RTI Tweeters
Answers
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this is exactly what I was looking for as I was also wondering about upgrading the RTi A7/CSi A6 tweeters on mine after I recap them and was wondering which one would be better replacement.
RTi A7:
Midrange/Woofer Crossover Frequency: 125 Hz
Tweeter/Midrange Crossover Frequency: 2,700 Hz
Csi A6: could not find this spec anywhere?
Tweeter/Midrange Crossover Frequency: 2,700 Hz???
Here are the specs along with frequency response graphs, looks like Dayton has the smoothest top end while other two might be bright?
-Peerless OC25SC65-04: 1.3kHz-20kHz, 96dB, 25 W
-Eminence SD28: 1.5kHz–20kHz, 92.5dB, 10 W
-Dayton ND25FN-4: 2.5kHz-20kHz, 90dB, 20W
or something different, 1" Dual Ring Radiator Tweeter?
-Peerless XT25SC90-04: 2kHZ-20kHz, 90 dB, 100W
Reading some reviews for Daytons looks like several folks used them for replacement on Polks and all were pleased with results:
https://www.parts-express.com/Dayton-Audio-ND25FN-4-1-Silk-Dome-Neodymium-Tweeter-Element-4-Ohm-275-053?quantity=1
Excellent factory replacement (Polk Rti-A9 tower)
Was listening to music when I felt that my right speaker sounded strange... After a few moments of inspection I found that the factory tweeter was not functioning at all. 20 minutes of research found that this is not terribly uncommon for Polk Audio. A little more digging and I came up with 2 models for replacement, this Dayton Audio and an Eminence model. Both were spec'd about the same but I liked the little cooling fin attached to the Dayton (factory model had this feature too) so I figured that was the way to go AND Parts Express posted pics of the Eminence model with a bent terminal which obviously means nothing but sort of makes it look cheap. Bought 2 pieces to make sure both channels matched in the end. After figuring out how to remove the factory pieces from the plastic trim housing I lined up the Daytons and carefully hot glued them on from the back. I'm not a pro but I think the results are awesome. The install was relatively easy and the end-result appears to be a great success.
Tweeter replacement in Polk Audio TSI300 towers
I used these to replace tweeters in my Polk Audio Tsi300.the faceplate needs to be modified by increasing the opening diameter.
I put them in and honestly,WOW!!..they are clean and smooth..way better than the stock Polk tweeters.the stock ones would break up on certain songs you could hear them starting to get compression.but the Daytons ,not an issue.If you dont mind modifying the tweeters faceplate to let the dome of the tweeters fit ..then definitely swap the out with these..they are a noticeable difference..i would recommend these.
better than Polk
I used these to replace my blown Polk Monitor 70 tower tweeters. These are extremely better than the stock Polk tweeters. More power handling, and more output . The sound is amazing. Very good quality.
these are great replacement tweeters for Polk Audio M70 Monitor towers. awesome power handling, and sound so much better. super happy with my purchase!
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exactly what I was looking for.
here are frequency responses for each:, Dayton looks best.
-Peerless OC25SC65-04
-Eminence SD28
-Dayton ND25FN-4
another out of the box possibility?
-Peerless XT25SC90-04 1" Dual Ring Radiator Tweeter
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exactly what I was looking for.
here are frequency responses for each:, Dayton looks best.
-Peerless OC25SC65-04
-Eminence SD28
-Dayton ND25FN-4
another out of the box possibility?
-Peerless XT25SC90-04 1" Dual Ring Radiator Tweeter
The RTI4's crossover at 1900 hz, and both the tweeter and midwoofer are 4 ohm, as are the Dayton, Eminence and Peerless you referred to. Not sure of the ohmage required for the drivers in the A7 and A6 models you mentioned, but can I assume 4 ohm as well? I think the Daytons produce the same highs but really excelled at the midrange levels compared to the Polks. And the Eminence has a mounting hole should anybody choose to swap over the heatsink from the back of the Polks, which, after removing the screw, pops off when gently rotated with large pliers. I would assume a dab of heatsink past before installing them is all that's required.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
I think A7 and A6 are crossed over at 2700 Hz and tweeters are 4 ohms as well.
