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General opinions on mixing a Skram with sealed subs. Is there much to be gained (below lets say 35hz)? Or is this too narrow to benefit (a home theatre), or will interference make it impractical (after basic DSP). 

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3 hours ago, Droogne said:

General opinions on mixing a Skram with sealed subs. Is there much to be gained (below lets say 35hz)? Or is this too narrow to benefit (a home theatre), or will interference make it impractical (after basic DSP). 

My 2 skrams are mixed with 8 sealed ht18s. Sounds great to me :)

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34 minutes ago, klipsch said:

My 2 skrams are mixed with 8 sealed ht18s. Sounds great to me :)

I might do something similar. Do you think you gained a lot? And do you let them overlap, or do you avoid mixing? Because originally I was gonna use my 2x skram(like sub)s tuned to around 20hz. If I cant combine them in the <40hz range, I'm not sure how much I will gain with (lets say) 4 sealed subs (similair to theHT18s). I mean, 4x 18" subs will also deliver stronlgy in the 40-80hz range. 

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4 hours ago, Droogne said:

General opinions on mixing a Skram with sealed subs. Is there much to be gained (below lets say 35hz)? Or is this too narrow to benefit (a home theatre), or will interference make it impractical (after basic DSP). 

I can only talk about the SKHorn, but I'm happy with the output in the 1/3 vents configuration down to 20Hz. Air velocities get out of hand below that, but above 20Hz it's certainly enough for me. A single cab might have a hard time at or below 20Hz, even if it's bigger and has more vent area compared to half the SKHorn. I never got around trying the SKHorn in the config with only one vent blocked, but I like it the way it is now. I actually have quite usable output down to almost 10Hz when listening to music at low levels, the track below sounds surprisingly clean, even if distortion grows quite quickly below the tuning point (I think it goes down to 13Hz or so; so much for "you can't hear below 20Hz").

Integration with sealed should be fairly easy if you stay away from the tuning point (I'd tune it to ~25Hz and cross at ~40 with a 4th order or higher slope). It will take A LOT of sealed subs to keep up with that cab's mid bass thou :P

 

 

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Curious myself as what frequency is the Skram covering over the sealed subs in others setups?

 

I was looking at sealed/skrams myself but wasnt sure if it would do much. I plan on building a few different designs anyways to finally find which one I prefer. I have never heard a FLH, TH, Hybrid and sealed verse each other. Wont happen until later on the year but hopefully family matters will be done so I can finally (after 4 years) start building again.

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On 8/26/2020 at 9:22 AM, Droogne said:

I might do something similar. Do you think you gained a lot? And do you let them overlap, or do you avoid mixing? Because originally I was gonna use my 2x skram(like sub)s tuned to around 20hz. If I cant combine them in the <40hz range, I'm not sure how much I will gain with (lets say) 4 sealed subs (similair to theHT18s). I mean, 4x 18" subs will also deliver stronlgy in the 40-80hz range. 

I started off with an independent coverage implementation idea (avoiding mixing) with a blending / crossover around 32hz. 18s would cover 0 to ~30 and skrams for ~30 upwards. Ended up with mixing as that enhanced the "chest thumping" and gave a flatter response at multiple listening positions. 

IIRC (have been enjoying the configuration for a while not and haven't messed with settings), the sealed 18s cover 0 to 60hz and skrams cover 25 to 110 with my mains covering 80 and up. Took the expected measurement path of adding one speaker of each type at a time and taking 3 measurements in different listening positions each to ensure no nulls and instead got the expected dB gain based on the watts/speaker added. 

I would measure 1 18.

Measure 2nd 18 independently.

Add 1st 18 and 2nd 18 together - measure. Ensure ~6db gain across three listening positions by adjusting delay, etc.

Measure 3rd 18 independently. Add 3rd 18 with 1st and 2nd 18. Ensure ~3db gain. Repeat until all 8 18s are blended achieving proper gain.

Measure Left speaker independently. Measure right independently. Blend L & R together properly. 

Blend L with all blended 18s properly. Add R and ensure results are proper compared to when R and L were together only. 

Measure SKRAM 1. Then SKRAM 2. Blend SKRAMS. 

Now add SKRAMs to all. Ensure dB gains via measurements.

I believe I got best results doing EQ for each group independently except for L & R. So EQ is global across the 18s group. Also global across the skram group. Independent for L and R. Then blend all together EQ wise. 

Enjoy the awesomeness. 

 

Edit: I should add that if I built 2 more skrams, I may do things differently. However, as they say, there is no replacement for displacement - having more displacement in different locations for the same frequencies really helps me to dramatically smooth the response across multiple listening positions in the theater. I could selfishly make the MLP for me be perfect (+-0.5dB) with the non-overlapping approach. However, with the overlapping approach, the front 3 seats achieve a very similar response and the back 4 seats aren't too bad, but with a +-5db range in the back VS +-2db range in the front. 

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Any pictures of these skrams and sealed setups?

 

Was curious do you have the sealed in the corners or how is it setup?

