Box simulation in WinISD

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Hi All!

I'm planning to build Closed cabinet sub, about 40L volume.
I have done simulations of several drivers and now I have 3 on my short list. These are:

  • Dayton Audio RSS265HF-4
  • Seas L26RFX-P
  • Peerless XXLS 835016
Based on WinISD simulation, Dayton has the best transfer function magnitude characteristic: 43Hz for -3dB and 31Hz for -6dB. Seas goes 44/-3dB and 35Hz/-6dB, Peerless 50Hz/-3dB and 37Hz/-6dB. Dayton has lowest efficiency (84dB) vs 87dB. Based on SPL characteristic, it looks like it needs twice power to get the same sound level.

Could you help me with picking the driver? Is it better to use Dayton (a little bit lower freq.) but more power needed or maybe driver with bigger SPL? At the beginning I was going to choose Dayton, now I'm more convinced with Seas.

Sub will work in room ~20 sq. m, with Dali Concept 6 as front speakers.

Bellow I've attached links to screens from WinISD simulations. From left to right: Transfer function, SPL (all drivers powered with 100W), SPL (Dayton 200W, others 100W), Cone excursion;

Regards,
Greg
 

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The Peerless is about the cleanest driver out there. 60L. Look at Linkwitz THOR. The low Q and combination of room gain is a most musical combination. I run 2 driven by a HCA 1200. If you insist on too much bass, than a low Q box allows use of an LT.

I have a Dayton RS 10" and I would say the RS is far better than the Titan III 10 inch, but neither is the match for the Peerless. I don't have the Seas.
 
The Seas, Peerless and Dayton are all certainly nice drivers, you should take a look how they do with a LT. very easy in winISD. You will need to balance max SPL, xmax, Pmax, box size and frequency response to your needs. I am working on a project just like this powered by a Hypex PSC2.400d. DSP is very handy for a project like this.

In my setup I will be using 4 drivers and 2 plate amps which should do ~110dB SPL with an F3 of 25Hz and a box size of 30L / diver (try simming it).

Also sim how a high pass filter affects the cone excusion, personally I use a second order butterworth @ 25Hz.

Good luck!
 
Some sims to show you the idea, 1 RSS265-4 in a 30l enclosure with a LT + high pass. Should sum up as a LR4 acoustic highpass.
 

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Hi,
Thank you all for replays.

@richie00boy - I'm not limited by 100W it was just to compare drivers "power consumption". Also 100W is a close to Prms for Peeless and Seas. I think that I don't need maximum possible power, just medium to sound levels.

@tvrgeek - 60L is much to much for me. I have to yet convince my wife to idea of having ~40L box in livingroom:)

@ Mark.Clappers - If I understand you well, I can use LT to boost low bass performance? I have done some simulations and plots looks well. I've combined LT with HP filer to keep max excursion in limits. What is the simplest way to apply LT to the project? Hypex PSC2.400d looks interesting but its too expensive for me. I don't want to build electronic circuits with filters neither. Will bass boost work similar as LT? I saw that some sub amps like Dayton or Bash can be modified to change boost freq.

Best regards,
Greg
 
Hi greg80,

Yes you can boost low bass with a LT. Take a look here: http://www.linkwitzlab.com/filters.htm a cheaper way could be miniDSP http://www.minidsp.com/

The big advantage of a LT is that you can fit a driver in a enclosure that is to small or to large and transform the system Q and frequency response. If you only want to apply a boost you should design your enclosure for your target Q and apply the boost you want to extend the frequency response. Most subamps have a subsonic filter that will limit excursion.

So if your spous agrees with a 30L enclosure the Rss265-4 should have a Q of 0.707 (max flat amplitude response)
 
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FYI,

My favorite of the suggested drivers is the Peerless XXLS 835016 that does well in a small footprint T-TQWT.. where the enclosure height only would be about 1.4 m and perfect to put grandmas picture on:

b :)
 

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I have both the Dayton in a 70L box and an 83500 in a 60L box. I would say the Peerless is lower distortion. ( I like low Q sealed boxes as they blend in real rooms well) I also modeled the Seas as I was looking at these three for my thin sub. It is probably a toss-up.
 
Thank's all for responses.

I've bought in good price Dali Concept SUB (12" about 50L closed box) (price was less than I've calculated for DiY SUB). I'm quite happy with it's performance, so I've postponed my DiY SUB project for now.

But I've one question: what is your opinion about DiY sub I've described before (Dayton or Peerless driver, closed box volume approx 35 - 50L) - would it better perform than Dali? If yes that in which aspect - low frequency response, accuracy, distortions?

Regards
 
IMO, to get good SQ and reasonable SPL (for light listening, not used in anger) a sealed enclosure will need equalization.
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At the very least a high order, high pass to protect the driver and a Linkwitz-Riley filter to increase low frequency response.
A TQWT, Tapped Horn or a ported quarter wave tube with an offset driver OD_ML_TL (offset driver_mass loaded_tuned length) will give fairly high SPL's with fairly high SQ and at much lower amplifier power.
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OD_ML_TL's can have a very small foot print but go from floor to close to the ceiling.
This type of design is easy to blend into normal decor.
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The increased efficiency is one of the big reasons that any horn will have lower distortion (when not used in anger)than a simple sealed enclosure which requires equalization and the higher operating power levels that are required to operate at Subwoofer frequencies.
That is, to operate at frequencies of which the sealed box does not want to operate.
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Also, Xmax becomes a real issue as you try to lower sealed enclosure frequency response.
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All that said, if you are not looking for 20 Hz content a sealed enclosure has much smaller delay issues than a ported box.

It is all a matter of preference.

Dave
 
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