Fostex FE206E or Philips AD 9710 M8

[69122s]

I have a pair of old speakers that were made by a mad scientist speaker maker back in the early 80s. They were quite good sounding and are a very unique and interesting design. I haven't used them for several years because the foam surrounds on the woofers went. I've now gotten around to fixing them so I can put these speakers back into service again. As part of this process I'm refinishing the cabinets, replacing the capacitors in the crossovers, etc.

The design employs 2 8" Peerless Woofers and a Peerless tweeter facing forward (one woofer plays low bass and the other handles the mid-bass.) On top of the speaker pointing upwards he had Philips 8.5" AD 9710 M8 full range speakers. These could be turned on or off via a switch on the rear of the speaker cabinet. No crossovers were used for those drivers.

I'm thinking about replacing the Philips full-range drivers with some new Fostex units. As I recall the Philips couldn't handle too much volume so I sometimes had to switch them off. I think the Fostex FE206Es will be able to handle a bit more power than the Philips units and I'm hoping they'll provide a bit better sound as well. But is this true ? I've read that those Philips AD 9710 M8s were quite respectable speakers in their day. Would the Fostex FE206Es be much better ? Would it be a worthwhile upgrade ? I have to modify the cabinet to accomodate the Fostex units as they're slighly smaller in diameter than the Philips drivers.

Thanks,

Roger

[planet10]

I thnk you'd be further ahead benching the Peerless (or using the woofers to make a pair of active push-push woofers), and putting FE206e into something like Dallas II or Sachiko... and there would stll be room to make things even better with some mods to the 206

dave

[69122s]

Thanks for the advice but I'm committed to going through with my original plans. The question is would I be better off swapping out the Philips full rangers for the Fostex units or should I just stay with the Philips ?

I think the Philips drivers were only rated for something like 15 W rms. The Fostex are rated around 90 W if I recall correctly. I'm replacing the Peerless woofers with brand new Bravox woofers which can handle a lot more power and have a nicer response curve. They should be a nice upgrade.

Are there any other 8" full range speakers available for around the same price as the Fostex FE206Es that I could also consider ?

A pair of Lowthers might be nice but they're so darned expensive...

[planet10]

In that case the 206 should be fine (assuming similar efficiency to the rest)... rated power hanling (for what it is worth) is 30 W continuous 80W music.

You might consider the FE207 since it is better suited in applications where you aren't horn loading the driver.

dave

[Simei]

Hi bro,

Philips 9710 M8 driver is one of the best FRs even in present day. You may not get anything better to replace it with Fostex 206Es.

9710 is very high efficientcy, although it is only rated at 15W but it can really sing quite loud in a reasonable big room.

You are lucky to own them!

David

[69122s]

Yes, I recall the Philips were very good sounding speakers and very efficient. The only problem I had with them is that they distorted badly at higher volumes and with certain types of music. I was thinking that switching to something with a bit higher power handling capability would help eliminate that problem.

Looking inside the cabinet it appears that the speaker maker put a 5 ohm resistor in front of them. I'm guessing that was because of their high efficiency and he had to cut them back a bit in order to balance their output with the rest of the front facing speakers. The speaker maker also recognized the fact that they couldn't handle higher volumes so that's why he also made it so you could switch them off and just run with the front facing woofers & tweeter.

So from what you're telling me, I probably won't get any better sound quality out of the Fostex so the only benefit I'm likely to see if I switch to them is better power handling capability.

Is there anything else I could do to mitigate the problems I was having with those Philips drivers distorting at higher volumes and with certain types of "challenging" music ? Put a little larger but better quality resistor in front of them ? Stuff some more fibreglass insulation in the enclosure to increase the dampening a little ? Suggestions anyone ?

But then maybe I'm making too much of this. I don't play my music as loud as I did when I first got these speakers. I was a young bachelor in my early 20s back then. I still like my music a bit on the loud side but my partner doesn't like it near as loud as I do (I think her hearing's much better than mine) so I rarely get to turn it up to the point where those Philips would start distorting.

But on the other hand my new Amp has HEAPS of power (PS Audio GCC 500) compared to my old amp, so I have good reason to worry about the low power handling ability of those Philips drivers. What to do ?

Thanks in advance...

[planet10]

Originally posted by 69122s
Is there anything else I could do to mitigate the problems I was having with those Philips drivers distorting at higher volumes and with certain types of "challenging" music ?

You could use a separate amp to drive them... probably half the energy you are sending is being burned in the resister.

dave

[69122s]

I should also mention that I'm looking at some 8" Panasonic Metal-FA full-range speakers that are sold on eBay.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300176543472

They appear to have a power rating of 60W Peak 120 W.

Sensitivity is only 92.4 dB 1W/1m vs the Fostex which are in the 95-96 db range. Not sure what the Philips ones are but I think they're somewhere up near the Fostex in that department. I do have a basic understanding of what sensitivity means but I'm not really sure how significant the lower sensitivity rating of the Panasonics is. Perhaps someone could educate me on that...

I contacted a couple of the people who have purchased the Panasonics before and they were both very impressed with them. They both said the quality of construction is very good and the sound is great. One of them told me he also owns Fostex but thinks the Panasonics are way better. Interesting to say the least...

These units are a very decent price so it wouldn't be a huge loss if I tried them out and then decided to go back to the Philips. With regular air mail shipping from Taiwan I can get a pair of the Panasonics for $150 USD. Compare that to the Fostex FE207Es which are $180/pr plus shipping from Madison, WI (probably $30 or $35).

What to do, what to DO ?

Any suggestions/advice/thoughts/input would be appreciated.

Thanks in advance.

[69122s]

Originally posted by planet10


You could use a separate amp to drive them... probably half the energy you are sending is being burned in the resister.

dave

Driving them with a second amp is not an option. Actually, the resistor didn't seem to have a whole lot of effect on the efficiency of those speakers. Those speakers as a whole were very efficient and required very little power. My old amp was only 60 Watts per side and I barely had to turn up the volume knob to make them real loud. I don't think the volume knob ever got over more than 1/3 of the way to the max before the sound levels reached dangerous levels. My new amp is 500 Watts per side into 8 ohms so power will never be an issue.

What about packing a bit more insulation or some foam in the enclosure to dampen them a bit more ? Would that help at all ? What else could I do (besides driving them with a separate amp to help them handle a bit more power without distorting ? Or is replacing them with a beefier driver the better answer ?

[planet10]

Originally posted by 69122s
the Fostex which are in the 95-96 db range.

Measured efficiency when i'm done wit them is 94 dB

The Panasonic would probably just require a drop in the size of the resistor.

dave