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Discussion Starter #1
I need help. I have some DIY skills but not speaker building but my budget of around $500 for a complete project has me looking to give building a sub a shot. I am looking for a HT sub (with a little music thrown in) that has high wife acceptance factor. I would love this thing to hit low and fill a 23' x 26' x 8' room. Is this possible on a tight budget? If so, could someone help a poor guy out with pretty specific recommendations (speaker, amp, design). I know I ask a lot but there seems to be a plethora of very knowledgeable folks on these threads. Thanks!
 

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No doubt it is a tall order! I have been killing myself trying to find something in my budget. Are you thinking a sonosub with the 11 cu. ft. enclosure? I am not against it - not sure about the wife. You can't really hide something that big. At this point I will run anything past her.
 

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Tight budget, fills a big room, has a high WAF.

Pick 2.

You can fill a big room cheaply but the sub/s will have to be BIG. You can fill a large space with a good looking, small sub, or 2 but it will be EXPENSIVE.
 

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I'll start with my usual "room filling" is a rather subjective term. Any idea how loud you like to listen and what's the likely distance from the sub to the main seating area?

How about a pair of Dayton 315HFs in 3.5 ft^3 each tuned to 20Hz? Build dual 3.5 cabinets or a single 7 ft^3, depending on WAF. Use a BASH-300 per driver. With the current sales pricing through 6/30 and free shipping, you're at $490 for for amps and drivers. Go with slot ports and your only additional costs are MDF, screws, wire, and finish.

The attached graph shows Mike's 11/18 Titanic-15 compared to the 315HFs in 7/20 with 600 watts. There appears to be a slight difference between our Titanic parameters. I also included the rumble filters in the HPA500 and the BASH300 in the model.

-Brent
 

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Just some additional food for thought on how much output is "room filling" since everyone's taste is different.

I use a single DVC15 in 6 ft^3 tuned to 17Hz in my theater room (24'x16'x9'). With our typical movie levels at -15dB below Reference, it's more than enough. Unfortunately, I can't remember what movies/scenes, but the times I've metered it, that's good for peaks in the mid 90dB range with all speakers/sub combined. Put another way, -15 can still be felt about 50' away from the sub and the theater room is a FROG that's fully insulated on the common wall with the main living area as well as having exterior doors between it and the main house...the previous owner finished the FROG after the house was built, so it was originally treated as unconditioned space.

Here are a few in room measurements that I have handy. The first graph is showing the DVC15 with Audyssey on/off ("on" produced the increased output below 25Hz). The second graph is a single of the 315HF I suggested above...3.5 ft^3 with 20Hz tune, but in my case it's not a BASH300 so there's no EQ from the rumble filter. Due to the lack of a rumble filter, I limited the start frequency of the sweep a bit. Both subs were measured in the same location at different times with different prepros...hence the difference in the >80hz response. Since the mains amp is powered off for sub measurements, the 315HF graph suggest there was a problem with the xover in my previous prepro. Anyway, these aren't max output runs, but they do illustrate what even modest 12" and 15" drivers are capable of. Measurement distance was 14' from sub to mic, mic is ear height and >5' from the nearest wall, subs are corner loaded in a 24'x16'x9' room, no EQ (except Audyssey as noted), no smoothing, no rumble filters.

-Brent
 

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Here's an idea to up the WAF on a big sub. How about building a frame covered with cloth that straddles the corner in front of the sub. paint the fabric the same colour as the walls. leave the bottom open where the sub fires so that the painted cloth does not interfere with sq.

That way you hide the ugly cylinder.

If you want to get real fancy, you can move the screen out from the sub and add some 3lb mineral or fibre board for bass trapping.
 

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There's quite a bit of difference between our Titanic models. Here's the file I'm using.

View attachment 14416
Looks like you pulled your parms from the spec sheet and I used the Dumax results. Regardless, in the same alignment the models track within .5dB or less of each other. Remember, I added the HPA500's default rumble filter into the graph I posted, which brings up the 20Hz region a bit.

-Brent
 

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Agreed. I'm willing to bet two 12 inch 315's in a 23' x 26' x 8' room wouldn't do it most people.
They'll do about as well as a single 15" and it's just submitted as another option to consider, especially given the sale pricing and the sound quality claims for the Reference Series. Dual 315HFs have about 22% more Sd than the Titanic15 (33% per Dumax) which will offset the Titanic's Xmax advantage to a degree. The T15 ends up with about 15% more one way displacement.

For satisfactory SPL, personal tastes and the distance from listener(s) to source will matter more than room size itself, which is why I asked the OP for more input. Room size and "room filling" don't establish objective output requirements.

As soon as I post this, someone will point out an exception... From the spectral plots of LFE channels I've looked at, most of the bass fests appear to be recorded around -30dBFS with a few getting up towards -20dBFS. When calibrated and played back at Reference level, those frequencies are going to be output at 85-95dB (given +10 for LFE decoder boost). With redirected bass, you're still probably not seeing more than 105dB required from the sub at the primary listening position. If you're sitting outdoors 12' away, that means the sub needs to be capable of 117dB at 3', which neither the T15 or dual 315HFs alignments suggested will reach. Fortunately, we're usually indoors where walls, ceilings, and floors screw up the whole -6dB for doubling of distance thing. I've actually measured greater output at some seats in a room at double the distance of others from the sub. Now, if someone decides to run their subs hot to WAY HOT, dial in a house curve, wants 105dB @ 20', etc...you'll probably need quite a bit more than $500 to be satisfied. As the hot rodders say, how fast can you afford to go? :spend:

-Brent
 
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