16 replies to this topic

[turdburst]

So I have been playing around with the idea of building a HT subwoofer. I have my old Brahma sitting around that needs a recone. It's currently a 12" but I can get a 15" basket and recone kit from Fi for like 130-150 depending on what options I take.

I just brought home a QSC ISA280 amplifier to try out on the sealed 15" Alpine Type R (getting to that tonight, tomorrow or this weekend) It will be wired to 8 ohms for about 600 watts.

So what I was thinking though was to get the ISA280s bigger brother, the ISA450, and bridge it into a 4 ohm load for about 1400 watts! So since I was probably going to go with the 15" I was thinking sealed. Then I'd have a little better power handling (not that I'm worried about blowing it) and the fact that it'd be a little easier to design to build the enclosure. But then I got to thinking and I remembered that I have 2 15" Acoustic Elegance Passive Radiators and thought that could make for an interesting build.

http://aespeakers.co...&products_id=40

I have talked about using these before but obviously never have. Anyone think these would pair nicely with the Brahma and power amp?

Another thing I was thinking too was that I could get a Crown CDi1000 for a little more money and that has built in DSP so if I need to do any low end EQing, that could be accomplished with the build in DSP and cover me in the future for when I get a set of mains that are worthy of their own amplifier.

Any more suggestions or comments, or even criticism would be great!

Thanks again.

Turd Burst

[alan monro]

todd.brust, on 29 August 2011 - 08:22 PM, said:

So I have been playing around with the idea of building a HT subwoofer. I have my old Brahma sitting around that needs a recone. It's currently a 12" but I can get a 15" basket and recone kit from Fi for like 130-150 depending on what options I take.

I just brought home a QSC ISA280 amplifier to try out on the sealed 15" Alpine Type R (getting to that tonight, tomorrow or this weekend) It will be wired to 8 ohms for about 600 watts.

So what I was thinking though was to get the ISA280s bigger brother, the ISA450, and bridge it into a 4 ohm load for about 1400 watts! So since I was probably going to go with the 15" I was thinking sealed. Then I'd have a little better power handling (not that I'm worried about blowing it) and the fact that it'd be a little easier to design to build the enclosure. But then I got to thinking and I remembered that I have 2 15" Acoustic Elegance Passive Radiators and thought that could make for an interesting build.

http://aespeakers.co...&products_id=40

I have talked about using these before but obviously never have. Anyone think these would pair nicely with the Brahma and power amp?

Another thing I was thinking too was that I could get a Crown CDi1000 for a little more money and that has built in DSP so if I need to do any low end EQing, that could be accomplished with the build in DSP and cover me in the future for when I get a set of mains that are worthy of their own amplifier.

Any more suggestions or comments, or even criticism would be great!

Thanks again.

Turd Burst

Good day Todd.
You didn't say what hall you were powering up .
How big is the Venue???????
With that sort of power You have no worries to cover any thing .
On reading back it is for a Home theater !!!!!!!!!!
My HT I was using 2 -15" cheap tiawan subs with 98db/m .
This was set in a stage under the screen . area 10x4x2 ft 80cuft
To make a short story longer , The amp was only 160w rms . It was more than ample for my pipe organ cds .At quarter power The sound of the lower notes hit you in the stomach and made you feel sick .
On DVDs The sub was so loud it was impossible to stay in the room .
The drywall plaster joints were cracking .
So , why have enormous amounts of power that will never be used .
With kind regards Todd ...... ...........Alan.

[turdburst]

I like the headroom And I didnt have 80 cubic feet IB to work with. Or that's how I understood.

I'd love to do a try infinite baffle, but unfortunately, I don't own the place I'm living at.

[alan monro]

todd.brust, on 02 September 2011 - 06:52 PM, said:

I like the headroom And I didnt have 80 cubic feet IB to work with. Or that's how I understood.

I'd love to do a try infinite baffle, but unfortunately, I don't own the place I'm living at.

todd.brust, on 02 September 2011 - 06:52 PM, said:

I like the headroom And I didnt have 80 cubic feet IB to work with. Or that's how I understood.

I'd love to do a try infinite baffle, but unfortunately, I don't own the place I'm living at.

Fair enougth !Alan

[turdburst]

So I have the 15" Type R rocking. Sucked terribly sealed so we added an ass ugly port but does a decent job. Still lacking a little on the really low stuff but that's just the tuning. I messed around with WinISD a bit and came up with a few designs. Plans have changed a bit too. I am thinking of going with a Crown CDi1000 so I have some DSP control. It's overkill for the sub, but I plan to use it to power mains in the future. THen I can really utilize the DSP



The Blue plot would be my Brahma with the 12" recone in a 2.6 ft^3 enclosure tuned to around 22 hz

The Orange Plot is the Type R 15 in a 18"x18"x18" enclosure with the 2 15" AE PRs

THe pink is the same PR enclosure except with the Brahma 15.

The Passive Radiator enclosures have a slight knee before roll off but they aren't more than a couple dB Anyone have any input? THe PR box is going to be built no matter what for the Type R, I just don't know if It'd be worth it to recone the Brahma to a 15"

[turdburst]

Haven't build the PR enclosure for the Type R yet, but I did put in an order for a Crown XTi1002 today! Oh yeah.

[Aaron Clinton]

Crown? I am jealous.

[turdburst]

I have the XTi1002 hooked up right now. It's all sloppily done now but When I build the new box, I will clean everything up.

Then I'll add the Surge Supressor/conditioner

[Tirefryr]

I had the Tempest in my first house in Adire's EBS enclosure, so I would assume the Brahma would perform even better.

BTW, I have a 15" twelve-spoke basket lying around collecting dust if you need it.

[turdburst]

What makes an enclosure an EBS anyways?

I may be interested in the basket too! That'd save me some money. I'll let you know when I get to that point. Thanks for the offer!

[Tirefryr]

It's basically just a flatter response with an ultra low f3. Sucks for music IMO, but great for movies.

[turdburst]

Hmm I plan on sticking to the PR with the Type R for the time being. See how i like the response of that. I think I would rather have the sub rock for music and be "okay" for movies personally. I'll just have to find a happy medium.

I can set up different presets on the amp, up to 100 I think. Different eq, crossover settings etc. I think this amp is way overkill for what I'm using it for. 5 or 6 bands of parametric eq or shelfs on the input, tons of xover control and another 5 or 6 bands of parametric on the output side.

[turdburst]

Well Got the PR box built yesturday! Need to figure out some feet for then thing though. The Type R is down firing, but the enclosure is on top of 4 Shlitz beer cans. Don't ask why they are here, I don't drink that crap! I'll get some pictures up as I continue work with finishing the enclosure.

Anyone have any suggestions with placement? I can't seem to get the output I want in parts of the room. The adjacent room gets plenty "loud" but thats not where I need the sound. Its currently in front next to the Right speaker next to the opening of the dining room. I thought about relocating it to the rear of the room next to the couch but it's only been a day. Haven't had enough time to play around yet.

[Deephaven]

Try the corners first and go from there

[turdburst]

Have been trying some new locations and found a location that works great! The LF response is impressive. Just need to pull wire though the crawl space below the living room and make some feet and finish the box. Probably add some extra bracing into the box.

It isn't as tight with some music as I'm used to. Any Ideas there? Could delaying some of that sound help with that or is it an enclosure issue?

[Deephaven]

What sort of box is it in?

[turdburst]

Passive Radiator enclosure (there's some more detailed info above)

1 15" Alpine Type R
2 15" AE Passive radiators (http://aespeakers.co...&products_id=40)

in a 3.75 cu ft. enclosure.