how do you score the fe207 & chr-70

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please forgive my ignorance, I only build a pair of chr-70 in ported box, and I feel very satisfied with it, and I wondering how do you score it compare to the fe207 ( like 90 for fe207, 70 for chr-70, assuming they are well designed box) .

my wife have asked me, you spend so much time on building this speakers, why don't you build a best one, I don't know which is best, I just know the fe207 is high recommended one. so this is why my question come out.


thanks for you opinion.
 
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They are quite different... which one is actually best will be greatly affected by your room and your amplifier.

As an example, in my main room (big) with my main amps (4W tube amps) the FE207 would be all over the CHR. In mu office (small) with my chip amp the CHR is better.

Note that when i talk about these drivers i'm really talking about CHR70eN & FE207eN (the modded drivers, to my ears anyway) far surpass the stock drivers, as good as they are, for musical enjoyment.

dave
 
thanks dave,
my room is 12' x 24', half of my room is dinning area, and this side is open, another side is closed, for my TV.

I don't know if I can call it big or not.
 

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Qingcai,

The difficult thing is to know which is "best" for you. There are so many directions to go. It's good if you can listen to a pair of what you want to build beforehand, but this is often not possible. The Fonkens, the Moose BVR, various MLTL designs, and BIB, they all seem to be popular. There's more designs than that too. Planet10's homepage is a very good site to look around, showing lots of plans for different boxes with different drivers. Also within this Full Range forum there is much information.

The Moose BVR "Lotus" with CHR70 may do well in that room (IMO) with the limitation being they cannot go super loud. If you can afford the larger Fostex drivers then the choices are many indeed. Are the speakers you just built lacking in any way? What is it that you are looking for that your current speakers do not provide? What sort of amplifier are you using to drive these speakers? The answer to these questions may help others more experienced than me to give you some good suggestions.

Good luck and happy building.

Ian.
 
thank you Ian and Dave,

the planet10 hifi website is definitely daily browsing site. I hope I can build every one in the site, but the garage is too hot in these days, LOL.

because I don't have experience with other hifi speakers, the only one I have is JBL music one, and I did enjoy the jbl a lot on movie wathing. after I done the port version chr-70, it does amaze me, so I just wandering if I done right, and where is this chr-70 position in all these full range drivers. and if there is better plan, or full range speakers in reasonable/affordable price.

I browsed this forum about half year, and know the fe207 is high recommend one, if from your opnions, let me know there is a big improvement exists between chr-70 port box and moose' bvr or dave's microtower, I would eager to try these boxs, and same to the fe207, if there is a big difference, I would like to build a pair too.

actually I don't know if the speakers I build have any short, I'd wait for my wife back at weekend , her ear are better than mine, LOL.

I feel little shy when talk about the amp, my amp is denon 1909, it's a 70w output/channel av receivers. the audio source are from two type:
1, laptop to sound card, which is equiped with pcm2702 usb chip with simple OP output , I build by myself. about 30$ cost. highly recommend from head-fi forum.
2, popcorn hour hd movie --HDMI--> denon decoding.

dave, do you think the amp is the weak point of my setup? or the sound source.
 
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With the Denon, i would suggest that the CHR has an advantage.

I would suggest that the 1st place you look to improvement is to get an EnABL kit from Ed, practise on some cheap speakers and practise and then do the CHR.

The stock CHR is good, EnABL transforms them.

Building one of the boxes with 2 CHR really helps in the dynamics department (and 8 ohms will make your Denon happier).

The microTower is not intended to be the be-all & end-all... it is a high WAF box that doesn't need a stand, is easy to build, yet large enuff to allow porting to extract more bass from the driver.

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For small boxes i'm sticking with sealed for the CHR, your use of a high aspect ratio port takes the BR design heavily towards aperiodic (ie between sealed & BR). Nice boxes BTW... what is the material? And how do you make them float in space like that 🙂?

dave
 
Let me search the forum to see show is Ed,

I will make good stand for the speakers. sorry to surprise you.

I did not use the round tube as port, just because I am lazy to find out the pvc tube material in home-depot. I notice the the wind flow from the port is less than the round one. maybe this changes the box a lot from the original design 😡

the box material:
1. the face is hard maple embedded with walnut.
2. the side is plywood, and cut into slice, then turn each slice 90 degree, then glue it together. then I can get a much thicker board, and I heard that it's more steady than 3/4 plywood.
3. the top is ash, cheapest wood in shop. and very easy to work with.

I just oiled it last night with lee seed oil, don't have pic yet, it's does look better.

