Sda in sealed boxes..any one done it?
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JonathanPeterson
Posts: 103
So I've heard various pros and cons of passive radiators.
Most would say passive radiator is still a trade off or a compromise
Cons:
1) boost narrow frequency range that they are tuned to
2) move out of phase with active woofers. There was an article saying you have to consider mass and sound path Length and once it's all calculated and if the right passive radiator is used it moves in phase
Pros:
1) can bring bass out of small space
I have tons of excellent quality mdf laying around and wanted to build better boxes for sda-crs+
But now thinking of getting rid of passive radiators. I don't need sub 60hz bass
Has anyone done passive radiator delete?
Most high end speakers have separate box for each driver. I am planning to do the same with sda-crs+.
Drivers to be used are
Mw6503 instead of 6510
Mw6502 instead of 6511
Most would say passive radiator is still a trade off or a compromise
Cons:
1) boost narrow frequency range that they are tuned to
2) move out of phase with active woofers. There was an article saying you have to consider mass and sound path Length and once it's all calculated and if the right passive radiator is used it moves in phase
Pros:
1) can bring bass out of small space
I have tons of excellent quality mdf laying around and wanted to build better boxes for sda-crs+
But now thinking of getting rid of passive radiators. I don't need sub 60hz bass
Has anyone done passive radiator delete?
Most high end speakers have separate box for each driver. I am planning to do the same with sda-crs+.
Drivers to be used are
Mw6503 instead of 6510
Mw6502 instead of 6511
Comments
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When I was experimenting with CRS+ setup, I had them mounted on custom wall brackets. I had the cabinets with larger enclosure volume and tried them sealed with a mdf passive block-off insert. They sounded great at low and medium volume, but the bass just didn't have the "kick" or "spl", if you will.
Not until I installed a set of Polk's Power Ports did the bass reach low 30's and the 40's and 50 Hz hit with serious authority.
I've since traded them, but I kept a 2nd set of the exact Power Ports and custom inner tubes for another future build.Don't take experimental gene therapies from known eugenicists. -
That dip I believe is indicative of all the passive radiator models.
What size enclosure will you build (LxWxH)?Don't take experimental gene therapies from known eugenicists. -
Bass is the foundation.
Do the world a favor, don't make a frankenpolk. Some folks a helluva lot smarter than you knew exactly what they were doing when they designed and built those speakers.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
IIRC, @ 1.2 cu. ft is what I calculated from factory CRS+ dimensions.
My earlier experiment with the boxes completely sealed, I had them literally a few inches from walls. Although lower output, bass was very controlled, and to me, it did clear lower midrange frequencies when they accompanied the lower bass frequencies at higher volume.Don't take experimental gene therapies from known eugenicists. -
Seems like, if you listen to digital sources, DSP would be another way to go to get a flatter room listening response that doesn't compromise the low end frequencies in any way.
I would be miserable without sub 60 Hz bass, but that's just me I guess.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Transmission line???
Can be vented, (some are sealed) boosts bass, stays in-phase if done right. -
JonathanPeterson wrote: »Did anybody else notice a dip in bass when playing some frequency generator spectrum like 10-200hz sound waves
Personally I like to listen to music.
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Or you can router out a set of PR block-offs and install a set of very inexpensive RTi Power Ports and fix the dip and keep all frequencies.
I'll posts the dimensions of what I used for the port tube.
I'm having trouble finding my old posts.Don't take experimental gene therapies from known eugenicists. -
I think the total length of the port was only 3" and the I.D. of tube was 2.25". Another beauty of the Power Port platform is the air encapsulated in the square area is used in the port calculation so the tube itself is shorter....
Don't take experimental gene therapies from known eugenicists. -
The RTi platforms I used are (L) 7.0" x (W) 8.0" and only stand out by 1.375"Don't take experimental gene therapies from known eugenicists.
