Hi I am contemplating committing to a three way speaker design despite my preference for my current two way speakers compared with various compression drivers horn combinations in both two way and three way configuration. The current speaker is comprised of a Beyma 15G40 15" woofer and CP755ND 1.4" compression drivers mounted to wave guides actively crossed crossed at 700hz per channel. I was originally considering supplementing the bass section of the speaker with a second 15" woofer in the hopes of achieving a lower bass response however after some suggestions from forum members I am now considering an alternative design.
These are the three way designs I am considering. Any suggestions are appreciated.
-A Ciare 15.00SW 15" subwoofer driver crossed at 100hz, a single or pair of Beyma 10MI100 10" drivers in an MTM or TMM configuration operating from 100hz to 900hz, and a Beyma CP755ND from 900hz to 20khz
-A Ciare 15.00SW crossed at 100hz, a Beyma 15MI100 crossed from 100hz to 900hz, a CP755ND from 900hz to 20khz
-A Beyma 15G40 crossed at 250hz, a Beyma 15MI100 crossed from 250hz to 900hz, a CP755ND from 900hz to 20khz
The primary question questions are, is there an advantage to using a single 10" driver versus multiple 10" drivers in an MTM or TMM configuration? And is there an advantage to incorporating to a single 10" or multiple 10" drivers for midrange duties, compared with a single 15" driver? Any help is appreciated. Thanks.
These are the three way designs I am considering. Any suggestions are appreciated.
-A Ciare 15.00SW 15" subwoofer driver crossed at 100hz, a single or pair of Beyma 10MI100 10" drivers in an MTM or TMM configuration operating from 100hz to 900hz, and a Beyma CP755ND from 900hz to 20khz
-A Ciare 15.00SW crossed at 100hz, a Beyma 15MI100 crossed from 100hz to 900hz, a CP755ND from 900hz to 20khz
-A Beyma 15G40 crossed at 250hz, a Beyma 15MI100 crossed from 250hz to 900hz, a CP755ND from 900hz to 20khz
The primary question questions are, is there an advantage to using a single 10" driver versus multiple 10" drivers in an MTM or TMM configuration? And is there an advantage to incorporating to a single 10" or multiple 10" drivers for midrange duties, compared with a single 15" driver? Any help is appreciated. Thanks.
Multiple drivers spread out any 'Floor Bounce' effects over a wider range of frequencies, which should make it easier to live with.
Ok. My main motivations are to insure than no voids or troughs in frequency response occur where the compression driver starts to roll off before the crossover at 700hz, reduce strain on the woofer by reducing the cutoff frequency, and increase low frequency performance by using a dedicated subwoofer driver. My primary curiosity is, is it advantageous to use a single, pair or quad of 10" drivers per channel, versus a single 15" to cover a range of 100hz-700hz. While intuition steers me towards the 10" route, I am not going rule that as the right choice until I have a concrete and logical answer as to why it would sound better if in fact it does.
See this thread about the disadvantage of horizontally spaced TMM woofers - https://www.diyaudio.com/community/...ass-section-2x15-vs-4x12.393971/#post-7221411
something about messing up the imaging in the voice range.
I looked up the beyma 15mi100 spec sheet, which says it is discontinued. I don't see why you would need more than one of these if you are crossing at 100 & 700. 100 db sensitivity 1w1m, 450 w AES, response pretty flat 120-1500 hz,, 5 db down at 100 hz. 10 db down @ 60 hz. I can get 126 db @ 430 w out of my Peavey SP2(2004) which has a 1505-8KADT woofer which is 99 db 1w1m. You need more than that? My box is down only 3 db @ 54 hz, may have to do with the porting since peavey doesn't provide standard baffle frequency response chart. I see no reason to do the machining for two 10" drivers unless they are a lot cheaper. One 15" would be 8 ohm, two 10" would be 4 ohm probably. 4 ohms would stress amps with less than 2 pairs output transistors.
Advantage of your 2 15" woofer setup, you can tune the sub box to 30 hz and not cause a dip at 50-100 hz in the main box tuned to 54 hz.
700 hz compression horn crossover may limit your pink noise power a lot. The Peavey RX22 1.4" cd is 70 w aes, which limits the SP2(2004) to 500 w pink noise. Peavey cross the SP2(2004) at 1800 hz, but built the box narrow at the back to prevent beaming of the woofer 1000-1800 hz. The beyma CP755nd https://usspeaker.com/beyma CP755nd-1.htm is 90 db aes which gives you more headroom. But at $499 (us) versus $160 for the RX22, you pay 240% for more power handling.
something about messing up the imaging in the voice range.
