Midrange placement....

I finally decided what my next attempt at audio sound quality perfection will be... a 4-way tower all active

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T
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Midwoofer
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I'm going with 2 15" Lambda TD's per side for midbass... playing to 100-150 or 200 hz ... this is kept low to avoid beaming from the large speaker... these have already been purchased
1 10" PHL/Seas Excel 10" midwoofer from 150 or 200-300 or 400 hz...

the midrange choice is quite a bit harder and filled with a lot of options...

Currently on my buying list for testing are the Seas Excel 5.5" midrange, PHL 6.5" midrange, CSS 4.5"
Does anyone have any uber high end SQ midrange beside these?

For tweeters I'm looking at a LCY 130 true ribbon tweeter with some modifications or a SS 9800 or a Seas Millenium (all of these I will buy and test)... any more fantastic domes/wide dispersion ribbons to consider?

Anyone with any suggestions on this setup?

Would setting it up this way

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Midwoofer
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be better?
 

derf

Member
2004-04-01 11:04 pm
Herts
I finally decided what my next attempt at audio sound quality perfection will be... a 4-way tower all active

Personally, if I was attempting "sound quality perfection", I'd be looking at moving away from the box towards an open baffle design. You'd only have the driver performance and baffle roll off to worry about then, rather than cabinet related problems(sound returning through the cone, box resonance...)

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Midwoofer
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That seems excessively complex, most good 15" drivers should be able to get cleanly up to 500hz before off-axis response starts to roll off significantly.

From between 200-300hz to 1khz-3khz(depending on the driver you choose), I'd implement a single midrange driver. Try a larger, more capable midrange driver, 8"/10" maybe even a 12" before deciding if you need two midrange drivers. More drivers=more problems

I'm going with 2 15" Lambda TD's per side for midbass... playing to 100-150 or 200 hz ... this is kept low to avoid beaming from the large speaker... these have already been purchased

As stated above beaming shouldn't start to occur until at least 500hz. I haven't been able to find any specs on this driver, but I'd think about using 4 per side in a H baffle configuration.


Currently on my buying list for testing are the Seas Excel 5.5" midrange, PHL 6.5" midrange, CSS 4.5"

Hmm, I think the Seas and CSS would have problems keeping up with the Lambda's. I'd go for a high efficiency midrange in keeping with the Lambda's, probably one of these:

B&C 8PE21
B&C 8PL21
New Precision Devices Neodymium midranges
JBL 2206H
PHL "X" Model(Would be a lot more helpful if they provided frequency response graphs...)

Haven't got any suggestions regarding tweeters, but I think a high efficiency ribbon tweeter would problem integrate well into this type of system.
 
derf said:


Personally, if I was attempting "sound quality perfection", I'd be looking at moving away from the box towards an open baffle design. You'd only have the driver performance and baffle roll off to worry about then, rather than cabinet related problems(sound returning through the cone, box resonance...)



That seems excessively complex, most good 15" drivers should be able to get cleanly up to 500hz before off-axis response starts to roll off significantly.

From between 200-300hz to 1khz-3khz(depending on the driver you choose), I'd implement a single midrange driver. Try a larger, more capable midrange driver, 8"/10" maybe even a 12" before deciding if you need two midrange drivers. More drivers=more problems



As stated above beaming shouldn't start to occur until at least 500hz. I haven't been able to find any specs on this driver, but I'd think about using 4 per side in a H baffle configuration.




Hmm, I think the Seas and CSS would have problems keeping up with the Lambda's. I'd go for a high efficiency midrange in keeping with the Lambda's, probably one of these:

B&C 8PE21
B&C 8PL21
New Precision Devices Neodymium midranges
JBL 2206H
PHL "X" Model(Would be a lot more helpful if they provided frequency response graphs...)

Haven't got any suggestions regarding tweeters, but I think a high efficiency ribbon tweeter would problem integrate well into this type of system.

thanks for the eventual reply ;)

the design was "reduced" several days ago... to simply a 3-way... the 15" lambda's off axis response at 60 degrees is flat to 500hz...

