[lacro]

Hey Danny,
 Would a single 8" servo sub work in a sealed box (.7 CU FT) to pair with XLS Encores in a small room arrangement. Any amp issues with a single 16 ohm woofer.

Larry

[Danny Richie]

Hey Danny,
 Would a single 8" servo sub work in a sealed box (.7 CU FT) to pair with XLS Encores in a small room arrangement. Any amp issues with a single 16 ohm woofer.

Larry

Hey Larry,

Brian had a lower Q version of the 8" servo subs made just for a sealed box. Each woofer only needs .35 cubic feet. He has them in 4 ohm and 8 ohm for running a single woofer or dual woofers on one amp. As soon as the new amps are available we will begin advertising them.

[cody69]

As soon as the new amps are available we will begin advertising them.

Danny, what is the ETA on these amps?

[cody69]

Danny, I have a need for a couple of small subs. When are you expecting the amps to be available?

[Danny Richie]

Danny, I have a need for a couple of small subs. When are you expecting the amps to be available?

I just spoke with Brian about the amps for the 8's. There were some QC issues that Brian is having them iron out that as delayed production. Brian is pretty big on making these amp bullet proof before sending them out in the field and failure rates of his amps are very low. I can appreciate the high level of quality and attention to detail, but like everyone else, I must patiently wait...

It is now looking like it will be near the end of February before I have those new amps available for the 8's. 

[cody69]

Completely understand, launching a new product has to be done right and not cut corners on QC -- that's what helps keep us loyal.

So there's some time to start planning the build. Will you have plans for these? A cube 10.5" (outside) gives the .35 cu.ft. mentioned above,
but I've heard mention cubes are typically not desirable for speaker enclosures. Also, for a sub this size, what kind of bracing will be needed.
I've made several of your "classics" and servo subs and am familiar with how those are braced.

[Danny Richie]

With a sealed box sub it really doesn't matter too much what the shape is.

I can see the 8's being used as lower woofers in a three way design more than just a stand alone sub. But it could be used that way for a small room set up.

The 12's only need 1.5 cubic feet of air space. So they aren't very big either. And they will not only play down to the rock bottom, but will also hit some pretty solid SPL levels.

[WC]

With a sealed box sub it really doesn't matter too much what the shape is.

I can see the 8's being used as lower woofers in a three way design more than just a stand alone sub. But it could be used that way for a small room set up.

The 12's only need 1.5 cubic feet of air space. So they aren't very big either. And they will not only play down to the rock bottom, but will also hit some pretty solid SPL levels.

Is there a certain minimum depth that the driver needs? I was thinking of using them as subs/helper woofers under a full range driver. The full range driver would be in a ported cabinet over the sub. Could you run two sealed 8" subs off of one amp? I realize that it is preferable to have 1 or 2 drivers running off each amp so you could have it in stereo, but the amps are not inexpensive.

[Danny Richie]

Mounting depth is 5". And that sounds like a good idea putting them under a full range driver. 

There is a sealed box version of our new 8" servo sub that Rythmik has in stock. They just haven't released them yet because the new amps are not in stock yet. They have a 4 ohm and an 8 ohm version. And the 8 ohm version is for using a pair f them on one amp. They also only need .35 cubic feet of air space each. 

[sl_1800]

I will be getting a couple of these for my bedroom system!!!   

[WC]

Mounting depth is 5". And that sounds like a good idea putting them under a full range driver. 

There is a sealed box version of our new 8" servo sub that Rythmik has in stock. They just haven't released them yet because the new amps are not in stock yet. They have a 4 ohm and an 8 ohm version. And the 8 ohm version is for using a pair f them on one amp. They also only need .35 cubic feet of air space each. 

Does more volume in the sealed sub hurt anything. Is there a maximum baffle size that the 8" drivers shouldn't exceed?

[sl_1800]

"Does more volume in the sealed sub hurt anything. Is there a maximum baffle size that the 8" drivers shouldn't exceed?"

Yes it's important for the volume of a sealed sub to match the manufactures specs.  As for the baffle size it's not that important for a subwoofer.

[WC]

"Does more volume in the sealed sub hurt anything. Is there a maximum baffle size that the 8" drivers shouldn't exceed?"

Yes it's important for the volume of a sealed sub to match the manufactures specs.  As for the baffle size it's not that important for a subwoofer.

