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First questions. Has anyone ever tried removing the passive radiators and sealing the back of Forte II's?

 

Second question. Should I buy ALK Engineering Crossovers or Bob Crites Crossovers for my Forte II's?   

forte (2).JPG

Forte side (2).JPG

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First questions. Has anyone ever tried removing the passive radiators and sealing the back of Forte II's?

 

Don't do it is my advice.

 

Second question. Should I buy ALK Engineering Crossovers or Bob Crites Crossovers for my Forte II's?   

 

ALK

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My question is, are those the factory woofers?  I don't remember them being "shiny" and reflective.

 

#1   Leave the passive in.

 

#2   Personal choice.  I've never bought from either, actually.  Built my own from scratch or updated with other brands of parts.

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Under no circumstances should you remove the passive. You will loose low frequency extension. 

 

My opinion is that swapping out crossovers (from the factory prion/design), typically yields small differences in sound quality. There are a number of other things that will yield bigger benefits. With the high cost of some of the crossovers, the decision is usually simple. 

 

Good luck,

-Tom

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If you really want to take out the passives, you would need to replace them with ports, like the Forte. Placement closer to the wall is probably better with the passive.

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On 7/30/2019 at 11:12 AM, yesmynameisking said:

First questions. Has anyone ever tried removing the passive radiators and sealing the back of Forte II's?

 

Second question. Should I buy ALK Engineering Crossovers or Bob Crites Crossovers for my Forte II's?   

 

 

Don't do anything for a while.  I am not trying to insult, but if you think that you need to remove the passive radiators, please become more familiar with the speakers before making any changes. 

 

At the end of the day, at the Forte's price point, you will likely just want to replace the capacitors if needed. There are some other easy mods, like Crites diaphragms, but use the speakers and learn about them first. 

 

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There is no reason why you should not remove the passive radiators and cap the opening air tight. I would suggest that you heavily stuff the cabinets with top quality damping material. You will loose some bass level at the old tuning point but you will obtain a roll off that is half that of the vented roll off so your bass level will actually extend farther than the vented system provides. You can play with damping material and quantity. Make sure the cabinets are air tight and make sure you seal off the holes drilled for the grill mounting fixtures on the inside with some sealant. You can always remove any damping material and re install the passives with zero harm done and much experience learned. Do keep us posted on your findings.

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I can't believe what I am reading.

If porting the cabinets was a good idea, then it would have been done at the factory (ports are cheaper than drones). 

Dampening the interior will only take you so far. Do the modeling! Not all drivers work well in sealed cabinets. Please do some design work before you start trashing the cabinets. 

Good luck, 

-Tom

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16 minutes ago, PrestonTom said:

I can't believe what I am reading.

If porting the cabinets was a good idea, then it would have been done at the factory (ports are cheaper than drones).  

 

If you do a search, you might find the posts where someone took out the passive and replaced the hole with a piece of wood with ports.

 

The Chorus line (see what I did there?), changed from ports to passives as well as the Forte series. Each has its advantages, they both accomplish the tuning. It is not such a crazy idea.

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2 hours ago, PrestonTom said:

I can't believe what I am reading.

If porting the cabinets was a good idea, then it would have been done at the factory (ports are cheaper than drones). 

Dampening the interior will only take you so far. Do the modeling! Not all drivers work well in sealed cabinets. Please do some design work before you start trashing the cabinets. 

Good luck, 

-Tom

Tom the public perception of a vent or two compared to a passive is this, they both do the same thing but most people do not know this but the public see the passive as an additional woofer in the system so they see greater value in the passive as compared to the vent(s). It is really that simple putting aside the fact that you can place a rear mounted passive physically closer to the front wall than you can a vent(s) but again most do not know this. So in the end it comes down to perceived value. A properly tuned vent will just about match up to a properly tuned and sized passive though the passive will have a small advantage in overall distortion due to reduced turbulence but most folks are not going to be aware of that so I think it is more than reasonable to consider a vent and a passive identical for such discussions as this.

