New to me 3.1tl... Upgrade

decato

Here are some graphs to help with understanding how the RC network affects the frequency response of the tweeter. The tweeter was modeled with a 5.6 ohm impedance.

The 2.0 ohm resistor shaves off approximately 1 dB in the 2 - 4 kHz band, rising gradually to the same output as the 1.3 ohm resistor affords at 10kHz and above. Combined with reversing the polarity of the tweeter (as is done in most second-order networks), the overall output in the crossover region is roughly the same as that of the original design, but to my ear, exhibits less of a 'metallic' harshness.

Removing the resistor altogether leaves two 12 uF capacitors in series, which is equivalent to a single 6 uF capacitor. Notice how much less output the tweeter has below 4 kHz.

westmassguy

gtianz wrote: »

in the list i posted above there is a 55uf inductor. Per Decato's comments and the schematic I believe this is a mistake and it is in fact a 55uf capacitor.

No such beast exist from claritycap or sonicap. The closest i found is 47uf cap from claritycap.

all these small discrepancies from the original specifications is somewhat disheartening. This is a project i want to tackle - But, without knowledge about the impact all the value changes will have makes me hesitant to try it. Throwing $800 at a beautiful completed crossovers for $500 speakers doesnt ring my bell. Similarly, I have had full shopping carts at both soniccraft and madisound websites. There are holes in both carts which has prevented me from pulling the trigger at the $200+ orders.

after 2 days plugging away at the web I am feeling a bit discouraged and overwhelmed.

- - Photography has been a hobby of mine for many years and is something that I am good at. Having a solid understanding of photography principles has always left me scratching my head at those who cant grasp a simple concept like the effect aperture has on the resultant image. I have a feeling this is precisely what is happening here regarding electronics.

gtianz, you're overthinking this, and getting all wound up. The 55uf electrolytic is easily replaced with two 27uf Metalized Polypropylene caps wired in parallel, and gives you a 54uf cap which is within 2% of the required value. The 27uf is available from both Sonicap and Clarity. The cap in question mounts on the upper right of the circuit board. If using the original board, you would do an over under attachment, with two belly band wire ties. The Gimpod Board, has provisions for two Caps in place of the single 55uf. He designed the boards with Sonicaps in mind. Replacing all the inductors is additional work which you don't "Need" to do. The existing inductors are fine for 95% of us who can't hear the difference. Here's an example of using the existing circuit board, and the over/under Capacitor installation on a pair of SRS 1.2s. Yours would look similar.

TNTsTunes

Now that shows me how to correctly lay out the caps so the crossover will still mount to the inducer. Thank you.

Nicely done. I really would rather rework the PO's crossover layout to match this instead or remounting them.

I'll probably need to replace two 12uf caps in my 3.1's to get longer leads for stacking... I can use the short ones over again in my 2.3 SRS crossovers though.

Great pictures. I enjoy seeing things done right.

gtianz

Wessmassguy.

Thank you! Your crossovers, photo's, and explanations have been perfect. I was wanting to just bomb into this project head first with the guns blazing.

I think that I will instead take a bit of time going through this process. I need to lay out a plan for all the upgrades.

westmassguy

What's not shown, is the 3M VHB tape under each cap where it sits on the circuit board. You will, in most cases, have to enlarge existing mounting holes, and drill new ones for the nylon wire ties. Don't be drill shy. As long as you mark everything, and double check on the bottom of the board, so you're not breaking a copper trace, you'll do fine.
The stacked caps also have cyanoacrylate brushed on where they meet, to lock them together. This is done after the nylon wire ties are cinched tight, and the caps are positioned correctly. I never use hot glue, unless there is no alternative.
You'll also note the three Mills resistors wired in parallel, to replace the Polyswitch.
This is only done on models with multiple tweeters.

gtianz

More great information! My shopping list continues to grow.

No polyswitches for the 3.1's.... Which you just confirmed.

westmassguy

gtianz wrote: »

More great information! My shopping list continues to grow.

No polyswitches for the 3.1's.... Which you just confirmed.

Your 3.1 only has a single tweeter, so a single .5 ohm Mills MRA-12, or Mundorf MOX .47 ohm will do fine, in place of the Polyswitch.

gtianz

Huh i read no polyswitches. Couple more resistors wont break the bank.

westmassguy

gtianz wrote: »

Huh i read no polyswitches. Couple more resistors wont break the bank.

My bad, your 3.1s are 5th generation, so the Polyswitches were already eliminated.

gtianz

Found a pair of sda srs2's. I havent bought them but thinking about it. The price is right.

Funny how things work in the audio world.

Should I consider replacing the 3.1's with older 2's (sl2000 tweeters - not in as good of condition)?

F1nut

Hell no!

gtianz

F1nut wrote: »

Hell no!

Hahaha. Ok. Then if anyone is interested there are a couple of pairs listed in Oregon (no affiliation / cross posted in the speaker deals thread).

Portland, OR. $350 SDA 1 signature
http://portland.craigslist.org/clc/ele/4750600127.html

Eugene, OR. $300 SDA 2
http://eugene.craigslist.org/ele/4746722118.html

Mike Reeter

I have to agree with F1nut, I've had two pair of SRS 2's over the years. They have moved on to new owners, the 3.1's are keepers and not going anywhere soon.

Upgrade your 3.1's and you will be rewarded for your efforts.

gtianz

Getting ready for stage 1 of modifications:

Carpet spikes (already installed - immediate / rather dramatic improvement)
Blackhole 5 (24" x 27")
Dynamat Extreme
Armacell
Loctite Power Grab
JB Weld Steel Stick

Hopefully I will get started this weekend (11/19) - just waiting on the blackhole 5 delivery.

