Your opinion please

HUNTER

Hey Johnny,
I wasn't referring to you in my statement. I think that people need to lighten up sometime too.

HUNTER

Ok,
This is what I have discovered by chatting with some people that are in the field of speaker building.

#1 when building a speaker you start with the drivers specs.
#2 build a box and provide port tuning based on the drivers specs.
#3 build or purchase a xover based on the drivers specs.

Where am I going with this you ask?
I started this topic in an attempt to understand polk speakers better and to attempt determine whether or not it would be possible to turn the RT800i speakers into a hybrid Cascade Array type speaker based on the rt3000p crossover.

From information that I have been told by those who are in this field, As long as the box is built and tuned to the driver specs and a xover is chosen for the drive specs and freq then the box size and tuning are not factored in when choosing a xover.

What does it all mean?
I beleive that if you take the xover from a rt3000p and install it on an Rt800i then you would end up with a floor standing rt3000p sat speaker with Cascade Array. Although the box is different the drivers are the same and since the xover is based on the driver and not the box then the speaker should sound great. This is all theory at this point. Now I will put my theory into practice.
If any one has information to refute this theory please advise
I am open to all information, advise and ridicule.

danger boy

I have a very simple question. Are my 800's three way or two way speakers?

Yeah they have a tweeter and a woofer.. but are the two 6.5 " drivers for midrange or to extend the bass?

thanks

jcaut

danger boy,

Your 800's are two-way speakers. The 6.5" drivers receive the same signal.

Hunter,
Concerning the 800's-to-3000's idea: IF the drivers are IDENTICAL then it might work. I say they're not identical, but you, and others here seem to think they are---and I'm not going to argue that, because I don't know.

I'm not saying the 800's are perfect, and can't be improved. I'm just saying that trying to turn them into 3000's by swapping crossovers is not likely to produce the desired result. I thought this thread started off as praise for the RT800i's....they're very nice speakers for the price! The fact that they were designed as two-way's and not two-and-a-half way speakers is really irrelevant, and certainly not a reason to become dissatisfied with them.

If you want to try and improve them by swapping crossovers, then that's your business. But if you want my OPINION (if you don't, then just ignore me), it's a bad way to go about improving them. I said repeatedly that I think you should contact Polk and ask about the crossover swap. I'm PRETTY SURE they'll tell you that the drivers are not the same and that swapping the crossovers would be a bad idea (but maybe not--just my opinion). If you don't believe them either, then just go for it and see what happens. Post back with the results.

That's ALL I'm going to say about this. And I'm not being sarcastic or "heated" or anything! I appreciate the fact that you want to improve the performance of the speakers, and wish you good luck in doing so! Just get some FACTS first, and not just opinions.

Jason

juice21

i would be interested if this did give you the desired results you are trying to acheive. if you go ahead with this 'tweak', keep us updated. i think there are alot of 'ifs' up in the air from the sounds of it, i would recommend talking this over with ken @ polk before you spend any time or money on it. he'll set you straight on what the facts are...

good luck.:D

Aaron

This is quality entertainment, let me tell you!

Aaron

rskarvan

FACT: the black drivers in the 3000 Sat are DIFFERENT than the blue drivers in the 55i. Supposedly, the 3000 drivers are slightly better.

fabian1

Im with Rusman, sorry its brief but he is correct, regards Fabian:)

goingganzo

if you have the non i verson of the 800 they have the non blue drivers

HUNTER

A brief history of this thread:
I became interested in a possible tweak for the rt800i using a rt3000p satellite crossover.
While researching the different Polk speakers to ascertain the similarities between the different models a learned a lot about these speakers.
Thru information provided by members, outside sources, and tech support I found some information some of you already knew.
Although the majority including myself felt that Polk utilized the same 6.5” drivers in all their models is incorrect. The rt55i uses a similar but not exact driver that the rt800i uses while the rt3000p sat uses a very different driver. (members, tech support, and visual inspection)
Although the rt55i and the rt3000p sat look similar in box size they are not. The 3000 is a smaller box that is sealed, while the rt55i is ported. (tech support and visual inspection).
Based on my research I cannot find any profound similarities between models; therefore I cannot rationalize the benefit of a xover change. I have in fact learned a lot about the Polk line and the model that I use, therefore I feel that my time was not wasted. I am still interested to see if changing the crossover will yield any benefit and may try it to see for myself.
I appreciate all the information that you guys have provided.
Thanks

HUNTER

I decided to put my money where my mouth was and try this tweak.
I purchased two rt3000i sat xovers and replaced the stock rt800i xovers with the new rt3000i xovers.