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21 minutes ago, Marvel said:

The Chorus line (see what I did there?), changed from ports to passives as well as the Forte series. Each has its advantages, they both accomplish the tuning. It is not such a crazy idea.

 

forte always had a rear passive.  12" in the original, 15" in the IIs.

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44 minutes ago, moray james said:

... I think it is more than reasonable to consider a vent and a passive identical for such discussions as this.

 

Agreed.  Actually, with everything you'd said.

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I would like to say I was just testing you, but you are correct.

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The reason for the passive is that the cabinet is too small for being able to get low frequency extension,  supplemental output from ports that are large enough based on that cabinet volume.  Passives let you cheat in ways to get better extension.

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Reflex loading be it via vent or passive provides a load to the driver at the low frequency system resonant point but remember that load is only very narrow in bandwidth 5-6 Hz. wide at most and then it is gone away fast with response of the system dropping at 24 db per octave. With a sealed cabinet the load is very broad and the response rolls off at 12 db per octave. Further with a sealed design you will have a very hard time over driving the woofer if the design is well implemented.

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Yes, the drop off is not as steep with a sealed cabinet (and you can exploit this with some corner loading if you place the cabinet accordingly). However the 3 dB down point with a ported cabinet (or passive drone) can be about 1/3 octave lower in frequency. So yes, there are tradeoffs and we agree on that.

 

If they went to the effort of using a drone, I assume they were having a problem getting the ports large enough or they were picking up some port noises (chuffing). By all means work out the numbers, but you will probably find out the "sealed version" has a cabinet that is too large (perhaps some over done bass) and it does not go as low. It may also be the case that the OP simply does not like the "klipsch sound". That is okay also, but a different system might make more sense than messing up the Forte cabinet. 

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Tom we are talking about different ways to skin a cat here. You may recall the Chorus and the very short vents required to tune that not all that far away from the tuning of Forte. Physical room for the vents required nor chuffing were likely the concern in the Forte when the decission to use a passive was chosen. Vents can actually be more easily be placed on the front baffle (compared to passives) to permit close placement to the front wall. I agree that venting can be a big boost to bass extension and output you can even dial in a hump just prior to roll off if the woofer has the physical travel capability to manage the throw required but then it goes away fast below that frequency and the woofer is left unloaded and susceptible to over excursion and or voice coil damage from over heating. All compromises. Don't forget that a fully stuffed sealed cabinet will pick up an apparent volume of about 25%. As I suggested if the op wants to experiment he is in no way going to damage the Forte and he can put it back the way he found it if he wants to.

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On 7/31/2019 at 3:14 PM, tigerwoodKhorns said:

 

Don't do anything for a while.  I am not trying to insult, but if you think that you need to remove the passive radiators, please become more familiar with the speakers before making any changes. 

 

At the end of the day, at the Forte's price point, you will likely just want to replace the capacitors if needed. There are some other easy mods, like Crites diaphragms, but use the speakers and learn about them first. 

 

 

21 hours ago, moray james said:

There is no reason why you should not remove the passive radiators and cap the opening air tight. I would suggest that you heavily stuff the cabinets with top quality damping material. You will loose some bass level at the old tuning point but you will obtain a roll off that is half that of the vented roll off so your bass level will actually extend farther than the vented system provides. You can play with damping material and quantity. Make sure the cabinets are air tight and make sure you seal off the holes drilled for the grill mounting fixtures on the inside with some sealant. You can always remove any damping material and re install the passives with zero harm done and much experience learned. Do keep us posted on your findings.

 

Looks like I screwed this one up!  😲

 

I would have not guessed that taking the passive or ports out would help. 

 

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9 minutes ago, tigerwoodKhorns said:

I would have not guessed that taking the passive or ports out would help. 

 

 

I like the Klipsch designs and engineering... 👍

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