Greetings,
I've gotten the itch to start playing with some loudspeakers again...
I know I really love the sound of Quested's 2-ways with the Volt woofers. I use a pair of Q108s on a regular basis and really like them. I'm thinking of building a 2-way using Quested's design as a starting point.
The two 8" drivers in contention are the B228.8 and the B220.2. From what I can tell, the B228.8 is probably a better choice for a 2-way.
As far as I know, the 8" Volt driver in the H108 / V2108 is a custom driver, and I'm sure Volt won't sell them to anyone other than Quested. On the woofer in the Q108, the number is B220.7. This is obviously different from the B228.8 (which I understand is similar or the same as the B220.8)- it's clearly a different cone material. Out of curiosity, does anyone know how similar / different the B228.8 is to the driver that Quested uses?
Besides the Morel MDT30, are there any tweeters I should be considering? I'm thinking of crossing somewhere in the 1.5 kHz - 2 kHz range, so something with decent bottom end is definitely important.
Lastly, how do the Volt woofers compare to the 7" Scan-Speak Relevators? The Volt drivers in the Quested feel very "fast", for lack of a better word. They handle dynamics really well. How are the Scan-Speaks in this regard?
I've gotten the itch to start playing with some loudspeakers again...
I know I really love the sound of Quested's 2-ways with the Volt woofers. I use a pair of Q108s on a regular basis and really like them. I'm thinking of building a 2-way using Quested's design as a starting point.
The two 8" drivers in contention are the B228.8 and the B220.2. From what I can tell, the B228.8 is probably a better choice for a 2-way.
As far as I know, the 8" Volt driver in the H108 / V2108 is a custom driver, and I'm sure Volt won't sell them to anyone other than Quested. On the woofer in the Q108, the number is B220.7. This is obviously different from the B228.8 (which I understand is similar or the same as the B220.8)- it's clearly a different cone material. Out of curiosity, does anyone know how similar / different the B228.8 is to the driver that Quested uses?
Besides the Morel MDT30, are there any tweeters I should be considering? I'm thinking of crossing somewhere in the 1.5 kHz - 2 kHz range, so something with decent bottom end is definitely important.
Lastly, how do the Volt woofers compare to the 7" Scan-Speak Relevators? The Volt drivers in the Quested feel very "fast", for lack of a better word. They handle dynamics really well. How are the Scan-Speaks in this regard?
Scott & i played with a couple Volt designs a long time ago.
Thanx for pointing it out.
It looks quite smooth (the curve is heavily smoothed). It will go into the low 30s (F10) in 18 litres, and response doesn’t suffer much if the box shrinks to 13 litres and has a nicer roll-off for room gain. Low tune, slow roll-off, in 18 litres reachs the high 20s.
dave
Thanx for pointing it out.
It looks quite smooth (the curve is heavily smoothed). It will go into the low 30s (F10) in 18 litres, and response doesn’t suffer much if the box shrinks to 13 litres and has a nicer roll-off for room gain. Low tune, slow roll-off, in 18 litres reachs the high 20s.
dave
Still waffling on the tweeter. The SB29RDAC looks interesting, though it's power handling is somewhat lower than the Morel. The SB29SDAC looks interesting as well, though it has an even lower maximum power rating.
Those Alpairs look interesting, though I feel like they'd be better as a midrange rather than trying to use them as a tweeter.
Those Alpairs look interesting, though I feel like they'd be better as a midrange rather than trying to use them as a tweeter.
The RDAC physically feels quite nice, with that cast metal face plate. I've had a pair through here for testing: decent, but a bit of a spread on Fs. Not catastrophic, but assuming a passive filter, unless you went with a lowish Q Fs impedance notch it would throw that out a little. The TW29R-B and SB26CDC are my favourite SB tweeters at the more affordable end -very tight pair-matching & the Satori is a definite step up in build & features from the standard units, even if a bald FR etc. plot doesn't suggest much difference. I've crossed it and its slightly more expensive neo moter stablemate at 1.1KHz before now. It handles it.
Beyond that, the evergreen Millennium is worth a look, though it's pricy. Again, on paper it may not appear especially distinguished but in practice it can handle most things that get thrown at it and works well at lower crossover frequencies. Scan's 6600 can take an XO down around 1.4KHz depending on ultimate SPL requirements too. There are others, but it depends how much you want to be spending.
Beyond that, the evergreen Millennium is worth a look, though it's pricy. Again, on paper it may not appear especially distinguished but in practice it can handle most things that get thrown at it and works well at lower crossover frequencies. Scan's 6600 can take an XO down around 1.4KHz depending on ultimate SPL requirements too. There are others, but it depends how much you want to be spending.
The maximum I want to spend on tweeters is about $80 each- in other words, I'd like to avoid things that are more expensive than the Morel.
That said, I'm willing to flex budgets a little if there's a noticeable improvement. Essentially what I'm getting at is trying to determine whether the Morel MDT30 is still the right choice in 2021. The Quested H108 was design in the late 80s and a lot of great tweeters have been released since that time, so I'm just looking to see what's out there.
I looked at the SB26CDC and I don't think it's going to work purely from a sensitivity point of view. It's a 4-ohm driver with lower sensitivity than the 8-ohm woofer I'm looking at. Let me know if I'm missing something here, but that I can't imagine that will work well.