Testing:
In order to see what the potential difference between the two speakers (stock and modified) rt800i would be, I replaced the xover in one speaker and performed an a/b test.

Music tested:
Fleetwood mac
Billy Holliday
Sinatra

Results:
The modified rt800i had more detail and separation than the stock rt800i. The music was more transparent and showed more separation from instruments.

My Thoughts:
I originally became interested in this tweak because of the slight muddyness of the midrange.
I feel that the difference between a good speaker and a great speaker are minor if you are not a true audiophile, and most are not. You can spend $500 on a good speaker and $1000 to $10,000 for better speakers. The question is how much better is the sound of a $10,000 speaker than a $500 speaker, a true audiophile would say night and day, but a normal enthusiast like myself would probably not notice a big difference.
For $120 in materials I would say that I turned a good speaker into a better speaker, and that the money was well spent. Whether anyone else tried it and would be happy with the resulsts remains to be seen.
So if you are a true die hard audiophile that listens to detailed riffs with the lights off, in a perfect acoustic environment, then buy yourself some $10,000 speakers for peace of mind.

danger boy

Nice work Hunter.. i'm sure the improvement.. even thou it may be slight, is an improvement.. we all like to get just a little extra umph out of ever component.. so thanks for posting your findings.
tonight i finallly bi wired my 800i's. and there again.. not a big difference.. but i did notice that they now seem to have a wider sound field... before it seems if you were not dead on in the sweet spot... it sounded lopsided ... now it appears that it's more diffused and open..
I didn't see much if any increase in bass or treble..
it was cheap and something i've been wanting to try out for myself. and yeah for about $50 in speaker cable and banana plugs.. i'm happy for now. ask me again in two months. ha ha ha

juice21

hunter, very interesting. did you contact anyone at polk before doing this tweak? they have any thoughts/comments/suggestions for you before you started this tweak? just curious. glad to hear you got a little improvement out of your 800's. right now, i am am more than satisfied with my 800's, but maybe when i haven't spent any money on anything for awhile, i'll play around with this out for myself, maybe...

Aaron

Do you get any bass from the speakers now, or do they drop off at 80Hz. like the RT3000 satellites?

Aaron

HUNTER

Hey juice,
Yes I did contact polk but of course, as I thought, the manufacturer always suggests that you only use replacement parts for your specific model. I understand the reason. They don't want people messing up their speakers.

Arron,
The 3000 xover has a 80Hz LPF on both drivers so you would want to run them as small but you still get good tight bass from 80hz up.
I have done plenty of testing with these speakers with and with out the tweeter connected. After hearing what the 6.5s sounded like running is "Large" I would run them is small. When the speaker is run as large the bass muddys up the mid range.
I may try in the future to remove the 80Hz LPF on the lower 6.5 to see how the bass extension works on a single 6.5.
For now my 800s perform great, good definision, separation, and transparency, not to mentions Tapered Cascade Array.

Aaron

I don't see why running them in "large" would make them sound worse. If anything they should sound better. If you run them in "small" you're going to be double filtering them (once in the receiver and once in the crossover). Even if you run them in the large, the speaker is still not producing anything under 80Hz. so I don't see how it could muddy up the bass. I also think that 80Hz. is too high to cross over a good subwoofer.

Aaron

RuSsMaN

Aaron, why are you even having this conversation? Whats the point of having an RT800 that plays down to only 80Hz? It would make more sense to use the RT55 and 'mod' it..... I mean, not even a kick drum out of these things....

Anyone using these for serious listening won't have a LARGE or SMALL setting to set anyway.....

Peanut Gallery, I'm tellin ya.....

Cheers,
Russ

Aaron

Call me a student of human thought.

