SDA SRS bracing

Mr. Bubbles

I see from looking at Lasareath's site that the bracing in his 12.tl's is drastically different from that in my SRS's. Does any one know why the change to what appears to be less bracing in the later versions. Has anyone made modifications to the bracing in either model? If so what were the effects. I can't imagine why but is there any reason to remove some of the bracing in my SRS's?

Joe08867

Not to be a jerk but you have asked this already. The last thing you really want to do is mod the cabs in these speakers. If you do not have the background in speaker building it can be a costly mistake. And like we told you in the other thread about SRS and 1.2TL's. They are very different in almost every way. Cabs, Drivers, Tweeters, crossovers are all different.

Doing something in one does not mean you can do it to the other.

Mr. Bubbles

Joe08867 wrote: »

Not to be a jerk but you have asked this already. The last thing you really want to do is mod the cabs in these speakers. If you do not have the background in speaker building it can be a costly mistake. And like we told you in the other thread about SRS and 1.2TL's. They are very different in almost every way. Cabs, Drivers, Tweeters, crossovers are all different.

Doing something in one does not mean you can do it to the other.

I apologize if it seemed that way. I do not see where i asked this question already. I asked specifically here about the bracing, not the drivers and crossovers as I did before. I have many years of cabinet building experience, but mostly in car audio and yes I realize this is a different environment, though many principals of cabinet design are the same.

Most Logic would sate that more bracing equals a stronger cabinet with much less sympathetic vibration which would then offer better speaker control and a less colored (cleaner sound). Why then as the models progressed (and theoretically got better) did they use less bracing over the early versions? This has led some members to add bracing back, which shows that none of these models are perfect even though they are entirely different. If everyone was satisfied with them the way they were originally built then there would be no mods at all. people adding the bracing to the Tl's are apparently making them a little closer to the SRS's in that aspect. All I'm asking is would there be and sound reasoning in me going a little closer to the other end of the spectrum. I can't see the reasoning but apparently the engineers at Polk did.

I am simply trying to find out why the cabinet bracing apparently went backwards as the model progressed. The guys at Polk designing these things were no slouches and they must have had a reason. Was it simply cost savings (i doubt it)? was it to save the internal volume of the cabinet without making it larger (not likely, but possible), were they trying to build a cabinet and instead of eliminate the cabinet resonance, simply control a part of it? This could be considered since the later versions have the routed grooves on the insides of the cabinets. This could very easily control some of the sympathetic vibrations of the panels while still letting them flex more than the earlier cabinet designs. Either way a good passive radiator enclosure is a good passive radiator enclosure though it may be tuned differently for the specific drivers it contains the design principles hold true for any driver used in that type cabinet. Just like bracing is used in any bass reflex design as well as a sealed enclosure or even an aperiodic enclosure. The principals of bracing remain constant.

heiney9

Cabinet bracing is another reason you can't turn SRS's into SRS 1.2's. They are different speakers so be happy with what you have and upgrade within the confines of all the tried and true methods you read about here.

If you want SRS 1.2TL's...........then buy them. Trying to retro-fit parts between these two models has been tried and the expense involved is greater than just buying a pair of SRS 1.2TL's and then you really don't have 1.2TL's.

Don't overthink, much of the successes here on CP have either been guided by Matt Polk himself or a combination of his comments and the engineering department and then people like F1NUT, DARQUEKNIGHT and a few others have done a lot of trial and error over the years. Lot's of tweaks can be made to each model but very few can be taken from stock form to an entirely other model.

The 4.1TL mod performed on certain CRS+'s and 2B's was a Polk sanctioned mod that was intended to be used in production, but SDA's ceased being built before Polk could implement it.

H9

Mr. Bubbles

Cabinet bracing is another reason you can't turn SRS's into SRS 1.2's.

OK, let me back up and say that evidently i have given the wrong impression; I am in no way trying or want to convert these to the TL models. However, cabinet bracing has nothing to do with the model being a TL or not since TL stands for Tri laminate (tweeter) and has nothing to do with the cabinet. however going from a SRS to a 1.2 this would be significant.

so be happy with what you have

Trust me, I am EXTREMELY HAPPY to have these speakers

upgrade within the confines of all the tried and true methods you read about here.

Hell no! Those are great starting points but until someone tried them they were not tried and true. Did Mathew Polk do this when he designed these speakers? ABSOLUTELY NOT. Did DK do this with all of his testing and upgrades, or even on a smaller scale; Larry with his rings? Also (I realize this is not car audio and I keep mentioning it here, due to my back ground) this is not how I designed and built the loudest car in the world 2 years in a row. WITHOUT a factory sponsor!

