Fullrange 100 hz and up

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Well i have my dipole setup done. It consists of 4 goldwood 1858 subs i got on clearance a while back for only 40 bucks a pop. These are built into the entertainment center/equipment rack i just constructed and i am now looking to build a smaller speaker that can produce from 100hz and up with a pretty good amount of spl.

These are for the living room in my house which isn't huge but is still fairly decent size. Probably 15' wide x 23' long with the listening position about 14 feet from where i would like to place the speakers.

The top of the entertainment center is only 23" high and my ear level when sitting is about 41" or so, but i would rather angle the speakers up ever so slightly than to build a taller enclosure (i.e. i'd like to just set the speakers on the entertainment center on spikes.

So we're looking at a speaker with MAX measurements of about 18" high, 14" wide and 20" deep or so. Can you guys reccomend something in the way of a smaller monitor or maybe some sort of mini horn? I'd like to use the Fostex fe207e if that helps. Hell maybe even an OB (but that qts is really low).

I am going to use a PLLXO on the amp (diyparadise charlize) for crossover duties, probably 1st order and will play around til i get it right.

Can i use a bass reflex enclosure tuned lower than normal, but filter out starting around 150 hz high pass first order to get the desired results? I figure this way i can minimize excursion and get max spl.

Or if you guys know of a horn style enclosure that i can make fairly small then let me know. Thanks.

Nate
 
FE207E in 9 liter sealed cab is roughly -3dB at 100Hz.

If you want to go lower, you can add some series resistance to bump up Qts and increase cabinet size to match.

To me, it makes no sense to build a vented or horn-loaded cab if you are going to hand off to the subs at 100Hz. With sealed .7Q cab, you get natural 2nd order rolloff and controlled excursion, no need for high-pass filter unless you want a steeper slope.

I recently installed the Decware-style phase plugs in my FE207E. I highly recommend it, upper mids and highs noticeably smoother.
 
Dumbass said:
FE207E in 9 liter sealed cab is roughly -3dB at 100Hz.

If you want to go lower, you can add some series resistance to bump up Qts and increase cabinet size to match.

To me, it makes no sense to build a vented or horn-loaded cab if you are going to hand off to the subs at 100Hz. With sealed .7Q cab, you get natural 2nd order rolloff and controlled excursion, no need for high-pass filter unless you want a steeper slope.

I recently installed the Decware-style phase plugs in my FE207E. I highly recommend it, upper mids and highs noticeably smoother.


I was thinking along the lines of an aperiodic or vented because i could control the excursion of the cone if the box is tuned low and crossed above the f3 point. That way im playing in the most efficient range of the box. I'm out of it though, it's been about two years since my last diy project so bear with me.

As for the amp impacting sound quality, will a PLLXO do anything besides add insertion loss? Or will it also adjust phase? I'm really not sure seeing as how it is before the circuit.

Thanks for your response.

Nate
 
I'm gonna agree with the guy with the bad name who we'll call erickson for simplicities sake;) . I would certainly think sealed would be your best option. ported or hornloaded do a better job at controling cone motion at lower frequencies, but since you won't be using your speaker at those frequencies it is not really necessary. Also ported and backloaded horn will add some coloration at higer frequencies, ussually the extra bass, and the better controled excursion make it worth while. However in your case I believe you would just be adding coloration with no real benifit. As far as phase, I don't know the answer to your question, but I doubt you will be able to get your 207's and subs perfectly in phase so I wouldn't worry about it as long as they are not perfectly out of phase it shouldn't be a problem.
Joe
 
Josephjcole said:
As far as phase, I don't know the answer to your question, but I doubt you will be able to get your 207's and subs perfectly in phase so I wouldn't worry about it as long as they are not perfectly out of phase it shouldn't be a problem.
And just to make it perfectly clear, being concerned about phase coherency is yet another reason not to add a vent to the whole equation. You turn a two-way system into a three-way. IMO venting, TL, or what-have-you should only be used on your lowest driver (if at all), because such tricks are specifically to extend your low-end.

And regarding my moniker, feel free to call me a dumbass, it's an homage to Red Forman in That 70s Show.
 
Dumbass said:
And just to make it perfectly clear, being concerned about phase coherency is yet another reason not to add a vent to the whole equation. You turn a two-way system into a three-way. IMO venting, TL, or what-have-you should only be used on your lowest driver (if at all), because such tricks are specifically to extend your low-end.

And regarding my moniker, feel free to call me a dumbass, it's an homage to Red Forman in That 70s Show.

Thanks for your help. Would the fe207 give me the volume that im looking for then (i like to listen to jazz and funk pretty loud)? Or is there a better suited driver for this application?