I am getting ready to recap mine first then look into tweeter swap..or maybe I should do it the other way around since swapping tweeters out is easier and costs less
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I think A7 and A6 are crossed over at 2700 Hz and tweeters are 4 ohms as well.
I am getting ready to recap mine first then look into tweeter swap..or maybe I should do it the other way around since swapping tweeters out is easier and costs less
If you're going to recap, you may as well do the resistors as well. I know in my case, the failed tweeters also took out a resistor on both crossovers.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
yes doing the resistors as well!
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how do RTi4s with new tweeters compare to RTi A3 (those should have same tweeters as A7/A6). Do you feel A3 are to bright on certain music? Are you going to change tweeters on rest of your set up?
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@gp4jesus did you swap yours, what are your impressions?
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how do RTi4s with new tweeters compare to RTi A3 (those should have same tweeters as A7/A6). Do you feel A3 are to bright on certain music? Are you going to change tweeters on rest of your set up?
Their is no comparison between the RTI4s (original or updated) and the RTIA3, other than they both have 2 drivers each. The RTIA3's handle the full sound spectrum whereas the RTI4's make having a subwoofer almost imperative. The A3's are warmer and cleaner with much more headroom, although the 4's are damn good for their size and I have no hesitation recommending them, especially if budget or space limitation is a concern. They hit way above their weight class. I wouldn't have upgraded to the A3's were it not for the fact my 4's crapped out (until I fixed them), and the temporary XT15's I bought were definately a step down from the 4's. Mind you, my viewing room is smallish (10 x 14) and I'm only 10' from them.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
better ring tweeter option: peerless xt25sc40-04
https://www.parts-express.com/pedocs/specs/264-1642--tymphany-xt25sc40-04-spec-sheet.pdf -
The OD on that one is about 3mm too wide to fit in the faceplate cup, at least for the RTI4's. You'd also need to enlarge the dome opening so much that there would be hardly any lip left on the faceplate to mount it to.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
you are right, missed that. Looks like CSi A6 has tweeter crossed @ 2200 Hz which is lower than A7s and this dayton tweeter has Usable Frequency Range (Hz) of 2,500-20,000 Hz per spec sheet despite the FR chart showing flat response until 1,500 Hz or so?
Your RTi4s are crossed even lower at 1900Hz?
Wonder if that would be a problem?
https://www.parts-express.com/pedocs/specs/275-053--dayton-audio-ND25FN-4-specifications.pdf -
you are right, missed that. Looks like CSi A6 has tweeter crossed @ 2200 Hz which is lower than A7s and this dayton tweeter has Usable Frequency Range (Hz) of 2,500-20,000 Hz per spec sheet despite the FR chart showing flat response until 1,500 Hz or so?
Your RTi4s are crossed even lower at 1900Hz?
Wonder if that would be a problem?
https://www.parts-express.com/pedocs/specs/275-053--dayton-audio-ND25FN-4-specifications.pdf
The spec sheet on the Daytons says 2500hz but the graph clearly shows linear output from 1400hz and up. I think the 2500hz figure was a misprint.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
so I wrote email to Tony - Humble homemade hifi to get budget cap recommendation for the RTi A7. He wrote back with his advice and provided me with the frequency response chart showing why these are so bright.
I guess there are two choices to do this, either replace tweeter with one that has more flat response curve (like dayton tweeter above) or attenuate existing tweeter with resistor in series after crossover to bend the top end of the curve down. He does not feel that recapping will tame down the brightness on its own.
3 ways to attenuate tweeter:
https://youtube.com/watch?v=zoLBnEdVP6c
Here is RTi A7 frequency response and review (you will need to use google translate)
https://audio.com.pl/testy/stereo/kolumny-glosnikowe/374-rti-a7
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My modded RTiA speakers are no longer bright, so...Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Don't take experimental gene therapies from known eugenicists.