Don't overthink

can't help it; that's who i am and my guess would be that there are at least several others on this forum with the same problem ( desire not to settle).

Lot's of tweaks can be made to each model

That is all i am trying to do; make the best of the model I have

very few can be taken from stock form to an entirely other model.

Once again this is NOT what I am trying to do. I simply want to make the best of what I have. If i wanted TL speakers I could very easily adapt the Tri Laminate tweets to these cabinets with only small crossover mods since that is what the TL means; it has nothing to do with the MW's or cabinet design.

What I want is the best synergy between all components of this system. Just like the rest of the guys here that mod their speakers. The only confines being my budget and my intelligence, and if I settle for what everyone else has done that makes me no more intelligent than the next guy, and trust me my budget is limited so I'm working the latter to the best of my abilities. I also realize that A LOT of this has already been worked out by others but am not ready to accept that others have thought of everything for this model yet. This is not only how speakers progress but life in general. We always start where others have left off and proceed from there. So when i ask the questions i ask i am trying to determine what others have done that worked for them and what they may have done that didn't work.

I would like to apologize if i have come across negatively in any way. I have not meant to do so. I simply desire to learn as much as I can about these speakers. I mean lets face it; the technology has been developed already. If someone wanted to build their own "SDA's" it could easily be done, with better components than what was designed for the Vintage Polks (driver technology as well as cabinet design and crossovers in particular have come a long way). But a lot of what we do is due to the satisfaction we get from having the Vintage equipment. (at least for me)

If you want SRS 1.2TL's...........then buy them.

I hope to own a pair of those some day as well a pair of the CRS+.

heiney9

Oliver, the cabinets of the 1.2TL's are different than the SRS's so YES the cabinet has everything to do with it being a 1.2TL. The drivers are different so they have everything to do with it being a 1.2TL, the x-over is different so it has everything to do with it being a 1.2TL.

I think you see my point. The SRS and SRS 1.2TL don't share anything in common outside of them being SDA's so it's not the Tri-laminate tweeter that makes them 1.2TL's, it's everything that makes them 1.2TL's.

Hope this helps

H9

P.s. As far as tried and true methods...........you seem to think you can do better, so have at it. You, by far, aren't the first and I'm sure you won't be the last.

FYI, most if not all of DK's work was done after extensive brain picking the engineers at Polk Audio, you know, the guys who spent 10 years doing all the research on SDA's.

heiney9

oliverbubbles wrote: »

If i wanted TL speakers I could very easily adapt the Tri Laminate tweets to these cabinets with only small crossover mods since that is what the TL means; it has nothing to do with the MW's or cabinet design.

Actually you can't, and YES the MW's and the cabinet are different. How would you solve the issue of the 1.2TL's being able to accomidate common ground amplifers with the use of the AI-1, but the SRS's can't? I guess you can't solve that problem with a small x-over modification........see what I'm getting at.

1.2TL's are completely different than original SRS's. There is no easy way to make them TL's.

H9

heiney9

I applaude your willingness to try something new or retry what has already been done.

H9

Mr. Bubbles

the cabinets of the 1.2TL's are different than the SRS's so YES the cabinet has everything to do with it being a 1.2TL.

Actually the cabinet is what makes it a 1.2 not the TL the cabinet in combination with the tweet is what makes it a 1.2 TL. The tweet IS the TL part of the equation.

I think you see my point. The SRS and SRS 1.2TL don't share anything in common outside of them being SDA's so it's not the Tri-laminate tweeter that makes them 1.2TL's, it's everything that makes them 1.2TL's.

I see your point exactly, but obviously i have not conveyed mine correctly. It is indeed everything that makes a 1.2TL over the SRS but it is only the tweet that makes a 1.2 TL over a 1.2. it is everything else that makes a 1.2 over the SRS.

Many owners are obviously not satisfied with their 1.2's the way Polk designed and built them and therefore they upgrade to the TL with a mod. this way they get the best sound from their speakers that they fell they can get and didn't settle for the way they were designed. that is all i am trying to do; determine possible mods that will make my speakers the best I can make them.

FYI, most if not all of DK's work was done after extensive brain picking the engineers at Polk Audio, you know, the guys who spent 10 years doing all the research on SDA's.

Already understand this, but also realize that If DK and others have improved on these guys design then the design is not the best it can be to begin with. How do you not see that i am trying to do the exact same thing here; since i don't have a contact list for the engineers at Polk, ( trust me I would rather go straight the source i am picking you guys brains (you know the ones that have already done that).

you seem to think you can do better

maybe maybe not, but I'm not willing to settle for what others tell me is an absolute, especially if they can't explain why.

and by the way, any body can be better at pretty much anything they want to be better at as long as they know where they are starting from.

