SRS 2.3 driver swap/ crossover mod thoughts.

TNTsTunes

I have a set of early 2.3's with the original drivers. I also have 8 like new MW6503 replacement speakers I would like to try. They would be arranged like a 2.3TL. I think the swap should work great. No tweeter changes.
Here's my research thanks to DarqueKnight and this forum.

2.3 wiring pdf
2.3 TL wiring pdf
SDA SRS
SDA 1C wiring pdf

Driver comparison
1 Driver Type Q BL Compliance DC Resistance Fs
MW 6511 1.405 4.34 N 3.496 E - 3N/M 3.13 Ohms 29 Hertz (SRS 2.3 stereo)
MW 6510 1.39 6.32 N 3.41 E - 3N/M 6.57 Ohms 31 Hertz (SRS 2.3 & SDA 1C dimensional)
MW 6503 1.82 5.24 N 3.55 E - 3N/M 6.54 Ohms 29 Hertz(SDA SRS)

The plan is to swap the dimensional and stereo driver sides to match the 2.3TL left and right driver arrangement. The plan is to run the MW6503's as the 4 stereo drivers like the SDS SRS uses in my 2.3's. The crossovers are the same. The overall ohm is rating very close with the MW6503's wired in series/ parallel.

I plan to rewire the crossover to use the original MW6510 dimensional drivers as bass drivers also. The bass speaker lead will be wired to the dimensional drivers just like in the SDA SRS(drivers basically the same overall ohm rating & crossover is the same) and in SDA1C's(same drivers & crossover is almost the same).

I don't see any reason this shouldn't work great... The slight change in ohm rating shouldn't matter since my speakers are bi-amped.

It should add both bass and midrange since there will be 2 more stereo drivers and all six drivers will do bass by using the dimensional drivers.

Crossover rebuilds/mods will happen in the future.

Your thoughts and input is appreciated. Thanks.

F1nut

The plan is to run the MW6503's as the 4 stereo drivers like the SDS SRS uses in my 2.3's. The crossovers are the same.

Huh what? What crossovers are the same?

It should add both bass and midrange since there will be 2 more stereo drivers and all six drivers will do bass by using the dimensional drivers.

All six drivers in your speaker already do bass and you already have 4 stereo drivers.

westmassguy

I'm confused.
If you want to improve their sound, do a recap, the "TL" Modification to the Hi-Pass Section, leave the Lo-Pass section as is, except for new caps, and new Sub-Base Drive Inductors.

TNTsTunes

F1nut wrote: »

The plan is to run the MW6503's as the 4 stereo drivers like the SDS SRS uses in my 2.3's. The crossovers are the same.

Huh what? What crossovers are the same?

It should add both bass and midrange since there will be 2 more stereo drivers and all six drivers will do bass by using the dimensional drivers.

All six drivers in your speaker already do bass and you already have 4 stereo drivers.

Nope... Check the 2.3 wiring pdf link to see how the speakers are wired.
Mine have the donut drivers above and below the dimensional drivers. the 2 stereo drivers are on the inside and 4 other on the outside or the opposite of a 2.3 TL design. My left and right speaker will switch sides after the swap to be like the 2.3TL arrangement.

Early SRS 2.3's have 2 stereo drivers(MW6510), 2 dimensional drivers(MW6511) and 2 sub bass drivers(MW6513). The dimensional drivers aren't sent a sub bass signal.

If you compare the original SRS to my 2.3's the crossovers use components with the same ratings. The difference is the separate sub bass driver circuit which is a simple change to make.

markamerica

Um, why? Or perhaps more properly, what exactly are you trying to accomplish? As per Westmassguy, I can understand if you were wanting to upgrade the HF circuits to accommodate moving to RDO-198s, but I don't understand what you're trying to accomplish on the LF side of this at all. Let me try to understand: What is the point of the modification you're proposing?
Are you trying to turn your 2.3s into 2.3TLs?

TNTsTunes

westmassguy wrote: »

I'm confused.
If you want to improve their sound, do a recap, the "TL" Modification to the Hi-Pass Section, leave the Lo-Pass section as is, except for new caps, and new Sub-Base Drive Inductors.