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3 hours ago, chrapladm said:

Any pictures of these skrams and sealed setups?

 

Was curious do you have the sealed in the corners or how is it setup?

Have moved things a bit since then, but basic idea...

http://data-bass.ipbhost.com/topic/742-riccis-skram-subwoofer-files/?do=findComment&comment=20883

Edit: Also running the SKRAMs wide open - no ports blocked

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So do you just have the single 18's? on top of the Skrams? Or  are those D.O. sealed drivers sitting on top?

 

My options here in OZ are limited but once things are settled I was hoping to have sealed subs with the Skrams. Didnt know if others were putting the sealed subs in corners or 1/4 wall or what. 

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1 hour ago, chrapladm said:

So do you just have the single 18's? on top of the Skrams? Or  are those D.O. sealed drivers sitting on top?

 

My options here in OZ are limited but once things are settled I was hoping to have sealed subs with the Skrams. Didnt know if others were putting the sealed subs in corners or 1/4 wall or what. 

There are 6 18s in that picture (2 more 18s in the room not pictured). In that picture, two D.O. sealed on top of the skrams and 1 D.O. sealed under the center channel facing sideways.  Another dual front firing config behind 1st row. I thought the details were in this thread right around the previous shared link. 

I've configed as best as possible the method of placement I cannot currently find. It involves placing the subs at each of the 1/3 height and width points (along with their intersections) in the front and back of the room. 

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Well, I finally blew a B&C Speakers 21SW152- 4ohm in a SKRAM running a QSC - PL380. Burnt the coil up real good. In my rush to get the system running on the Playa I accidentally hit the clip limit switch OFF on the PL-380. I currently am working on a RECONE and am having trouble deciding on the glue to use. 

Regarding the SKRAM design after using them now for 6 months. 

OUTSTANDING!!!!  With a quality driver like the B&C 21SW152 the Bass is as others put it, LUXURIOUS! Paired with Meyers Sound Tops, incredible!

 

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12 minutes ago, Tahoejmfc said:

Well, I finally blew a B&C Speakers 21SW152- 4ohm in a SKRAM running a QSC - PL380. Burnt the coil up real good. In my rush to get the system running on the Playa I accidentally hit the clip limit switch OFF on the PL-380. I currently am working on a RECONE and am having trouble deciding on the glue to use. 

Regarding the SKRAM design after using them now for 6 months. 

OUTSTANDING!!!!  With a quality driver like the B&C 21SW152 the Bass is as others put it, LUXURIOUS! Paired with Meyers Sound Tops, incredible!

 

Bummer about the drive man, that sucks. got any deployment pictures from the playa?

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Crispy coils are what's for dinner! 

Sorry to hear about that Tahoe. PL380 is a serious amp. How many Skrams do you have? All 21SW152 loaded? 

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11 hours ago, Ricci said:

Crispy coils are what's for dinner! 

Sorry to hear about that Tahoe. PL380 is a serious amp. How many Skrams do you have? All 21SW152 loaded? 

I have 2 SKRAMS, both with B&C 21SW152 4ohm. And Yes, Crispy ass coils, wow did it ever fry those wires. i did learn while rebuilding, that their is alot of space inside the space the coil moves within. The backside of the 21SW152 has multiple holes that vent heat and the space is about 5-8mm wide. 

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On 10/18/2019 at 10:23 AM, menace said:

This is what I have come up with so far. Was thinking of fixing the mesh at the end of the mesh that's easy to get at with screws and washers and the other end will kind of grip into the wood by the sharp ends it has from being snipped to size. The mesh is about 1.6mm strand size, its easy enough to bend by hand but will still have a bid of tension on it from being pulled into position by the screws.

What do you guys think? Could it vibrate perhaps?

 

 

IMG_20191018_095150.jpg

IMG_20191018_095302.jpg

FWIW, i need to report back again with how this has turned. I continued to use this solution and after initially hearing some vibrations at close range on the first one of two listening sessions I have not noticed it again since. SO i believe the solution is good although considering there were vibrations initially its is not a solid solution with out some modification like thicker wire in the mesh and perhaps attempting to fasten both ends on the mesh where i I only fixed one end of the mesh and the other end is kind on jammed into place against some pieces of thick ridged felt type polyester type acoustic paneling I had laying around(I dont have pics unfortunately) the sharp ends on the cut wire found them selves fairly sturdy homes.

 

IMG_20191126_152749.jpg

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I know some people have had issue with t nuts spinning. Here is what i did to ensure against that, small screws and a bit of epoxy I had on the shelf. Fairly crude but simple and will be effective..

IMG_20191030_134327.jpg

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Something that might help is to put gasket tape in the areas where the metal grill makes physical contact with the wood.

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21 hours ago, klipsch said:

Nice texture on that finish! 

Thank you, that was actually the fist time I've worked with Warnex (European equivalent of Duratex), but it worked very well.

I used two 1KW stage lights to speed up the drying process, which shortened drying time to 15 minutes, which was a massive help. Gonna get some curing lamps for future projects.

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