Hello everyone, I recently built some bookshelf speakers which I simply called "Classic 25" due to the shape, design and use of a pair of widely used Seas 8" + 1" drivers, the CA22RNY woofer and the 27TFFC tweeter . Among the various audio constructions that I have made over the years for my personal enjoyment, I decided to show them to you because, in my opinion, they sound very good, they are easy to build, practical to use and have a cost which, although not low in absolute, it's pretty low compared to what they offer.
Let's start immediately from the end, the sound. As you can see, the filming takes place in a very ordinary dining room, without acoustic treatment and with some critical surfaces (mirrors, glass cabinets, tiles), measuring 25m2. The Classics are placed on a sideboard (bookcase, desktop, TV stand, etc.) a few centimeters from the back wall and two meters from each other.
Let's start immediately from the end, the sound. As you can see, the filming takes place in a very ordinary dining room, without acoustic treatment and with some critical surfaces (mirrors, glass cabinets, tiles), measuring 25m2. The Classics are placed on a sideboard (bookcase, desktop, TV stand, etc.) a few centimeters from the back wall and two meters from each other.
Nice design, I have always liked the combination of an 8 inch plus tweeter.
As there are lots of retro designs from commercial manufacturers maybe the concept will become popular once again.
I saw see mitred corners in the cabinet build, and front panel veneered, so woodworking skills involved.
For acoustics, no reflex port, tweeter spaced away from the woofer, do you want to tell us about the design and crossover choices. Is the volume 25Litres ?
As there are lots of retro designs from commercial manufacturers maybe the concept will become popular once again.
I saw see mitred corners in the cabinet build, and front panel veneered, so woodworking skills involved.
For acoustics, no reflex port, tweeter spaced away from the woofer, do you want to tell us about the design and crossover choices. Is the volume 25Litres ?
Sì, presto pubblicherò il circuito e i disegni del mobile con tutti i dettagli. Saranno semplici schizzi fatti a mano, ma sufficienti per chiunque voglia farne una copia o sperimentare.
In premessa devo dire che questi diffusori inizialmente non sono nati come coppia stereo, ma come un unico altoparlante al quale collegare un finale ed un mixer per amplificare chitarra e voce, in modo da avere una buona fedeltà del suono nella musica dal vivo in sale. di piccole e medie dimensioni. Fino all'anno scorso avevo utilizzato per questo scopo un amplificatore per chitarra a due vie del costo di circa mille euro, ma il suono era piuttosto insoddisfacente a livello timbrico e dinamico. Ho quindi deciso di costruirmi un diffusore amplificato per avere qualcosa di meglio dal punto di vista timbrico e ho acquistato due woofer Seas (CA18RLY e CA22RNY) e due tweeter (27TFFC) per fare alcune prove. Per il cabinet ho utilizzato multistrato di betulla da 12 mm per avere dei diffusori leggeri e facilmente trasportabili. Il due vie con il CA18RLY+27TFFC è ormai il mio diffusore amplificato portatile da 16 lt, quello con il CA22RNY+27TFFC mi è piaciuto così tanto che ho deciso di replicarlo per farne una coppia stereo da usare in casa.
Quello che vi presento qui nasce quindi con un cabinet sottile e moderatamente risonante per essere leggero (!) e trasportabile (circa 9,0 kg). Il fatto che suonasse molto bene fin da subito mi ha portato a dedicare molto tempo alla calibrazione del crossover, alla sistemazione delle risonanze interne e alla messa a punto del reflex.
I più esperti sapranno sicuramente come migliorarli e non avranno bisogno delle mie considerazioni, ma se volete provare a costruirli così come sono per avere esattamente questo suono, vi consiglio di non apportare alcuna modifica al cabinet, né al materiale interno , né al crossover, perché questi diffusori sono stati sviluppati nel mio ambiente con decine e decine di smontaggi e rimontaggi e sono molto sensibili a certe variazioni costruttive.
