upgrading FE127e to a Mark Audio....

[Bigun]

I have some ported boxes of about 6 litres which house some FE127E's. I am looking to upgrade them to gain less 'shout' and better ability to handle LF in a home theatre surround application which in my mind means more xmax. I'm looking at drivers of a similar physical size so that I can use them without extensive surgery to the boxes. I've tabulated some options (attached) and this leads me to Mark Audio as the best choice.

As far as I can tell only the EL-70 is currently available. But it's 4 Ohm and I'd prefer 8 Ohm - although this may not be the deal-killer it once was as I'm sticking with SS amps for this application. The CHP/CHR-70 are similar drivers but with the promise of 8 Ohm.

Question: what's the latest estimate for availability of CHP/CHR-70 drivers ?

Question: with the EL-70 (or CHR-70), do you believe I'll achieve a worthwhile improvement over the FE127E in the areas I've mentioned above ?

Thanks.

[chrisb]

Originally Posted by Bigun

I have some ported boxes of about 6 litres which house some FE127Es. I am looking to upgrade them to gain less 'shout' and ability to handle LF in a home theatre surround application which in my mind means more xmax. I'm looking at drivers of a similar size so that I can use them without extensive surgery to the boxes. I've tabulated some options (attached) and the conclusion from this leads me to Mark Audio as the best choice.

As far as I can tell only the EL-70 is currently available. But it's 4 Ohm and I'd prefer 8 Ohm - although this may not be the deal-killer it once was as I'm sticking with SS amps for this application. The CHP/CHR-70 are similar drivers but with the promise of 8 Ohm.

Question: what's the latest estimate for availability of CHP/CHR-70 drivers ?

Question: with the EL-70 (or CHR-70), do you believe I'll achieve a worthwhile improvement over the FE127E in the areas I've mentioned above ?

Thanks.

some quick thoughts ( quick, not deep)


Which channels of "surround" set up to you have in mind? Wouldn't the required bandwidth and X-max be far less for effects surrounds ( ie. rear / front height) than for the front row? As I've nattered about numerous times, my own little HT rig crosses over singles of Alpair7 in each of the front 3 channels at approx 110Hz to dual corner mounted woofers, and since my listening never reaches 105dB reference levels, I've yet to find this system's excursion limits.

I'm even getting closer to fabrication a pair of corner / soffiit mounted enclosures for rear surrounds, which will utilize AP6Ms for timbre matching to the fronts. I think that's a very important factor to consider - and was the reason for choosing A7 for fronts - as good as they sound, the smallest enclosure in which it'll fit is still too large for my current furniture arrangement.

Pensil7 001.jpg

Pensil7 002.jpg


The total volume of this room is approx 2500 ft^3 - and yes, there's still some work to do on the aesthetics of the set-up.



The EL70 are still currently available either in stock form from Bob at CSS and treated from Dave. It's proven to be a great alternative to FE127E.

6 liters is quite on the small side for FE127E to achieve it's potential, but certainly within the comfort range of the EL70 ( see the mMarKel70)
http://homepage.mac.com/tlinespeaker...map-231009.pdf

I think any of the MA drivers would be a great choice for your application - while we've waited quite a few months for the newer Fostex offerings, and it's unlikely they'll present any major disappointments, the MA are already well proven, with a range of enclosure designs built.

[Bigun]

hi Chris, that's a nice set-up you have there, nothing wrong with the aesthetics !

Originally Posted by chrisb

Which channels of "surround" set up to you have in mind? Wouldn't the required bandwidth and X-max be far less for effects surrounds ( ie. rear / front height) than for the front row? As I've nattered about numerous times, my own little HT rig crosses over singles of Alpair7 in each of the front 3 channels at approx 110Hz to dual corner mounted woofers, and since my listening never reaches 105dB reference levels, I've yet to find this system's excursion limits.