The PHL 1120 is the midrange I chose... and it's 97db efficent...


the tweeter of choice is a modified LCY ribbon... if no domes that I purchased for testing beat it (I bought the SS 9900 and the Seas Millenium already)...

I don't really want an OB design... I neither have the space for it... or like the sound it gives you... however in all my testing (choosing what drivers I want) It will be in an OB setup... so if it turns out I like the sound... I might keep it...

problem with going with a larger than 6.5" or 8" driver for the midrange is that the midrange won't be as clean (Thy has pointed out that midrange from his 1120's is a good deal superior to the PHL 8"... though Andre from E-speakers boasts that the PHL 3450 a 10" midrange has the best SQ of any midrange out right now)

but... andre is out of the 3450's :(
 
Audiophilenoob said:


problem with going with a larger than 6.5" or 8" driver for the midrange is that the midrange won't be as clean (Thy has pointed out that midrange from his 1120's is a good deal superior to the PHL 8"... though Andre from E-speakers boasts that the PHL 3450 a 10" midrange has the best SQ of any midrange out right now)

but... andre is out of the 3450's :(


I have had the 3451 and 1120, they are very good drivers when crossed over right on big enough baffles - alternate drivers that are as good or better is the Audax PR170MO (on sale at Madisound) or the JBL 2123H (even better than the PHL 3450/ 3451 but only to be found used) - I'm using the 2123 JBLs now in a push pull, back to back sealed quasi-dipole (about 103 db sensitive) and have to say it sounds quite a bit better than the open baffle PHL 1120, Audax PR170MO and JBL 2123 mids I've used. More linear, better dynamics and better low mid response. IOW it's killer.
 
ScottG said:
I doubt their is a better overall driver than this one for the bandwidth you desire:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=56270

The enhanced eff. should make this driver quite dynamic.. and a superb compliment to the LCY ribbon..

I wonder about those -C90-T6 PDF

How have you used them? With baffle step correction in that range they would only be around 86 db with a watt at a meter

Take a look or listen to these JBL 2123H . At least on paper they they make the Accuton look like a toy. In the systems I've built with them I find little fault. Compared to the the PHL 3451 the PHL 3451 is nasal and peaky (fatique, colorations) and has a problem finding 300 cycles- The smaller PHLs and Audax's need to be used in pairs to compete with the lack of compression exhibited by the larger 10" beasts - and the smaller drivers never really sound totally real even when biamped and driven with a good high powered amp. A pair of PR170MO's can sound really nice out to 2.5-3k if they are spaced very tightly.

Or the newer 2012H some say it may be better in a horn - it has a higher mass rolloff I'd like some comments from users here on this driver if there are any??
 

ScottG

Member
2003-02-04 12:23 am
US
Magnetar said:


I wonder about those -C90-T6 PDF

How have you used them? With baffle step correction in that range they would only be around 86 db with a watt at a meter

Take a look or listen to these JBL 2123H . At least on paper they they make the Accuton look like a toy. In the systems I've built with them I find little fault. Compared to the the PHL 3451 the PHL 3451 is nasal and peaky (fatique, colorations) and has a problem finding 300 cycles- The smaller PHLs and Audax's need to be used in pairs to compete with the lack of compression exhibited by the larger 10" beasts - and the smaller drivers never really sound totally real even when biamped and driven with a good high powered amp. A pair of PR170MO's can sound really nice out to 2.5-3k if they are spaced very tightly.

Or the newer 2012H some say it may be better in a horn - it has a higher mass rolloff I'd like some comments from users here on this driver if there are any??


no, I haven't used them or have even listend to them. I have however listened to speakers that use their lesser cousins and they are in some respects more transparent than high eff. high guass motor speakers like the more expensive Nd Lowthers (which are more transparent overall then you'll likely find in most high eff. mids - JBL included.. though they have a retched rising response). The lesser cousins do sorely lack in dynamics though, but typically the greater the eff. the better the "jump" factor - so this new driver should be better. Dynamics (and ultimate spl) will of course be inferior to the JBL's BUT, consider the other drivers he is planning on using ..the motors and the driver's and the mms are not substantial enough to "blend" with the JBL's - if you were to do so the effect would be a fast "slammin" midrange with a "limp" top and bottom. Additionally of course the JBL's really are not full midranges (don't go high enough correctly) because the off-axis response starts to suffer lower in freq. due to the larger diameter of the speaker. The best bandwidth for this driver (2012H) without horn loading appears to be effectivly only one octave (400 Hz to 900 Hz).