Doing a TL mod to 2.3's isn't worth the added expense do to the difference in crossover design.

This is a test before the crossover rebuild.

westmassguy

The added expense for the "TL" isn't that great, some of the small inductors can be reused, and the others can be ordered. Not a great expense. The other crossover modifications, are also not that extreme. I'd rebuild the entire crossover as a 2.3 TL. The cabinets can be flipped, and you'd end up with a functioning pair of 2.3TLs. What you're planning is a "Frankenpolk" with unknown results. Just my two cents.

TNTsTunes

markamerica wrote: »

Um, why? Or perhaps more properly, what exactly are you trying to accomplish?

Are you trying to turn your 2.3s into 2.3TLs?

I'm trying to gain 2 stereo drivers and have the dimensional drivers fed the sub bass signal. Basically I'm changing the low pass to have the same driver arrangement the 2.3TL's used.

Here is a comparason speaker picture. The SRS 2.3 are on the outside and SRS 2.3TL are on the inside.

TNTsTunes

westmassguy wrote: »

The added expense for the "TL" isn't that great, some of the small inductors can be reused, and the others can be ordered. Not a great expense. The other crossover modifications, are also not that extreme. I'd rebuild the entire crossover as a 2.3 TL. The cabinets can be flipped, and you'd end up with a functioning pair of 2.3TLs. What you're planning is a "Frankenpolk" with unknown results. Just my two cents.

To flip the cabinets and turn them into 2.3TL's on the low pass would require replacing the sub bass drivers with stereo drivers, wiring them correctly and the planned wiring changes to the crossovers low pass need to be done also.

As for being a "Frankenpolk" the resulting crossover set-up is a proven SDA SRS combination, the only difference is 2 less dimensional drivers which is corrected by the use of the 2 MW6510's instead of 4 MW6511's for the same overall ohm rating. The SDA1C uses the planned 2 dimensional driver set-up which is proven there also.

westmassguy

They're yours to do with as you please, so knock yourself out

TNTsTunes

westmassguy wrote: »

They're yours to do with as you please, so knock yourself out

I'm not asking for approval, just input. I don't want this to become an argument though...

I did realize some members were unaware of the different 2.3 main driver layouts. That was one reason I included the pdfs, which show it.

The SDA SRS 2.3 has six low pass drivers, 2 of which produce the full low pass 2 just do sub-bass and 2 just produce dimensional sound. This results in 4 drivers handling the stereo bass signal and 2 producing stereo sound.

The SDA SRS 2.3TL has six drivers, 4 produce the full low pass and 2 handle the dimensional sound along with a stereo sub-bass signal. This results in all 6 drivers handling the stereo bass signal and 4 producing stereo sound.

If you compare the crossover pdf links I included you'll see the SDA SRS and SDA SRS 2.3 crossovers use the same components in the low pass other then the low pass is sent to separate drivers instead of the dimensional array.

I would just be duplicating the stereo crossover and driver combo in the stereo array.
The sub bass would just be added to the existing dimensional array on the crossover. The crossover would then match the SDA SRS crossover and the dual MW6510's ohm rating is correct for it. The SDA 1C's use the same crossover specs and drivers except the inducer is a 16.0mh instead of a 16.8mh inducer like the SRS/SRS 2.3 uses. When I update the crossover I can change that if I feel it needs it at that point.

Basically I'm just swapping 4 drivers in each speaker and relocating a few wires. I'm not trying to re-invent the wheel or use any black magic here...
I was just looking for input, I should have just done it instead since I have spent more time trying to explain it then it would take to do it.

westmassguy

No argument here, you misunderstood. You asked for opinions, I gave mine. There was no malice or malevolent intent. I tell everyone, they're yours, do whatever you want with them.

F1nut

If you compare the original SRS to my 2.3's the crossovers use components with the same ratings.

The low pass of the SDA SRS 2.3 and the SDA SRS are not even close. However, the SDA SRS 1.2 and the SDA SRS 2.3 are.....somewhat. That said, there's the overall balance of the speaker to consider. Doing what you purpose will result in Frankenpolks, IMO.

