# Can I easily swap out the plate amp on my Infinity Entra?



## PRAYER (Jun 18, 2011)

I just bought an Infinity Entra, everything except the amp.

I was looking at PE plate amps like the BASH 300W model, and I was thinking that I could simply get a peice of metal machined to account for BASH's smaller plate size ( the Entra has a 12 1/2 by 6 1/2 opening).

Besides cabinet volume differences, will I have any trouble with this?


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## tesseract (Aug 9, 2010)

In a ported alignment, the driver is unloaded below the port tune. Without a high pass filter you may reach driver xmech, risking damage. I would call PE and ask if the BASH 300W has an internal High Pass Filter. If not, have them recommend a suitable amp with a HPF.


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## Mike P. (Apr 6, 2007)

The Bash 300 has a default HPF at 17.7 hz. It can be changed by soldering in 2 different resistors. The frequency response of the Entra subwoofer is 34-150 Hz. The Bash 300 HPF can be changed to 31.6 hz and it would have 2 db of boost in the 36 - 40 hz range. The resistor values are here:

http://www.parts-express.com/pdf/300-750.pdf

You can do the modification yourself or if you buy the amp from Creative Sound Soutions they will do it for you fro $15.

http://creativesound.ca/details.php?model=BASH300


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## tesseract (Aug 9, 2010)

Good info, Mike. :T


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## PRAYER (Jun 18, 2011)

Mike P. said:


> The Bash 300 has a default HPF at 17.7 hz. It can be changed by soldering in 2 different resistors. The frequency response of the Entra subwoofer is 34-150 Hz. The Bash 300 HPF can be changed to 31.6 hz and it would have 2 db of boost in the 36 - 40 hz range. The resistor values are here:
> 
> http://www.parts-express.com/pdf/300-750.pdf
> 
> ...



Thanks for the information!
So is this mod a necessity mainly to accommodate the port on the Infinity? I am totally cool with soldering them in, just wondering.

And I guess thats that huh? just that mod and I should be good to resume operation as normal?

I do appreciate the help!

Bill


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## Mike P. (Apr 6, 2007)

The mod is port related, it's a necessity to protect the driver from over excursion below the tuning frequency. What isn't known about the Entra is if the driver is 4 or 8 ohm. If it's 8 ohm the Bash 300 will match the power output of the original amp. If it's 4 ohm you'll have more power than what you need, be careful not to over drive the sub. 

I'm assuming you have the Entra Sub One and not the Entra Sub Two.


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## PRAYER (Jun 18, 2011)

actually I believe it is the Entra sub two... but now I am not sure.

I'll post a pic tomorrow but I do think I'll need help identifying it because I cant find any photos of this exact model online.

It looks like the Entra two except it is beige colors, has a fader on the front of the cabinet, and has larger feet.

Sound familier anyone? 

Anyhow, I believe that it is most definitely a 4 ohm speaker.

I'll be ordering the amp as soon as I get more info and my plan is to take off the BASH plate, and have a custom plate machined to fit the infinity box.


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## PRAYER (Jun 18, 2011)

actually, the subwoofer is an Infinity modulus.

Guess it was part of a satellite system; but the thing is heavy enough that I'm sure it will serve great as part of my full range array..


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## Mike P. (Apr 6, 2007)

Since the sub is a Modulus then the appropriate HPF would 28.9.


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## PRAYER (Jun 18, 2011)

Mike P. said:


> Since the sub is a Modulus then the appropriate HPF would 28.9.


Unfortunately that store doesnt ship to the US.. 

Any idea where I could get the resistors done elsewhere (the chart in that PDF is a little confusing. I can solder but I'm still not too great at electronics)

Thanks a ton Mike


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## DiscoDuck (Jan 11, 2012)

I too have the same subwoofer with a blown amp. I plugged the amp hole with mdf and installed a binding post. I now power it with a component amp.


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## PRAYER (Jun 18, 2011)

DiscoDuck said:


> I too have the same subwoofer with a blown amp. I plugged the amp hole with mdf and installed a binding post. I now power it with a component amp.


Interesting.. did you account for the gain of volume inside the box in any way? 

.. secondly... any chance you would sell me your dead plate?


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## DiscoDuck (Jan 11, 2012)

I will check and see if i still have the plate amp intact. My son likes to take apart electronics. I have acquired a few "blown" subs from local classified ads and then power them externally. I will check on it.


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## DiscoDuck (Jan 11, 2012)

I didn't worry about the change in volume but I could add some insulation inside which might offset the difference


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## tesseract (Aug 9, 2010)

The back wave has to weave around the fibers, adding insulation actually "fools" the speaker into thinking the box is larger. A straight line is the shortest distance!


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## PRAYER (Jun 18, 2011)

tesseract said:


> The back wave has to weave around the fibers, adding insulation actually "fools" the speaker into thinking the box is larger. A straight line is the shortest distance!


So instead of insulation you should actually just fill some space right? Making the box smaller?



> I will check and see if i still have the plate amp intact. My son likes to take apart electronics. I have acquired a few "blown" subs from local classified ads and then power them externally. I will check on it.
> 
> Read more: Home Theater Forum and Systems - HomeTheaterShack.com - Reply to Topic


If you have *at least* the outer plate, I would love to use that as a template to custom fit a new plate onto the BASH 300's electronics.
(also I actually don't have the Entra as stated in the beginning of thread, it is actually an Infinity Modulus II)

thanks folks!


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## tesseract (Aug 9, 2010)

PRAYER said:


> So instead of insulation you should actually just fill some space right? Making the box smaller?


This is correct. You would want to add the same amount taken out.


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## DiscoDuck (Jan 11, 2012)

I looked in my pile of plate amps and I guess I bought the entra sub without the amp. I don't know what volume would have been there. I got it for $20 without the amp and connected it to a 600 watt component amp and thought it sounded pretty good. What is the approximate volume of the amp you have?


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