Back After a Long, Long Break

markamerica

Good evening! Several years ago, I first signed into the forum and spent most of my time reading. I was impressed by the expertise, experience, and knowledge of the various posters, and I've looked around just enough to know that some of my very favorites are still here. I had lurked a long, long time before I posted, and I began to discuss a number of small things with folks like DarqueKnight and MadMax and a number of others, and I began to actually enjoy the forum even more as a posted and exchanged.

A disaster struck my family shortly after, and I basically abandoned this and every other non-essential concern. My audio equipment has remained basically idle for that time, as I simply didn't feel much like music for a very long while. What started out as a near-fatal car accident with my teenaged daughter at the wheel became a long fight to see her psychological state repaired as she had some head trauma and brain injury as a result. She's alive, and she's leading a productive life now, but things will never be the same.

It's taken me this long to begin to rekindle my interest in much of anything else, and I think it was inevitable that I would come back, so I am glad to find things still running along. My system now includes a pair of SDA SRS and they're bi-amped with a pair of my Soundcraftsmen A5002s. I'm going to be checking everything out and firing them up this week.

Where I last left off when I basically shelved everything was that I had been considering an extension of my project. I had replaced the polyswitches which seemed to have been tripped a few times before I acquired the speakers, and would trip at the drop of a hat. Once I replaced them, things cleaned up substantially. The last time I listened to them, they sounded wonderful.

Now it's time to start back into things. I'll probably ask some more inane questions and drive the more experienced and technically competent members nuts, but maybe I'll finally make some headway. First up: Learning about the differences between my narrow-blade/wide-blade equipped IC and those of the pin/blade variety. Somewhere along the line, I had acquired on Ebay an item that I have since learned looks suspiciously like it was inspired by DarqueKnight's Dreadnought, and I also noticed there's a person on Ebay who works on crossovers who is a member here. That's another project I'll want to take up.

Lots to do. Still a busy guy, but maybe I can work in some time for my own pursuits now.

Thanks to all for keeping this all alive, and thanks for reading!

Mark

brgman

Welcome back!
I am sure I speak for all in saying we hope your daughter is doing much better.Nothing worse than a sick or injured child.
Ask away and I'm sure you will get the answers you need to get back up and running with the gear.
Good luck!

Toolfan66

WOW Mark!! Welcome back, and more important, glad your daughter is still here with you.

If you have the original SRS's with the blade/blade variety, you can't use the dreadnought, and your amp has to be common ground, but that part I'm guessing you know..

I'm sure the fellas will chime in soon..

Enjoy!!

EndersShadow

As a new father of a 6 month old daughter I cannot imagine what you went through.

And trust me, we will GLADLY answer your questions about upgrades. Personally I wont because I dont know jack about that myself, so I will let the other more veteran folks.

craverk

Mark I just rediscovered this place today after hanging out here a dozen years ago so our paths have never crossed. Welcome back nonetheless and best of luck.

Keith

markamerica

Thanks Brgman! So since you encouraged me, everybody gets to blame you now when I go off the deep end, right?

When last engaged, I was working on several projects simultaneously. One involved figuring out some amplifier-related things, and one involved an absolutely insane idea hatched in the mind of a goofball. (That would be me, of course.) So I had acquired the SDA SRSs and I found my single Soundcraftsmen way insufficient to the task at hand, and as it turned out, I acquired another here, and then I bought one on Ebay for parts that turned out to need just a couple small things, and then another and so on and so forth...blah blah blah. There came a point at which I began to wonder about bridging some amps.

That's when I was informed that the SDA circuitry forbid it without an isolation transformer of some sort, even if I could bridge the A5002s. (Which I found I could using a device also made by Soundcraftsmen called an AB-1)

I acquired two AB-1s and then tragedy struck and I basically dropped it all, and there it has lain ever since. I basically decided this past weekend, after dusting off components that hadn't been powered on in years for the umpteenth time that I was going to jump back into this. I started looking at my notes, but they seemed incomplete, and probably because of my nearly instantaneous abandonment of everything audio-related.

Here was where I was aiming: Four(4) Soundcraftsmen A5002s, bridged in pairs and then bi-amping the SRS with one bridged pair driving the high end, and the other pair driving the low end. Where it came apart was the question of building a isolation transformer.

It must have been a year or so ago, and I was just looking around on ebay, looking at prices on SDAs and associated parts, I think because I had begun to long to get back into things again, and I ran across an item for sale/bid that I now know must have been born of Darqueknight's Dreadnought project. I bought it thinking "one of these days..." It has sat in its box about ten feet from the place I unpacked to check it for damage ever since.

So that's where things sit. I'd like to pick back up at that point and figure out what I need to do to go forward.