Aaron

HUNTER

For one thing the rt800i doesn't have a true base driver. A 6.5" driver is considered a mid/bass meaning it is really a midrange driver that has the ability to be driven by a lower freq.
When is the last time you saw a 6.5 woofer, you don't, they are midrange drivers and really designed to play freq above 80Hz. In my humble opinon the wider variation of freq that you run through a driver the more muddy it becomes. You will see what I mean if you disconnect your tweeter and listen to a song with the speaker set to large, it sounds like crap, but you don't realize it with the tweeter connected because it masks some of the muddyness. Now try it on small and listen to the improved clarity of the midrange.
A speaker should not be run as large unless it has true bass drivers, of at least 8", by running a midrange driver down in the lower freq you are hindering the midrange performance. Using a powered sub will give you all the bass you need and still allow the midrange to do its job.
What I did by changing the xover was to give the 6.5s different signals so that they could be free to handle their respective freq.

Consider the rt1000i for a second; Why would you wan't a single 6.5 driver to run the mid and bass and then ram those freq through it with an amp. It makes no sense, That is why the 1000 should be run as small as well but then you just wasted money for the amp. A better solution in my opinon would be to take a speaker like the 800 and power the lower 6.5 for the lower freq. Before you reply with what ifs and whys test them for yourself. I'd bet that most people don't have their speakers set correctly and if they sat down and really listened that in most cases a small setting will yeild cleaner sound.

Hey Russman,
If you want a full range speaker so that you can hear your kick drum then you wouldn't want to use the 800 even set to large. If you are hearing deep bass from any 6.5 driver then you are missing some detail in a flute, guitar, symbol, etc. Do you honestly think that you are going to hear the detail of every instrument playing at one time. The more variation of sound that any driver plays the less detail those sounds become so why then would you further muddy up the sound by forcing the driver to go into the low freq. If you what to hear it all out of a tower then it must have a built in woofer to play the lower freqs. If you want a comparable sound to a full range tower then get a good sub and use the 800s for midrange.

RuSsMaN

You stick your neck out, with what some would call, radical, even nonsensical posts, but there is a certain amount of respect I give you, at least for consistency.

The point you are trying to make, I can see, but is purley subjective. I have speakers that I'm pretty sure you would swear a sub was playing, and the midrange was very clear, almost foward. And all that out of a 6.5 inch 2-way system. I've heard folded horn designs, with nothing more than a 5 1/4, and they had PLENTY of low end. Even the $14 6.5 dayton cheap-o (actually, a pretty decent driver) has an F3 resonant frequency of 32Hz.

Ask the SDA guys, largest ACTIVE driver is a 6.5 in their systems. Is the bass lacking, or the midrange muddy? No, and I can say that from experience. I spent a very intimate evening with the 2b's, and they were pretty much 'right on'.

I can't continue this discussion really, because the terms you are using, small and large, don't play into the same scenarios I use. When I listen to a speaker, I send a FULL RANGE signal to it, beit receiver, or amp/pre combo. I could give a rat's **** about filtering in a receiver, and 5.1 settings.....(build a passive or active xover yourself, then we can talk) This tweek you have done is simply 1 coil, and 1 cap, and could be done without modifying the xover at all. (soldered inline) While we are the mod subject, why not do a zobel network also, to smooth out the impedance curve?

I do think the speakers (800's) could sound better with the 2.5 way design , but disagree on the bandpass 80Hz filter....unless you built a passive sub, with matched SPL and impedance to pick up the low end. Wanna really go out on a limb? Get your router out, and lets see a side firing 8", and mod the network further.

Powered subs and serious music listening do not even belong in the same sentence, as far as I am concered.....(and I did have the 800's for quite some time, and I would never limit the low end, the actually handle it very well)

(maybe a VERY few exceptions on the sub statement , REL, Vandy's....etc)

Enjoy your tweak.

Thank you, Cheers, Hasta la Vista,
Russ

Aaron

For one thing the rt800i doesn't have a true base driver. A 6.5" driver is considered a mid/bass meaning it is really a midrange driver that has the ability to be driven by a lower freq.
When is the last time you saw a 6.5 woofer, you don't, they are midrange drivers and really designed to play freq above 80Hz.

