Hi everyone! My project is a Pinnacle Classic Gold Tower upgrade which uses two 8 inch woofers with the lower woofer using a 1st order coil at 150Hz. Crossover point for top woofer and new tweeter is no higher that 2K. I will be building new crossovers to meet the needs of the new tweeter. If this was your project, what tweeter would you consider. My budget is <$70. I have had good experience with HiVi and Peerless dome tweeters in the $20-$30 range but would like to consider a tweeter considered a step up.
Yes. I recently tested this tweeter. For $52, it is very hard to find another tweeter with the combination of high sensitivity (93 dB) and low FS (600 Hz) and good sound quality. In a 2.5 way, you will appreciate the sensitivity and the ability to cross it as low as 1.6k.
@profiguy - in your opinion, does the Morel offer enough advantage over the SB to warrant the higher cost?
@hifijim Yes, the CAT378 is worth the extra money if you want a tweeter capable of a low / shallow xover. It sounds better at higher SPL than most tweeters under $100 and maybe more. It also has a better, more powerful motor. The SB has a little more low level detail, but at expense of a little more THD. That may change if used x with a WG, but that bumps up the price close to the Morel.
The SB29SDA does look like it checks all the boxes. At a crossover point of 2000 Hz this tweeter will match the the woofers frequency response and sensitivity of the original Vifa aluminum tweeter which was 91dB. I never found the original Vifa tweeter to my liking which ignited this project in the first place.
Any thoughts on what the advantages/disadvantages would be comparing the Morel CAT378 vs the SB29DA?
Any thoughts on what the advantages/disadvantages would be comparing the Morel CAT378 vs the SB29DA?
@mteetank The CAT378 is a little smoother sounding at lowxover and higher output levels than other SB tweeters of similar cost. It can deal with low and shallow xover slopes while keeping the xover simple. In a large 3 way system with a higher xover, this tweeter can do some incredible dynamics and very low HD. It also gels very well with midrange domes like the MDM55 and 4 - 5" paper cone mids. Of course, the big advantage of the CAT378 is the recessed acoustical center really benefiting integration with cone mids.
The SB soft domes are likely the best value in tweeters. Audax, Seas and Peerless would be my second choices under $100. The great thing about most SB tweeters is their copper demodulation rings and vented VC formers, which are features found in much more expensive drivers. I'm not aware of any other common brand that uses copper rings and a vented VC in a $35 compact neo tweeter, ie. the SB26STCN, being another great value. This is my favorite compact neo tweeter under $100, although not quite as good at lower xover compared to the larger dome drivers.
Without considering budget, other tweeters I'd consider for low xover is the Seas T35-C002, Morel TSCM1044/1104 and Bliesma T34A/B/S.
The older Vifa metal dome isn't as clean at lower xover. It sure was used in ALOT of designs, but often crossed too low. Seas makes great metal domes, some of which are sophisticated designs. The smaller metal dome I like the most is the Audax TW025A20/A28. It sounds like an electrostat HPed above 3.5k
The SB soft domes are likely the best value in tweeters. Audax, Seas and Peerless would be my second choices under $100. The great thing about most SB tweeters is their copper demodulation rings and vented VC formers, which are features found in much more expensive drivers. I'm not aware of any other common brand that uses copper rings and a vented VC in a $35 compact neo tweeter, ie. the SB26STCN, being another great value. This is my favorite compact neo tweeter under $100, although not quite as good at lower xover compared to the larger dome drivers.
Without considering budget, other tweeters I'd consider for low xover is the Seas T35-C002, Morel TSCM1044/1104 and Bliesma T34A/B/S.
The older Vifa metal dome isn't as clean at lower xover. It sure was used in ALOT of designs, but often crossed too low. Seas makes great metal domes, some of which are sophisticated designs. The smaller metal dome I like the most is the Audax TW025A20/A28. It sounds like an electrostat HPed above 3.5k
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Forum member Petr did a nice 8"-1" design that underlines the benefit of using a waveguide for the tweeter. Alexander Gresler did another.
If you hesitate to mod things, even a standard Monacor WG-300 plus DT-300 would outperform virtually all 'bare' tweeters with respect to uniformity of the directivity pattern. You don't want to end up with a speaker that has either an on axis response hole in the upper mids (around 1,5k) or too much off-axis energy in that range. To me that is the price of combining an 8" with a tweeter.
If you hesitate to mod things, even a standard Monacor WG-300 plus DT-300 would outperform virtually all 'bare' tweeters with respect to uniformity of the directivity pattern. You don't want to end up with a speaker that has either an on axis response hole in the upper mids (around 1,5k) or too much off-axis energy in that range. To me that is the price of combining an 8" with a tweeter.
