Driver replacement-upgrade question:

EricH

Is it possible to find a superior replacement for the 6.5" drivers in my RTi70's, If so, what do I look for- V-max, FR, max watts RMS etc? I'm just curious at this point, but may indeed try it if feesible. Is this a bad idea?

F1nut

Bad idea, there's nothing wrong with the drivers. If you looking for better performance try upgrading the components on your crossovers.

EricH

o.k. What would upgrading my crossover components consist of, or a website that I can reference? I'm trying to gain knowledge in this hobby and there's a lot to learn. Thanks, Eric.

VR3

If you are not satisfied with the RTi70, may I suggest you sell them?

EricH

Because I have eleven speakers in my house that use the same tweeter, and like it that way. I just want more midrange punch.

VR3

Have u tried setting your speakers to large? Getting a seperate amp?

Early B.

Are you using separate amplification? I used to own a set of 70's, and when I hooked them up to a separate amp, they really started to sing. You'll get your punch, my friend.

EricH

I am crossing them at 60hz and it is much better than 80hz I must say. I just can't cross a 40hz speaker (+-3db) that high. Too much wasted bass.

Just using a HK AVR 630 for now, but plan on a 200 wpc amp in the near future.

EricH

Originally posted by Early B.
Are you using separate amplification? I used to own a set of 70's, and when I hooked them up to a separate amp, they really started to sing. You'll get your punch, my friend.

Our gear is not too dissimilar:

Power HK AVR 630
Mains RTi70
Center CSi40
Surrounds CSi30
Rears CSi30
Sub SVS PB2+
PEQ Rane PE-17

The biggest difference is that my 75 watts per channel looks more than a little anemic up against your power. I've got a "Want to Buy" listing in the Flea Market and am combing Audiogon and Ebay, so hopefully I can find a good 3 channel unit for my frontstage. Thanks, Eric.

gatemplin

You can build whatever you want. You would need a program like Speaker Workshop (free) and a mic and build a "workshop jig". If you can invest the time and money into learning how to use this, you can build your own speakers the way you want them. It's a great hobby but it takes a lot of time. Jcaut knows how to use speaker workshop.
http://www.audua.com/

EricH

Hello Graham,

Thanks, I've bookmarked that site for future reference.

F1nut

To upgrade your crossovers you'll need a schematic which is available from Polk customer service, next you'll have to know how read it. After that you shop around for replacement parts that are better than the stock ones, don't worry they aren't hard to find. Next, plug in the soldering gun and go to town swapping parts. Short of that, take them to a hifi mod shop and have them do it.

Having said all of that, without better power you'll never get better sound out of your speakers, so start there first. If you really want a sweeter mid range, add tubes.

RuSsMaN

I'd suggest swapping caps first, resistors second, and leaving the inductors alone.

Even if your replacement inductor has the same value, but for example, not the same guage of wire, you can change the overall Q of the driver, and really screw up the sound.

Cheers,
Russ

Tour2ma

Originally posted by EricH
I am crossing them at 60hz and it is much better than 80hz I must say. I just can't cross a 40hz speaker (+-3db) that high. Too much wasted bass.

If you feel you are wasting bass,why not run the 70's set to large?

EricH

My goal is to run all of my frontstage on large, but with the 75 watts that I have been running, bass below 60hz was starting to distort. However, crossing them at 80hz makes them sound like small bookshelf speakers. I have found a Anthem MCA-3 that should allow me to get the sound that I've been looking for.

Tour2ma

10-4... I believe you have answered your own question...

scottnbnj

Originally posted by EricH
I just want more midrange punch.

how much have you experimented with placement?

if they were bookshelves i'd say place the mid-driver midway between the floor and ceiling for a quick and dirty looksee at what's possible.

i've been playing with this placement with my lsi9's and the punch is so strong that i can hear and feel popping (that shouldn't be there) on some tunes depending on sidewall distances, room clutter and whatnot.

depending on your room you might get a boost with the speaks placed the same distance from the sidewalls as the height of the mid-driver with no toe if there aren't obstructions on the floor and wall first reflections points. if that places speaks too far apart on a wide front wall you might try multiples of the height, but in addition to problems that equal distances might cause, there might be a couple more.

if you get the punch you want from this but it throws something else out of balance first things to try might be the distance from the front wall, toe and/or treatments depending on what's wrong.

if you get too much punch, then toe, movement in relation to the sidewall and/or incremental diffusion or dampening treatments will help.

also, if your speaks are on an unstable surface, say if the spikes don't get enough bite into carpet and padding to eliminate rocking, that can kill punch. search the forum for "patio blocks".