I realize now as I did then that there will be those who will ask: "Why?" There's a complicated answer behind that question with which I'll bore you to tears on some other day. Life goes on. The project must be completed if possible. Other tragedies and circumstances await behind every tick of the clock, and I don't feel much like wasting too many more of them waiting to see when the other shoe will drop.

Thanks for the words of encouragement. Where then to begin? I suppose the first place to look is at the SRSs themselves, since they are completely stock, with wide-blade/narrow-blade IC, just as they shipped from the factory going on three decades ago. To make the isolation transformer business work, I think I will need to start there, no?

Mark

markamerica

Toolfan, wow, reading my post before I posted it... Pretty tricky! Okay, so if the blade-blade crossovers won't work with dreadnaught, what are my options? Can I upgrade/mod? Is it worth it? This is the part where the heavies walk into the room and crush me, but I'm up for it. Craverk, EndersShadow, thank you! Feels good to be back.

markamerica

EndersShadow, you're at the best part. Treasure the next three years. I think my daughter's first Halloween jaunt at four(just to the immediate neighbors houses) in a little tiger suit was pretty much as good as it gets. As for the questions about upgrades/etc, yeah, I'm with you...LOL

TNHNDYMAN

Welcome back Mark. There are plenty of experts here to help with your upgrade ?'s. I'm not sure the reason for not being able to biamp those SRS's, but I'm hoping F1 or DK himself may shed some light on the subject with a few links to get you started reading the particulars. Even if you can not use the transformer you would still be able to take those original speakers and upgrade them to an entirely new level with new capacitors, inductors ect... Getting to the end of a project is nice but sometimes that journey gives the best moments.

markamerica

TNHNDYMAN,

Thanks. I am bi-amping with a single pair of the A5002s now. That works fine. What I was looking to do was to bridge pairs of A5002 and then bi-amp with the bridged pairs. Anyway, thanks for the welcome. As I remember, everybody here was helpful back then, and folks don't seem to have changed in that respect.

Mark

oldrocker

Welcome back Mark, kinda been thru the same things, so very glad things have gotten better and I can say with experience, things get better!!!!

markamerica

Thanks Oldrocker! Somethings may never be the same, but at least they have improved substantially.

oldrocker

And when you get that system back, walk over to the volume button, turn it way to the right and imagine how everyone who hears it says YEA, I need one of those!!! Laffs, well maybe not that far to the right as thats what usually gets me in trouble:)

Toolfan66

TNHNDYMAN wrote: »

Welcome back Mark. There are plenty of experts here to help with your upgrade ?'s. I'm not sure the reason for not being able to biamp those SRS's, but I'm hoping F1 or DK himself may shed some light on the subject with a few links to get you started reading the particulars. Even if you can not use the transformer you would still be able to take those original speakers and upgrade them to an entirely new level with new capacitors, inductors ect... Getting to the end of a project is nice but sometimes that journey gives the best moments.

It's not about not being able to bi-amp, it's about using a dreadnought. With the SRS's using lets say a set of mono block amps, the only way you can use them is if you can bridge the negative terminals from amp to amp, making them common ground. (You cannot do this with all amps) check with the manufacture if your not sure. With the 1.2's/1.2tl's you can use the mono blocks without bridging the negative terminals, as long as you use a dreadnought/AI-1 interconnect. Even with later SDA's the amps must be common ground if your not using the dreadnought..

With the original SDA SRS's blade blade, the dreadnought cannot be used, there are earlier SDA's that fall into this as well. The blade/blade usually gives this away, as the original AI-1 interconnect from Polk comes in pin/blade form only.

markamerica

Toolfan, so if I read you right, then either my Soundcraftsmen amps won't work(as I don't think you can do the neg-neg with them,) OR the SRSs need to become 1.2/1.2TLs, right?

Okay, so this might deter others... There may be a good reason for that.

Toolfan66

Taking a set of SRS's and making them 1.2's or 1.2tl's is a waste of time and money, for starters the crossovers are not even close to one another, and you would need to change out 8 drivers, let alone wanting to upgrade the tweeters, so your at about $800 right there, and you haven't even touched the crossovers.

The passives are different, and the bracing in the cabinets are different as well. It's just not worth it, and the speakers are great as is, and doing the so called normal upgrades is the way to go..

Just find the right amps to power them with..

markamerica

Toolfan,

I'll buy that. They do indeed sound great as-is, and I'd hate to screw that up.

Thanks!

Toolfan66

Mark,

I'm not saying dont upgrade the components in the crossovers, that I would do.. Just don't try and make the speakers something their not.. Putting in new capacitors, and resistors, and maybe new inductors, will make them shine. VR3 can help you with that..

Enjoy!!

markamerica

Yes, I think I'll head that direction, while squirreling some $ away for the day I run across some 1.2/1.2TLs...

THEN I'll do it...