I have done some research on wave guides but to tell you the truth that approach might be just too much for my noodle to absorb. I do value you taking the time to point me in that direction. The Wavecor TW030 and the SBAcoustics SB29SDAC000-4 look a great match for the the 8" woofers. With the Wavecor sensitivity at 91 and the SB29 sensitivity of 93, what effect does the wave guide have on sensitivity/output compared to the SB29? Any thoughts on which one of these two would have an advantage over the other?
The DT300 I suggested does 93dB according to Monacor. The WG300 actually doesn’t add much at higher frequencies, the advantage really lies in the lower range from about 1,5k and up. Long story short: the WG enables lower coupling and/or reduces distortion. You’ll have a hard time trying to use the ‘bare’ domes mentioned at 1,5k at reasonable levels without distortion problems. Check Hificompass if you are not convinced.
Sounds like fun project , love 8" speakers.
Trick is for directionality off axis.
8" likes to be crossed low.
Around 1,400 to 1,800 Hz
So your usually looking at large tweeter
or something with low resonant frequency.
Usually want to be 2x over Fs
so tweeter in the 600 to 700 Hz
resonant frequency is ideal.
Usually a 1 1/4 " , 1 1/8 " to 2"
tweeter to get Fs low enough.
Then with steeper 3rd or 4th order crossover
should help get a tweeter that low
with lower distortion.
GRS A25-2T = 2" tweeter
730 Hz Fs
Dayton RST28A-4 = 1 1/8" tweeter
775 Hz Fs
A suffix = Aluminum Dome
Dayton RST28F-4 = 1 1/8" tweeter
710 Hz Fs
F suffix = Fabric Dome
Notice I show both with truncated
Bessel mounting plate.
This allows slightly closer mounting
to woofer. To get tighter center to center
spacing
Trick is for directionality off axis.
8" likes to be crossed low.
Around 1,400 to 1,800 Hz
So your usually looking at large tweeter
or something with low resonant frequency.
Usually want to be 2x over Fs
so tweeter in the 600 to 700 Hz
resonant frequency is ideal.
Usually a 1 1/4 " , 1 1/8 " to 2"
tweeter to get Fs low enough.
Then with steeper 3rd or 4th order crossover
should help get a tweeter that low
with lower distortion.
GRS A25-2T = 2" tweeter
730 Hz Fs
Dayton RST28A-4 = 1 1/8" tweeter
775 Hz Fs
A suffix = Aluminum Dome
Dayton RST28F-4 = 1 1/8" tweeter
710 Hz Fs
F suffix = Fabric Dome
Notice I show both with truncated
Bessel mounting plate.
This allows slightly closer mounting
to woofer. To get tighter center to center
spacing
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I agree, 8” really need to be crossed low, but with the right tweeter they can really shine. I am not really worried about off axis since my listing is centered about 8’ from my speaker bank. The RST28F-4 = 1 1/8" tweeter interests me as well as the SB29SDAC000-4 which to me would meet my budget and audio enjoyment.
I am working on designing a 2nd order modified 2 way for the W2 (lower woofer) based on using the Pinnacle OEM components. This will roll the woofer at 150Hz and the 2nd order capacitor will kick in at 450Hz.
Back to the tweeter, I am really leaning towards the SB29. It has a Fs of 600 and meets the lower crossover target of 1.8K – 2.2K.
I now understand why a 3rd order crossover for the W1 and T1 would be better. I have never built one of those so that should be fun to do. I have been learning Xsim but do not have the actual freq and induct files for the OEM components so the final crossover design will be somewhat a variance from perfect. :>) I will post as soon as I get the design done.
I will update as long as there is input from those interested.
I may seem persistent, but here are my final 2ct. Get yourself a (cheap) measurement mike and use it. And directivity (off axis behavior) matters, it is not about off axis listening but about sound power distribution in your room. Read Toole and Geddes. Especially when you are 8 ft from your speakers. Lot of room interaction and little direct field.
Adding to what markbakk said above...I don't think you need to actually read Toole and Geddes, but feel free to if you want. While having a relatively flat on-axis frequency distribution is desirable, it is only ONE factor. Your speaker is going to radiate sound in all directions and it is going to reflect off walls, the floor, ceiling etc. So you also need to take into consideration Power Response, Listening Window and Early Reflections. If you Google search those terms or just search here at diyaudio you'll find what you need to know.
Me too as Altec was a 'broken record' WRT sound power distribution and the proper time delay regardless of room size.
I like the Wavecor TWO30 series nice smooth and xover low, the TWO30WA11 Fs is a low 410Hz.
Not that pricey here in Aust @$99