Also what is the consensus on helper tweeters rolled in around 10k hz or higher just to help get a broader sweet spot? I'll probably just run the 207 only until i hear it broken in and all.

Nate
 
Nate_Taufer said:
Thanks for your help. Would the fe207 give me the volume that im looking for then (i like to listen to jazz and funk pretty loud)? Or is there a better suited driver for this application?

Also what is the consensus on helper tweeters rolled in around 10k hz or higher just to help get a broader sweet spot? I'll probably just run the 207 only until i hear it broken in and all.

Nate
I'm pretty sure the 207 will give you more than enough SPL, especially since you've got subs covering the bottom two octaves. That's assuming you're not using lo-watt SET, anything else should be fine.

Use of supertweets is totally subjective, but I don't feel the need with my 207s, especially after installing the phase plugs.

For best stereo imagery over a wide area, overtoe the speakers so their axes cross well in front of the main listening spot. It is somewhat counterintuitive, but it really works and produces a large "sweet spot". What happens is that a listener who is off to one side or the other is closer to one of the speakers, but more on-axis to the other one, so there is a balancing-out of the proximity effect. In essence, you are using the slight beaminess (inherent in any full-range driver) to your advantage.
 
Dumbass said:
I'm pretty sure the 207 will give you more than enough SPL, especially since you've got subs covering the bottom two octaves. That's assuming you're not using lo-watt SET, anything else should be fine.

Use of supertweets is totally subjective, but I don't feel the need with my 207s, especially after installing the phase plugs.

For best stereo imagery over a wide area, overtoe the speakers so their axes cross well in front of the main listening spot. It is somewhat counterintuitive, but it really works and produces a large "sweet spot". What happens is that a listener who is off to one side or the other is closer to one of the speakers, but more on-axis to the other one, so there is a balancing-out of the proximity effect. In essence, you are using the slight beaminess (inherent in any full-range driver) to your advantage.


Okay thanks. I'll probably order the drivers here in a week or two. I'm going to be driving them with the charlize tripath amp from diyparadise.com unless there is a better candidate for under 100 bucks (not including power supply).

Nate
 
johninCR said:
Since you have dipole below 100hz, why not go dipole on top?


I really like to crank the volume and i don't think that the fostex will be able to dip down to 100 hz in a dipole configuration with the volume i'm looking for.

I have thought about it though and i am going to let them burn in via open baffle and see how they do after 5 or 6 days of playing straight. Hopefully they can still wail in that configuration. But if they don't work out so well i'll just go sealed cab and be done with it for the mean time.

Nate
 
I wouldn't think a 127 on an open baffle would be able to reach very high SPL's due to a limited excursion. The 207 would probably be alright on open baffle at high volumes, I would however make sure to have it crossed over at 100Hz. Note that the response of the driver will already be falling by this point so you take a carefull look at your crossover point/slope. And depending on the size of your baffle some EQ might be needed.
I would probably stick with a sealed design if you wanted to keep the complexity down. I don't know about bass, but I think as far as treble/midrange a large sealed enclosure can perform (please no flames) quite well, and will hold it's own against open baffle. Everybodys taste and priorities are different though.
Joe
 
I use the FE206 on OB, but it definitely needs a helper woofer. You might be able to use a shallow slope XO on your woofers and a little EQ on the 207's to get away with not using an additional driver.

Since you already have OB for the bottom end, I think using a FR that gives you the ability to go OB results in more flexibility. You can always put them in a box later.

Re the FE127, I've run mine pretty loud (approaching 100db) without a high pass filter, so cutting them at 100hz may get you there for under $100/pr .
 
johninCR said:


Re the FE127, I've run mine pretty loud (approaching 100db) without a high pass filter, so cutting them at 100hz may get you there for under $100/pr .


100db in open baffle with no crossover? I would think you would be pushing well past the excursion limits on a regular basis. Fostex drivers are not exactly known for their huge excursion capabilities. Have you tried it with a high pass? I would have to imagine it would clean up the sound. I ran my 108's in a sealed enclosure for a while with no crossover, I've since switched to running them with a capacitor to ease the load on the little guys. It's really helped clean the sound up quite a bit.
just a thought.
Joe
 
That was just temporary. I didn't play them that loud with any bass heavy music. I'm just waiting on my active XO to arrive. I tried them on my Denon HT receiver, using the small setting, but I could hear that XO too much and they were much smoother with it running full range. I can't wait to see what they sound like with a good high pass filter. I have a feeling I'm going to like them better than my FE206's with the helper woofer.
 
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