sda crs mid bass driver upgrade

[dam]

i have enjoyed my sda crs for many years but have always had to watch out for bottoming out the mid bass drivers when playing some cd . my amp is a adcom 555 and 555 preamp 200watts per channel 8 ohm 325 4 ohm. i talked to a few companys madisound, speakercity and parts express about replacement drivers that would allow higher playback volume without bottoming. i was informed about morel drivers by parts express they recomended the nm164 it is 6 1/4 inch outside diameter poly treated paper cone with a 3inch voice coil and double magnet structure handling150 watts continuous and210 watts peak. after checking morels web site i found morel usa the distibutor was located 2 hours from me . i called and the owner said i should bring one of my speakers in and i cojld see if his drivers fit .I heard the same driver in a transmission line speaker and was very impressed i endedup coming home with 4 nm164 drivers . after removing the original drivers i installed the new ones using mortite caulking to seal them in. i am still breaking them in but have found them far superior to the original drivers they work just fine with the original crossover and tweeters there is no strain at all at the high volume levels i play on rock music i used to have to always run and turn the volume down on some tracks with low bass note i run my preamp flat with no bass boost or eq. if anyone wants more detailed sound and depper bass check out these drivers it cost me 302 dollars for 4 and I could not be more pleased i had been thinking of larger floor standing speakers and have found my modified will stay in my system i have not heard many other systems even larger ones that sound better

[steveinaz]

Cool. That's a great speaker, and it sounds like you found some great replacement elements. Welcome!

[I-SIG]

How did the driver affect the SDA reproduction?

Wes

[dam]

hi again the sda efect was not effected at all these drivers are even more open sounding then the originals the magnet structure is at least twice as large as the polks they also have rubber sourounds and the voice coils use hexagonal aluminum wire it stacks and winds together without the air gaps inbetween round wires .also the magnets have a back vented pole . I cant wait untill ther fully broken in.

[Early B.]

This thread is a couple years old, but I was wondering if anyone else has attempted to replace the drivers with non-OEM ones? Surprisingly, this guy says he replaced the drivers with Morel nm164 without changing the crossover, but I can't find any info on these drivers.

[Loud & Clear]

Are we to assume then, that the replacement drivers for vintage polks aren't an upgrade along the lines of the tweeter replacement upgrades? I see it written that the SDA mid drivers are out of date technology and that the SDA's are limited based upon that. If so, and if the replacement drivers offer no solution to this, I'm surprised that someone, somewhere, hasn't been able to find a driver of better quality that works within acceptable tolerance of the specifications of the original drivers.

[F1nut]

BS! There's nothing wrong with the Polk drivers. I've had my CRS+'s cranked and I mean cranked. I've never had a problem with the drivers bottoming out. Dam's real problem is the amp he's using as it's not able to control the drivers.

[Early B.]

BS! There's nothing wrong with the Polk drivers. I've had my CRS+'s cranked and I mean cranked. I've never had a problem with the drivers bottoming out. Dam's real problem is the amp he's using as it's not able to control the drivers.

Unlike Dam, I don't have a problem with the drivers. My question really has to do with whether or not there is a drop-in upgrade for them.

[dorokusai]

I'm sure there are many current drop in replacements available, that would outperform all the vintage drivers, but if that's the case, build your own speaker. SEAS/Morel make a bonafide DIY trendsetter and it wouldn't suprise me if it's an easy tweak.

I think that some chamber data on those drivers would be best, but other than that you are stuck with your ears and specs.

[ESavinon]

BS! There's nothing wrong with the Polk drivers. I've had my CRS+'s cranked and I mean cranked. I've never had a problem with the drivers bottoming out. Dam's real problem is the amp he's using as it's not able to control the drivers.

I totally agree with jesse. I've had the sda crs + powered by different amplifiers and i have never heard any bottoming out.