Crown xli 2500 for dual SI ht-18

[Kevin001]

I was basically gifted a xli 2500 and was wondering, with it being 750x2 @4ohms, if it would be good set-up for a single ht-18 for now and eventually 2. I have read so much conflicting information on using crown amps at ultra low frequencies. This will be my first DIY attempt. I'm coming from some cheap Polk subs. Thanks.

 

[Pogre]

I know @lovinthehd uses crown amps for his subwoofers and really likes them. I haven't diy'd anything yet, but if you use 4 ohm speakers/wiring it should be good. Don't take my word on that part though. There are members more knowledgeable than I who can answer your questions better.

 

[lovinthehd]

Should work fine...what box are you building? These are the original HT18's? D4 or D2?

 

[Kevin001]

Thanks for the replies. I'm looking at ht-18 v2. They appear to be on sale. It looks like they only have the 2 ohm version. The box, for simplicity sake, was gonna be a flat-pack from diysoundgroup.com. They have both a 4.0 sealed and 5.4 ported. Still not sure which one I want yet. It will be in a dedicated theater room.

 

[panteragstk]

FWIW I'm using a Crown XLS 1500 for my subs and it works great.

 

[lovinthehd]

Thanks for the replies. I'm looking at ht-18 v2. They appear to be on sale. It looks like they only have the 2 ohm version. The box, for simplicity sake, was gonna be a flat-pack from diysoundgroup.com. They have both a 4.0 sealed and 5.4 ported. Still not sure which one I want yet. It will be in a dedicated theater room.

I thought that driver was gone already but I do see it there on the site, haven't been paying attention for a while (I used older v.1 D2s and while I have run them bridged for more power I don't need those levels so just run one per channel using XLS1500s). If you're primarily a movie guy and are just going with one to start, I'd go ported for the advantage deeper in the response. How big is the room?

 

[lovinthehd]

Oh, as to the sub-20hz performance for the Crowns there is some conflicting info out there but I wouldn't worry about it, especially with the ported box.

 

[Kevin001]

The room is 23 x 19 dedicated theater room. The ceiling is 12 feet. However, it has 3 rows of risers each. First row at 12" from floor, second 24" from floor and third 36" from floor. There are 4 seats in the 1st and 2nd row only. The room without the risers would be over 4000 cft. I'm guessing at least 30-40% reduction in room volume with the risers as they do go from side wall to side wall.

 

[Kevin001]

The riser is also is completely hollow underneath. I assume this bad for acoustics. It has a trap door on the highest level where I can get under and move around a bit before it tapers off and gets too low.

This room was a addition that was put on house we recently purchased. The room was set-up, as far as I can tell, without much research being done. The first row of seats is too close at 9 feet from the would-be screen wall. The projector cut-out in the ceiling is 10 feet from the wall, wiring for the LCR speakers are terminated 10 feet up on the screen wall and various other things that need to be addressed.

 

[lovinthehd]

Some build risers for their acoustic properties, especially on concrete floors; some even install tactile transducers (aka bass shakers) to the risers themselves for effect. I'd still want at least two subs for the frequency response smoothing possibilities across more seats as well as the volume of the room, tho I can't check your math due lack of dimensions on how much the risers subtract from the room total, when empty, of 5244 cuft. I'd love to play with a dedicated room like yours...but I'd have to build one....mebbe some day.