RT3000P Subs

sburns

I have a question regarding these unit. Why does everyone sell just the subs on EBay. Are the upper units really RT55i's ? Could one purchased the subs and add the RT55's to build a completed RT3000P system. I just seems odd that this happens all the time.

Ceruleance

respectively: I don't know. no. no. me too.

Airplay355

actually the top unit is the rt55, not the rti55i. i thought you could buy the subs and add rt55s to it if u wanted to, why wouldnt u be able to? you can add speakers to a regular sub.

Dennis Gardner

I understand that the crossover points aren't the same. The top of the 3000 is not a full range speaker.

But then again, I could be mistaken.

Dennis

warlocks1

The 55 is not the same. I don't know all the specifics. The 3000 is not ported and has a crossover of 80 HZ( blocks all frequency below 80 HZ). The problem with running the 55 as the top half is the frequency response. You set the 3000p's to large with the sub and it will also send full range frequencies to the 55 which could damage the speaker. I have been looking a long time for the top halves of the 3000p with no luck. Call Ken at Polk for the specific differences.

sburns

Ok, so the 3000P has a crossover in it, 80Hz and below to the subs, all the rest out to the upper unit. The RT55, is available as a standalone speaker, so it would be designed to handle the full frequency range for those who do not have a sub.

So the RT55x on top would only get stuff above 80Hz. Even though it can handle the lower stuff (maybe not as well as a sub) should it not be ok ? I could see that the crossover within the RT55 may be different than the RT3000p uppers as in the RT3000p configuration it knows the mids would not need to handle as broad of a range as it knows the 80 and below was bled off by the subs on the bottom.

Does this make any sense ?

warlocks1

Sorry I wasn't clear. The subs send full range frequency to the top half. There is no crossover for the signal leaving the sub. You will be sending full range to the top half. The 55 can't handle the low freuencies and could be damaged at high volumes. There is no high level crossover in the sub. I am sure I am not explaining it properly, but I asked Ken about it and he didn't recommend it. You could split the main line outs from the preamp and use some line level filters before the amp to block the low frequencies. You would run one split cable to the ine level input on the sub and run the speaker level outputs from the amp to the top speakers. I have a pair that reduces anything below 80 Hz by 6 dB's but will have to look for them to see who makes them I hope I have explained this properly.

Airplay355

nvm i guess u guys r right, i always thought u could buy them as seperate units and put them together later if u felt like it

Ceruleance

warlocks, dude you have some mis-information. RT55's and RT55i's are full range speakers, if you send them regular music with low frequency content they won't be able to play those lows accurately or loudly at all, but it won't damage them either. I mean sure, if you get a 20 hz test tone and then crank up the gain, you might be able to cause some bottoming and some damage, but other than that you should be fine.

On using 55's in place of 3000p tops:
One of the problems is the frequency response, if the RT55's are not set to roll off at 80, and the sub is set to roll off at 80, between 50 hz (the natural drop off of the 55's) and 80 hz,
you are going to get reinforcement and a bloated freq. response.

As to whether it's a good idea to use RT55's with 3000p subwoofers, yes and no. The 3000p's were designed as an integrated system, so obviously the tops and bottoms should integrate very well and sound the best. However, the 3000p subwoofers are a subwoofer just like any other. If you have the 55's (or any other speaker for that matter) crossing over to the subs so that there is no overlap in the frequency response, you should have a fairly viable solution. An external crossover such as a Paradigm X-30 may aid in this task.

although the speakers may use the same drivers the 3000p tops were designed to maximize frequency resp. above 80 hz, while the 55's were designed to be full range, so obviously if you cross both speakers at 80 and polk did their job, the 3000p tops should sound better.

On another note I believe the 55's are wider than the 3000p tops, which would make for a not very attractive speaker on top of the subs.

RuSsMaN

So in other words....

Originally posted by Ceruleance
respectively: I don't know. no. no. me too.

Cheers,
Russ

Ceruleance

Originally posted by RuSsMaN
So in other words....



Cheers,
Russ

Pretty much. I tried to give 'em the easy route.. :rolleyes:

warlocks1

Cer, I believe that is what I said. Anytime you run full range to a speaker not capable of reproducing it you are risking damage to the speaker at loud levels. I agree with your "music" statement, but it isn't true in respect to movies. You can easily get 25-30 hz going to the mains which could result in damage, especially at reference level. An active crossover is a good solution, but can be expensive. I am not familiar with the Paradigm X-30, but I imagine you would need one for each side.
BTW, I wouldn't call the 55 a full range speaker.

PolkWannabie

Don't most speakers, full range or otherwise have high pass filters that roll off below wherever the manufacturer thinks they should ? and shouldn't this prevent damage ?

BobMcG

Among the differences:

sat - 60lbs pr.
55i - 76lbs pr.

sat - 8"W x 8 1/2"D Base Dimensions
55i - 9 1/2"W x 14 3/8"D " " "

sat - 50 - 500 watts/channel recommended amplification
55i - 20 - 200 " " "

sat - 92dB Efficiency
55i - 91dB Efficency

Scale:
Every 3dB increase is double the output level. (Twice as loud.)

And yes, the sats. are ported.

warlocks1

Thanks Bob. I forgot my 3000p's were ported. How would you compare the 3000p to the SRS? Mostly in terms of soundstage and imaging?

BobMcG

I've used the 3000's for music and not that "I didn't like them" I just don't like them nearly as well the 2.3's. I can't get the bass to behave the way I like with the 3000's.

I.M.O. the sats. are the 3000's strong point and the subs their weak point. Even with the 3000's being used for HT duty I have the switches set for music not "boosted" (+3dB) in movie mode.

On the other hand the 2.3's are not only Polk Bass Braced to the wall, they are also spiked to the floor. In addition they are equipped with TEKNA Vibration Absorbers. C-10's upper and C-12's lower. They are biamped, biwired and connected via a Polk AI-1. )They are also wearing two pairs of Vampire Wire's best gold binding posts.) The bass is incredible. Deep, tight, precise, under control. The overall sound is clear/clean and with the wide, deep sound stage SDA lovers enjoy so much.