I hope you can see my point now.

heiney9

oliverbubbles wrote: »

Actually the cabinet is what makes it a 1.2 not the TL the cabinet in combination with the tweet is what makes it a 1.2 TL. The tweet IS the TL part of the equation.

Perhaps I misread something, so you have SRS 1.2's not Original SRS's? If you have SRS's they are different than SRS 1.2's and the cabinet as well as different type of drivers and x-over is what makes it an SRS 1.2.

Is that better for clarification? Believe me, it's not necessary for you to school me on SDA difference's I am well aware of them.

H9

P.s. yea, we aren't communicating effectively in written form. I have no idea what you're trying to say at this point.

SRS
SRS 1.2 and SRS 1.2 TL's are all different and really can't be one or the other.

Mr. Bubbles

Perhaps I misread something, so you have SRS 1.2's not Original SRS's? If you have SRS's they are different than SRS 1.2's and the cabinet as well as different type of drivers and x-over is what makes it an SRS 1.2.

As far as this is concerned you did not misread anything. I indeed have the SRS's. However, at whatever point you thought I was trying to upgrade to the TL, something was misread. and when i was describing what makes a TL it apparently was misread that I meant a 1.2TL when I only meant TL and that is why I only wrote TL.

Believe me, it's not necessary for you to school me on SDA difference's I am well aware of them.

I am in no way trying to school anyone on SDA's as I am the newbie and that is why I am asking questions. I can tell that you are aware of the many differences but you don;'t appear to be aware of why the differences are there to begin with. that is what I am trying to find out with this thread, Not to convert one to the other.

P.s. yea, we aren't communicating effectively in written form. I have no idea what you're trying to say at this point.

Agreed! this seems to be turning into what my dad would call a measuring contest, when measurements don't really matter so much as the satisfaction gained from the experience. I think that is what everyone on this forum is after in the long run.

Joe08867

So you are looking to mod your crossover to use the SL3000 tweeter instead of the SL2000 tweeter?

Honestly just upgrade the SL2000 to the RD-0194 replacement and you will be very happy. Cause trying to TL that crossover is going to open a big bag of worms. You will have to change four of the drivers as well as the tweeters.

It isn't as simple as switch this for this. The tweeters have different ohm ratings as well as response curves. The sound of a 3000 compared to 2000 is night and day.

heiney9

I can tell that you are aware of the many differences but you don;'t appear to be aware of why the differences are there to begin with.

As to the why's, you'd probably have to talk to engineering. I can't tell you why the side wound voice coil MW's are better than the older style. I have no idea since I am not an engineer nor did I work for Polk on those speakers.

I have no idea why some drivers are 4 ohm and some are 8 ohm used in the same spots in different models, or how each one interacts with the original x-over or newer x-overs. I have no idea why they varied the frequency output for the SDA signal in later models, or why they simplified x-over of SDA's which can accept non-common ground amplifiers with the use of the AI-1.

My assumption is to make the experience better, more realistic, for use with wider types of electronics, less cost, simpler is usually better, better understanding of what they were trying to accomplish as they worked with the speaker concept.

H9

Mr. Bubbles

I could tell this thread was headed the wrong direction.

So you are looking to mod your crossover to use the SL3000 tweeter instead of the SL2000 tweeter?

No. I have copied my original question below. All i want to know in this thread is why the bracing in later models is much less than the bracing in earlier models. Also has anyone tried removing some of the bracing in the SRS models and if so what was the effect. i have read where bracing is to be removed in some of the earlier smaller models as a mod. This seems to go against normal logic. Please read my original question below. I am trying to wrap my head around why making a seemingly weaker cabinet is an improvement.

I see from looking at Lasareath's site that the bracing in his 12.tl's is drastically different from that in my SRS's. Does any one know why the change to what appears to be less bracing in the later versions. Has anyone made modifications to the bracing in either model? If so what were the effects. I can't imagine why but is there any reason to remove some of the bracing in my SRS's?

I know from my car stereo days that the path of the sound wave effects the wavelengths/ nodes at specific points in the cabinet and or listening environment. This is exactly why Polk recommended nothing be inf front of the speakers in the listening environment. i also know that this can greatly effect sound pressure level. My assumption is this is the reason for the bracing changes due to the sound waves passing from the MW's to the radiator but it would also seem that the weaker cabinet may color the sound.