000+ posts]

That's less than a cube per sub. 2.5" VC... I think near 50hz.

My 8's have a 2 - ½" voice coil. I was thinking of switching to 4 - AB HD 10's. 3" voice coils and 300 ounce motors. What do you think?

 

[ThxOne Premium Member]

My 8's have a 2 - ½" voice coil. I was thinking of switching to 4 - AB HD 10's. 3" voice coils and 300 ounce motors. What do you think?

I don't know... less than a cube per sub and a lot of port area. Maybe 3 10's?

 

[Bobbytwonames 5,000+ posts]

I don't know... less than a cube per sub and a lot of port area. Maybe 3 10's?

It's not worth changing to 3 - 10's. The 17% increase in cone area isn't really worth it. I want to compete at 150 db in the cab. I want 4 - 10's on a 5K. I'm running 4 - 8's on 3.500.

 

[ThxOne Premium Member]

It's not worth changing to 3 - 10's. The 17% increase in cone area isn't really worth it. I want to compete at 150 db in the cab. I want 4 - 10's on a 5K. I'm running 4 - 8's on 3.500.

Slapping 4 - 10's in there is going to add the physical mass of the subs to the enclosure greatly reducing airspace... I think the tuning is going to go way up. You say 33hz now... reduced space, more moving mass. I say your 33hz tune jumps to near 40hz with a weird peak near 50hz.

 

[Bobbytwonames 5,000+ posts]

Slapping 4 - 10's in there is going to add the physical mass of the subs to the enclosure greatly reducing airspace... I think the tuning is going to go way up. You say 33hz now... reduced space, more moving mass. I say your 33hz tune jumps to near 40hz with a weird peak near 50hz.

My peak meter is 31 hz. right now. The displacement of the subs will probably change the net of the box from 3.9 net to 3.7 net. That would leave .925 cubes for each 10. I think that is doable with high power (5K).

 

[ThxOne Premium Member]

My peak meter is 31 hz. right now. The displacement of the subs will probably change the net of the box from 3.9 net to 3.7 net. That would leave .925 cubes for each 10. I think that is doable with high power (5K).

Only one way to find out... pull the trigger. <--- see what I did there. I am curious how it would change your output.

 

[Bobbytwonames 5,000+ posts]

Slapping 4 - 10's in there is going to add the physical mass of the subs to the enclosure greatly reducing airspace... I think the tuning is going to go way up. You say 33hz now... reduced space, more moving mass. I say your 33hz tune jumps to near 40hz with a weird peak near 50hz.

I'm going to up the power to a 5K. It's currently a 3.5K.

 

[Bobbytwonames 5,000+ posts]

Only one way to find out... pull the trigger. <--- see what I did there. I am curious how it would change your output.

Will be done. Chasing 150.

 

[some dude]

The box looks huge to me. Like way bigger than 3.9 cubes.
What are it's dimensions?

 

[hispls 5,000+ posts]

The box looks huge to me. Like way bigger than 3.9 cubes.
What are it's dimensions?

I expect it is 3.9 and will be a little less with the larger subs. It's very narrow and the port probably displaces a fair bit how lot he has it tuned.

Really no way to guess how the peak frequency will change, have you modeled the 4 subs in that airspace and tuning? What does box software predict?

 

[Bobbytwonames 5,000+ posts]

The box looks huge to me. Like way bigger than 3.9 cubes.
What are it's dimensions?

53-½" L x 7" top 11" bottom W x 24" H wedge box. The notch is 9" L x 2" W x 24" H. The port is 3-½" wide at the top and 5-¼" at the bottom and 10" tall. The length of the port is 22-¼". I did some math and it's 5.69 cubes before port and sub displacement. The box is made with ¾" MDF.