Troels Gravessen has recently posted a new project of a large 3 way speaker with a 12+6+1 driver compliment.
It looks like a nice project with the possibility of using an active dsp amp for the bass section and in the future a fully active setup with hypex upcoming fusion plate amps.
What do you think of the concept of the speaker and any concerns I should worry about?
It looks like a nice project with the possibility of using an active dsp amp for the bass section and in the future a fully active setup with hypex upcoming fusion plate amps.
What do you think of the concept of the speaker and any concerns I should worry about?
Yup, that one!
Not worried per se, but I have seen some criticism of some of his designs here. Overall I don't think I can go wrong maybe I'm just looking for reassurance before spending around 2k on a speaker kit.
The BMS 12N630 speaker is not on eBay or Amazon or USSpeaker. 230Euros in the UK .... How very European!
The BMS 12N630 has excellent specs and models well in a small 1.4cuft ported box tuned to 33Hz (-F3=37Hz) SPL=89.5db. In a 3cuft ported box tuned to 27Hz for a -2db bass-shelf alignment -F3=28Hz .... I would favor this 3cuft box volume/tuning with the expectation of minor room gain to compensate for the -2db bass shelf.
Troels's Fusion uses 55-l (1.94 cuft) box tuned for -F3=35Hz.
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In the USA a BIG BMS 3-way worth using a separate woofer amp will cost you about $1200/speaker in drivers. 18" woofer: 18N864, 12" midrange: 12N820, 1" compression driver: 4552Nd
The BMS 12N630 has excellent specs and models well in a small 1.4cuft ported box tuned to 33Hz (-F3=37Hz) SPL=89.5db. In a 3cuft ported box tuned to 27Hz for a -2db bass-shelf alignment -F3=28Hz .... I would favor this 3cuft box volume/tuning with the expectation of minor room gain to compensate for the -2db bass shelf.
Troels's Fusion uses 55-l (1.94 cuft) box tuned for -F3=35Hz.
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In the USA a BIG BMS 3-way worth using a separate woofer amp will cost you about $1200/speaker in drivers. 18" woofer: 18N864, 12" midrange: 12N820, 1" compression driver: 4552Nd
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Just curious as to what criticism? I myself have two criticisms with regards to his designs.
1. Aesthetically, his speakers could look a bit more appealing.
2. I would like to see him take a bit more risk in his speaker voicing, a bit more spicy. His voicing is a little on the safe side. It sort of appealing to a wider audience which is OK for low cost drivers, but most of his recent designs use pretty much SOTA drivers so it's like having a Ferrari and all you can do is cruising around town.
I agree that some of his designs do look bad on paper but this design doesn't look bad at all from a frequency response point of view.
I kinda don't like the 3dB bump that starts at 2800Hz and ends at 4000Hz. I don't like crossover frequency between midrange and tweeter at 2000Hz - i think that it should be lower, especially using this tweeter, it can take it very well. It would make for much better of axis response. Region at 700Hz could/should be flatter than that.
That being said, i've seen factory loudspeakers that measures far worst than this and costs much more money.
It's not plug'n'play project in my opinion. I'd be dancing with it a little bit to suit my taste and measure a little better. But it is a good starting point.
That being said, i've seen factory loudspeakers that measures far worst than this and costs much more money.
It's not plug'n'play project in my opinion. I'd be dancing with it a little bit to suit my taste and measure a little better. But it is a good starting point.
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I agree that some of his designs do look bad on paper but this design doesn't look bad at all from a frequency response point of view.
Just curious which design is this?
Gonna disagree with 2. If you want "spicy", slap a Lowther on an OB with a high Q 15" bass driver. Use a misaligned 1st order crossover and enjoy a system that can only play 3 pieces of music because it sounds awful on anything else.
What he's got there is something that's +/-2dB across a very wide bandwidth, which is to be commended.
If I was to actually criticise the design, I'd look at the following:
- Diffraction around the tweeter isn't great. Look at all those sharp edges!
- That is NOT how you bi-amplify a speaker. You're still feeding both amplifiers full-range signals and feeding them through passive crossovers.
Chris
I'd like to see a +/-3dB fr and still sounds sweet. And a little more treble would be nice. I'd like to feel it when the singer purses her lips.
It sounds good on 3 pieces? 😉
Agreed, the frequency / magnitude response looks quite good on the design axis. Balance looks quite good, & follows the slightly declining HF trend that many like & advocate (e.g. Toole, Linkwitz, Olson). I'd like to see the individual driver rolloffs, but it's a kit design & probably most of his buyers aren't too bothered about that -after all, if you're paying for a kit, you're paying for the skills and voicing approach of the designer in addition to the components. The impedance load is broadly resistive > the usual reflex peaking also, which is nice to have.
Agreed. No off-axis plots either, where the potential compromises in the stepped baffle & diffraction behaviour would likely be more apparent. I'm not over-fond of stepped baffles myself for this reason, but we all pick & choose what compromises best fit our needs & it does allow the LR2 filters Troels likes without a ladder delay network.
It wouldn't be my first choice either, but passive biamping in that way may be of some benefit, and it does avoid the need for active filtering, which has many benefits but isn't a panacea either.
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I think Troels is a terrific DIY man offering so much for so long without any explicit charge other than the usual Jantzen parts being recommended. Anyone disagreeing with Troels' way of measuring and design philosophy is free to make everything to one's own preference. Setup your own web site and offer better kits, if you dare! 😀
If Troels himself doesn't mind the constructive critique why do you ? OP wanted to hear opinions about Troels new design and he is getting it. Everything is worth analyzing.
And yes, Troels is a good guy imo.
Anyone who is bothered by constructive criticism of other people's work is free to open his own law firm and offer legal consulting to the guys whose work is being criticized, if he dares 😉
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Looks-wise, I'm not much into a 15" wide speaker. That type of design is immediately reminding me of something from the 70's and 80's. Maybe the woofer section could have been 15" while the upper section 9". Nothing modern looking about it, and in my book that counts too, regardless of how good it may or may not sound. But please, no lawsuits.
WAF here dictates that a big box is better than something with a pyramid on top or angled sections.
Regarding the bi amping of the speaker, troels is working on the partial and fully active versions, using hypex DSP plate amps. He recommended I started with the passive version with a single amplifier and if my room presents too much of a problem then I should dig into the active bass section.
Regarding the bi amping of the speaker, troels is working on the partial and fully active versions, using hypex DSP plate amps. He recommended I started with the passive version with a single amplifier and if my room presents too much of a problem then I should dig into the active bass section.
That's my only issue with Troel's designs; the cabs are not to everyones tastes and the crossovers are fixed for that particular shape