Different Fullrange boxes+SB34NRX75-6 bass towers

[waxx]

This works, when i'm playing full power on this subs (that is 50w) there is almost no panel resonance. I could add more, but it was not needed.

A frame is much more sturdy than a plate somewhere and damps on more spaces the panel. That is the whole clue of it, it saves a lot of wood for similar results.

 

[planet10]

A frame is much more sturdy than a plate somewhere and damps on more spaces the panel.

If i get the meaning of plate, to mean something like the holybraces we use, i would disagree on sturdy stiff, the frame may have more damping because it flexes a bit?

dave

 

[waxx]

Well, i measured it in the way i could, with a car stetoscope (the ones that are used in car workshops to find problems in engines) and the vibration of the the panels is way less with this system, than with the same driver in it's old box with traditional bracing like most of you do.

And yeah, i may use the wrong words, as English is only my 4th language (after West-Flemish (my mothertongue), Dutch and French. But i mean the wood panels you use with holes drilled in it.

 

[planet10]

That is how i measure too. Very effective.

if your box passes that test with real music as a source then it is good :^)

dave

 

[umut1001]

Volume is doubled. Any vents are doubled. Magnets tied together.

The simpliest way:

It is the small push-push box at the end of this document: http://www.planet10-hifi.com/downloads/SDX10-woofPlans-240418.pdf

dave

What about sealed seperated bipolar design? What are pros and cons?I want It because i read that little boxes are more effective when stuffed.
Sub Box Polyester Fiberfill
So i can build smaller box with deeper bass.
I am sure i like sealed sound ,it has great transient response i like it much and will not build a ported, i want to make box as small as possible but with deep bass.

 

[planet10]

I see no point in putting bipole drivers in separate enclosures.

Damping increases the apparent size of the box by a small amount.

dave

 

[AllenB]

Sub Box Polyester Fiberfill
So i can build smaller box with deeper bass.
...
box as small as possible

There are some comments on that site which could mislead, to thinking a larger box is not good.

 

[umut1001]

Oh sorry , i like big boxes and know it is better for bass but wife does not want big boxes.The only reason of trying to make smaller is WAF

 

[planet10]

A box can be too big. With isobarik you could put 4 woofers into not much more than the volume of 1 of them, giving you the output of a 2 x as large box with 2 woofers.

Or look for woofers with lower Vas/Qt that make for smaller boxes. I loved the CSS SDX7. 2 could be fit into anywhere from 14 to 40 litres sealed (and thus ameniable to a touch of EQ).

dave

 

[umut1001]

Hi.Where can i buy the SDX7 in Europe?(Especially France is good at shipping rates,others may be expensive)I could not find a seller.Or equalivent is also ok.

 

[zman01]

Tang Band W6-1139 as a sub-woofer

IIRC works in a small box.

 

[planet10]

Hi.Where can i buy the SDX7 in Europe?(Especially France is good at shipping rates,others may be expensive)I could not find a seller.Or equalivent is also ok.

SDX7 is NLA for sometime now :^(

Enuff requests to the ness CSS might bring it back.

dave

 

[umut1001]

XBL2™ Power 7” Woofer
The SDX7 was designed as a drop in replacement for Adire Extremis 6.8 from 600
Hz down (i.e. in 3-way designs or subwoofers) with significantly improved
performance. See the application notes for recommended enclosure designs.
• low mass woven carbon fiber cone with rubber surround
• high power, low inductance design based on the patented* XBL2 ™ motor
topology used under license, with dual Neodymium slug magnets
• 4 layer 1.5" voice coil
• solid pole piece, machined copper phase plug and axial gap vents for reduced
thermal compression & low aerodynamic noise
• high excursion suspension
• attractive cast aluminum basket design with narrow spokes & substantial under
spider venting
• high quality
gold plated
terminals


I think you are right to love this woofer.It seems it is excellent.If available what will be the price.I am glad to buy 4 of them if not expensive.

 

[planet10]

low mass woven carbon fiber cone with rubber surround

You do need to coat the cone with 4 coats of decreasing amount of thinned puzzlekoat/ModPodge. THis ectends the smooth response up to about 1.7kHz (otherwise there is a serious whoop above 700/800 Hz. It also removes the sound of the loose carbon fibers rubbing together.

dave

 

[umut1001]

crossovers and amplifiers

Hi.I am building active crossovers(i will build a better discrete active crossover later with matched 2sk209gr, i also need a good regulator like Salas or superregulator ,this is just for trying) and connecting Class D amplifiers for this project.SB34NRX75-6 each have 200w max power.I have 2pcs 500w IRS2092 amplifiers and 2pcs LLC smps 500w.Is it ok if i connect 2 amplifiers to one SMPS as max power of woofers already should not exceed 200Watts.And i can use other LLC smps for another application maybe?

 

[umut1001]

Hi.I could find some time( stayed at home because of Covid-19 )and could finish the tower about 1 week ago.Now there is a big cube 100 liters on the left corner and 65 liters(about 80 liters effective with stuffing) on the right of tv .Empty weight about 19 kilograms and full weight including SB34woofer it is about 25 kilograms.
Now bass is better distributed in the room.It sounds enough even with TP22 Topping amplifier for bass channels,i am happy with the sound but i will add more powerful amps soon.I crossed at about 100Hz for now ,1 order PLLXO.But i will try different variations.I will listen to it at 340Hz SB34 woofer facing forward while wife not at home

 

[umut1001]

some more pics

 

[Juhazi]

Lookingreally good! Now just play with dsp/xo to find best crossover. I recommend again Minidsp 2x4HD, but with every dsp-system you can set several presets for different woofer direction and main speakers. As well delay adjustment is easy. And testing is free and easy.

With the woofer on-axis towards listener you can easily use xo 200-500Hz and get more directivity in midrange. Sideways position must have xo below 200Hz (my rough estimate)

 

[umut1001]

Hi.Thank you for your comments!Yes after some burn in it sounded even better. I am not sure i want mini dsp as it has extra adc- dac conversion. I run it with PLLXO with styroflex caps for top(it has 3x100nF epcos blue stacked caps for bottom but i will change it with mkp caps).It is very simple and sound is pure (sorry for the cable crowd). For the crossover frequency above 300Hz i do not have much knowledge. It may need extra effort.

 

[planet10]

A PLLXO does have significant limitations in application, but if the loudspeakers have been designed to overcome those shortcomings — something very doable with a WAW, it brings 2 VERY big advantages,

1/ it is dirt cheap, like yours the RCAs and the extra cable probably swamp the cost of the 6 passive parts required. And maybe the cost of a box, irecycled an old Apple 3.5” floopy disk case for this one.

(this one was an early one and has 8 parts, 2 Rs could be lost)

2/ because it is passive (no PS) & so simple it is very transparent, subtracting little information with no “electronic haze”

miniDSP certainly gains you a huge amount of versatility, but 2 good DACs + the device itself costs considerably more, i have not heard one yet so i cannot comment of its sound, but IIRC it is still only 96/24.

dave