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so I wrote email to Tony - Humble homemade hifi to get budget cap recommendation for the RTi A7. He wrote back with his advice and provided me with the frequency response chart showing why these are so bright.
I guess there are two choices to do this, either replace tweeter with one that has more flat response curve (like dayton tweeter above) or attenuate existing tweeter with resistor in series after crossover to bend the top end of the curve down. He does not feel that recapping will tame down the brightness on its own.
3 ways to attenuate tweeter:
https://youtube.com/watch?v=zoLBnEdVP6c
Here is RTi A7 frequency response and review (you will need to use google translate)
https://audio.com.pl/testy/stereo/kolumny-glosnikowe/374-rti-a7
So you also have to remember that the original crossover was designed to the driver parameters for the original tweeters. The Dayton won't share these parameters so it will affect the overall frequency response.
If you like it there's no problem with that.
I wonder how big of a difference a simple crossover rebuild would make to the RTiAs, or even bright speskers in general. I can't wait to get a UMIK-1... -
well you and several others have swapped these out with daytons and reported improvement over the original tweeters so they can't be that far off (parameter wise). I would say SD28 are probably close to original tweeter spec wise.
now if I can only get my hands on couple of Rti tweeter bezels/faceplates so I can use those to try daytons out..
according to the midwestspeaker.com Eminence SD28: 1″ Dome 4 ohm Tweeter is a good replacement for many Polk Audio tweeters that are discontinued. Some modification is needed. You will need to remove the bad tweeter from the face plate (acetone will help soften up the glue) and mount this tweeter on the original Polk face plate.
The Eminence SD28 soft-dome tweeter offers unmatched performance to value in an ultra-compact design. With an overall diameter of less than 1.5 inches, this 4 ohm silk dome tweeter delivers smooth high frequency reproduction from 1.5 to 20 kHz. Perfect for home audio, car audio, ATV, RV, or any other application where space is limited.
SPECIFICATION
Type N/A
Throat Size N/A
Dispersion 60°
Power Rating 10W (AES), 20W (EIA-
Nominal impedance 4Ω
Minimum impedance 3.5 Ω @ 4.4 kHz
Sensitivity 92.5 dB
Resonance 1.5 kHz
Usable Frequency Range 1500 Hz – 20 kHz
Low Rec. Crossover 1.5 kHz
W x H (in) 1.48″ x 1″
W x H (mm) 37.6 x 25.4 mm
Cut Out Rear mount
Weight 0.1lbs, 0.05kg
Material Silk DomePost edited by zvucnik on -
F no!Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Ah, mea culpa. Must have been the phase plugs, good job.Don't take experimental gene therapies from known eugenicists. -
you are right, missed that. Looks like CSi A6 has tweeter crossed @ 2200 Hz which is lower than A7s and this dayton tweeter has Usable Frequency Range (Hz) of 2,500-20,000 Hz per spec sheet despite the FR chart showing flat response until 1,500 Hz or so?
Your RTi4s are crossed even lower at 1900Hz?
Wonder if that would be a problem?
https://www.parts-express.com/pedocs/specs/275-053--dayton-audio-ND25FN-4-specifications.pdf
The spec sheet on the Daytons says 2500hz but the graph clearly shows linear output from 1400hz and up. I think the 2500hz figure was a misprint.
So I emailed dayton about the usable freq range for this dayton tweeter and asked weather it would work with 2700 Hz A7 and 2200 Hz A6 crossover points.
This was their reply:
question about Dayton Audio ND25FN-4 usable frequency range
Especially with tweeters, frequency response or range doesn’t always correlate with usable frequency. General rule of thumb for tweeters is that you want to use a 12 dB high pass at or above double the resonant frequency (Fs). So for the ND25FN-4, that’s going to be about 2,700 Hz. Fine for the A7 speaker. Pushing it a bit for the A6 unless it’s a higher order 18 dB crossover.