Non escludo di apportare modifiche in futuro e di tenervi informati sui risultati, così come sarei felice se poteste condividere con me il frutto dei vostri esperimenti. Inoltre, pur essendo un musicista, non sono un professionista nel campo dell'elettronica audio, quindi il sistema è aperto a futuri contributi e miglioramenti, soprattutto da parte di chi ha una conoscenza approfondita della progettazione e sa usare gli strumenti di misura. Io, che faccio altro nella vita e ho poco tempo da dedicare a questa passione, ho una conoscenza minima di progettazione senza strumentazione (grazie @Allen B) e metto a punto i miei altoparlanti usando solo le mie orecchie. Qualsiasi contributo che porti a miglioramenti udibili sarà quindi sicuramente apprezzato.
Pubblicherò qualche foto, a presto i disegni.
@raymondj sono circa 25 litri e la porta reflex è sul fondo.
In premessa devo dire che questi diffusori inizialmente non sono nati come coppia stereo, ma come un unico altoparlante al quale collegare un finale ed un mixer per amplificare chitarra e voce, in modo da avere una buona fedeltà del suono nella musica dal vivo in sale. di piccole e medie dimensioni. Fino all'anno scorso avevo utilizzato per questo scopo un amplificatore per chitarra a due vie del costo di circa mille euro, ma il suono era piuttosto insoddisfacente a livello timbrico e dinamico. Ho quindi deciso di costruirmi un diffusore amplificato per avere qualcosa di meglio dal punto di vista timbrico e ho acquistato due woofer Seas (CA18RLY e CA22RNY) e due tweeter (27TFFC) per fare alcune prove. Per il cabinet ho utilizzato multistrato di betulla da 12 mm per avere dei diffusori leggeri e facilmente trasportabili. Il due vie con il CA18RLY+27TFFC è ormai il mio diffusore amplificato portatile da 16 lt, quello con il CA22RNY+27TFFC mi è piaciuto così tanto che ho deciso di replicarlo per farne una coppia stereo da usare in casa.
Quello che vi presento qui nasce quindi con un cabinet sottile e moderatamente risonante per essere leggero (!) e trasportabile (circa 9,0 kg). Il fatto che suonasse molto bene fin da subito mi ha portato a dedicare molto tempo alla calibrazione del crossover, alla sistemazione delle risonanze interne e alla messa a punto del reflex.
I più esperti sapranno sicuramente come migliorarli e non avranno bisogno delle mie considerazioni, ma se volete provare a costruirli così come sono per avere esattamente questo suono, vi consiglio di non apportare alcuna modifica al cabinet, né al materiale interno , né al crossover, perché questi diffusori sono stati sviluppati nel mio ambiente con decine e decine di smontaggi e rimontaggi e sono molto sensibili a certe variazioni costruttive.
Non escludo di apportare modifiche in futuro e di tenervi informati sui risultati, così come sarei felice se poteste condividere con me il frutto dei vostri esperimenti. Inoltre, pur essendo un musicista, non sono un professionista nel campo dell'elettronica audio, quindi il sistema è aperto a futuri contributi e miglioramenti, soprattutto da parte di chi ha una conoscenza approfondita della progettazione e sa usare gli strumenti di misura. Io, che faccio altro nella vita e ho poco tempo da dedicare a questa passione, ho una conoscenza minima di progettazione senza strumentazione (grazie @Allen B) e metto a punto i miei altoparlanti usando solo le mie orecchie. Qualsiasi contributo che porti a miglioramenti udibili sarà quindi sicuramente apprezzato.
Pubblicherò qualche foto, a presto i disegni.
@raymondj sono circa 25 litri e la porta reflex è sul fondo.
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Troels Gravesen speculated a design with the CA22RNY at the bottom here http://www.troelsgravesen.dk/Snell-E-III.htm fore more inspiration.
Enzo3875 thank you for the response.
An interesting development cycle.
Which sums up how a design can progress.
The CA22RNY is a very nice speaker, "muscular" and reactive, it does not seem to go into crisis with complex musical messages either at low or high volume, capable of a rather sweet and persuasive midrange, also rich in information with a filter of first order. But to create a crossover with the first acoustic order I had to struggle a bit looking for the correct value, because near the crossover area two turns more or less on the inductance are clearly audible and the fine tuning could be on the single turn wire.
It seems like an exaggeration, but for me it was like this...
Status quaestionis in my home listening
As a lover of music played at home, over the years I have listened to many speakers of the most diverse sizes and technologies, from small two-way to large three-way - not to mention a complicated self-built single-way speaker - through magnetodynamic and electrostatic. When I started building them for fun, I focused on two-way bookshelf speakers with medium-large cones and soft dome tweeters, because they are musically complete enough for my needs, simple to make, cheap and transportable.
The system I currently prefer is the 8" + 1" in a 25-30 liter box, with a small reflex duct placed in the lower part, in order to have a certain load of the low frequencies, but without directly listening to what comes out of a tube front or having to manage the resonances of the rear one. For this reason my speakers have 15 mm feet and can be conveniently oriented a few degrees upwards, in order to align the emission centers of the drivers and obtain small variations on the load of the reflex and on the height of the musical scene. Once positioned on a shelf, a short distance from the rear wall, they are not very sensitive to vertical and horizontal inclinations because both the speakers and the crossover favor good dispersion.
Construction
I built some two-way bookshelfs with 6.5”, 7” and 8” woofers. The latter have the advantage of magnifying the musical scene more realistically, but it is not easy to make them sound good in the midrange in the crossover area, especially in the medium-high region of the human voice, achieving perfect integration with the tweeter. For this reason, I decided to use speakers from the same brand, tonally coherent and complementary, with very regular emission, without resonance peaks. This would have made my work on the crossover easier and perhaps allowed me to try a first order one, accepting a certain reduction in the maximum power manageable by the tweeter. So it was.
I fiddled around with a second order crossover for a couple of weeks, and then finally switched to a first order one. Incidentally, mixing first and second order did not give me audibly pleasant results in blending the two speakers, destabilizing the scene in certain frequency ranges.
In this regard, Seas declares a certain power handling of the tweeter, cut at a given frequency, with a second order slope. Using the first order I had to cut quite high and accept a reduction in the maximum manageable power, which I was able to do with the 27TFFC because with this acoustic order it turned out to be particularly good-sounding in my project and much more robust than my ears can perceive distortion and tolerate acoustic pressure. Maybe it won't be able to soundproof a square or pierce the neighbors' walls, but it can certainly satisfy the majority of domestic needs, giving a sweet, open and extended tone, without compressions, close to what I get with my Beyerdynamic DT 880 headphones (except the different frequency response).
To a recent question about my doubts about the power handling of the tweeter, Seas kindly responded by saying that they could not express themselves with certainty on the first acoustic order, but that having cut it quite high (4.7uF) in my case there should not be any sealing problems. Common sense, however, advises not to exaggerate with the power, reaching close to the limits declared for the second order, also because as it is it sounds really loud with a breath of current.
The CA22RNY woofer, for its part, is capable of linearly rising in frequency up to the crossover area, without showing critical resonance peaks, which are difficult to manage with a first order filter. However, great care is needed in determining the value of the coil, which in this case is not standard, but can be obtained simply by removing a certain number of turns from a common 2.2 mH to bring it precisely to 1.95 (I do not guarantee, however, the accuracy of the measurement with that cheap card). In practice, I used a 2.2 mH Jantzen Air 000-1299, 1.2 mm wire, removing exactly 8 turns from it.
Even if the reduction in mH seems insignificant, it is not insignificant in a filter with only three components that cross large parts of frequencies, if you want to obtain the best fusion of the two speakers. In fact, with an inductance of 1.8 the midrange of the woofer advanced and shrilled too much for my taste, while with 2.2 it was a little too far back with some voids. If a 2.0 mH inductance were on the market, we could possibly start from there.
Similarly, the value of the attenuation resistance of the tweeter can vary based on subjective tastes between 2.2 (light) and 2.7 ohm (dark), keeping in mind that in this or speaker a difference of 0.22 ohms is well audible. For me, currently, a 2.2 audio grade with a 4.7 uF capacitor is perfect. The first order cutoff with the 2.2 should be around 4000 Hz.
Be careful that here the length of the reflex duct also has its say, as it affects the audible resonances in the mid range, so in the end I adjusted it to 60 mm (32 external diameter) not so much for the low range but to obtain the best contribution to the box resonances in the mid range.
Finally, while tuning the crossover, I used a certain amount of damping material in the cabinet (30mm thick self-adhesive) to adjust the resonances of the box and the output of the drivers. What you see in the photo seems small and curiously arranged, but it is the result of dozens of movements and variations made simultaneously on the crossover, damping and reflex tube. A lot of work!
Here are the drawings of the cabinet and the crossover.
For those who celebrate, happy Easter holidays.
As a lover of music played at home, over the years I have listened to many speakers of the most diverse sizes and technologies, from small two-way to large three-way - not to mention a complicated self-built single-way speaker - through magnetodynamic and electrostatic. When I started building them for fun, I focused on two-way bookshelf speakers with medium-large cones and soft dome tweeters, because they are musically complete enough for my needs, simple to make, cheap and transportable.
The system I currently prefer is the 8" + 1" in a 25-30 liter box, with a small reflex duct placed in the lower part, in order to have a certain load of the low frequencies, but without directly listening to what comes out of a tube front or having to manage the resonances of the rear one. For this reason my speakers have 15 mm feet and can be conveniently oriented a few degrees upwards, in order to align the emission centers of the drivers and obtain small variations on the load of the reflex and on the height of the musical scene. Once positioned on a shelf, a short distance from the rear wall, they are not very sensitive to vertical and horizontal inclinations because both the speakers and the crossover favor good dispersion.
Construction
I built some two-way bookshelfs with 6.5”, 7” and 8” woofers. The latter have the advantage of magnifying the musical scene more realistically, but it is not easy to make them sound good in the midrange in the crossover area, especially in the medium-high region of the human voice, achieving perfect integration with the tweeter. For this reason, I decided to use speakers from the same brand, tonally coherent and complementary, with very regular emission, without resonance peaks. This would have made my work on the crossover easier and perhaps allowed me to try a first order one, accepting a certain reduction in the maximum power manageable by the tweeter. So it was.
I fiddled around with a second order crossover for a couple of weeks, and then finally switched to a first order one. Incidentally, mixing first and second order did not give me audibly pleasant results in blending the two speakers, destabilizing the scene in certain frequency ranges.
In this regard, Seas declares a certain power handling of the tweeter, cut at a given frequency, with a second order slope. Using the first order I had to cut quite high and accept a reduction in the maximum manageable power, which I was able to do with the 27TFFC because with this acoustic order it turned out to be particularly good-sounding in my project and much more robust than my ears can perceive distortion and tolerate acoustic pressure. Maybe it won't be able to soundproof a square or pierce the neighbors' walls, but it can certainly satisfy the majority of domestic needs, giving a sweet, open and extended tone, without compressions, close to what I get with my Beyerdynamic DT 880 headphones (except the different frequency response).
To a recent question about my doubts about the power handling of the tweeter, Seas kindly responded by saying that they could not express themselves with certainty on the first acoustic order, but that having cut it quite high (4.7uF) in my case there should not be any sealing problems. Common sense, however, advises not to exaggerate with the power, reaching close to the limits declared for the second order, also because as it is it sounds really loud with a breath of current.
The CA22RNY woofer, for its part, is capable of linearly rising in frequency up to the crossover area, without showing critical resonance peaks, which are difficult to manage with a first order filter. However, great care is needed in determining the value of the coil, which in this case is not standard, but can be obtained simply by removing a certain number of turns from a common 2.2 mH to bring it precisely to 1.95 (I do not guarantee, however, the accuracy of the measurement with that cheap card). In practice, I used a 2.2 mH Jantzen Air 000-1299, 1.2 mm wire, removing exactly 8 turns from it.
Even if the reduction in mH seems insignificant, it is not insignificant in a filter with only three components that cross large parts of frequencies, if you want to obtain the best fusion of the two speakers. In fact, with an inductance of 1.8 the midrange of the woofer advanced and shrilled too much for my taste, while with 2.2 it was a little too far back with some voids. If a 2.0 mH inductance were on the market, we could possibly start from there.
Similarly, the value of the attenuation resistance of the tweeter can vary based on subjective tastes between 2.2 (light) and 2.7 ohm (dark), keeping in mind that in this or speaker a difference of 0.22 ohms is well audible. For me, currently, a 2.2 audio grade with a 4.7 uF capacitor is perfect. The first order cutoff with the 2.2 should be around 4000 Hz.
Be careful that here the length of the reflex duct also has its say, as it affects the audible resonances in the mid range, so in the end I adjusted it to 60 mm (32 external diameter) not so much for the low range but to obtain the best contribution to the box resonances in the mid range.
Finally, while tuning the crossover, I used a certain amount of damping material in the cabinet (30mm thick self-adhesive) to adjust the resonances of the box and the output of the drivers. What you see in the photo seems small and curiously arranged, but it is the result of dozens of movements and variations made simultaneously on the crossover, damping and reflex tube. A lot of work!
Here are the drawings of the cabinet and the crossover.
For those who celebrate, happy Easter holidays.
Attachments
Last edited:
At the end of this diyaudio experience, I leave you with some considerations on the materials I used and the tests I did.
Materials for the box
Crossover components
As regards the quality of just the three components of the crossover, already with a simple Janzten in permite inductance, a common ceramic resistor and a MKP or MKC Wima or ERO capacitor a good result is obtained, however the difference with the audio grade components is feels and is absolutely worth it, since there are only three.
Inductance. I tried the one in permite (no disc) and the one in the air. The 2.2 mH 1.2 mm permite (reduced to the necessary value) returns a fairly faithful timbre, rich in harmonics (but perhaps with some spuriousness), slightly open in the mid range, does not veil the sibilants, has a precise bass and a fast sound, certainly also due to the halving of the resistance. It doesn't muddy the sound even at high volume, as it gave me the impression of doing the same in permite with 1.0 mm wire, which I do not recommend. The 1.2 mm air one has a sweeter timbre than the permite one, especially in the mid range, but the sound is less ready and clear (it has approximately double the resistance). No loud crises. In the end I preferred the latter, but the choice between the two can be a matter of personal taste.
Capacitor. I initially tried ERO's MKT and MKC. I immediately discarded the first ones, the second ones were already better, but they gave me a slightly flat and narrow sound in the tweeter. With the Jantzen Superior-Z I immediately had greater sweetness, refinement and three-dimensionality, with the tw tending to disappear, especially at high volume.
Resistence. The difference between a Jantzen Superes or a 10W Ohmite AG and a common ceramic can be felt almost as much as the capacitor, that is a lot. The ceramic gave me the impression of introducing a bit of dirt and a sense of "glassiness" into the sound, causing me a bit of fatigue when listening for a long time. With it I had to increase the value by at least 0.15 ohm (2 x 4.7 ohm) so as not to hear too much screeching from the tweeter. None of this with the Jantzen and the Ohmite, which however cost 10 times as much. Furthermore, Jantzen has the value of 2.4 ohm in its catalog which can be convenient to have, together with the 2.2, to decide whether to give it a touch of extra sweetness.
