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Elite Shackster
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Discussion Starter · #1 ·
Ive delivered the last subs I built (well it got collected), and moved on to this project now. These are as per title and using the drivers I know well. These will be forward firing single driver cabs, that will eventually be finished in gloss black. They are 115 litres each, minus driver, bracing and amp displacement.

So far I have both cabs assembled, and both have been filled and sanded down. I need to fill and sand the rears of the cabs yet, and give them a last skim over before a final super smooth sand and routing to round the edges. Grills will use magnets for the invisible fixing effect.

Pics below, some of which are taken with a phone, so I apologise now if any arent upto scratch.
 

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Nice work Dan. Them plate amps look cool. No fan noise issues either eh? (as with the pro amps), and 1300 watts from a plate amp. Nice. Look forward to the finished product. :T
 

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Yes, excellent work and excellent documentation of the project. I was looking at the new SVS sealed subs but this makes me want to reconsider DIY.

What are the final dimensions of the box, if I may ask?

Thanks.

Bob
 

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Outstanding.

Love your work.
 

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Elite Shackster
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Discussion Starter · #7 ·
Looks good. How many watts is the plate amp?
Another excellent build brought to us by Dan. That is very good work. Looks like a 1300 watt class A/B amp.
It is a 1300 watt plate amp, so well spotted lsiberian :T. Its actually the LT1300 from Elemental Designs, delivered direct from the US. I actually have one up and running and I have to say this amps initial impression is that is a cut above the bash 500 amp and doesnt seem to have any problems powering this sub. Ive found that 500 watts isnt really enough for this design, and I was hoping the amp was going to show it ability. I'm pleased to say, it certainly sounds very good.

Yes, excellent work and excellent documentation of the project. I was looking at the new SVS sealed subs but this makes me want to reconsider DIY.

What are the final dimensions of the box, if I may ask?

Thanks.

Bob
The final box comes in at about 115 litres, which is a 550mm cube. The forward baffle is 2" thick for strength and I found it a fair job lifting this on my own :devil:

Outstanding.

Love your work.
Cheers for the kind words :T
 

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Nice work! I also have the ED LT1300 plate amp powering my AE AV15X sub with PR's and is up to the task. The LT1300 amp has enough power to drive the AV15X sub for sure.
 

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Elite Shackster
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Discussion Starter · #10 ·
Ok Finally got these all painted up and completed. Well, more or less, just need to complete the grills now. Ive just moved house so ignore the decor :sweat:, hope you enjoy:
 

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I'm still seeing a bit of image distortion in the reflections. Maybe another 40 hours of hand polishing and they'll be finished.












^^ Humour. Very nice work indeed there.
 

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Elite Shackster
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7,142 Posts
Discussion Starter · #15 ·
To conclude . . . . .

I decided to get the other sub in, do some eq'ing, put my thing down and see what I could do with respect to optimising the system response of the subs. As if by magic, the 50hz dip the single sub had has vanished and the overall response is much much smoother with dual subs. Looking at the drivers in action, I would even say there is some room to eq in a house curve for sub bass junkies, in my room at least. In the images you can see the overlays of the individual subs, so you can see how one subs fills in where the other has a dip etc. The end result is a pretty flat response, superior to any I have achieved for myself before, which is undoubtedly entirely due to having dual subs.

Ive also included a graphs with Audyssey on and off for comparison, with each subs overlay, and a final graph of the combined response, which includes a 100db measurement (amp at -10) so you can compare how volume affects the response. Its quite easy to see just how good a job this basic Audyssey does in the right hands. The images are titled, and you can see the legend to each graph so everything is easy to see. I have to say, they sound fantastic, and even with the volume right up they are so composed and accurate.

Any questions, feel free to ask.
 

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May I ask if You use an ACTIVE SERVO with each sub or the amps drive the subs are different
and without active servo. I read about huge improvement with Active Servo enabled subwoofer vs non servo and the much lower Watts requirement to drive servo enabled drivers as well ? more on this on vendors web site and I'm curious what is the real final feeling on sound differences comparing direct servo vs non servo with the same drivers, in the same enclosure ? (direct servo switched off)

Cknub B.
 

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Elite Shackster
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Discussion Starter · #17 ·
These arent servo driven (I know little of servo technology as it happens though). I have simply used very high quality drivers and ensured I chose amps with plenty of stable power. The sound quality on this pair is fantastic, and looking at conversations around the net, modern driver technology with high end drivers doesnt really require active servos. From what I gather servo technology is a cost addition that can make subs expensive, like the Velodyne subs were. Also, the servo design doesnt really improve on the end results if you compare a servo driven sub with a normal sub using a high quality driver, as the drivers response is very linear anyway.

