GPA 902s for 846A cabinet?

[theophile]

Gentlemen,

I managed to blow a diaphragm on one of the 806A-16ohm compression drivers in my diy 846A Valencia system.

I was considering buying two new diaphragms for both of my 806s,when I considered;Could two new GPA 902s fit dimension-wise in my Valencia cabinets(without alterations)?

[bowtie427ss]

Should fit without modifications of any kind Theo.

Have you investigated the failure to determine if it is the result of a broken lead in conductor or a damaged coil?

FWIW, i have an original diaphragm with a repaired lead in conductor going on it's 2nd year since repair in a 9846 w/500hx XO.

[theophile]

Should fit without modifications of any kind Theo.

Have you investigated the failure to determine if it is the result of a broken lead in conductor or a damaged coil?

FWIW, i have an original diaphragm with a repaired lead in conductor going on it's 2nd year since repair in a 9846 w/500hx XO.

Thanks for the reply bowtie.

I thought from looking at the pics on the GPA site,that the 902 might fit.

Would I be correct in speculating that an older alnico 802 wouldn't fit?

I haven't opened-up the back of my Val yet to see exactly what the problem is.I have been able to rule-out a fault in the active crossover(Accuphase F-25,Gorgeous) or the monoblock feeding the 806A(Kenwood L06M,also gorgeous).Which leaves only the compression driver.I have a pair of B&C DE250s here which I have been intending to use on a four-way active project that I have pencilled-in for this year:

2 x Altec 411 subwoofers(already in my posession) below 70 Hz
the 2 x 416Zs which will be left in the 846 Valencia cabinets between 70 Hz and 380 Hz
2 x Altec 288K-8 ohm mated to Aussie Azurahorns from 380 Hz to 5000 Hz

I had planned on using the B&C DE 250s mated with Aussie Azurahorns for whatever they could provide above 5000Hz.It now occurs to me that I could buy a pair of GPA 902-16 ohms and use them in my Valencias,until I am ready to continue with the 4 way project where they could forseeably be use with Azurahorns to take the role of the driver for the frequencies above 5000Hz.

I have all of the frequency modules for the Accuphase F-25 crossover(70 Hz,380 Hz,5000 Hz).I have the amps that I want to use:

Kenwood L-08M monoblocks for the Altec 411s Sunwoofers
Kenwood L-06M monoblocks for the Altec 416Zs(in the Valencia cabinets)
Kenwood L-06M monoblocks for the Altec 288Ks
Kenwood L-06M monoblocks for (either)the B&C DE 250s(or possibly) the GPA 902s.

Is there a reason why I should not consider the GPAs a for(temporary)use in my Valencias,or for inclusion in my planned,not far from finalisation,four-way project?

I ask this,not in a challenging spirit,but rather hoping to garner opinion regarding choices and suitablity,given that I already have the B&C DE 250s but could easily see the GPAs fitting the bill also.The GPA swould be nice to listen to in my Valencias in the short to medium long term also(I suspect).

[bowtie427ss]

Would I be correct in speculating that an older alnico 802 wouldn't fit?

If your back panels have the small access plates behind the HF driver, there might be just enough room. I "think" the cover of an 802 will extend into the hole, but doesn't contact the masonite cover plate. It's been ten years since i had Valencias and i just don't remember what i successfully tried for sure.

The 802/808 body is only about 3/8 inch deeper, maybe you can determine with the 806 in place if there's enough additional clearance for an 802.

Is there a reason why I should not consider the GPAs a for(temporary)use in my Valencias,or for inclusion in my planned,not far from finalisation,four-way project?

I can't think of a good one, especially considering the geography involved here. A GPA purchase guarantees you're going to get exactly what you're expecting as opposed to a private transaction thru ebay or the like. It might be a good time to order up a pair of replacement phragms for those 806's, new GPA phragms for them would greatly enhance their value in Oz i suspect. They'd also fit 802 or 902 bodies if you happened into them at a later time. New phragms on hand are like a security blanket for me, of course i have yet to need even one.

[Mustang Marvin]

I have a pair of 846B Valencias. One of the contact ribbons on the 806's burned into. I repaired it myself and the driver worked again as usual. I sent them to GPA for rebuilding and Bill said the repair was still in good condition over 15 years since the repair was made. I went ahead and had him replace the diaphragms and remagnetize them anyway. I don't know if the damage to yours is the same, but repairs can be successfully made sometimes.

I also built a pair of 825 A7 500's. I used the 902T compression drivers from GPA on the 511 horns. I was informed the 902's were superior to the the 806's. They both sound good to my old ears anyway.