In the mean time, upgrades it will be. I was doing some preliminary research on this back when too. Seems like coming up with CAPs of the right sort/values was the issue. I am definitely a D-I-Y guy.

Toolfan66

markamerica wrote: »

Yes, I think I'll head that direction, while squirreling some $ away for the day I run across some 1.2/1.2TLs...

THEN I'll do it...

In the mean time, upgrades it will be. I was doing some preliminary research on this back when too. Seems like coming up with CAPs of the right sort/values was the issue. I am definitely a D-I-Y guy.

VR3 can help you with values, as well as darkknight, they are out there..

markamerica

I've seen VR3's work on Ebay. Those are some mighty fine looking crossovers. I am certain they are worth the money, but I have to live in my world where such items, while beautiful and undoubtedly worth it, are much too big a bite at one time for my wallet. I have to acquire such things as budget permits, so for me, a re-capping and so on is going to take a while. Buy pieces and such until I have what I need, and then put it together. On the other hand, I'm pretty handy with things, which is why I tend to D-I-Y most everything. It's the costs of the pieces/parts and knowing which ones to acquire. I may never have invented the wheel, but I know how to copy one.

Thanks!

Mark

Moose68Bash

Definitely contact Trey at VR3 Mods. He can help you spec the parts you need and get them through him at a price you can afford, and I'll bet he'll advise you about what to do with the when you have them in hand, as well. He doesn't just do the "no-holds-barred" crossovers you've seen on eBay.

markamerica

Moose68Bash,

Thanks. Those units on ebay are a work of art. They may be no-holds-barred, but that doesn't stop a fellow from dreaming, right?

Besides, given the tools and materials(or parts,) I'm pretty good at building things. It's just figuring out the parts I need(and can afford. I've been away so long, I can afford to be a little patient!

I've messaged VR3 here, and I hope he doesn't get too bored and delete my long-winded spewage...

Thanks again!

Mark

Schurkey

markamerica wrote: »

My system now includes a pair of SDA SRS and they're bi-amped with a pair of my Soundcraftsmen A5002s. I'm going to be checking everything out and firing them up this week.

Danger, Will Robinson!

I would not expect this to be a workable solution, unless you're using one amp for both HF sections, and one amp for both LF sections.

The SDA circuitry in the low-frequency section of the crossover will not appreciate the lack of common ground if you use different amps for left and right channels.

Bridged amps CANNOT be common-ground, therefore totally un-suitable for blade/blade SDA speakers as long as the SDA cable is plugged in (A few SDA 1C and 2B speakers were made with leftover blade/blade sockets and cables, but that's not the case with your speakers.)

markamerica

Schurkey,

That's right. I'm connected with one amp to the HF on each, and the other amp to the LF on each. Works pretty well. Sounds nice anyway.

Sorry if my muddled wording caused misunderstanding.

Mark

drumminman

Welcome back to CP, MA. Glad to hear things are heading in the right direction for you. If you can read schematics, go here:

http://www.polkaudio.com/forums/showthread.php?55888-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-Stereo-Dimensional-Array%28SDA%29

You can make a list of all the caps, resistors and inductors needed for you speaks. It's not necessary to replace the 750 pf caps as they were only used to bypass crappy caps to make them sound better. A high quality film cap in this spot is all you need.

Other mods that improve sound quality include:

Larry's (Toolfan) Rings or Hurricane nuts - couples transducers to front baffle much better than stock screws in mdf

Black Hole 5 - cleans up mid range congestion

dynamat on speaker and PR baskets - stops ringing of the bare metal

Spikes - increases clarity, esp. bass and mid range

New speaker gaskets (if needed) made from Armacell

New 10 AWG inductor for SDA circuit - improves bass, imaging

Replace blade blade socket with Cardas or Vampire Binding post and build a new IC (SDA) cable out of better quality wire.

I've done all these and can recommend them without hesitation.

markamerica

Drumminman,

Thanks! I am looking at most of those mods/improvements. Not familiar with Black Hole 5, however.

I'm certain I'll discover it before I'm through. Putting it in my notes now, along with the rest.

Mark

drumminman

markamerica wrote: »

Drumminman,

Thanks! I am looking at most of those mods/improvements. Not familiar with Black Hole 5, however.

I'm certain I'll discover it before I'm through. Putting it in my notes now, along with the rest.

Mark

Blackhole 5 is available from several sources; I bought mine from Sonicraft here:

http://www.soniccraft.com/products/damping/blackhole5.htm

1 sheet is all you'll need as you cut it into 3-4" wide strips to place on the back wall opposite the MW's. Some also place strips on side walls.

George Grand

I hope all the bad times for you and your family are in the past.

markamerica

Drumminman,

Thanks! That's definitely going on the to-do list.

Mark

markamerica

George,

I hope so too. It's been a long while. Thank you!

Mark