SDA SRS cabinets differences

gregmoyers

I have 2 questions. On the srs originalal cabinets are the top and bottom woos caps solid or are they laminated?
How do you get the side wood pieces off?
Thanks!

F1nut

The end caps are made up of strips of solid wood boards. You can see the end grain and joint lines on the left and right sides of the end caps. I've seen plenty that suffer from separation at the glue joints. Later SDA models have MDF end caps with wood veneer, which is much better.

The side panels are attached with treelock fasteners. You can pry them off by slipping in a thin putty knife and gently prying up. Be very careful as the panels can easily break.

gregmoyers

Thanks brother! I have the originals but the caps are perfect. I’ve had them since 1987.
I noticed they looked solid compared to obvious laminate on later versions.

gregmoyers

I keep reading how the srs1.2 and 1.2tl cabinets are so superior to the original srs cabinets. Can someone tell me in what way they are superior? Structurally, sonically? Without the bracing that the srs’s have there is acoustic differences but I’m sure Polk engineered accordingly. The material look’s different and has grooves all over. I know the top and bottom finished caps went to veneer instead of the beautiful solid wood on the originals. What I see is they were cutting costs. Looking for reasons that the cabinet on the TL’s are superior. Thanks

VR3

I think it's just a different way to tackle the same animal while reducing weight and construction costs to be honest.

I have heard all three multiple times and once fully hot rodded and done up... The performance gap between them become very very minor

pitdogg2

First SRS is particle board from my understanding. 1.2&1.2tl is MDF. The grooves broke up standing waves within the cabinet.
They went to veneer tops because the solid split/warped and the edge grain looked like crud.

F1nut

pitdogg2 wrote: »

First SRS is particle board from my understanding. 1.2&1.2tl is MDF. The grooves broke up standing waves within the cabinet.
They went to veneer tops because the solid split/warped and the edge grain looked like crud.

^This^

What I see is they were cutting costs.

Nope, the exact opposite.

gregmoyers

Ok. So the grooves on inside are to break up standing waves. Does BH5 accomplish the same?
I see most discussions on BH5 pertain to 1.2 cabinets. Should I try it in my original cabinet and what results should I expect?
It’s hard to agree with the laminate caps being an improvement. I guess I’m just lucky cause mine look beautiful. Not so much for the laminated ones I have seen. I bought mine new in Japan, moved to SF, San Diego and have had them here in Las vegas for the last 30 years. The wood is perfect.
I do like what VR3 says about the 3 models after all the mods being very close. I am constantly wondering if it would be worth parting with my mint condition originals for some 1.2tl to start all over with. I think I’m good. Just always wondered the cabinet changes.

gregmoyers

gregmoyers

Plus they are upstairs ! Not worth it.
😉

F1nut

BH5 is a bit different than the grooves. BH5 is a damping material, it absorbs back wave reflections. The grooves break up standing waves.

Glued up boards of solid wood is generally not a good choice. Polk tried to reduce one pit fall of using solid wood by making the boards rather narrow and flip flopping the grain of each board to help reduce cupping and shrinking.

MDF is inert making it ideal for speaker cabinets. The wood veneer can have no to very few seam lines for a more pleasing appearance. The edging is face grain, so no end grain shows like with solid wood. Again, for a more pleasing appearance.

All bets are off if either of the above gets soaking wet.

pitdogg2

BH5 and dacron both slow the wave to make it appear the cabinet is larger that it is. BH5 is superior to dacron. Both need to be used, you're not deleting the rolled up dacron due to the BH5 use.

gregmoyers

Solid wood for me.
If you buy expensive furniture it better not be veneer. I guess I’m not going to veer from that.🤷🏻‍♂️

pitdogg2

gregmoyers wrote: »

Solid wood for me.
If you buy expensive furniture it better not be veneer. I guess I’m not going to veer from that.🤷🏻‍♂️

You're comparing apples to oranges in this case.
Yes we both agree on the solid wood quality furniture. It last for generations and is a hand me down.

F1nut

Such a mistaken notion about veneer. It's been around since at least the Egyptians. It is the only way to obtain certain appearances. Once applied it is extremely stable. Most of the finest, most expensive furniture in the world has veneer on it.

One of the many disadvantages of solid wood is it never stops moving. Humidity makes it expand. Lack of humidity makes it shrink. The seasonal changes cause up to a 1/4 inch of movement. That leads to splits, cracks, cupping, warps, etc.