TNTsTunes

F1nut wrote: »

If you compare the original SRS to my 2.3's the crossovers use components with the same ratings.

The low pass of the SDA SRS 2.3 and the SDA SRS are not even close. However, the SDA SRS 1.2 and the SDA SRS 2.3 are.....somewhat. That said, there's the overall balance of the speaker to consider. Doing what you purpose will result in Frankenpolks, IMO.

I meant the SRS 1.2...
It is the pdf link I posted.

I kinda feel the extra midrange and bass might improve the balance of the speaker.

I already had the MW6503's which are freshly broken in and the rest is simple wiring which all can easily be reversed if the sound balance/quality suffers.

It won't cost me anything to try it and I just might like it... I'd bet a better SDA inducer would help too. I just wanted to try it before doing other mods to see how I like the change. To my ears the midrange could use the boost and having all 6 drivers do bass like planned was an upgrade Polk did to the SDA 2.3TL's. I'm guessing there was a reason they switched to 4 stereo drivers too, I kinda hear why too...

They just might wind up as a scary good sounding Frankenpolks, only one way to find out though...

markamerica

TNT,

Like others, I wouldn't presume to tell you what to do with your speakers. I was looking at the schematics when I posted my question. I'm not entirely confident you will get the desired result from your proposed mods, as you've explained them. It could be that I'm not understanding your proposed mods, or that I am, but that I simply think they won't work out as intended. That said, like others, I say "have at 'em." No offense intended.

westmassguy

I'm one to tinker myself, my 2As are heavily modded, and include an Un-Sanctioned "TL" Mod. I will say this, your crossovers are over 25 years old. Those original caps are well past their prime, and the electrolytics, were crap even when new. The crossover point for the SDAs is around 2K if memory serves. That's handled almost entirely buy the woofers, with harmonics picked up by the tweeters. Replacing the Caps in the Hi-Pass and Lo-Pass with quality metalized polypropylenes, and upgrading the tweeters will completely change the character of the 2.3s. Replacing the sub-bass drive Inductors with low resistance Inductors, will also improve the low bass.

TNTsTunes

I intend on rebuilding the crossovers, but wanted to try this first to see the change this makes. It may determine what I exactly need to do with my crossovers. To properly do a TL mod to 2.3's it would require different caps and drivers arranged like this. I plan on using new drivers as part of the rebuild if this doesn't work out, but I just happen to have 8 fresh MW6503's sitting in a box to try first. This mod with rebuilt crossovers would sound even better, but I need to see how well it works first to determine if it's worthy.

I'm just not a fan of the sub-bass drivers and lack of bass signal to the dimensional drivers. I prefer the TL's design, but RDO194's work fine for me too...

I've hot-rodded SDA 2's so there were two stereo drivers and a bass signal to the dimensional driver with great results a few years back. I guess I just don't mind being different...

westmassguy

Like I said, they're yours to play with.

TNTsTunes

Thanks, I do appreciate your input. I know you understand what goes on with the crossovers and also do this stuff as a business besides. Your time counts.

drumminman

If you decide to move ahead with this please report your findings so we can increase the knowledge base here. Thanks!

Toolfan66

That picture you posted, I know the guy that used to own those and I was lucky enough to hear them with my own ears, and I'm going to tell you right now what you are wanting to do is a big waste of time...

The 2.3's do not lack any bass response next to the 2.3tl's..

I honestly hate the fact that the tl's get such high praise around here that it gets people like you to think of doing this project..

The only thing better about the tl's is the tweeters, and the RDO-198's are only slightly better then the RDO-194's..

Listen!!! upgrade the the crossovers, put in the RDO-194's and be happy with them, as well as the other small tweaks we do to these SDA's..

And if you still think you are lacking any bass look at the rest of the chain because it's not the speakers!! HeII if you think your lacking bass now I would look at the rest of the chain now!! It's not the speakers I can assure you that...

End of rant!!

zane77

Larry, you rock when you go on a rant!