In all, for a 2.2 mH 1.2mm Jantzen Air, a 4.7 Superior-Z and a 2.2 ohm 10w Superes I will have spent around 50 euros for each crossover. Obviously, I mentioned these components only because they were the ones most easily available to me, but I think that the level is equally good in components of equivalent cost from other brands, without prejudice to the tonal peculiarities of each.
Last two cents, I had the impression that the sound was veiled a bit both after veneering the front and after inserting the crossover into the box. However, they are more beautiful and simple this way. How difficult life is!…
Conclusions
In the end, with the work of a couple of weekends and a relatively low cost (let's say so!) you get a pair of high-fidelity bookshelfs with around 90 dB efficiency and a good sound impact, with a predilection for classical music and acoustic instruments in general, so easy to drive that even my 2A3 monotriode was at ease. On the other hand, the large magnet of the woofer, the type of crossover and the controlled resonance of the cabinet allow a transparent, coherent and detailed sound even at low listening volumes, so they are enjoyable even at night. If you then wanted to raise the volume and sound larger rooms, you could happily use the class D amplifier with which I developed them, the ICEpower 125ASX2 (https://www.diyaudio.com/community/threads/simple-amplifier-with-icepower-125asx2.373970/), and make the neighbors dance too. However, be careful with your hearing and tweeters! With this speakers you realize the listening volume when you are in the next room. In most cases, with just one watt you fill the whole house with sound and the volume tends to remain high for many hours.
But from tonight, alas, I will no longer have this temptation, because they will have gone away forever with their new master, my audiophile brother-in-law, and who knows when I will be able to rebuild a pair.
The only certain thing will be the wood for the next front, given to me a few days ago by a kind retired carpenter.
Ad maiora semper.
Materials for the box
- 12 mm birch plywood, plus a second 22 cm piece glued under the woofer and then cut with the front, to have a resistant 24 mm thick frame.
- 0.6 mm veneer, glued with Bostik 99. The crossover must be set up with the veneer glued and the cabinet painted, otherwise tonal variations may be audible.
- Adam Hall 4904 Feet - 25x15 mm.
- Osmo Polyx 3011 paint, two coats.
- Reflex tube 32 x 60 mm (internal 29), cut from a tube for electrical networks.
- 30mm self-adhesive soundproofing. Side dimensions 13 x 18 cm (h x w), bottom (around the reflex tube) 16 x 18, rear (under the crossover, in correspondence with the center of the wf) 6 x 18.
- 1.5mm OFC copper cables, 42cm long from crossover to speakers and 20cm from crossover to connectors.
- Connectors 7.2cm from bottom, spaced 3cm apart.
- Handles 6.5 cm from the top and 19 cm between them.
- The 6mm birch plywood crossover base can be conveniently enlarged to 12 x 8.5cm.
Crossover components
As regards the quality of just the three components of the crossover, already with a simple Janzten in permite inductance, a common ceramic resistor and a MKP or MKC Wima or ERO capacitor a good result is obtained, however the difference with the audio grade components is feels and is absolutely worth it, since there are only three.
Inductance. I tried the one in permite (no disc) and the one in the air. The 2.2 mH 1.2 mm permite (reduced to the necessary value) returns a fairly faithful timbre, rich in harmonics (but perhaps with some spuriousness), slightly open in the mid range, does not veil the sibilants, has a precise bass and a fast sound, certainly also due to the halving of the resistance. It doesn't muddy the sound even at high volume, as it gave me the impression of doing the same in permite with 1.0 mm wire, which I do not recommend. The 1.2 mm air one has a sweeter timbre than the permite one, especially in the mid range, but the sound is less ready and clear (it has approximately double the resistance). No loud crises. In the end I preferred the latter, but the choice between the two can be a matter of personal taste.
