newbie: 2226H and 2426H DIY, thanks!

[badman]

There are some that push the limits and need a LOT of box accordingly. Some of the GPA altecs have >600L Vas, as they have low Fs, moderate Qts, and high efficiency.

It isn't JBL, it is physics. There is no woofer made by anyone that has accurate deep bass and a sensitivity greater than 93dB-96db. Anyone who says their woofer will do what you are asking are stretching the truth or have a different definition of deep bass.

There are countless "music lovers", "audiophiles", "audio enthusiasts" or whatever term you find is positive and not a damning title who believe their high efficiency system has great bass... and that is fine, but the fact is that it will not have a linear response. If you can accept some gross inaccuracies in response, and many avid listeners who are members of the previously mentioned groups above seem quite accepting of them, then you have a number of choices, but since you were not lulled into audio nirvana by the A7 sound, I'm going to guess you will not be happy with any of these high efficiency offerings.


Widget

[Mr. Widget]

There are some that push the limits and need a LOT of box accordingly. Some of the GPA altecs have >600L Vas, as they have low Fs, moderate Qts, and high efficiency.

Even in an infinite baffle, I don't think you can find a driver that goes against what I was saying... The old EV 30" woofer does go fairly low and is high efficiency, but it has other issues.

I suppose if cost were no object and sensitivity the primary goal, someone could build a large diameter driver with a field coil motor that would satisfy the sensitivity requirements at frequencies below 40Hz... but??? I also agree that with a properly large, read that very large horn there are possibilities, but again???

I think Lee's suggestion of going a bit larger and going the 4435 route is likely the best compromise... for a fairly simply two way of exceptional sensitivity and using the 2426.


Widget

[badman]

Have you reviewed the drivers I mention? I agree that there's a balance to be struck between factors, but you can up the motor strength and achieve more deep stuff with high sensitivity, at the cost of having to go to very low clearance gaps, and usually give up some Xmax too. These definitely put a limit on how loud it'll go low, but they'll do low at home levels, assuming you take appropriate care in system design.

ALL woofers have "other issues"

I'd prefer to stick with a single higher-sensitivity midwoof, since if you want the sensitivity matched through the midrange, and without introducing extra lobing, you'd need to go 2226h or some such in a decent size vented box. True deep bass would require subs. Anyway, if a 2235 is pumping out deep bass it's not going to sound very good at 1kHz, and if you have 2 of them run full-range, you're going to have horrid polars.

Even in an infinite baffle, I don't think you can find a driver that goes against what I was saying... The old EV 30" woofer does go fairly low and is high efficiency, but it has other issues.

I suppose if cost were no object and sensitivity the primary goal, someone could build a large diameter driver with a field coil motor that would satisfy the sensitivity requirements at frequencies below 40Hz... but??? I also agree that with a properly large, read that very large horn there are possibilities, but again???

I think Lee's suggestion of going a bit larger and going the 4435 route is likely the best compromise... for a fairly simply two way of exceptional sensitivity and using the 2426.


Widget

[spkrman57]

I use 2226's in my system and enjoy the efficiency and I'm content with LF response down to approx 50hz in my 12' x 16' room.

I use tubed amps with < 10 wpc because I don't ask my system to provide unrealistic demands.

Most of my music does not have notes below 40hz and when that situation does occur I can live with the result.

It is all a compromise of one sort or another. The dynamics of a high-efficiency spkr system coupled with using SET (300B) amps is more important "to me" than the bottom end LF response.

You have to decide on what your compromise will be!

Just my 2 cents worth!

Regards, Ron

[Mr. Widget]

Have you reviewed the drivers I mention?

No, but I have used similar drivers...

I agree that there's a balance to be struck between factors...

Yes, all of this is about compromises... some will accept some compromises and other folks prefer a different set.

...but you can up the motor strength and achieve more deep stuff with high sensitivity, at the cost of having to go to very low clearance gaps, and usually give up some Xmax too.

This is where we differ... you can throw all the flux density in the world at it and you won't get a linear response from 30-35Hz to 1KHz and a sensitivity above 96dB... with a cone diameter of 15" or less.... you just can't. Perhaps I should define linear... I like to keep it within a couple of dB. Down 10 or more dB just isn't linear in my book.

Anyway, if a 2235 is pumping out deep bass it's not going to sound very good at 1kHz, and if you have 2 of them run full-range, you're going to have horrid polars.