On the larger sealed servo subs, there is an acceptable range. I was thinking of making the sub a stand for a fullrange driver, so I may have more than 0.35 cu. ft. These 8" drivers will probably be crossed over high enough that you would be able to determine the location, so they would be acting as less than 80Hz subs. I would think in this case baffle size would matter.

[Danny Richie]

Below 200Hz or so the baffle size (within reason) will have little effect as that range is very omni directional. The wavelengths are also too long to react to surface reflections very much either.

[WC]

Danny,

Based on what you said in the full range thread, does it make any sense to build a combo with a full range driver in a ported upper chamber and a single 8" servo in a sealed box beneath it. If they were built as one unit you would still have the resonances, right? There also could be an issue with the difference in baffle widths between the full range compartment and the sub? May just be better to make it as a sub sat combo where each stereo sub sits next to the sat. In either case I would install a HP filter on the full range driver and send a full range signal to the sub for the sub crossover to set the full range signal.  I am guessing my crossover would be between 100 and 150 Hz.

Are the sub amps for the 8" drivers going to be priced the same as the larger amps?

[Danny Richie]

Based on what you said in the full range thread, does it make any sense to build a combo with a full range driver in a ported upper chamber and a single 8" servo in a sealed box beneath it. If

If you are in a small room and limited to how far you can pull them out into the room, then such a design would be a consideration.

they were built as one unit you would still have the resonances, right?

You have to deal with panel resonances whether they are separate individual boxes or in separated common boxes.

There also could be an issue with the difference in baffle widths between the full range compartment and the sub?

Yes and no. Baffle width has little effect on the sub. However wide baffles are to be avoided for ranges above 200Hz or so.

May just be better to make it as a sub sat combo where each stereo sub sits next to the sat. In either case I would install a HP filter on the full range driver and send a full range signal to the sub for the sub crossover to set the full range signal.  I am guessing my crossover would be between 100 and 150 Hz.

HAL is working on a design that will allow the customer to use any full range driver they want. It is then supplemented with or 8" servo subs. I am sure you have seen the thread. 

Are the sub amps for the 8" drivers going to be priced the same as the larger amps?

The amps for the 8" woofers are smaller amps and we are going to try to keep them under $300 a piece.

[WC]

If you are in a small room and limited to how far you can pull them out into the room, then such a design would be a consideration.

You have to deal with panel resonances whether they are separate individual boxes or in separated common boxes.

Yes and no. Baffle width has little effect on the sub. However wide baffles are to be avoided for ranges above 200Hz or so.

HAL is working on a design that will allow the customer to use any full range driver they want. It is then supplemented with or 8" servo subs. I am sure you have seen the thread. 

The amps for the 8" woofers are smaller amps and we are going to try to keep them under $300 a piece.

The room is 20' x 16' x 8' ceilings. Speakers are 6' apart and the main seating is 6' from the speakers. The speakers sit on a 12" high fireplace mantle. So OB would be difficult to accomplish.

The ones HAL is working on are OB. Can it be used for sealed boxes also?

Could the bottom sub portion be triangular shaped or would the sub driver like an even width?

[Danny Richie]

The room is 20' x 16' x 8' ceilings. Speakers are 6' apart and the main seating is 6' from the speakers. The speakers sit on a 12" high fireplace mantle. So OB would be difficult to accomplish.

Yeah, that is not good placement, and rules out OB designs.

The ones HAL is working on are OB. Can it be used for sealed boxes also?

The same thing can be done in a sealed box and just using two of the 8 ohm *' servo woofers below. 

Could the bottom sub portion be triangular shaped or would the sub driver like an even width?

With them being sealed boxes you can make them just about any shape that you want.

[WC]

Yeah, that is not good placement, and rules out OB designs.

The same thing can be done in a sealed box and just using two of the 8 ohm *' servo woofers below. 

With them being sealed boxes you can make them just about any shape that you want.

Is there a benefit to using two vs one 8" servo driver/drivers in a sealed box other than SPL?

[Danny Richie]

Is there a benefit to using two vs one 8" servo driver/drivers in a sealed box other than SPL?

Two drivers sharing the load means each works half as hard to hit the same SPL levels. So less movement is required, less stored energy, less distortion from any cone flexing, etc. Cleaner sound...