What I know is based on things I have read from others though, like I say, servo technology isnt something Ive ever got that involved with, but suffice to say, I believe driver technology has come a long way in the last ten years or so, and kind of made servos redundant, in much the same way push pull has become.
 

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@ Moonfly

Thank You for Yours quick response,
I made my main passive four way speakers some 10 yrs. ago and it that time I chose to provide in the design phase an option for the isobaric loading the bass driver FC at 125 Hz. While at my first test design phase I use only a single bass driver in a test enclosure and on top I put the MidBass, Mid. and Tw. enclsure. Well, the sound was very good and I was already think to leave the system as is but then I just remove one bass driver from the left channel bass enclosure and install it in the R CH enclosure.. jut for curiosity what the difference will be,.. I was shocked, only single bass driver (To eff. work out of my R CH enclosure) to my room was immediately change my minds.. vow, I was surprised with the bass definition I have never heard before, the whole new dimensions also in the finest small nuances in the lower bass was so evident that I was definitely decide to finish both enclosures with Isobaric loaded bass drivers. After extensively tested and precisely measured The whole system in a anechoic chamber I realize that the great extent of the inner chamber modulation was very effectively reduced via internal bass driver and the output from external driver was fare the most pure signal which come from bi-amped power amp dedicated to bass only. After I finish my project I was then evaluate many high end speakers with cost xx K. Eur but in the bass response none of them come close to Isobaric... I then learn that Isobaric loading system was so effective that no SINGLE BASS DRIVER IN ANY POSSIBLE CONFIGURATION CANNOT COMPETE even TL ! and no mater who the manufacturer IS. So here come in to play the newly developed DIRECT SERVO DRIVE with a single driver to the great extent, the active direct servo very similarly achieve the same bass quality as the isobaric loading and eliminate the need for the second inner Woofer and a huge xxx W power amp too not even to mention to lower the bottom end significantly. the only disadvantage between Active Servo and the Isobaric principle is absence of one add. driver motor from driver inside the enclosure. The direct active servo also effectively reduce the inner box DELAYED MODULATION to great extent. It is possible to summarize all expenses and after a comparation with the convetional design and the final sound outcome the direct servo approach is less expensive because there is no NEED for KW ++ amp while the "Direct Servo is already Integrated in theirs power amplifiers.. Finally with LESS POWER NEEDED, (MORE GREEN) and with better final outcome for the same size BASS DRIVER & with better low extension --- less cost too.

Maybe this will be interesting reading: DIRECT ACTIVE SERVO...
http://www.rythmikaudio.com/re-radiation.html
http://www.rythmikaudio.com/DS1500ci_info.html see Fs, Bl, ....
http://www.rythmikaudio.com/amplifiers.html

Now it is possible to design the high quality audiophile grade subs and highly effective too.

As I plan to move in the future my current main speakers into full active... I'll strongly
consider RythmikAudio Direct servo drivers & plate Amps... :)

Cknub B.
 

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Elite Shackster
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Discussion Starter · #19 ·
Well, using high quality drivers, lots of power, combined with electronic eq, its supposed that you get results any servo could match. Looking at the driver in your link, and the amps, the driver motor looks quite small, which would suggest lower power handling and lower motor strength. The servo amps are 370 watts or less, which would marry with the driver appearance.

With electronic eq you can use a signal that effectively does what the servo sounds like its intending to do, and thats mange the response of the subwoofer at all levels. With a high power handling and very linear driver with plenty of xmax, you can use amp power and electronic eq to control the driver, improve the low end response of the subwoofer and achieve an overall better end result, and combining 2 subwoofers to do that gets fantastic result IME.

aving never really looked at servos, I couldnt honestly comment on how good they are,how well they meet their claims, or comment on the end quality. I dont know how good the sound quality is from the servo drivers either, so if that isnt upto scratch, even with high performance you will still loose something. The servos could be fantastic, but I would have to build a sub and compare it side by side against something like the subs I have built in this thread, to really compare the two, and weigh up end results vs sound quality vs overall performance. Only then could I really have any sort of answer on the best of the two methods.
 

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Wow! Dan you do some awesome work, do you shoot the cabinets yourself or outsource it, if so what do you use for a gun and paint? Anyhow nicely done.:sn:
 
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