I shoot these photos with my cellphone, lots of noise on the pic

IMAG0024.jpg

An externally hosted image should be here but it was not working when we last tested it.
 
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Hi qingcai and fellow thread readers,
I'm taking a little breathing time before I start building New CHR-70's and Alpair 7's next week.

Re gingcai's Fe207 - CHR70 comparison question. Not wishing to disappoint but comparing these drivers to each other is impractical and potentially misleading. These drivers are very different, both in their design and operational envelopes.

Regarding Dave's comments on Enabled and stock drivers, I've had some time recently to test a pair of Enabled CHR-70 drivers and compare them to stock versions.

Quantitative measurement:
The test was carried in an anechoic chamber using LMS (see chart). There's no significant differences in the frequency tracks between the stock and Enabled drivers. The T/S parameters changed little. The only notable difference was the reduced SPL of the Enabled drivers by 1dB. I should add a note of caution. This test should only be viewed as "marginal indicative". For greater reliability, a larger sample of drivers would need to be tested. All the same, there's nothing that significantly stands out from the standard anechoic sweep tests.

Qualitative
I've managed about 4 hours of listening between the stock and Enabled versions in my Hong Kong studio. An additional 3 hour session was held with my HK audio friends, 2 of which are Japanese and very familiar with Fostex.
My my perspective, I enjoyed listening to both stock and Enabled units in similar measure. I liked the Enabled units for their smoothness while I enjoyed the stock units for their clarity. I haven't had time to check the effect of Enabling process on the cone's resonance pattern at the micro-resonance level. However, it is likely that Enabling is applying a subtle damping factor in the mid-high range.
Now comes the really interesting bit. The listening session that included my 2 Japanese audio mates brought something of a division of opinion. For half the group (4 guys), the Enabled drivers weren't favoured over the stock drivers. The damping factor was felt to be too intrusive upon the CHR-70's "character". In particular, 2 recordings got a debate going. Pie Jesu (Requiem Reference recording - Dallas Women's Chorus), the final vote went to the stock drivers for revealing more of the nuances in the soloist's voice. However, the Enabled drivers got the "thumbs up" on Manuela's (Musiclab) rendition of Stand By Me, by way of a silky delivery.

Conclusion
No doubt the debate will carry on with some heat, not only on the effects of Enabling but for all driver enhancements. My own feeling is Enabling is having an effect that may benefit some tracks and for some listeners, will be an enhancement in their listening pleasure. However, for those who want to see measurable beneficial differences, they may be in for a long wait.

I'd like to congratulate Dave on his efforts to enhance drivers. I've encouraged Dave to set up blind trials to further explore the Enabling experience.

As a driver maker, I'm all for experimentation and believe its important to support the the Custom build community in most of these endeavours. Variety is the spice of life, the greater choice in speaker drivers, the more interesting the hobby becomes. I'm continuing to work on every batch of drivers so there's a few modest "tweaks" in the CHR's coming your way soon.

Cheers - Mark.
 

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Thanx Mark.

When listening to EnABLed vrs stock drivers, the biggest thing i note is that the imaging becomes much more 3-dimensional, and the boxes the drivers are mounted in become harder to localize. Sometimes this is hard to hear, but it seems once it catches you it is hard to live without...

This does require a very low noise box. I would speculate that a typical MDF box might have trouble as they tend to ooze low level grunge that can bury extra micro-detail (ie greater downward dynamic range).

I do find that some of the high frequency edge on drivers is removed, i find this a positive thing most of the time, but indeed some people find this a deficit.

dave
 
I do notice the stock chr-70 stage image is wider than the jbl music 1, and position is very clear. I did not try EN version yet.

can i ask if any device can measure the stage ?

since the best we can hope for is verisimilitude to the artists'/recording engineers' "vision", your listening is exercising as reliable a pair of instruments and software as any
 
since the best we can hope for is verisimilitude to the artists'/recording engineers' "vision", your listening is exercising as reliable a pair of instruments and software as any

It really requires 2 ears + a brain. Quantiying imaging, envelopment, soundstage is one place where measuring kit really falls flat on its face.

dave


that folks, is syncronicity
 
Interesting 🙂 Cheers for the measurements Mark. Looks like a lot of this is going to end up pointing in the direction of psycho-acoustics & perception of low-level detail changes in complex signals etc., as none of the standard checks thus far (AFAIK at any rate) have indicated any major changes, beyond perhaps a small degree of damping.

I'm not going to hold my breath re 'new' measurement methods though, so I think the idea of holding blind trials to try & obtain some statistically significant data & ascertain specific trends is a good one if it could be arranged somehow.
 