The ScanSpeak D2606/9220 looked mildly interesting as well, though I don't think it can cross quite low enough.
That said, I'm willing to flex budgets a little if there's a noticeable improvement. Essentially what I'm getting at is trying to determine whether the Morel MDT30 is still the right choice in 2021. The Quested H108 was design in the late 80s and a lot of great tweeters have been released since that time, so I'm just looking to see what's out there.
I looked at the SB26CDC and I don't think it's going to work purely from a sensitivity point of view. It's a 4-ohm driver with lower sensitivity than the 8-ohm woofer I'm looking at. Let me know if I'm missing something here, but that I can't imagine that will work well.
The ScanSpeak D2606/9220 looked mildly interesting as well, though I don't think it can cross quite low enough.
Well, the impedance is an irrelevance unless you have some specific reason for using a tweeter with the same nominal as the LF unit. WRT sensitivity, the BM228.8 is numerically rated at the same 89dB as the SB26CDC tweeter, the 220.2 at 90dB. More pertinently, eyeballing the FR plots they're all much of a muchness under anechoic IEC baffle conditions. Unless you are intending to flush-mount into a wall, you are likely to lose between 3dB - 6dB through step-loss in the LF, so it's unlikely you'll have much difficulty with level matching.
Well, just ordered a pair of BM228.8 woofers from Solen. The rep from Solen says they have a shipment with two of them coming later this week, so if all goes well I should get them within the next couple weeks. Still haven't made the decision on tweeters, though the SB ring radiator is probably the most likely choice.
Crossing to a 8" driver should be better at 1.5KHz than 2KHz for directivity reasons. The best you can do is to use a waveguide. Alternatively one tweeter that can be crossed low is the SS 9130, for the SBA tweeters I'd pick the SDAC instead of the RDAC, or even better the SB26ADC. The power rating you see on the datasheet means almost nothing, as it is calculated with a 2nd order crossover at 2.6KHz. Besides that with only 4mm of xmax the woofer won't handle lots of power before exceeding excursion, depending on the cab volume and tuning you are in the 30W ballpark.
Ralf
Ralf
I was planning on crossing somewhere around 1.6 kHz.
Out of curiosity, why would you pick the SDAC instead of the RDAC?
Out of curiosity, why would you pick the SDAC instead of the RDAC?
Even better if you can get that down to 250-450 Hz and gain C-C speacing of less than the “magic" quarter wavelength.
dave
Looking at the HiFiCompass measurements for these, it definitely looks significantly better. Shouldn't have any problem crossing in the 1.6 kHz range from what I can tell.
My plan is to do an active biamp setup using an XTA digital crossover for testing since it's pretty easy and quick to change slopes and frequencies with it, so it should be pretty easy to find the optimal solution.
I would consider an Augerpro _8" 3D print waveguide. The low end directivity will match nicely the big unit and they are SB26 tweeter serie proof. Due to the wave guide, the top end will be shyer... which is more or less what you maybe liked in the Morel in the original loudspeaker you want to copy (Dynaudio and Morels have not flat hi-end) ?! Horn are also good to recess a little the tweeter for a better horizontal spacing.
There is also the horned Morel cat378 (but maybe not able of a 1500 kHz XO?) of course and Augerpro has also horn models for 3/4 tweeters.
my two cents
There is also the horned Morel cat378 (but maybe not able of a 1500 kHz XO?) of course and Augerpro has also horn models for 3/4 tweeters.
my two cents
The waveguide idea is an interesting one, though from a "fit feel and finish" perspective I'd like to come up with something other than 3D printing, just because the 3D printers I have access to don't really meet my requirements in that regard. I'll have to do some more digging.
WGs can be diy'ed by using old speaker cones and can accept 1-2 in drivers (domes or cones)
The diameter of the WG must be scaled, i.e. for a 8"WG pick a 10" woofer
The diameter of the WG must be scaled, i.e. for a 8"WG pick a 10" woofer
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Good idea😎.
Advantage using Augerpro design is the horn is elleptical so center to center is lower and seems such a shape has some good use in the Revel design for example.
But why not using cheap elleptical cone you can see in old radio andnold tv or car drivers, ?
Will call for a sealed back chamber though not to be a passive driver moved by the main driver. And voila, keep the rubber surounding and you have both a passive bass driver and a wg for the tweeter😀
Advantage using Augerpro design is the horn is elleptical so center to center is lower and seems such a shape has some good use in the Revel design for example.
But why not using cheap elleptical cone you can see in old radio andnold tv or car drivers, ?
Will call for a sealed back chamber though not to be a passive driver moved by the main driver. And voila, keep the rubber surounding and you have both a passive bass driver and a wg for the tweeter😀
So does anyone have a less janky idea for a diy waveguide? I'm not at all opposed to the waveguide idea so long as it can be made to look presentable. Alternatively, I'm fine with buying an off-the-shelf waveguide for this.
Solen has this thing in stock which looks vaguely interesting:
Solen Electronique Inc. | WG148R
Solen has this thing in stock which looks vaguely interesting:
Solen Electronique Inc. | WG148R