While I'll agree that the RT800i's don't have a true "bass driver," I wouldn't agree that a 6.5" driver can't be used as a woofer. The better they make the driver materials, the more performance you can expect from them. Look no further than the B&W CDM9NT. That's a $2600 3-way speaker that uses dual 6.5" woofers. They go reasonably deep, certainly below 40Hz. Multiple drivers are used to retain the surface area of a larger driver and the speed of a smaller driver. Still, I'd rather have an 8-12" woofer if I have the amplifier balls behind it. That's another thing; the smaller drivers are an easier load to drive.

In my humble opinon the wider variation of freq that you run through a driver the more muddy it becomes....Now try it on small and listen to the improved clarity of the midrange.

Sure, this is true. You'd made this point abundantly clear.

Consider the rt1000i for a second; Why would you wan't a single 6.5 driver to run the mid and bass and then ram those freq through it with an amp. It makes no sense, That is why the 1000 should be run as small as well but then you just wasted money for the amp. A better solution in my opinon would be to take a speaker like the 800 and power the lower 6.5 for the lower freq.

While the RT1000i's spec sheet doesn't show the crossover topology, I would be willing to bet that they essentially did what you suggest for the RT800. I don't think that single 6.5" is asked to produce the low bass. It probably only goes low enough for the 6.5" "sub" to kick in.

Now, I still have some qualms with your configuration. I'm going to reiterate one of my previous points: you can't expect a good subwoofer to produce frequencies up to 80Hz. (that's why they call them subwoofers, not woofers) You won't get a nice, even blend as Russ suggests.

All of this begs a simple question: why don't you buy bookshelf speakers? If you're going to obsess about not letting those "incapable" 6.5" drivers handle any bass, why waste all of that enourmous cabinet. You're going to get better performance from a bookshelf, not to mention better imaging. Get a bookshelf speaker and hook your sub up using line level connections. Damn that 80Hz. high pass filter to hell (not to mention that damn receiver SMALL filter).

Aaron

johnnyamerika

Having the 1000's, I've listened to them with the sub off and they handle pretty low frequency's, I'd say below 80Hz definatley. Also, if you've ever heard the RT35's, they produce far below 80Hz with just the single 6.5. So I'd definately agree that you don't want your sub to pick up at 80Hz, the effect of that would probably be more 'muddy' that that single driver droping past 80 to begin with! There is something pretty cool about tinkering with your speakers to tweak them out, but personally I wouldn't do it. There's far too many factors in play to make this work right. A very cool experiment, though, it's certainly raised alot of debate.

HUNTER

Where should I start,

Russman,
You say that I stick my neck out with nonsensical posts. Since this is the “Opinion Forum” and not the “Technical Forum” one could ascertain that I am merely giving my opinion. As I have stated time and time again this is my opinion.

I never stated that you couldn’t get good bass from a 6.5 driver. I stated that I felt that attempting to use a single driver for midrange and bass muddies up the sound. I did say that a 6.5 driver is not a woofer. I further stated that a 6.5 driver should not be ask to deliver full range bass and midrange at one time.

As I have stated I am not a true audiophile, at least “not one of your caliber”. I do use a subwoofer which sounds great to me. I doubt that a true audiophile would consider the speakers that we are using audiophile quality.

From your statements of your vast knowledge about drivers and electronics I would have thought that you would have designed and built your own equipment rather that settle for a non-audiophile speaker.

As far as “Asking the SDA guys” about bass response from a 6.5 driver maybe the question should be what is the xover frequency for the drivers because I doubt that they are asking a single driver to handle bass and midrange.

You can’t install a decent 8” driver into the 800, not enough room and no decent Q.

The reason I didn’t build my own xover is because I could buy an inexpensive xover that fit my needs.

As I stated in a previous post I am looking into removal of the 80hz HPF for the lower driver.

Aaron,
Even though by definition a 6.5 is not considered a woofer I did not state that one could not produce good bass response. I stated that attempting to produce full midrange and low bass frequencies would muddy the sound.

As far as the B&W CDM9NT speaker goes. I would assume that the xover frequency does not force a single driver to produce a full range.

