RTA11T Xover Upgrade Specs/Suggestions

Pauly

So looking into upgrading the Xovers and was wondering if the specs were the same on the T's vs the TL's. Didnt see anything listed for just the T's so i would "Assume" but would rather check with the DIY'ers

RTA 11TL
12uF capacitor
16uF capacitor
34uF capacitor
1.5 ohm resistor
.3mH inductor
1.55mH inductor

Havent taken anything apart as of yet. Just wanted to start the ordering of parts and been getting my read on. Any advise on what brands etc to get. This would be a first for me.

Thanks

Pauly

F1nut

You should pull one of the crossover's out, it's easy to do, and verify the values you'll need. Forget about changing the inductors.

Sonicap's work well as do Mills resistors.

Whatever you do, do not use Solen's in the high frequency circuit.

Pauly

F1nut wrote: »

You should pull one of the crossover's out, it's easy to do, and verify the values you'll need. Forget about changing the inductors.

Sonicap's work well as do Mills resistors.

Whatever you do, do not use Solen's in the high frquency circuit.

Yeah i can do that. As stated this would be my first so im just trynig to make sure everything is kosher before i dive in. I'll pull one this week and report back and go from there.

Thanks

P

skrol

I wouldn't assume that the XO of the T is the same as the TL (although they could be if it is a very late T that has the SL-3000 tweeter). The "T" used the SL-2000 tweeter vs the SL-3000 in the "TL". Even if the same model number there can be changes to components. I have seen at least 2 different XO for the Monitor 5A both using the Peerless tweeter.

As stated above, the best bet is to look at the components used in your crossovers if you want to stick with the original design.

ben62670

F1nut wrote: »

You should pull one of the crossover's out, it's easy to do, and verify the values you'll need. Forget about changing the inductors.

Sonicap's work well as do Mills resistors.

Whatever you do, do not use Solen's in the high frequency circuit.

Yes sir!
Dayton"s are decent upgrades to the high pass if Sonicaps are out of the question, but as usual I recommend Sonicaps on the highs and Dayton's on the lows.
Ben

MillerLiteScott

From memory the RTA 11t per speaker

2 12 uF
1 34uF

1 2.0 ohm resistor
1 2.7 ohm resistor

Scott

skrol

I am not trying to hy-jack but thought that this might be helpful to the cause.

I had used Clarity Cap PX for the highs and Jantsen Cross Caps for the lows. After the fact I had heard some negative opinions of the Cross Caps. Did I go wrong?

It may just be me but I sometimes feel that the mids (male vocals) are a tad over emphasized. Would this be a result of my capacitor choices?

F1nut

Possibly. Did they have a polyswitch and if so, did you remove them?

Apostile

K, Jesse and har I got the wiring diagrams yesterday in the mail. I pulled a crossover and took some pictures of them as well. I'm by no means an electrical engineer, and I'm having some trouble reading these and IDing the parts on the actual x-over, but there are only 3 differences between the two crossovers that I can see. I'll scan these in and post them as soon as I can.

If you could maybe take a look at them and let me know what I'll need for parts I'll get them ordered up!!

Brian.

They scanned as .pdf files so I'll need to mail them to you.

Pauly

MillerLiteScott wrote: »

From memory the RTA 11t per speaker

2 12 uF
1 34uF

1 2.0 ohm resistor
1 2.7 ohm resistor

Scott

So just by that they arent the same as the TL xover. Im gonna pull out and snap some pic so we have the T on file as im getting more hits on the TL.


On a side note whats a ball park figure on upgrading the Xover cuz i havent a clue. Also whats the best place to order from? Partsexpress?

Thanks

Pauly

skrol

F1nut wrote: »

Possibly. Did they have a polyswitch and if so, did you remove them?

Mine did to have poly switches.

It seems like the strong mid-range is coming from the MW's. Would the bypass capacitor in the LPF have this effect?

Pauly, for cost of the upgrade, it can be all over the map. There are some super expensive caps out there. You need to weigh what is practical. My upgrade for the XO, replacing the caps and resistors only came to about $25 per speaker. Based on what you read above, I might have been better off spending a little more for better components but the jury is still out. I got my parts from different vendors based on part availability and price. Parts Express is good, I also bought from Madisound. A few others are Sonic Craft, e-speakers, and Partsconnexion.

Pauly

So lets just say mine have

1 34uf
2 12uf

the 34uf would be the High and the 12uf would be the low? make sense but im a rookie at this

Pauly

Face

No, the smaller values are for the tweeter. That's where you would want to use high quality caps.

Pauly

Face wrote: »

No, the smaller values are for the tweeter. That's where you would want to use high quality caps.

Ok i thought since there was 1 it would goto the tweeter cuz there is only 1 and 2 for the mids cuz there are two. I got it backwards.

Thanks

Pauly

F1nut

Mine did to have poly switches.

It seems like the strong mid-range is coming from the MW's. Would the bypass capacitor in the LPF have this effect?

Did you remove the poly's?