TNTsTunes

Toolfan66 wrote: »

That picture you posted, I know the guy that used to own those and I was lucky enough to hear them with my own ears, and I'm going to tell you right now what you are wanting to do is a big waste of time...

The 2.3's do not lack any bass response next to the 2.3tl's..

I honestly hate the fact that the tl's get such high praise around here that it gets people like you to think of doing this project..

The only thing better about the tl's is the tweeters, and the RDO-198's are only slightly better then the RDO-194's..

Listen!!! upgrade the the crossovers, put in the RDO-194's and be happy with them, as well as the other small tweaks we do to these SDA's..

And if you still think you are lacking any bass look at the rest of the chain because it's not the speakers!! HeII if you think your lacking bass now I would look at the rest of the chain now!! It's not the speakers I can assure you that...

End of rant!!

Love it, great response.

Umm, I've heard both and felt the 2.3 lacked midrange sound when compared to the 2.3TL's. Neither lack bass.

The added midrange response is what really appeals to me, the bass increase is kind of a bonus to balance the out the change. I don't plan on building TL's, some RDO-194's are fine with me. With a upgraded crossover and the other tweaks of course.

They kinda seem somewhat like 1C's with some added highs and bass. Not a bad thing, but the 2.3TL's seemed to have a fuller midrange sound to me. Having them set-up with the SRS 1.2 stereo array should fill it in.

I'm just not a fan of the separate sub-bass drivers and the separate dimensional driver arrangement. The dimensional drivers work great with the sub-bass signal sent to them, why not use them. It allows the use of two additional stereo drivers to gain some sound in the middle, above the separate sub bass drivers range they are replacing.

I believe Polk moved away from them to stereo drivers and combination dimensional/sub-bass drivers for a reason.

This should be a good way to find that out. At least it's free to see.

Thanks for the rant.

TNTsTunes

Well the MW6513's and the MW6511's have been swapped out for MW6503's.

My SRS 2.3's now have 4 stereo drivers and 2 dimensional drivers.

The sub bass pass was added to the dimensional driver circuit also.

I didn't do any other changes, I'll add the rings and more later.

This change worked out better then expected. I've very impressed so far.

I wish I would have do it sooner...

It gets 2 thumbs up from me for sure.

TNTsTunes

After an extended listening session I can see why Polk didn't build them this way. They give the 1.2's a run for the money now IMO.
This change made the speakers kick it up a notch, to say the least. They have a different presence about them overall.

They sound very close to 1.2's, is the only way to explain it.

This upgrade is a success in my book and a keeper. Now I can work on the other upgrades I have planned...

F1nut

Polk used the donut drivers in the 2.3's because they had too much mid-range otherwise. Nothing to do with them sounding too close the 1.2's, that's just silly talk. Personally, I don't care for the sound of the 1.2's anyway, so in my book that you find the 2.3's sounding like them is not a good thing.

TNTsTunes

For me I felt they lacked some midrange, some songs they seemed held back, somewhat restrained at times.

I gained the midrange I wanted and some bass besides since now all six drivers handle bass instead of four. I kinda like 1.2's but preferred 2.3TL's to them. The 2.3's lacked the midrange the 2.3TL's have.

I now feel the speaker is well balanced and would choose them before 1.2's for sure. Someone else might feel otherwise. For me it was a noticeable improvement and the added midrange fixed my main complaint about the 2.3's.

If anything the tweeters are just a bit bright(SL2000's)but RDO's will handle that. I plan on upgrading the sub bass inducer for better bass response by using one with a lower DCR rating, adding Larry's rings, rebuilding the crossovers and more in the future.

It took about 30 minutes to convert each speaker and is very simple to do.

TNTsTunes

Adding the AI-1 Dreadnought has made these sound incredible.

It totally balanced the addition stereo sound output by making the dimensional array do their job to match the added output.

I would never go back to stock. No way, no how...

Now its time to move on to Larry's speaker rings and dampening the cabinets and drivers.

This story has a very happy ending.

Next up is following the standard SRS upgrade stories.