If you have any questions on the GPA products, don't hesitate to contact Bill at GPA. Great guy and very helpful. He saved me a great deal of money by advising me to NOT have my 416's rebuilt since it was not necessary. You don't hear something like that much anymore.
Good Luck...

[Old Guy]

The 902 isn't as deep but is almost 1 1/2" larger diameter? I think it is short enough not to hit the back. If it did the hole would have to be resized, but I think that is not an issue, I think it will fit.

Should give slightly improved HF.

For my money though, I would keep the 806's, maybe have a fresh charge put on the mags.

I would spend my money on a newer xover, something like a Model 19 unit with the HF EQ.

Don't GPA and Iconic have stuff? For that matter, considering the drivers involved, wouldn't Jeff's excellent modded one work?

I think that would give more bang for the buck that replacing the drivers...

Gearfreak had some used GPA drivers....dunno if he's still got them for sale.

[theophile]

The 902 isn't as deep but is almost 1 1/2" larger diameter? I think it is short enough not to hit the back. If it did the hole would have to be resized, but I think that is not an issue, I think it will fit.

Should give slightly improved HF.

For my money though, I would keep the 806's, maybe have a fresh charge put on the mags.

I would spend my money on a newer xover, something like a Model 19 unit with the HF EQ.

Don't GPA and Iconic have stuff? For that matter, considering the drivers involved, wouldn't Jeff's excellent modded one work?

I think that would give more bang for the buck that replacing the drivers...

Gearfreak had some used GPA drivers....dunno if he's still got them for sale.

Old Guy,and Mustang,thanks for the replies.

I'm only considering the GPA 902s because they cost only slightly more(in my opinion)than a pair of replacement 'phragms for the 806s and they have a more extended frequency response,plus I could utilise them in my four-way project.Add on the cost of shipping my 806As for remagging somewhere in Australia,and return(a round trip of nearly 3000miles....) and you can see why I'm considering the purchase of the GPA 902s.The cost of the 902s delivered in Australia is not a giant amount more than purchasing new diapragms for the 806s plus the remagging and shipping costs for the 806s.Then factor-in more extended high ferquency response of the 902s,plus the fact that I could utilise them in my projected four-way,and I think I have convinced myself of what my next step shall be...

I just wondered if they'd fit into the Valencia cabinets.It looks like they would.

Good.

I would use the 902s in my Valencias via my Accuphase F-25 active crossover.

[Mustang Marvin]

I was going to replace the 806's in my Valencias like you, but then I was informed that the Valencias would be more valuable in their original form. This is something you may want to consider. I believe the 902's are better. That's why I put them in the A7's and kept the Valencias original.
But of course, it's your call...

[bowtie427ss]

I don't think Theo plans on parting with the 806's for exactly the reasons you point out Marvin.

If i understand, he's just considering the 902's for the time being as they're ultimately designated for a different project, but the Valencias are his current main loudspeakers, and the recent HF failure begs the exploration of options.................... if i understand correctly.

[voice of the theater]

I'm not sure how this works with the active crossover Theo is using, but I own a pair of Valencia 846 A's and they are a 16 ohm speaker system as opposed to the 846 B's which are 8 ohm. The 416z woofer that you now have in your Valencias is a 16 ohm woofer and the 902 driver from GPA is an 8 ohm driver. From what I understand, if you were using the stock Valencia crossover, some kind of modification would be necessary to replace the 16 ohm high frequency driver with an 8 ohm driver--but I may be wrong. Can someone out there who's more knowledgeable please let Theo (and me) know if this is an issue as I suspect? I don't think anyone has mentioned this in this thread yet. This thread raises some questions for me as well. First of all, is the GPA 902 driver essentially a model 19 driver? Secondly, does it have the radial phase (tangerine) plug and extended high frequency response that you get from the model 19 driver? Thirdly, if I decide to upgrade my Valencia stock 16 ohm high frequency drivers with GPA 902's do I need to do some sort of modification (as I suspect) to the Valencia stock crossover I'm using to accommodate the GPA 8 ohm high frequency drivers being used with the 416 z 16 ohm woofers? Would the end result be similar to a model 19 in that it's a 416 woofer with a 902 hf driver/811 horn in a valencia cabinet? If I install the 902's, would it be worth my while to replace the stock Valencia crossovers with Model 19 crossoevers? BTW, if I do this upgrade, I'll be sure to keep the original 16 ohm Valencia hf drivers and crossovers so that in the unlikely event that I ever sell the Vals, I can reassemble them to be all original again....