[dftkell]

Dual Stonehenge build***Updated with measurements

First of all, many thanks to Erich at DIY Sound Group. This is the third pair of subs I've built from flat packs and they've all been great. Without DIYSG, I probably never would've attempted a sub build.

My previous subs were Dayton 18" HO's in 4 cu/ft sealed boxes. I was happy with them. But then, I started planning to install an electric AT screen, and I wanted something that would be a bit closer to the wall. Plus, I always wondered...should I have gone ported vs sealed???

The Stonehenges fit the bill with a relatively shallow depth as well as having the benefit of raising up my center channel so that it's almost in line with my L/R's.

So far they sound great. I'll be taking measurements in the next couple days and posting comparisons of the sealed 4cu/ft boxes vs the Stonehenges in my room. Stay tuned.

Here's some pics...

 

[chadamir]

Nice job. What did you paint them with?

 

[dftkell]

Nice job. What did you paint them with?

Thanks. They are two Benjamin Moore colors that go with the wall color of the room. Deep Caviar and Silver Gray.

 

[bgtighe23]

Very nice and clean build! You make it look as easy as possible.

 

[dftkell]

Very nice and clean build! You make it look as easy as possible.

Thanks. The flat packs are really easy to assemble. It was the size and weight of these boxes that became difficult, especially after I lined the inside with denim insulation.

My first thought was to veneer them like I did with my previous set of subs but these were so big and heavy that I painted them instead. They're not perfect if you look up close, but from a few feet away they look nice.

After I get my screen and projector up and running, I might go back and build some grills for them.

 

[spieg]

Nice build! Im interested to see the measurements and impressions.

 

[clubwerks]

Very nice looking subs.

 

[luisev]

They look great! Fingers crossed they come back in stock soon as I would like to build one. Which plate amp did you use?

 

[dftkell]

They look great! Fingers crossed they come back in stock soon as I would like to build one. Which plate amp did you use?

Thanks.

I'm using Dayton SPA1000 plate amps.


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[bgtighe23]

Thanks. The flat packs are really easy to assemble. It was the size and weight of these boxes that became difficult, especially after I lined the inside with denim insulation.

My first thought was to veneer them like I did with my previous set of subs but these were so big and heavy that I painted them instead. They're not perfect if you look up close, but from a few feet away they look nice.

After I get my screen and projector up and running, I might go back and build some grills for them.

Flat packs are great! I agree about the size and weight, well, being that I had to carry them up to the 2nd story of the house It was all worth in the end though.

Thanks.

I'm using Dayton SPA1000 plate amps.


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Any reason you decided on Plate amps instead of separate amps such as Behringer or Crown?

 

[dftkell]

I have all of my AV equipment in the adjoining bedroom hidden in a closet and controlled with my Harmony remote and IR repeater. From what I saw, it didn't look like the Behringer could be operated with IR. Plus I had already run two 50 ft runs of subwoofer RCA cable through the floor across the garage and up through the bedroom for my previous subs. I'm also a MAC guy and it looked like I needed a PC to set up the dsp in the Behringer.

I know the Behringer and Crown offer more bang for the buck than a plate amp. But I paid more for convenience in the end. And the 1000 watts each seems to be plenty.


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[dftkell]

Gonna do some measurements tonight.


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[dftkell]

I just ran some measurements using Fuzzmeasure and the same equipment I used when I ran measurements with the sealed boxes last year. I'd like to get some opinions on them.

The blue graph is the Dayton 18 HO's in the old 4 cu/ft sealed boxes. I measured them probably a year ago and from what I remember I applied a boost around 20hz with the plate amp. (Phase of both subs was "norm.")

The green graph is the new Stonehenge boxes in the same locations. The phase of both subs is set to "norm" and I applied a small cut at around 53hz. (Not a big result but helped a little.)

The red graph is the Stonehenge's in same locations with the sub in the front set to "norm" and the phase of the rear sub set to "rev."

And the last graph, is an overlay comparison of all three.

The measurements I'm getting from sealed vs ported appear very close. It's making me question if all of the work I put into the new boxes was worth it.

What does everyone think?

Thanks.

 

[dftkell]

sealed vs ported

Here is a direct comparison of the sealed vs ported. After levels were calibrated, each had a 3db bump so they're a little hot.

Blue = same drivers in 4 cu/ft sealed boxes with PEQ boost around 20z (from what I remember)

Orange = same drivers in Stonehenge boxes

 

[vitod]

They pretty much have the same response. Try different sub placements. I know it'll look off, but try it if you can. Maybe put both subs up front? Move the rear sub to the left?

 

[dftkell]

When I had the sealed subs, I tried every combination of dual subs I could think of--both in various setups up front, both in various setups behind the couch and multiple setups of one up front and in the rear.

This front-back setup gave me the best overall response.

Thanks.


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[vitod]

When I had the sealed subs, I tried every combination of dual subs I could think of--both in various setups up front, both in various setups behind the couch and multiple setups of one up front and in the rear.

This front-back setup gave me the best overall response.

Thanks.


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Ah. Then it's just your room. I think if your room were sealed, they'll be a difference. Or a driver upgrade? UM18?

 

[spieg]

Interesting results. Not really what I expected to see. I wouldve guessed the lower end wouldve rolled off faster at the port tune on the stonehenges and that there would be a a couple more db gained at port tune and a little higher (looks like there is only a db or so gained there). I think showing graphs with both configurations without any EQ would be ideal, but I know thats not necessarily possible now that things are switched over. Thanks for sharing your results!

 

[Face2]

Ah. Then it's just your room. I think if your room were sealed, they'll be a difference. Or a driver upgrade? UM18?

That box is a bit small for the UM18.

I too am a bit stumbled why the responses are so similar. Although, it is possible that there is now more headroom.

 

[dftkell]

Interesting results. Not really what I expected to see. I wouldve guessed the lower end wouldve rolled off faster at the port tune on the stonehenges and that there would be a a couple more db gained at port tune and a little higher (looks like there is only a db or so gained there). I think showing graphs with both configurations without any EQ would be ideal, but I know thats not necessarily possible now that things are switched over. Thanks for sharing your results!

Yeah, it's not really possible since I only kept the best measurements I could get from the sealed boxes when I measured them back in May. From what I remember I gave them a PEQ boost at around 20hz. And that was with 500 watt plate amps. I now have 1000 watt plate amps on the Stonehenges.

Anyway, I went back and took the measurements again. Here is a comparison--Sealed boxes is blue, Stonehenges with a slight cut at 53hz is red. Crossover is set at 60hz--same as it was before. This yielded a slightly better FR.

The results are so close that the differences are negligible, in my opinion. Which is disappointing because I went to a lot of trouble to build the new boxes. But if I hadn't, I would have always wondered, "what if?" Either way, they sound great.