I figured that I would do this round of modifications first. I haven't pulled any speakers yet so I haven't seen the crossovers. Seemed like it would make sense to check out the crossovers before I drop a bunch of money on them.

Any other suggestions while I have the speakers open?

Is the Armacell a one time application or will I need to replace it every-time I pull a driver?

F1nut

If your stock gaskets are not damaged there's no need or advantage in replacing them.

gtianz

F1nut wrote: »

If your stock gaskets are not damaged there's no need or advantage in replacing them.

Thank you F1nut.

They look perfect (tweaters - havent checked any others) but, the radiator pressure test will only hold the midranges for a second or two. The cabinets definitely arent sealed well.

And given that it cost like $6 for armacell i cant see the issue with doing it.

F1nut

People don't always understand the test. Push the PR in and hold, the mid-drivers will pop out for a second, maybe two then recede to their resting position. The whole process might run 3 or 4 seconds.

The issue is a lot more work than needed for no gain.

Instead, you should install Larry's rings, if you can get them. If not, install 8-32 Hurricane nuts and use cap screws to secure the drivers. Either will make a vast improvement.

Mike Reeter

F1nut wrote: »

Instead, you should install Larry's rings, if you can get them. If not, install 8-32 Hurricane nuts and use cap screws to secure the drivers. Either will make a vast improvement.

Without question, this is one of the best mods you can perform on any SDA.

This will "tighten up" your cabinet considerably and snap the imaging into focus.

"IF" you also install new gaskets, you will have to go back and re-torque the machine screws at least a couple of times, as the Armacell will compress over time.

xjghost

F1nut wrote: »

People don't always understand the test. Push the PR in and hold, the mid-drivers will pop out for a second, maybe two then recede to their resting position. The whole process might run 3 or 4 seconds.

The issue is a lot more work than needed for no gain.

Instead, you should install Larry's rings, if you can get them. If not, install 8-32 Hurricane nuts and use cap screws to secure the drivers. Either will make a vast improvement.

Yea good luck with those rings.

Elinvader

Is Larry making a comeback with the rings ? I guess giving myself a bit of hope before I go crazy with the hurricane nuts !!!!

F1nut

Send Toolfan66 a PM to inquire about the rings.

gtianz

F1nut wrote: »

People don't always understand the test. Push the PR in and hold, the mid-drivers will pop out for a second, maybe two then recede to their resting position. The whole process might run 3 or 4 seconds.

The issue is a lot more work than needed for no gain.

Instead, you should install Larry's rings, if you can get them. If not, install 8-32 Hurricane nuts and use cap screws to secure the drivers. Either will make a vast improvement.

I have emailed Toolfan about the larry's rings.

Installing hurricane nuts will be a last resort. Talk about excessive work.....drilling out holes, using a screw and washer to install the nuts on approximately 40 holes per speaker.

I will do one or the other.... I'm sure the hurricane nuts are the cheaper alternative.

TNTsTunes

Elinvader wrote: »

Is Larry making a comeback with the rings ? I guess giving myself a bit of hope before I go crazy with the hurricane nuts !!!!

I just got a set of rings two weeks ago from him.

westmassguy

gtianz wrote: »

F1nut wrote: »

People don't always understand the test. Push the PR in and hold, the mid-drivers will pop out for a second, maybe two then recede to their resting position. The whole process might run 3 or 4 seconds.

The issue is a lot more work than needed for no gain.

Instead, you should install Larry's rings, if you can get them. If not, install 8-32 Hurricane nuts and use cap screws to secure the drivers. Either will make a vast improvement.

I have emailed Toolfan about the larry's rings.

Installing hurricane nuts will be a last resort. Talk about excessive work.....drilling out holes, using a screw and washer to install the nuts on approximately 40 holes per speaker.

I will do one or the other.... I'm sure the hurricane nuts are the cheaper alternative.

You have to drill those 40 holes for Larry's rings too.
Hurricane nuts are easy once your set up to do it.

Mike Reeter

[/quote]
You have to drill those 40 holes for Larry's rings too.
Hurricane nuts are easy once your set up to do it.
[/quote]

I've installed hurricane nuts on two sets of 2.3's. Get a Hexhead driver for your small cordless drill and set the torque very low, and adjust accordingly.

I've also installed Larry's Rings on three sets of SDA's, not a lot of difference in the outcome....It takes a little time and energy for either method.

gtianz

Looks like i will be waiting another week or two to get started on the upgrades. I've added a couple things to the list and i would rather do as many upgrades as I can at the same time.

Round 1 of modifications:

Carpet spikes (already installed - immediate / rather dramatic improvement)
Blackhole 5 (24" x 27")
Dynamat Extreme
Armacell
Loctite Power Grab
JB Weld Steel Stick

Added:
VR3 terminal plate kit
Larry's rings

Crossovers will definitely be round two as I've already invested close to what I paid for the speakers to begin with.

xjghost

I would love to see detailed pictures of the round one mods. I've never done any of this kind of stuff but am eager to try.

gtianz

Will do xjghost! I have a nice camera/tripod and all the goodies to go with it.

voltz

for the Hurricane nuts I used 3 different drill bits and started small and then work my way up in size like Dave taught me and it worked out just fine (this was for my Monitor 10's)

xjghost

voltz wrote: »

for the Hurricane nuts I used 3 different drill bits and started small and then work my way up in size like Dave taught me and it worked out just fine (this was for my Monitor 10's)

I have a set of 10's I bought when I was in my teens or early 20's I want to modify to the hilt and keep till I die. They are probably my favorite speaker. I have them hooked to a parasound hca 850 and carver ct 24 and they sound amazing.