Parts Express/Dayton Audio
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I ran the Daytons with my RTI4's which crossover at 1900hz and didn't notice any signal dropoff or dead zones. Looking at the Dayton graph, it shows flat output from about 1400hz and up. I can only assume that means "usable range" as the output at 1400hz is the same as the output at 20 khz.Polk RTIA3 Fronts
Polk CSIA4 Center
Polk PSW Sub
Pioneer VSX-521-K AVR
And a friendly Labrador Retriever -
At least Dayton gave you an answer but in my book that's called making a statement without explaining why, which is sometimes a bit aggravating. I mean, is the output distorted in a large band above the resonant frequency, so even though the sPL doesn't suffer, the quality does? Does it have to do with phase angle?
Crossover point to me means that the tweeter output is already some significant dBs (depends on the rollover rate dB/octave) of attenuation at that point, and the same is true for the mid. The two add together for a flat response, assuming no phase cancellation (there usually is an effect from phase though).Post edited by Gardenstater onGeorge / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
internet tells us 2 to 3 times tweeter resonant frequency, you can go lower if you have higher order high pass filter. Combo of resonant frequency, impedance curve and phase shift all come into play.
CSi A6 and RTi A7 are 2nd order if I am not mistaken?
A7 is fine @ 2700 Hz, but A6 has tweeter crossed at 2200 Hz so that could be a problem if pushed hard - does A6 home theater use qualify as hard?
Asked Dayton for alternative recommendations given what A6 crossover looks like, here is their response:
Hello,
The crossover for your A6 is second order, one capacitor and one coil. Third order for a tweeter would be a capacitor followed by a coil, then another capacitor.
There are a few other frameless tweeters with lower resonant frequencies you could consider, like these:
https://www.parts-express.com/Peerless-XT25SC40-04-1-Ring-Radiator-XT-Tweeter-4-Ohm-264-1642
https://www.parts-express.com/Peerless-OX20SC00-04-3-4-Fabric-Dome-Tweeter-264-1002
Thanks! -
the “1.9K…” where the HP/LP curves* meet or “crossover**.” If you study them* carefully (at least the tweeter anyway) the response pretty much flattens above ~ 2.5K.I ran the Daytons with my RTI4's which crossover at 1900hz…
**per Polk, the RTi A1*** curves XO @ 1800. However, in a test I saw as above**. Further, when I compared their*** HP component values (8uf vs 12uf) to the A7’s “2.7K,” I then realized the A1 F3 is actually higher than the A7’s F3.
Samsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work -
the “1.9K…” where the HP/LP curves* meet or “crossover**.” If you study them* carefully (at least the tweeter anyway) the response pretty much flattens above ~ 2.5K.I ran the Daytons with my RTI4's which crossover at 1900hz…
**per Polk, the RTi A1*** curves XO @ 1800. However, in a test I saw as above**. Further, when I compared their*** HP component values (8uf vs 12uf) to the A7’s “2.7K,” I then realized the A1 F3 is actually higher than the A7’s F3.
@gp4jesus What about A6?
Did you swap tweeters on yours with daytons?
Thoughts, how do they sound? -
You know where you can shove your phase plug.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Issuing a correction and an addition* to my previous post “from memory…” the series HP C1 filter values
A3 & A6*: 8.2uf
A1**: 9.1uf (
A7: hafta get back to ya
** direct descendant from the RTi4. Note: I don’t claim they both use the componentsPost edited by gp4jesus onSamsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work -
Issuing a correction and an addition* to my previous post “from memory…” the series HP C1 filter values
A3 & A6*: 8.2uf
A1**: 9.1uf (
A7: hafta get back to ya
** direct descendant from the RTi4. Note: I don’t claim they both use the components
here are the values:
A7
A6
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The A7 crossover looks like a 3rd order Butterworth high pass filter with a notch filter added and a 1st order low pass for the midwoofer.
Pretty good articles here:
https://www.diyaudioandvideo.com/Tutorial/DesignBuildCrossover/
https://www.parts-express.com/crossover-faqGeorge / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform
