Last time, I planned to get the 2242H 18", but when I load this driver at Boxplot software and WINISD, it doesn't have an f3 of 25hz or 30hz, something like 42hz, while the 2241H has a f3 of 35hz which means it can go a little lower than the 2242H. Is this true?

The 2206 on the other hand is 96db 1w/1m and is dead flat from 100Hz to 2KHz.

The other components in the system all need to be attenuated to the level of the lowest sensitivity component in the system, so there isn't an issue here regarding matching efficiency between subsystems. A simple driver attenuation circuit or an L-Pad can do this.

Regarding SET amp's, the 2206 is actually more suited to them. The impedance at resonance is a lot lower on the 2206 than the 2020, so a SET amp is going to have a lot easier time driving this load instead. High sensitivity is not the only thing to look for when finding suitable drivers for tube amp's, the complex impedance of driver's is the major issue.

About the 2242, your 100% correct. That's why I said you need to use active EQ to boost the low end on the 2242. I suggested use of the Behringer PEQ2200, and I think I even told you what Q, center frequency and boost level to set the EQ to using the box size and tuning I suggested. Check up my old post though to see exact values.

The Behringer parametric EQ costs US$99 though, which is actually not a bad price. However if you really do not want to spend $99 on an EQ unit, there is another way to extend the F3 of the 2242. This is by mass loading the cone. Adding mass to the cone has the effect of lowering driver Fs and raising Qts, and lowering referance efficiency. That means deeper F3. For this particular setup though, it doesn't lower efficiency in the subbass range, as the driver is already -6db to -9db in this region. Adding an extra 110g of mass to the cone results in the following parameters for the 2242:

Fs=26.86Hz
Qts=0.357
Qes=0.378
Qms=6.514
Eff= 1.38% or 93.4db 1w/1m (only change is eff above 100Hz, bass region without extra mass is already this level anyway because of the low Qts and high Fs).

Those are the two options available. Either use parametric EQ, or if you don't wish to pay for an EQ, add extra mass to the cone. Both methods will extend your F3 to below 30Hz, they are just different ways to get there.

Adrian

Thanks for your continued support and help.

The 2241 and 2242 are almost the same. Since the 2241 has a higher Qts, it doesn't form an EBS alignment if you want an F3 of 35Hz, but the 2242 will form a -3db shelf. There is nothing wrong with this, but I'm just pointing it out as you asked for the difference. Bass efficiency between the two are almost identical, with the -3db shelf reversed by the higher referance efficiency compared to the 2241, so the two are just about equal.

The DBX 480 can do some neat things but it won't make up for a bad design. No electronics will, at least not fully. We won't have you do a bad design though, so you don't need to worry.

I can't remember if you are going to use a super tweeter or not. My advice was not to use one, and instead employ compensation on the HF horn instead to have it reach 16KHz. If you do go down this route, the best suggestion I can give is to use the Pi Speakers passive crossover compensation network. I guess you could sort of simulate the curve using a graphic EQ to an extent, however the real crossover provides the exact slope needed. There is also an active version available.

Don't be scared about the crossover, you won't be in it on your own. Members of this forum, including myself will give you whatever guidance or help ou need.

The 2241 can reach 25Hz as well if you EQ it. You can use a 250L box tuned at 25Hz. Parametric EQ centered at 25Hz with a Q of 0.7 and +4db boost will extend the anchoic F3 to 30Hz. Corner load it in an average sized living room, F3 will drop near to 20Hz.

Adrian

My original plan is to add a dedicated tweeter like the 2404H of JBL or the Beyma CP-25 at less than half the cost. Here are a few of my other questions:
what is the difference between a 100 x 100 dispersion and a 100 x 40 dispersion in a home environment, will the 100 x 40 be enough for hi-fi use in a tweeter?
if i use a tweeter, will it be better for me to use a 2" exit driver to have more freq. range? and can also go down to 1khz?

we also compared 2" exit drivers of BEYMA CP800ti, CP650ti, JBL 2450nd (old) and also an old EV, and I think the Beyma's are not left behind in sound and still found the JBL2450's to be still a little forward sounding for my taste. My other companions during that comparisons all liked the EV better than the JBL's, but the EV's are more than 3x the price of Beyma and a little more expensive than the JBL2450's

thanks for the help!!

The Beyma 18LX-60 is the one suited for deepest bass extension. It has the lowest Fs of them all at 27Hz. An SBB4 vented box alignment will work best for this woofer, 305L tuned at 27Hz. Anchoic F3 is roughly 33Hz and F6 is 28Hz. If corner loaded, expect F3 to drop to around 25Hz and F6 at 20Hz. This alignment works nicely.

Don't run a subwoofer from a tube amp. SS or other high power style amplifiers are a must. Its "law" that drivers which hit subbass notes generate a lot of back EMF, so impedance at resonance is high and this is hard for a tube amp to drive. If you search this forum you can find out more on this. You can use a tube amp on the main's though, if their characteristics make them suited.

> what is the difference between a 100 x 100 dispersion and a 100 x
> 40 dispersion in a home environment,

Dispersion angle doesn't change between environment. The difference between those is that one has 40 degrees of vertical coverage, and the other has 100 degrees of vertical coverage.

> will the 100 x 40 be enough for hi-fi use in a tweeter?

"Enough" is not really the term that should be used here. It depends on what your design goals are. If your trying to fill a mid or large sized area with just one or two speakers, then wide horizontal coverage would be wanted. On the other hand, very large area's would have arrayed horns in which each horn would require a very narrow dispersion angle, and CD horns are typically used.

I like between 60 to 90 degrees horizontal coverage per speaker in a home environment when using two speakers. If your got a midrange horn and HF horn, then it's common that you would want the dispersion of each of them to be the same horizontally and vertically. Then comes the issue of matching DI at the crossover frequency which takes a lot of precision to get right.

Vertical coverage on the other hand can be made a lot smaller than the horizontal coverage. It will minimize comb filtering and vertical lobing between drivers which is good. Technically there will still be gaps in the polar response around the crossover frequency, but it's still better to keep vertical coverage angle small to make it as best as possible.

> if i use a tweeter, will it be better for me to use a 2" exit
> driver to have more freq. range? and can also go down to 1khz?

I think I've mentioned this before to you, although it may have been someone else. Look at the frequency response curve of the horn/compression driver combo that you want to use. It will tell you what the device is capable of. Generally speaking, the 2" device will be able to reach lower than a 1" device because their larger diaphragms let them have a lower resonance. Regarding HF extension, a smaller 1" exit throat provides impedance matching to a higher frequency than a 2" exit, so it's got the capability to reach higher. As I have mentioned in the past, I like to use 1" exit drivers and use compensation electronics on them to make them reach 16KHz.

> we also compared 2" exit drivers of BEYMA CP800ti, CP650ti, JBL
> 2450nd (old) and also an old EV, and I think the Beyma's are not
> left behind in sound and still found the JBL2450's to be still a
> little forward sounding for my taste. My other companions during
> that comparisons all liked the EV better than the JBL's, but the
> EV's are more than 3x the price of Beyma and a little more
> expensive than the JBL2450's

Interesting. Thanks for your thoughts on Beyma and EV!

Adrian

Bill W.