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tryrrthg

It's the receiver that's causing your lack of punch!

A few weeks ago I went to forum member gmorris' place and brought along my McCormack seperates. His RTi70's sounded OK on his onkyo receiver but once we put the seperates in the mix it was a whole different speaker. We were both amazed at the difference. Those babies were pumping out the bass. Get a high quality amp and don't touch the speakers!

EricH

Thanks for all of the replies. The amp should be here soon and I'll give a report after it's hooked up.

I was over at my brother's house and thought that his system almost sounded better on music than mine. He's got my old HK125 with 45 wpc, my old HK 100 watt 10" sub, and a pair of Boston A70's circa 1980. Are room sizes are fairly similar, but his has a sloping cathedral ceiling that goes up to approx. 15 ft, as apposed to my flat 7.5 ft ceiling. plus his Bostons are up on stands. I think maybe my room just sucks.

I'm going to re-install carpet spikes on the RTi70's, and will play with the FL-FR placement.

Russman & F1nut, on upgrading the caps, resistors etc, significant or subtle difference? Also, is there a superior brand of these parts? I've got a Parts Express catalog and there's many to choose from. I probably won't touch them for a while, but have schematics coming from Polk.

Tour2ma

Originally posted by tryrrthg
It's the receiver that's causing your lack of punch!

The answer I was referring to my post above..

Even members that have been happy with the sound of their big Polks have gone slack-jawed when one "brute" amp or another gets ahold of them at a Polkfest or other occasion.

An old 45 wpc HK on a air of A-70's? When classics collide, good stuff does tend to happen...

EricH

Hey Tour, how many watts would you consider brutish? The Anthem will be 170 wpc-all channels driven.

gatemplin

Originally posted by EricH


Russman & F1nut, on upgrading the caps, resistors etc, significant or subtle difference? Also, is there a superior brand of these parts? I've got a Parts Express catalog and there's many to choose from. I probably won't touch them for a while, but have schematics coming from Polk.

Some say upgrading the crossover parts (not inductors) makes no audible difference. Some are so sure it does that they will pay over $2000 for an upgraded crossover for a pair of $2000 speakers (VMPS).
If you are interested, www.solen.ca has very highly regarded caps and inductors, but good (like 2mm) inductors get berry spensive.

Generally poly caps and air core inductors are preferred over electrolytic caps and iron core inductors. As was mentioned before, if you replace an inductor, make sure the DC resistance is the same.

Tour2ma

Originally posted by EricH
Hey Tour, how many watts would you consider brutish? The Anthem will be 170 wpc-all channels driven.

Before others jump in I'll say it...
Not just watts.. amperes, too... effortless clean power is the ticket...

Just on watts the Anthem is a middleweight, but if its 60-ish amperes peak to peak it could take on some heavy weights.

Brutish in my book? Hard to pinpoint an exact figure, but >300 wpc continuous into 8-ohm with > 50 amperes peak-to-peak is in the ball park...

One thing you can try with your 3 ch (correct?) Anthem... Rig the "extra" ch up to bi-amp one of your speakers and see if you notice a difference. A mono source would seem best for this test, but stereo (with you swapping out which main gets the added boost) should also tell the tale...

EricH

Originally posted by Tour2ma
Before others jump in I'll say it...
Not just watts.. amperes, too... effortless clean power is the ticket...

Just on watts the Anthem is a middleweight, but if its 60-ish amperes peak to peak it could take on some heavy weights.

Brutish in my book? Hard to pinpoint an exact figure, but >300 wpc continuous into 8-ohm with > 50 amperes peak-to-peak is in the ball park...





Right, and it's difficult to get that figure out of many manufacturers. My HK avr 630 has a "High Instananeous Current Capability" of +-50 amps. I thought that was decent, but I guess you need both watts and amps.

o.k. I'll try the bi-amp thing. No issue putting a 170 watt channel to my tweeters? (Of course I wouldn't crank it up too loud).

Tour2ma

Originally posted by EricH
(Of course I wouldn't crank it up too loud).

No issues so long as you maintain that attitude...

goingganzo

i have the 800i and at higher volume they would get muddy with my onkyo 787 now i have a adcom with 125 wpc and they just sing till the get 2 loud a good amp will be the best bet.

VR3

According to Outlaw Audio, there is no 'standard' for amperes/current. They said most every other company measures it differently...

Hard to go by that. Not to mention Peak-to-Peak amperes would mean peak current to peak current, no? That kinda reminds me of 200 continuous watts, but 400 dynamic watts!