Capacitor. I initially tried ERO's MKT and MKC. I immediately discarded the first ones, the second ones were already better, but they gave me a slightly flat and narrow sound in the tweeter. With the Jantzen Superior-Z I immediately had greater sweetness, refinement and three-dimensionality, with the tw tending to disappear, especially at high volume.
Resistence. The difference between a Jantzen Superes or a 10W Ohmite AG and a common ceramic can be felt almost as much as the capacitor, that is a lot. The ceramic gave me the impression of introducing a bit of dirt and a sense of "glassiness" into the sound, causing me a bit of fatigue when listening for a long time. With it I had to increase the value by at least 0.15 ohm (2 x 4.7 ohm) so as not to hear too much screeching from the tweeter. None of this with the Jantzen and the Ohmite, which however cost 10 times as much. Furthermore, Jantzen has the value of 2.4 ohm in its catalog which can be convenient to have, together with the 2.2, to decide whether to give it a touch of extra sweetness.
In all, for a 2.2 mH 1.2mm Jantzen Air, a 4.7 Superior-Z and a 2.2 ohm 10w Superes I will have spent around 50 euros for each crossover. Obviously, I mentioned these components only because they were the ones most easily available to me, but I think that the level is equally good in components of equivalent cost from other brands, without prejudice to the tonal peculiarities of each.
Last two cents, I had the impression that the sound was veiled a bit both after veneering the front and after inserting the crossover into the box. However, they are more beautiful and simple this way. How difficult life is!…
Conclusions
In the end, with the work of a couple of weekends and a relatively low cost (let's say so!) you get a pair of high-fidelity bookshelfs with around 90 dB efficiency and a good sound impact, with a predilection for classical music and acoustic instruments in general, so easy to drive that even my 2A3 monotriode was at ease. On the other hand, the large magnet of the woofer, the type of crossover and the controlled resonance of the cabinet allow a transparent, coherent and detailed sound even at low listening volumes, so they are enjoyable even at night. If you then wanted to raise the volume and sound larger rooms, you could happily use the class D amplifier with which I developed them, the ICEpower 125ASX2 (https://www.diyaudio.com/community/threads/simple-amplifier-with-icepower-125asx2.373970/), and make the neighbors dance too. However, be careful with your hearing and tweeters! With this speakers you realize the listening volume when you are in the next room. In most cases, with just one watt you fill the whole house with sound and the volume tends to remain high for many hours.
But from tonight, alas, I will no longer have this temptation, because they will have gone away forever with their new master, my audiophile brother-in-law, and who knows when I will be able to rebuild a pair.
The only certain thing will be the wood for the next front, given to me a few days ago by a kind retired carpenter.
Ad maiora semper.
Hi Enzo, do you take some frequency measures, in particular about bass region? how much they go down? thx
Unfortunately I am not equipped for the measurements, perhaps not even my environment would allow them to be reliable in the low range. The tuning frequency of the reflex should be around 32-33 hz, but the length of the tube, after trying several close measurements (+/- 5-10mm), was established to have the midrange I wanted. Probably, due to the characteristics of the wf, the volume, the reflex tube and the positioning in my environment, we will be around 50 Hz at -3dB.
Particularly interesting to me was the way in which this 22 wf reproduces the low range, differently from how 17-18 cm woofers do it at the same frequency: the scene expands a lot, the large instruments are rightly enlarged and the sense of of materiality of sounds. It is unlikely that we will go back to listening to smaller woofers, as I am doing at the moment with my 16 liter portable speaker (CA18RLY + 27TFFC) in mono, which I am modifying to implement a first order crossover here too. I miss the big ones...
Particularly interesting to me was the way in which this 22 wf reproduces the low range, differently from how 17-18 cm woofers do it at the same frequency: the scene expands a lot, the large instruments are rightly enlarged and the sense of of materiality of sounds. It is unlikely that we will go back to listening to smaller woofers, as I am doing at the moment with my 16 liter portable speaker (CA18RLY + 27TFFC) in mono, which I am modifying to implement a first order crossover here too. I miss the big ones...