F1nut

gregmoyers wrote: »

Solid wood for me.
If you buy expensive furniture it better not be veneer. I guess I’m not going to veer from that.🤷🏻‍♂️

You'd be surprised at what you think is solid wood furniture is not.

F1nut

A few examples of VERY expensive furniture using veneer for an appearance that would be impossible using solid wood.

gregmoyers

Very nice.
I love my wood. Don’t we all??
😂😂😂

txcoastal1

I loved the high gloss veneer finish of my Dynaudio C4 speakers

Emlyn

One significant difference I observed between original SRS and TL models was the midwoofers and passives were bolted to the cabinets via small metal inserts in the SRS. I figured the chip board material was the reason for the glued in insert mounting method. On the TL cabinets the drivers were just attached with wood screws with a few of them stripped out over time. On the other hand some of the inserts on the SRS also failed. Larry’s rings were a major remedy to these air leak and loose driver problems.

michaeljhsda2

My 1.2TL's did not have any metal inserts on the passive radiators, just wood screws. Same for the tweeters. The mid-woofers had threaded metal inserts of which some were stripped out.

gregmoyers

Yes. My srs’s have metal inserts that are screwed in not glued. I have had a few come out with the screw when removing a driver so I removed all of them and put a small amount of loc tight power grab and secured them all. You can buy these inserts at Home Depot but I would take a look at hurricane nuts instead. There is not a lot of material around the drivers so it seems kinda risky. I would do Larry’s rings if they were still available. I was thinking of having some made.

gregmoyers

https://us.v-cdn.net/5021930/uploads/editor/76/a6d2m3he9tbs.png
Beautiful.

michaeljhsda2

gregmoyers wrote: »

I would take a look at hurricane nuts instead.

At least 10 years ago I brought up this issue with the stripped out inserts so I used T-nuts by cutting the tabs off and using adhesive to set them (t-nuts can't penetrate MDF). I had the right idea but @F1nut pointed out that I should use hurricane nuts instead so I switched to them. Simple and very effective! Not long after that solution to the problem, Larry @Toolfan66 came up with the rings idea.

gregmoyers

Wish I had rings.

gregmoyers

All this talk about solid wood and veneer got thinking.
How cool would granite be?
Mine are fine now but F1 got me waiting for them to crack and warp.

F1nut

Plenty of examples here and online.

Jazzhead

In a former life I did quality control at Drexel-Heritage furniture in NC (before the industry was woefully offshored and destroyed...). F1 speaks the truth regarding solid wood vs veneered MDF core-stock panels. Properly constructed solid wood panels are glued-up with pieces oriented with alternating grain direction as F1 described above):

Alternating grain direction attempts to make the panel dimensionally stable (equalizing shrinking and swelling from changes in temperature/humidity). MDF is much more dimensionally stable than solid wood (an MDF core-stock with veneer applied). Veneering core-stock lets one create those lovely bookmatched designs F1 posted above, which would be impractical/expensive/wasteful from a solid chunk of crotch or burl grain wood (which would likely not behave dimensionally over time). One practice to mitigate problems with solid wood panels is to make sure all sides/edges have a finish applied so each surface is absorbing/releasing moisture at the same rate (discouraging glue joint failure, cupping, twisting, splitting etc.).

pitdogg2

How cool would granite be?

Some rocks ring like chuch bells. I would never have believed it until it was proven to me. Once at a gem and mineral show I witnessed a demonstration on the matter. The gentleman had some petrified wood, some was petrified with iron based content and the other was petrified with silica based content. It was amazing and completely different rings. He then moved on to granites and marbles. Once again how those two came to be in the earth had very different sounds.

Had I not experienced it right before my eyes I would never have believed it.

Emlyn

I put something that weighed a few pounds on top of one of my SDA-SRS speakers once to see what the effect would be and it had the effect of deadening the music and sucking the life from that one. Not good.

Jazzhead

pitdogg2 wrote: »

gregmoyers wrote: »

Solid wood for me.
If you buy expensive furniture it better not be veneer. I guess I’m not going to veer from that.🤷🏻‍♂️

You're comparing apples to oranges in this case.
Yes we both agree on the solid wood quality furniture. It last for generations and is a hand me down.

Also, I shouldn't imply that you can't build great solid wood furniture. In fact all that furniture F1 posted above probably has solid, glued-up core-stock under that veneer (built before the use/development of plywood, MDF etc.). With the right design, joinery, fasteners (that accommodate the inherent movement of wood) solid wood furniture is great (we have a house full of old solid pieces). For an air tight speaker cabinet, MDF/veneer is optimal.