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Hi Dave, Chris, Scott and readers,

Yes, it was very interesting to get the feedback from 8 guys. The up-side is none of the group came out and said they totally disliked Enabling. It was more a question of degree and personal preference. Summing the group's preferences, those who were sensitive to, or concentrated on detail least supported Enabled. Conversely, the guys who thought more about tone saw Enabling as a way to smooth of a driver's audible output.

One very important thing that came out from the discussion over the LMS results, is that the whole group agreed that Enabled didn't negatively affect measurable overall performance. This is a good result considering Enabling is, by its very nature a reductive process.

As a engineer-driver maker, cooking up cones and alike, I'm trying my best to create sounds that please for a given price point. The CHR's sales results suggest that I'm on the right track. Diyer's vote by way of their purchases so I'm much encouraged by the acceptance of the CHR-70 into the custom build community. The same applies to Enabling. Some listeners will enjoy what Enabling has to offer while others won't see it as a benefit. Enabling has been around for some time so there are custom builders who enjoy Dave's work. So it's fair to suggest that Dave's efforts are yielding some benefits for a number of listeners.

I've briefly mentioned my micro-measurement technology in other threads. It may shed some further light on the damping effect. However, the measurement technique won't tell us how Enabling relates to the listening experience in terms of the human perceptive differential from stock drivers. Scott's right on the money, the way to go is blind trials with as large a listener sample as possible.

Personally, I'd love to see the day when I could build 100% dedicated drivers for Dave. Guess this is some way off but it's nice to have this aspiration.

Cheers,
Mark
 
Hi Dave, Chris, Scott and readers,

Yes, it was very interesting to get the feedback from 8 guys. The up-side is none of the group came out and said they totally disliked Enabling. It was more a question of degree and personal preference. Summing the group's preferences, those who were sensitive to, or concentrated on detail least supported Enabled. Conversely, the guys who thought more about tone saw Enabling as a way to smooth of a driver's audible output.

One very important thing that came out from the discussion over the LMS results, is that the whole group agreed that Enabled didn't negatively affect measurable overall performance. This is a good result considering Enabling is, by its very nature a reductive process.

FWIW, after a good 2 years of active forum discussion, I think it's still not entirely clear exactly what the process is doing/how it works. Of course, any manually applied post production driver modification(s) includes the chance of mis- / over-application of material(s), or other damage that could affect the measurable and/or perceived performance in any number of undesirable ways.

As a engineer-driver maker, cooking up cones and alike, I'm trying my best to create sounds that please for a given price point. The CHR's sales results suggest that I'm on the right track. Diyer's vote by way of their purchases so I'm much encouraged by the acceptance of the CHR-70 into the custom build community. The same applies to Enabling. Some listeners will enjoy what Enabling has to offer while others won't see it as a benefit. Enabling has been around for some time so there are custom builders who enjoy Dave's work. So it's fair to suggest that Dave's efforts are yielding some benefits for a number of listeners.

I've briefly mentioned my micro-measurement technology in other threads. It may shed some further light on the damping effect. However, the measurement technique won't tell us how Enabling relates to the listening experience in terms of the human perceptive differential from stock drivers. Scott's right on the money, the way to go is blind trials with as large a listener sample as possible.
Ever since Bud unleashed EnABL, and a few curious folks decided to just listen to it and post their impressions, much of the technical debate has been exactly how to measure / analyze the mechanism(s) that effect a clearly audible (to some) change ("improvement"). I think the technology is yet a long way from defining measurement regimens for any component in the entire audio chain that can accurately predict how each unique musical brain will process and perceive the "data stream". Until then, no investigative efforts would be entirely wasted.

After conducting a few informal and unscientific listening comparisons/demonstrations ourselves, I'm of the opinion that regardless of "experience" or degree of "trained listening", not all folks are equally sensitive to all aspects of what is going on here, and just don't "hear" the same things. Then add to that the whole mumbo-jumbo semantic soup that we like to use to describe what we hear, and well ....

Personally, I'd love to see the day when I could build 100% dedicated drivers for Dave. Guess this is some way off but it's nice to have this aspiration.

Cheers,
Mark
oh yeah, that could be some interesting synergy


Me too... some work to do yet before we are ready for that.

🙂

dave
 
I like the speakers very much, my wife like it either, her ear is picky than mine.

btw , this is the 1st woodworking really satisfied my wife after I bought the table saw.


very pretty work

if you can satisfy your wife with both the sonics and aesthetics, you're only one step away from a trifecta - but you'll have to revert to private messages for discussion or bragging rights on that one. 😛
 
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