Have you heard about the 4430 and 4435? Have you heard them? The 4435 does not use 2235Hs or run two all the way up to 1KHz... and I don't think anyone was advocating that solution. I personally like these 44XX systems more than any of the high efficiency designs that I have heard... though they do not have that ultra tenth degree of dynamics that some of the more efficient designs have.


Widget

[badman]

No, but I have used similar drivers...

Yes, all of this is about compromises... some will accept some compromises and other folks prefer a different set.


This is where we differ... you can throw all the flux density in the world at it and you won't get a linear response from 30-35Hz to 1KHz and a sensitivity above 96dB... with a cone diameter of 15" or less.... you just can't. Perhaps I should define linear... I like to keep it within a couple of dB. Down 10 or more dB just isn't linear in my book.

Actually, you can. It requires rebalancing of other components, but the rising response and decreased Qts can both be dealt with with rebalancing the moving assembly. More flux can allow more bass or more efficiency, so a higher flux density would allow someone to increase the bottom end of a driver like the 2226h by decreasing Fs and raising Qts with added mass. Naturally there are limits here, but it's possible and has been done, as evidenced by the Altec drivers, which have several more dB of sensitivity available in the bottom octave while retaining similar axial sensitivity to some of the more sensitive JBLs like 2226h.

The tradeoffs are in what you have to do to get there. The boxes needed are huge, the drivers have limits in displacement that are more confining than the more practically oriented drivers without the effort made towards doing both deep and sensitive.

Have you heard about the 4430 and 4435? Have you heard them? The 4435 does not use 2235Hs or run two all the way up to 1KHz... and I don't think anyone was advocating that solution. I personally like these 44XX systems more than any of the high efficiency designs that I have heard... though they do not have that ultra tenth degree of dynamics that some of the more efficient designs have.

Widget

I'm familiar with them, and my point was that to get the sensitivity of the midwoofers higher with 2235s you'd have to run them both up to the horn, which would be a mess. The 2.5 way design of the 4435 is certainly one way to go about it, but I tend to feel that one is better accepting a low frequency limit and keeping sensitivity higher, and add subs. This shouldn't be a surprise since I'm a long-term advocate of multisubs, so subwoofers are assumed anyway. If you want a standalone speaker, then the 4435 method might be more viable. Focusing upon good bass extension, though, tends to make for a midwoof, in a 2 way, that's not performing as well as it can be near the higher crossover points required for a 2 way.

I've made a few CD 2 ways like the 4430, and just did a survey of 15" woofers, including the JBL 2226h, Eminence Magnum 15HO, and BD BD15.

I think the key component is that you want more deep bass from the mains, at the cost of sensitivity, where I feel the better compromise is a more efficient loudspeaker and subs if you need more bass (better anyway). Just a philosophical difference.

I couldn't live with a 4430. The breakup of the 2425h is too much for me, I'd rather have given up the >10kHz top end and added a cheap supertweeter, but naturally that's more XO. I don't know if it's the diffraction slot (I believe it to be), but there seems to be another source of harshness there too, at higher levels. My own CD waveguides were commented by a forumite here, who owns and uses the 4430, to be the best sound he's heard from the 2425/6 driver family, and didn't have this problem much. They had a top end that was allowed to roll off instead of trying to squeeze 18k out of a diaphragm in breakup.

[Mr. Widget]

The tradeoffs are in what you have to do to get there...

I think we are agreeing more than we are disagreeing...

...but I tend to feel that one is better accepting a low frequency limit and keeping sensitivity higher, and add subs.

I don't disagree at all about the benefits of multiple subs and quality midbass speakers but, this thread is about two-ways to be used in the home with a small amp at moderate to low SPLs.

I couldn't live with a 4430. The breakup of the 2425h is too much for me, I'd rather have given up the >10kHz top end and added a cheap supertweeter, but naturally that's more XO.

Again, 95% in agreement... I don't like cheap tweeters... OK, I don't have a problem with cheap tweeters if I can get an excellent tweeter inexpensively.

Good old Zilch and I chased this issue round and round for years as he advocated squeezing the last bit of break up out of every HF unit he could and I would cringe in the listening... he generated nice looking plots, and I don't think he could hear the problem with the razor edged highs he created. Ultimately he was an engineer, and inventor, and a tinkerer and his goal was somewhat different than mine. I agreed with him that a two-way is an elegant solution and some are better than others, but pulling it off well was tricky.

Only once while listening to a pair of his creations did I hear a pair of CDs that sounded good stretched up top... he was using a particularly clean pair of unmolested vintage LE85s. Those drivers happened to be tame enough to actually work. He gave that pair of drivers to me before passing and one day I hope to build a pair of Zilch memorial two-ways with LE14H3s below... he and I always agreed on those woofers.