I'd better explain - I built 5 of the little boxes aimed at a 5.1 set-up, but before they were done I started off by using my PMC FB1's. These things provided such a magnificent room filling sound (they're flat down to 27Hz) I can't take 'em out and replace them with the little boxes I made. So the PMC's stay and the little boxes are doing duty front centre and rear surround. And because my rear surrounds are ceiling mounted and too far back (can't be moved) I'll use the last pair of little boxes I have to add surrounds closer to the sides of the seating position.

I've seen the cones on the rear surrounds moving way more than they should. I may have them XO'd too low. But with so much low end grunt available from the front I need better LF than the 127E's are giving me or the 'surround' is simply too 'thin'. The front centre FE127E does a nice job of the vocals, but it can be strained.

Originally Posted by chrisb

I'm even getting closer to fabrication a pair of corner / soffiit mounted enclosures for rear surrounds, which will utilize AP6Ms for timbre matching to the fronts. I think that's a very important factor to consider - and was the reason for choosing A7 for fronts - as good as they sound, the smallest enclosure in which it'll fit is still too large for my current furniture arrangement.

If timbre matching is more important than retaining the benefits of Full Range drivers then I could consider something that is better matched. PMC would recommend the DB1, their smallest 2-way. These are too expensive, so I'd be wanting to clone them. If this is a better solution ????????? I'd be willing to give that a go, but obviously it's the 'more work effort' route and I suspect that upgrading the drivers in the little boxes would be a more reasonable solution.

Originally Posted by chrisb

The EL70 are still currently available either in stock form from Bob at CSS and treated from Dave. It's proven to be a great alternative to FE127E.

6 liters is quite on the small side for FE127E to achieve it's potential, but certainly within the comfort range of the EL70 ( see the mMarKel70)
http://homepage.mac.com/tlinespeaker...map-231009.pdf

I think any of the MA drivers would be a great choice for your application - while we've waited quite a few months for the newer Fostex offerings, and it's unlikely they'll present any major disappointments, the MA are already well proven, with a range of enclosure designs built.

Are the current EL-70's the last of the line ? I was wondering if Mark wanted to continue making them after bringing forth the new generation CHP/CHR's ?

[planet10]

Originally Posted by Bigun

Are the current EL-70's the last of the line ? I was wondering if Mark wanted to continue making them after bringing forth the new generation CHP/CHR's ?

Yes. They still remain the bass king of the MA range (at least of the 4"). In an optimal sized enclosure they have about 10 Hz on the others.

I was really hoping to see the CHBW take (and maybe extend) on the capabilities of the EL70 in the bottom, for use as a helper woofer with a CHP or A6.2, but the lobby that won turned it into a midbass not much different from the CHP.

Box-wise the CHP70.3 seems to be closer to the new CHR70.3 than an evolution of the EL70+CHP70.

A7.3 & CHBW it in a slightly smaller (optimum) box than the CHR/CHP. CHBW + ERT26 should be an interesting combo (XO somewhere around 5-6k)

Don't expect any of the new drivers until the last half of July.

dave

[chrisb]

To be honest, my experience regarding timbre matching in a surround system is so far only related to the front 3 row. In experimenting with different sized drivers by both Fostex ( ie, 167 L/R & 127 C) and MA (Alpair12 L/R and 7-C) I noted various degrees of timbral discontinuity, which did not occur with all 3 the same size.

How close you get to "cloning" the PMCs for rears is a very interesting question, better addressed by others.

[Bigun]

Maybe this is off-topic, but how big a deal is timbral matching in your opinion - without some idea of how important it is makes it more difficult to know what else is worth trading off to achieve it ?

[tuxedocivic]

It may be a personal thing, but I find timbre matching very important. Having said that, it doesnt come up often. When a voice pans from left to right, it's AWFUL ( to me ) when the voice changes.

[planet10]

I'd suggest that no centre is better than a centre that doesn't match.

dave

[tuxedocivic]

^ Does or doesn't ? You're agreeing I think.

To add, I find front to back less important. A lot less. Still prefered if possible.

[planet10]

timbre matched centre v important.

dave