My PANASONIC RX-A5 ** Project Kumonga
- Thread starter Cpl-Chronic
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It's time to party now!!! 
Thanx peeps!! I'm going to clean out an area of the basement tonight to do a side by side comparison between the A2 & my 8 woofer A5 so may use a couple of your suggested tracks if I like them.....hardmen said:
Cpl
Both radios are rated at 15w per channel RMS, probably 10% THD. It really moves air & the grills actually vibrate so much you can hear them hitting the plastic woofer rings so I have to secure them with standoffs somehow....jimmyjimmy19702010 said:
Cheers,
Cpl
SOME BASS HEAVY beats to check out if your speakers or laptop can hang with the near sub-sonic...Still have to add deadmat to the cabs & sort out some bleeding air from screws, seams etc...overall for a dry run, it rocks hard & heavy for sure....
https://www.youtube.com/watch?v=mYnKTRZ3zLk
Stay tuned....
Cpl
https://www.youtube.com/watch?v=mYnKTRZ3zLk
Stay tuned....
Cpl
1 more BASS BASHING DUB to signal the first hurdle complete & a victory lap back to the bench for proper sealing & tuning, etc.
https://www.youtube.com/watch?v=w5HSMShkkN8
I can deadmat the leaks & add weight to the back panel so its resonant frequency is lowered to react to the woofers better. It's a simple concept but to pull it off again takes patience in rooting out every little rattle & leak until you have an airtight, tuned enclosure....
I chose to leave it sealed since they are the easiest to tune & EQ out the bump in mid-bass & extend the bottom end...I think if I put rubber washers on the screw heads, that will seal up any air coming from around the screw heads...I heard fluttering from the screws & holes they went through on the outer cabinet...photos to come on sealing the cabs.....
I also had to put a thin double strip of deadmat in the cabinet seams where they fit together so that air can't escape there. Also, deadmat was used to seal around the back connection plate from the inside...
Stay tuned....
https://www.youtube.com/watch?v=w5HSMShkkN8
I can deadmat the leaks & add weight to the back panel so its resonant frequency is lowered to react to the woofers better. It's a simple concept but to pull it off again takes patience in rooting out every little rattle & leak until you have an airtight, tuned enclosure....
I chose to leave it sealed since they are the easiest to tune & EQ out the bump in mid-bass & extend the bottom end...I think if I put rubber washers on the screw heads, that will seal up any air coming from around the screw heads...I heard fluttering from the screws & holes they went through on the outer cabinet...photos to come on sealing the cabs.....
I also had to put a thin double strip of deadmat in the cabinet seams where they fit together so that air can't escape there. Also, deadmat was used to seal around the back connection plate from the inside...
Stay tuned....
Well, got the cabinets damped down in the upper-midbass & beefed up the bottom end, 40-60Hz, which is awesome....the deadmat really works wonders with rigid plastic & panels..hardmen said:
Here's some pics of the deadening material I used along the seams & various locations inside the cabinets...
OK, Hardman.
Needle to the groove coming up.....
Good work! Anyone who knows HiFi will say if you have a sealed setup, it must be fully sealed to get those lows pumping!
James....
James....
Well, I had taken a break from breakin' in the new cans & thought on how to improve the sound. I poked around with my ear & deduced the following deficiencies that needed remedy.
1. Every screw hole was bleeding pressure from the bass notes & causing a fluttering, fuzzy bass noise I couldn't let pass. Air leaks are the number 1 enemy to good bass.
2. The screens vibrate & make noise since they are only attached at the top & bottom edges.
3. If the cabinets were a bit more rigid & had another dead-mat layer, they would go deeper but the sound is punchy overall so I will do more listening tests & decide later if I want to pursue that detail.
So far, I've sealed all the leaks with rubber sink washers & the dead-mat treatment along the edges of each cabinet seam are holding firm & the sound is much tighter & cleaner now. There is still a bit of back-wave slap at high volumes but these cans scream & are extremely efficient, all the way down to about 50Hz & can easily do 30 in the right cabinets...
Once I can iron out issue 2 & 3 I will be more than ready to take on ALL contenders & see where my SS-A5 stands in the crowd of heavy pipe-hittin' blasters....Modded or not...Floyd's big 12" EVIL 2000 Master Blaster will be the dragon to slay if I hope for greatness...
This beast weighs in at over 50 lbs already & is STUPID LOUD!!! on its own gas. No T-amps need apply. Just add REAL woofers & a decent audiophile cap for the tweeters's 12db filters... 
a lot of time is taken up by applying deadmat in all the right places to tighten up each cabinet & by far is the biggest challenge of the project, so far......
In the meantime, listen to the soothing sounds of the Dust Bunny Bros. & Bradd Pitt at a very LOUD 1/3 volume & peaks hitting 0db mark on the LED VU's....BAM!!!
!!!WARNING!!! HEAVY BASS & LOUD MUSIC!!! Turn your speakers down before attempting to play this video....
https://www.youtube.com/watch?v=86r9J_xjPPc
'I say...deliver me from perfect original restorations'.....
1. Every screw hole was bleeding pressure from the bass notes & causing a fluttering, fuzzy bass noise I couldn't let pass. Air leaks are the number 1 enemy to good bass.