Widget

[4313B]

Good old Zilch and I chased this issue round and round for years as he advocated squeezing the last bit of break up out of every HF unit he could and I would cringe in the listening... he generated nice looking plots, and I don't think he could hear the problem with the razor edged highs he created.

That was the whole point. People don't like graphs that aren't flat from 20 to 20k.

[badman]

I think we are agreeing more than we are disagreeing...


<<BREAK!>>>
He gave that pair of drivers to me before passing and one day I hope to build a pair of Zilch memorial two-ways with LE14H3s below... he and I always agreed on those woofers.


Widget

I hope you get to do a project around them, they sure seem to be superb. And yep, we're agreeing much more than disagreeing.

[Mr. Widget]

I hope you get to do a project around them, they sure seem to be superb. And yep, we're agreeing much more than disagreeing.

As it turns out, I could use a new pair of speakers for my shop... something "quick and slightly dirty" should do the trick.


Widget

[grumpy]

My own CD waveguides were commented by a forumite here, who owns and uses the 4430, to be the best sound he's heard from the 2425/6 driver family

I'll nut-up... I'm guessing that was me . A non-fatiguing sound indeed.
I still need to drop the 2421's I got from Earl G into the 4430's and see how that goes...

[badman]

I'll nut-up... I'm guessing that was me . A non-fatiguing sound indeed.
I still need to drop the 2421's I got from Earl G into the 4430's and see how that goes...

I didn't want to "out" you . I'd be very interested to hear the 2421 phragms in your rig- they certainly seem to be the closest we'll be getting to truExtent for the 2425/2426 for a while.

Off topic, we need to touch base sometime soon. I'm listening to a quite different set of speakers than last time- I have since implemented my dipolar heil AMT horns with larger, vented, low diffraction bass cabs.

Ack... bad pic!

[manolito]

Thanks to everyone for your kind information.

We´ve found 4 nice alnico 2205 15" drivers, so we´ve changed our project to:
- d´apolito design
- approx 8 cubic feet box
- bass reflex
- 2 x 2205 (maybe these will be reconed to 2235)
- 1 x 2426H (maybe with radian 1225 diafragms)
- autotech tractrix 350 horn
- XO point around 800 hz
- probably biamped with a Crown DC300A amp (or Sansui BA-2000 or BA-F1) and a tubed SET amp for the horns

I don´t know:
- 2205s seem to be OK, are they worth reconning to 2435?
- how will radian diafragms work?

[ivica]

I am trying to understand the parameters around which you want to work. ...... But perhaps deciding now what size cabinet is too early in the decision process. What could be tempting is using two 2235 woofers per bass reflex cabinet. One does full spectrum (20-800Hz) and the other only does 20-50Hz) for that deeper bass (and using two woofers will raise the efficiency by 3db. Then use a 2426H on top with a 2344 baby butt horn and you'll end up with a 4435 ................ Each 2235 requires a 4,6cft volume. each one will give F3 at 36Hz, and this is why you'd use two woofers. The one that only does 20-50Hz will flatten the bottom... Attachment 53652

I just want to pay your attention that in such configuration , where are two bass near each other [ under 'normal condition' ] that would produce the rise of +6dB for the frequency whose 'wave length" is larger the double distances ( d ) between the speakers, so for 15-inch drivers mounted 'nearby' mentioned rule would be applicable up to about 200Hz.
That is presented in figure with 'blue' line.
More can be find in:
http://www.zainea.com/mutualcoupling.htm

I think that was the reason why JBL in 4435 there are a pair of 2234 used instead of 2235 pair.

Not to mention here that such LF boost in TWO-box combination (usual stereo), has the same ADDITIONAL effects, but for the frequency up to about 50Hz (for 3m speakers apart).
So for very low region that would be +12dB boost if we have 2 boxes with a pair of driver in each.

[manolito]

thanks ivica

in this new idea, the woofers are intended to be in a vertical d´apppolito enclosure, reflex loaded: one woofer down + tweeter horn in the middle + one woofer up (something like the K2-9500, but a tractrix horn in the middle)

the front of the cabinet would seem like this (not exactly of course, it´s just an idea about the drivers placement ...)



for bass it could be, per cabinet:
- one 2205 down, (maybe reconed to 2235) from bottom to less than 200 hz, to avoid coupling
- one 2205 up, full range from bottom up to 800 hz or so