as for baffle loss, yup you could have problems if your bass (or midbass in his case) driver doesn't provide output to "fill-in" the response (depending on the amps used and the wiring method), but he seems fairly flexible with crossover points and perhaps crossover types.
 
--------no, I haven't used them or have even listend to them. I have however listened to speakers that use their lesser cousins and they are in some respects more transparent than high eff. high guass motor speakers like the more expensive Nd Lowthers (which are more transparent overall then you'll likely find in most high eff. mids - JBL included..

RE: lowthers - You have got to be kidding???? They are so wretched I can't bear to listen to them for more than a minute - the big back horn AER trounced (IMO) the lowthers I've had and heard and still are vielded compared to the 2123's.

--- though they have a retched rising response). The lesser cousins do sorely lack in dynamics though, but typically the greater the eff. the better the "jump" factor - so this new driver should be better.

At a usable 88 - 92 db I think we can call them 'hi-end' regular efficiency -

-- Dynamics (and ultimate spl) will of course be inferior to the JBL's

Yes

----BUT, consider the other drivers he is planning on using ..the motors and the driver's and the mms are not substantial enough to "blend" with the JBL's -

That's nuts - The JBL's work great with real ribbons - I built a pair for a guy (twin 2123's in an MTM) and he recently took a trip to NY - listened to the big dollar JM Labs - here is what he said:

"I just got back in town form New York an hour ago. Just for the hell of it, I listened to the $85,000 JM Lab Grand Utopia BE (their top of the line speakers) what a joke!"

---if you were to do so the effect would be a fast "slammin" midrange with a "limp" top and bottom.

Nope - where do you get this? The ribbon will surely 'poop out' before the mid but with a good xover this isn't much of a problem. Of course a high efficency (100 db/watt+) should be used in the bass.

--- Additionally of course the JBL's really are not full midranges (don't go high enough correctly) because the off-axis response starts to suffer lower in freq. due to the larger diameter of the speaker.

They are fine from 200- 3K -- best used to 200- 2k - that IS the midrange.

--- The best bandwidth for this driver (2012H) without horn loading appears to be effectivly only one octave (400 Hz to 900 Hz).

They MUST be horn loaded - without a horn they rise at around 3 db per octave from 300 to 5k - that is what I should have asked - Anyone here using the 2012H properly? Compared to the 2123H in a horn???[IMGDEAD]http://hometown.aol.com/batespm/images/gpstar.jpg[/IMGDEAD]
 

ScottG

Member
2003-02-04 12:23 am
US
Magnetar said:


RE: lowthers - You have got to be kidding????

Nope - where do you get this? The ribbon will surely 'poop out' before the mid but with a good xover this isn't much of a problem. Of course a high efficency (100 db/watt+) should be used in the bass.


They are fine from 200- 3K -- best used to 200- 2k - that IS the midrange.

They MUST be horn loaded - without a horn they rise at around 3 db per octave from 300 to 5k - that is what I should have asked - Anyone here using the 2012H properly? Compared to the 2123H in a horn???[IMGDEAD]http://hometown.aol.com/batespm/images/gpstar.jpg[/IMGDEAD]

Nope, not kidding..

From experience.. The LCY may sound uncompressed and low in distortion IF crossed over fairly high with a steep slope - BUT it simply doesn't have the motor or the mass to compete dynamically with type of midrange driver you are suggesting. Go back and listen to your ESG1's again and compare them to your compression drivers. Is the physical impact comparable? Then consider that the LCY's are about 10 db less eff. with less than a quarter of their mass.

As for asking about the quality of the 2012H, this should be placed on another thread.. your likely to get more responses, additionally its more than a little off-topic here.