2. The screens vibrate & make noise since they are only attached at the top & bottom edges.
3. If the cabinets were a bit more rigid & had another dead-mat layer, they would go deeper but the sound is punchy overall so I will do more listening tests & decide later if I want to pursue that detail.
So far, I've sealed all the leaks with rubber sink washers & the dead-mat treatment along the edges of each cabinet seam are holding firm & the sound is much tighter & cleaner now. There is still a bit of back-wave slap at high volumes but these cans scream & are extremely efficient, all the way down to about 50Hz & can easily do 30 in the right cabinets...
Once I can iron out issue 2 & 3 I will be more than ready to take on ALL contenders & see where my SS-A5 stands in the crowd of heavy pipe-hittin' blasters....Modded or not...Floyd's big 12" EVIL 2000 Master Blaster will be the dragon to slay if I hope for greatness...
This beast weighs in at over 50 lbs already & is STUPID LOUD!!! on its own gas. No T-amps need apply. Just add REAL woofers & a decent audiophile cap for the tweeters's 12db filters...
a lot of time is taken up by applying deadmat in all the right places to tighten up each cabinet & by far is the biggest challenge of the project, so far......In the meantime, listen to the soothing sounds of the Dust Bunny Bros. & Bradd Pitt at a very LOUD 1/3 volume & peaks hitting 0db mark on the LED VU's....BAM!!!
!!!WARNING!!! HEAVY BASS & LOUD MUSIC!!! Turn your speakers down before attempting to play this video....
https://www.youtube.com/watch?v=86r9J_xjPPc
'I say...deliver me from perfect original restorations'.....
This tank HITS HEAVY!! The volume is clean & easily overpowers my video mics. BASS is punchy & rich while the treble has that delicate imaging you need for clean stereo sound....the A5 EQ is very clean & I am quite surprised what a good 5 band EQ can do to smooth out the dips & bumps.
Disco Kumonga is hungry...
Cpl
Disco Kumonga is hungry...
Cpl
And people wonder why open backed one piece boxes tend to be bass shy.
You've done well to get it down to 50hz with such small drivers - the sealing work does make a huge difference.
It's always an uphill battle getting deep bass out of small speakers. Thin plastic cases are very difficult to 'keep quiet' so it will be quite the achievement if you're successful!
Are you going to attach the speakers permanently?
James....
You've done well to get it down to 50hz with such small drivers - the sealing work does make a huge difference.
It's always an uphill battle getting deep bass out of small speakers. Thin plastic cases are very difficult to 'keep quiet' so it will be quite the achievement if you're successful!
Are you going to attach the speakers permanently?
James....
Thanx brother!jimmyjimmy19702010 said:And people wonder why open backed one piece boxes tend to be bass shy.
You've done well to get it down to 50hz with such small drivers - the sealing work does make a huge difference.
It's always an uphill battle getting deep bass out of small speakers. Thin plastic cases are very difficult to 'keep quiet' so it will be quite the achievement if you're successful!
Are you going to attach the speakers permanently?
James....
The woofers are really good & made to be used in arrays for a very strong bass/midrange response. Boston Acoustics is a good company that is known for it's woofer array towers. There are some more BA's with a foam surround for sale at 15 bucks a pair if anyone else wants to try it but you have to have a firm background in cabinet preparation & troubleshooting of sorts when it comes to sealing it up & eliminating the rattles, standing waves, etc...The other reason they are kick-arse woofers for this is they boast a very good response from about 50Hz to about 10KHz & have a sensitivitly of above 92db. The high frequency range of 4 small woofers works perfectly with the 2nd order filter on the tweeter side to sound pretty balanced overall & seamless. I left the woofers wide open & simply upgraded the 4.7uF Electrolytic capacitor that cost the manufacturer a penny with a 2 dollar eBay polyester/metal-film cap which smoothed out the highs quite nicely. Electrolytics have a crisp & brassy quality which sounds impressive at first but can be harsh after a while. I find Poly's a lot more subtle & open but that may be open to impression & interpretation so you would have to judge for yourselves....
The plastic boxes are surprisingly rigid but need some weight to them so their resonant frequency isn't so high in the bass region. I could barely flex the long sides even a millimeter & the plastic sounded more like hard wood than the usual plastic thud when you knuckle it.
So adding weight & inertia by using the dead-mat layers is the final piece of the puzzle to making a kick ass stack out of my A5
...Here's another Fight Club classic working out the 8 woofers of doom..
https://www.youtube.com/watch?v=YvoKTdoafI4&feature=youtu.be
stay tuned for more refinements & listening tests...
Cpl
My V2 box responded really well when I completely filled the cabinets with professional acoustic fill (an old pillow stuffing!).
The fill will also slow down the air.
The fill will also slow down the air.
I have a whole box of the loose fill for speakers & I also have some egg-carton acoustic foam I may try out instaed of the stock blanket insulation. The only problem with loose fill is it can tend to move around & get into the baskets of the woofers so I'm trying to avoid using it. So far the only internal damping is the blanket insulation for the back panels...jimmyjimmy19702010 said:
Stay tuned....
Thanx Floyd!JVC Floyd said:
The difference in sound & pure SPL's are night & day compared to the oold woofer/passive system. The tweeters are really good drivers & sound very clean, crisp, etc. Will do a bit more with the cabinets & then I'm calling it finished... 
Cpl
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