Suggestion for a replacement to the Peerless MT20 HFC

[jansch]

Are your 9710 speakers in bad condition too? In Sweden you can buy a set of OA5type2 for less than 50Euro with working 9710 and hopefully at least 4 MT20 in good condition.
How many 9710 do you need?

[Villee]

Hey!

All 9710:s are okay, except one "woofer", which had a worn surround and a wire to cone was snapped (this unit was with totally destroyed bass-energizer). I repaired the unit by adding some thin paper to the surrounds backside and re-soldered the wire. DC-resistance is now okay (6,0 ohms) and the unit sounds okay except for bass response, which is rather poor compared to the other mint 9710 woofer.
I think that I need a pair for 9710:s (to replace the "woofers"), or I change places with midrange and woofer. Although it would be nice some day find some last generation 9710:s with ferrite magnet to be used as a "woofer".
Some guy close to my apartment have tried to sold over a year a pair of OA-5 type 1 with perfect working condition with 90 euros price . Let´s see if he would lower the price to max 50 euros:)

Ville

[faulhund]

...
I think that I need a pair for 9710:s (to replace the "woofers"), or I change places with midrange and woofer. Although it would be nice some day find some last generation 9710:s with ferrite magnet to be used as a "woofer". ...

Yes, you are right. You will definitely have an advantage of using AD9710/M8 (=ferrite) as the woofer. According to "TSP data" on 9710 swirling around here on the forum (and which are said to emanate from Ingvar Öhman), Xmax = +/- 0,7 mm (alnico) oder +/- 1,45 mm (ferr). I have one of each, and the ferrite on definitely is louder (in spite of the impedance being slighly higher). (The other one has no Xmax left, since it is uncentered after being mounted horizontally for decades.)

You might also use Visaton BG20 as a one-to-one replacement for the woofer, as jansch recommends in this thread on OA-6 .

Per Gulbrandsen sold a couple of AD9710/M8 last month ...

[jansch]

Yes, I use Visaton BG20 and it's perfect! Lower load for the bassenergizer and sounds great.

If you want a 9710 I can sell one (ore 2) for 25 Euro/piece + shipping. Used but in OK condition.
But you will have a better bass with BG20. You have to plug the old holes for the screws and use som clips instead.

[jansch]

Faulhund - a "dirty way" to fix your speakers is to make larger holes (oval) for the screws between the magnet and the basket. It works if they have been facing down as the basspeakers in OA6type2.

[Villee]

Hello!

Thank you for all good advices! I think that I´m going to buy a pair Visaton (but I also ponder that I should keep the original design, because 9710 used as a woofer is so unique) when I get the bass-energizers work properly (few stupid flaws which I should have noticed much before), and when my finance is better. Although better bass (and perhaps a bit more volume with Visaton?) would be nice regarding that sometimes I would like to play a bit louder (of course trying to take notice of the bass-energizer´s limits).

Ville

[Villee]

Philips 9710 problem is solved, if I want, I could buy a pair V-1 with 20 euros It would be funny to hear how these cubes sound...

[faulhund]

Faulhund - a "dirty way" to fix your speakers is to make larger holes (oval) for the screws between the magnet and the basket. It works if they have been facing down as the basspeakers in OA6type2.

Yes, I agree that this is "dirty", since the surround would still be heavily offset and non-linear. (Its DC response is in the relation 1 mm in and 3 mm out for the same magnitude of the current!)
Instead I "fixed this problem" today by a good deed: I gave this single, heavily used 9710 away to a young collector of radiograms, so that he can make closer acquantance to the Philips wonder ...