HI, I would like your opinions on Eminences and Polk Audios setup..

[License2ILL]

Hello this is my first post on here but I've read quite a few threads and learned a lot from you all.

Was wondering your thoughts on what I have planned thus far.

I have an old pair of Polk audios Monitor10s that were given to me by my father 1 working and another with cheapo replacement drivers. Monitor10s came with a tweeter and (2) 6.5 inch polk audio midbass drivers in the center and below a passive 10 inch radiator.

I have my eye set on replacing all the 6.5 inch midbass drivers with Eminence Alpha 6C (4ohms). Which are basically 4 ohm versions of the Alpha 6A's (8 ohms). From what I have understood these are excellent upper midrange drivers for their prices which is what I want.

I plan on removing the passive 10" radiator and replacing it with a Polk Audio 10" DB104 DVC with the really cool G10 grill covers.(original black cloth polk audio speaker covers has been long gone for years)

Now currently from the internal old Polk audio crossover there is a feed that goes direct to the tweeter and then another to the first 6.5 speaker that then feeds the other 6.5(in parallel).
So it must be a 2 way Xover with close to full range on the (2) 6.5 mids.

My short term intentions are to run the wire first to the newly added 10"sub then wire parallel the other 2 Eminince 6.5 drivers to it (basically all 3 in parallel). I want to also run a cheap passive crossover cutting out I'm guessing mostly anything under 500hz or 1Khz going to the 6.5's?

affording me some time to research a quality X-over.

I am definitely on a budget. So if you want to counter my speaker selection please keep that in mind.

Also I know you guys work with much newer speaker setups and boxes but these do have a sentimental value for me going back to 11 yrs old while the old man was at work I'd crank that Denon amp and kill the neighbors with some Dire straights Money for NOTHING pumping through those old Polk Audios with crystal clarity.

Hence also my choice in adding the 10" sub from Polk Audio.
My only real debate is going with either the DB104's or the SR104's. big difference in pricing is leaning me on the cheaper DB104s but the 20hz drops of the SR104s are HARD to overlook.

I am a basshead....but have and will always appreciate clarity as well.

Can I run those speakers in parallel like that? Untill I get a new replacement X-over? Also are dual voice coils less stronger than a single voice coil in durability or stress factors?(high volumes)

Is my budgeted plan retarded by your standards?

Thank you,
License2ILL

[bluesmoke]

Why cannibalize such a great classic...? You might be able to find/get replacement Polk parts. They have a great forum on their website, and they also have great phone tech-support, even for the vintage models. Worth a look at least, and might be cheaper than what you are proposing.

With original spec parts, they will sound fantastic. Does your pair have the peerless or SL2500 tweeters?

You could always just add an external sub after (if needed)...

[License2ILL]

Well the reason being is I want to upgrade to a 3 way design.
I want to make the two 6.5's emphasize clarity...
And by bringing in a 10" sub or woofer I can take the load off the 6.5's to do that while emphazing BOOM.

An external sub is out of the question since these were destined for the srapyard due to their size to begin with. I saved them becuz I appreciate old school thunder over the very echoey and empty miniature new school designs. But adding an external unit to these "hulks" is not desirable.

The guys over at parts express mentioned this X-overs for me:

http://www.partsexpress.com/pe/showd...number=260-150

I'm leaning more in this direction:

http://www.partsexpress.com/pe/showd...number=260-230

Except that the wattage seems low.

The parts express guys mentioned to me as well that my choice in subs is too low for this application and my mids will roll in too high for them. And that I should consider a woofer rather than my Polk Audios DB104's that I was interested in as an effort/homage to these boxes.

I'm just right this second considering reviewing if the Emi Alpha 6c's can roll in at 200hz after the subs end(28-200hz for DB104 and 20-200hz SR104).

But I am lost on overlaps I think the guy was trying to tell me the woofers should overlap into the mids...and the mids into the tweeter as a rule of thumb I guess.

Do you guys really think the Polk 10" subs will die sharply after 200hz???(no charts@polkaudio.com!!) I mean they can't possibly be good for another 200hz? covering the overlap..into the Alpha's if they in fact can pick up after 200hz or 300hz.

I think this conversion is necessary and will make these boxes sound better than ever. The only remaining question is will I need to port them??? and can I port them to the rear?

[bluesmoke]

Understandable. I'm just a big polk fan~.

You have to remember that it will be a sealed system, hence a huge rolloff in the low end unless compensated in some way. Also, since the tweeters/mids aren't compartmentalized (have their own enclosure), you risk damaging those drivers by the internal pressure with an active woofer.

[sreten]

Hi,

What a bizarre design, from the British school perspective.

TBH the whole thing sounds like a disaster waiting to happen, off
the shelf crossovers simply do not work well, but they are better
than nothing in PA speakers, for hi-fi they are too hit and miss.

No 10" driver that can hit 20Hz will ever match two Alpha's.
The Alpha's will likely overpower the tweeter as well.

"Upgrading" to a 3way is a very moot point. I'd keep the 10" PR's,
the original c/o and tweeters, and either source two more Polk
6.5's, or replace all 4 6.5's with suitable modern units.

Are the originals 8 ohm or 16 ohm each ? presumably 8.