Get rid of the bypass cap.

skrol

I did not remove any. Where would they be located? You can see pics of my XO before and after in the following link (#41).
http://www.polkaudio.com/forums/showthread.php?t=73017&page=2

Stan

Pauly

Cant find any 34uf caps in my search. Will a 33uf suffice or will that cause chaos?



Pauly

Face

33uf is fine.

F1nut

Stan,

Ok, looking the schematics you should have a 12uF, 16uF, 34uF and one 1.5ohm resistor. There is no polyswitch. I take it you piggybacked two caps to get the proper value, yes? If the proper value is not available, it's better to use two caps as close in value as possible like an 8 uFand an 8uF rather than say a 15uF and a 1uF.

Anyway, back to your issue. Try using a 2 ohm resistor in place of the 1.5 ohm and see if that doesn't tame things down a bit.

I take it that these crossovers are fully burned in, yes?

F1nut

33uf is fine.

Or you could use two 17uF's to get the 34uF value.

skrol

Yes, I did parallel the caps to get the proper value. They should be burned in by now as I did the upgrade back in Dec and the system is used several hours throughout the week and even more on weekends. I may try changing the resistor.

One thing that I did find is that they sound better balanced if I am horizontally on-axis with the speaker (ie. sitting). I notice the stronger mid-range if I am standing. The speakers are located in my sunken family room. If I am in the kitchen, which is about 8" higher, I really notice the mid-range. I did angle the speakers pointing up a tad and found improvement.

F1nut

One thing that I did find is that they sound better balanced if I am horizontally on-axis with the speaker (ie. sitting). I notice the stronger mid-range if I am standing. The speakers are located in my sunken family room. If I am in the kitchen, which is about 8" higher, I really notice the mid-range. I did angle the speakers pointing up a tad and found improvement.

Well, that's your issue right there. The sitting position is where you should be judging the sound.

skrol

I guess I just don't sit enough. Is it the MTM configuration that makes these speaker so vertical (had that wrong before) position dependent? If so, this may explain the addition of the spoiler above the tweeter.

I know that it is a different beast but I didn't notice this position sensitivity with my Monitor 5A's.

Face

Your tweeters should be horizontal to or aimed towards your ears.

EDIT: Yes, driver configuration can affect dispersion.

skrol

I'll see what I can do to make that happen.

Sorry, I didn't mean to take over the thread.

Now back to the original topic

Pauly

F1nut wrote: »

Or you could use two 17uF's to get the 34uF value.

would it make a big difference if i use a 33 vs two 17's?

F1nut

Pauly wrote: »

would it make a big difference if i use a 33 vs two 17's?

Probably not too much seeing as the originals were +/- 10%, but I like to get things as close to spec as possible. I mean, they spec stuff for a reason.

F1nut

skrol wrote: »

I guess I just don't sit enough. Is it the MTM configuration that makes these speaker so vertical (had that wrong before) position dependent? If so, this may explain the addition of the spoiler above the tweeter.

Just about every speaker has a sweet spot and will sound different off axis. Some designs sound pretty much the same wherever you are and I've heard others that when you get off axis, the sound completely disappears. :eek:

skrol

The RTA11TL seems pretty amazing for horizontal off-axis. I can be inches in front of one speaker and still hear startling detail in the music coming from the other speaker. I think the vertical off-axis must be pretty tight. I think that the sales literature eludes to this though they put in terms of resistance to reflections off the ceiling and floor.

heiney9

skrol wrote: »

The RTA11TL seems pretty amazing for horizontal off-axis. I can be inches in front of one speaker and still hear startling detail in the music coming from the other speaker. I think the vertical off-axis must be pretty tight. I think that the sales literature eludes to this though they put in terms of resistance to reflections off the ceiling and floor.

That's because it's a true D'Appolito array.

D'Appolito
A loudspeaker configuration developed by and named for Joe D'Appolito, in which a high frequency driver, or tweeter, is positioned between two midrange or low frequency drivers that each cover the same frequency range. Depending on the exact implementation the speakers can be positioned with a vertical and/or horizontal orientation. In either case the two midrange drivers serve a couple of purposes: they combine to create a larger effective woofer or midrange driver size, and they also serve to control the dispersion of the tweeter. The tweeter's output is somewhat corralled or contained by the sound coming from the midrange drivers in a similar way to how two parallel surfaces control dispersion. There are some variations on the design where two same sized woofer/midrange drivers may cover slightly different frequency ranges, however those aren't considered true D'Appolito designs.

The D'Appolito design specifies a third order crossover network. �The tweeter is coordinated with the woofer so that at the selected crossover frequency, the drivers all have similar horizontal dispersion. �(This is not easily accomplished because many drivers behave badly at the extremes of their range.) The advantage of doing it all correctly is one of the most seamless blending of drivers possible. �The result is an absence of any sudden change in directivity with frequency. �This may not mean much for monitors where there is a limited listening area, but in a typical room where a large percentage of the sound is reflected by the room, the effect is dramatic

H9

P.s. RTA 11T or TL are very nice sounding speakers.

skrol

Thanks. That is great info.