The RT1000i has a single 6.5 driver so where is the other driver that would be asked to kick in. (I stand corrected don't own it and didn't see it)

Guys,
The reason I did not go out and buy bookshelf speakers was because I wanted floor standing speakers which I already had.
As I have stated from the beginning this is my opinion, my money and my speakers. I did nothing to permanently alter these speakers in any way and can change them back at anytime.
Both of you seem to think that the Idea is sound except for the 80Hz HPF which can be removed, and as I stated in an earlier post I will look into this option in the future.
I stated in an earlier post that I could find no rational data to suggest that changing the crossover would work nor did I find any to suggest that it would not work so I tried it. Guess what it works great, go figure. So rather than argue as to why it will not or should not work try it for yourself and give your opinion as I have done.

johnnyamerika

Originally posted by HUNTER
The RT1000i has a single 6.5 driver so where is the other driver that would be asked to kick in.

Just to clarify, the 1000's have two seperate 6.5s...one is a mid/bass and one is an active powered sub.

HUNTER

I stand corrected on the rt1000i.
Thanks

HUNTER

I'm finished with my modification,

I am posting my final results so that those that have been following this topic and are still interested know the outcome.

I replaced the xover in a pair of rt800i with one from the rt3000p sat. None of the modifications are permanent and can been changed back to the original design at anytime.

The results turned out to be great. The clarity, separation, and transparency are greatly improved. Initially I only modified one speaker so that I could do a/b testing and I noticed a subtle difference but not overwelming. I think this is because of the dead time between the a/b switching. After modifying both speakers and testing with a wide variety of music and dvd I really saw the package come together and noticed the quality of the sound.

I ended up removing the 80Hz HPF on the new xover to get the bass extension back.

The only problem that I noticed after my modification was that that now I could really tell the difference between a bad recording and a good recording. I hear everthing that was recorded, Oh well', I hear that this is a problem with really good speakers so I guess that I should be honored.

Anyway,
Thanks to those of you who provided information, criticism, and interest in this thread. I enjoyed the debates.

Thanks

danger boy

I think it really comes down to who has more bass. Similar in guys.. as to who has the bigger truck theory. Every guy always wishes he had another 2 inches where it counts right? in the subwoofer. ha ha ha.

no seriously guys. I have the 800i's and three days ago i bi-wired them. I have to say that every time I listen to a DVD in either DD or DTS, i am amazed how much bass these suckers produce. yeah they have small drivers and are only a two way speaker. I've never heard this amount of bass from any other speaker design with such small drivers.

Several things of course come into play when using these or any speakers. YOu all know this as well as I do.. so I won't dwell on it.
You all know that room acounstics, amp/receiver power, speaker cable/interconnects and volume will all play into how much bass comes from your speakers. So what is fine and plenty of bass from my 800i's might sound like a tiny AM radio to others. I think, and I may be way off here.. but my Marantz receiver might sound a little warmer than other people receivers... so there again. that factors in to how much bass I hear. I tweak the bass and treble knobs on my receiver for everything I watch. I'm constantly adjusting them, depending on whether i'm watching DVD, SAT or music.

so yeah if you wanna mess with the crossovers, low pas filters, speakers, or buy yellow grills for you 800i's. just keep in mind that so many factors come into play when it comes to good bass and how much is enough.

HUNTER

Dangerboy,
I'm not sure I understand what you were trying to say but my purpose was not to get more bass it was to improve the clarity and reduce muddyness. Removing the 80Hz HPF was to get my original bass extension back after the xover change.

To say it in your terms;
I not trying to have the "biggest dick", the size is fine, I have just refined the way It is used!

Aaron

Did you notice a degradation in sound quality after you removed the HPF?

Aaron

HUNTER

Aaron,
I havn't noticed a difference in the midrange definition as of yet but I suspect that when driven down in the lower frequency I will lose some. I am going to test the xover with the HPF completely removed as well as attached to the upper driver that has an LPF @ 2k.
I think that if I cut the upper driver at 80Hz and allow the lower driver to run full frequency I will retain definition and bass.

80Hz HPF removed:
driver #1 (bottom) 2nd order LPF @ 1.2kHz;driver #2 (upper, near tweeter) 2nd order LPF @ 2kHz.

80Hz HPF on upper driver:
driver #1 (bottom) 2nd order LPF @ 1.2kHz;driver #2 (upper, near tweeter) 2nd order LPF @ 2kHz, 80Hz HPF.