Driver Complement
Subwoofer 1 - 10" Diameter (25.40cm)
sub bass radiator
Midrange 2 - 6-1/2" Diameter (16.51cm)
drivers
Tweeter 1 - 1" Diameter (2.54cm)
Polk SL2500
Electrical
Overall Frequency Response 25Hz - 25kHz
Lower -3dB Limit 37Hz
Upper -3dB Limit 25kHz
Nominal Impedance 8 ohms
Recommended Amplifier Power 20-250 w/channel
Efficiency 89 dB
Dimensions
Cabinet Size 28" H x 15" W x 12" D
(71.12cm H x 38.10cm W x 30.48cm D)
Shipping/Other
Total Shipping Weight 46.00 lbs. (20.87kgs)

Assuming mids are 8 ohm in parallel and baffle step in the crossover :

these could work :

http://www.partsexpress.com/pe/showd...number=296-165

/sreten.

[License2ILL]

Hey thanks for your help...you guys are both 100% correct.

I've definitely re-thought the whole thing!!

Especially because just like you said this is a sealed box.

So here's my latest trick:

1 eminince alpha 6.5inch

1 goldwood 6.5 inch
http://www.partsexpress.com/pe/showd...number=290-352
Check the spec sheet on this one it's really good bass dedication for low low price.

Then maybe this 625hz/5000hz crossover to replace the tired one in there and to "officially" go "3 -way":

http://www.partsexpress.com/pe/showd...number=260-154

I really don't think these latest speaker selections will counter the box's design. I'm trying to put that passive radiator to use.

Do you really think that that X-over above doesn't out do the older 20 yr old unit(it does work!! btw)??
I am considering this one as well st least to limp me by for cheap and to test out the setup initially:
http://cgi.ebay.com/1-PAIR-3-WAY-PAS...QQcmdZViewItem

About my 2 different speaker selections...I just want at least one to be able to do something (even 765db) down low in the 20hz-ish.
Then want the clarity of one that can extend past 1Khz/2Khz.

Another idea that is hard to shake truthfully is to NOT go 3 way.
And to keep the 2 way design but still use both these speakers above. Not replace the old crossover.
In essence feed the alpha the range the current x-over is sending and then maybe hookup another passive before the Goldwood to cut the Goldwood out at anything above 800hz or 1Khz. (since it's fairly useless and would mud things up...according to specs)

In this scenario both 6.5s would be working that passive radiator however best they can when they have to go low. Becuz by not going 3 way I wouldn't be cutting out the Alphas under 800hz which from the specs it does a little something......thereby aiding the Goldwood from 100hz up.....working that passive!!

I think I am aiming in this direction big time.

I had considered the B&C 6.5 over the alpha for awhile:
http://www.partsexpress.com/pe/showd...number=294-650

But think that the Alpha for the price comes mighty close to it.
And the B&C might end up too loud. if there is such a thing.

This is the sub I'd really like:
http://www.partsexpress.com/pdf/264-832s.pdf
But it only comes in 4 ohms.

Well I think this is a step in the right direction maximizing and truly upgrading this unit. I really don't think stock replacements can match these later designed drivers.(both in the db and the ranges I'm trying to see)
My only blank area is what to use to clip the lowend 6.5 sub from receiving over 1Khz.

Then maybe later have the original X-overs maybe re-capped or rebuilt.

I'm almost sold on sticking 2way ...2 different types of speakers.....1 complimenting the subwoofer in the low ranges however it can....and the subwoofer being clipped from ruining upper ranges.

Let me know your thoughts. I'm dieing to order something already!!! all this blasted planning....!! but it's worth it.....damm Xmas rush is scary tho.

[License2ILL]

Ok the guys at partsexpress say I HAVE to pair up for numerous reasons extending to the laws of the universe physics and quantam theory.

They say my choices are strictly:
http://www.partsexpress.com/pe/showd...709397#reviews
or
http://www.partsexpress.com/pe/showd...138951#reviews

I personally wanted these:
http://www.partsexpress.com/pe/showd...number=297-305

But they say they won't work right because of the size of my enclosure and some other values....guy was very knowledgeable.

the daytons give up a lot of mid range.
Original Xover is crossing at 3Khz.
I guess im looking at the pioneers.

I wanted those Vifas cuz they seem to offer more down low.
What do u guys think?...would I be dumb to go against some good advice?

The polk audio people say they charge 60.00 for the MW6503 replacements. But had no frequency ranges or schematics to give.

[sreten]

Hi,

Well the size of the enclosure has nothing to do with it, it suits
a pair of the Vifa's just fine. The Daytons would be best if the
Polk crossover has no baffle step, the Pioneers / Vifa's if it has.

What other values of the Vifa's are not suitable ?

/sreten.

[License2ILL]

what do u mean baffle steps?
how can I reference that?

And he said the vifas wouldn't work right because after punching the Vb and F values or something like that into a calculation (or maybe software) those don't show to be a good match to the acoustics layout ( i think).

I was interested in the Daytons at first but his suggestion is those should roll off at 2Khz anything above that they're not so good......and I do want some clarity.....so I'm stuck with the pioneers.......

But I'd like to run the Vifas cuz it looks like they offer more on the low end and seem to retain the same efforts as the pioneers on the high end.

Tuff call.....I dont remember what else exactly was the problem he said about running the Vifas....oh he did say something about having to run 4 of them to match the 2 pioneers....cuz the pioneers were that much better suited.

The Vifas do show bass reflex as part of their design which I dont think a sealed box is intended for but is all that so incredibly impacting?

[sreten]

Hi,

The pioneers on paper are louder (and less bass) than the Vifa's.
According to the speaker specs @ 89dB the Vifa's will be fine.
The 93dB given for the Pioneers is unrealistic, in reality they
are a little more sensitive than the Vifa's.

Box volume I estimate at 2cuft which is plently for the Vifa's
and too much for the Pioneers by a factor of 2 so I've no
idea what said numbers were being plugged into.

On paper the Vifa's are the best bet.

/sreten.