I looked up the beyma 15mi100 spec sheet, which says it is discontinued. I don't see why you would need more than one of these if you are crossing at 100 & 700. 100 db sensitivity 1w1m, 450 w AES, response pretty flat 120-1500 hz,, 5 db down at 100 hz. 10 db down @ 60 hz. I can get 126 db @ 430 w out of my Peavey SP2(2004) which has a 1505-8KADT woofer which is 99 db 1w1m. You need more than that? My box is down only 3 db @ 54 hz, may have to do with the porting since peavey doesn't provide standard baffle frequency response chart. I see no reason to do the machining for two 10" drivers unless they are a lot cheaper. One 15" would be 8 ohm, two 10" would be 4 ohm probably. 4 ohms would stress amps with less than 2 pairs output transistors.
Advantage of your 2 15" woofer setup, you can tune the sub box to 30 hz and not cause a dip at 50-100 hz in the main box tuned to 54 hz.
700 hz compression horn crossover may limit your pink noise power a lot. The Peavey RX22 1.4" cd is 70 w aes, which limits the SP2(2004) to 500 w pink noise. Peavey cross the SP2(2004) at 1800 hz, but built the box narrow at the back to prevent beaming of the woofer 1000-1800 hz. The beyma CP755nd https://usspeaker.com/beyma CP755nd-1.htm is 90 db aes which gives you more headroom. But at $499 (us) versus $160 for the RX22, you pay 240% for more power handling.
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Does the OP require extremely high output levels with the system? If so, a single 15" up to 100Hz will prove totally inadequate.
Thank you for your replies. I do not require extremely high output levels. Though this introduces two other questions. A 10" driver or smaller even, seems like a more standard and intuitive choice than a large 15" driver -- looking at JBL a JBL 4345 which incorporates a 10" driver, large Genelec monitors which use a single or pair of mid woofers, and other similar three way speakers. In the interest of moving more air and creating a "bigger" sound, is there a risk to incorporating a pair of 10" drivers rather than a single 10"? I am using very stable class D amps so the 4ohm load poses no risk the amplifier and the 4ohm and 8ohm loads measure virtually identically with a higher clipping threshold at 4ohms. This would be a TMM configuration after all. The design which I have in mind also incorporates a pair of satellite subwoofers positioned in the corner of the room behind the speakers.
Regarding subs, crossed up to 100hz, there are several designs and drivers of interest and I am curious to hear anyones' opinions and suggestions. I have Beyma 15G40s, and Great Plains 515c drivers which I will test. I also plan to experiment with a few other configurations, the drivers are Faital 15PR400s, Faital 15XL1400s, Ciare 15.00SW8s. These are 15inch drivers, there are 18inch variants of these drivers too. Will a pair of 15 inch drivers be superior to a single 18 inch driver, will a pair of 18s be superior to a pair of 15s -- all crossed around 100hz. The designs I have in mind are ripoles; corner dipoles sort of like this, https://projectgallery.parts-express.com/speaker-projects/corner-dipole-subwoofer/, either in a single or multi driver configuration; and an open baffle configuration similar to a Linkwitz LX521. This also introduces another question, is there an advantage to a driver like the Seas L26ROY over the drivers which I mentioned. The final option of interest is a pair of Rythmik F8 active servo subwoofers. Again would these yield superior results to the aforementioned options.
I am not intending to play at crazy volumes however, nor do I need excessive bass to drown out the rest of the musical range. My goal is to achieve the cleanest and least strained bass response from a subwoofer design and driver selection. And one that allows for versatile crossover selection so as to be able to experiment and integrate with other speaker design projects in addition to the one mentioned in this thread. Thanks.
Regarding subs, crossed up to 100hz, there are several designs and drivers of interest and I am curious to hear anyones' opinions and suggestions. I have Beyma 15G40s, and Great Plains 515c drivers which I will test. I also plan to experiment with a few other configurations, the drivers are Faital 15PR400s, Faital 15XL1400s, Ciare 15.00SW8s. These are 15inch drivers, there are 18inch variants of these drivers too. Will a pair of 15 inch drivers be superior to a single 18 inch driver, will a pair of 18s be superior to a pair of 15s -- all crossed around 100hz. The designs I have in mind are ripoles; corner dipoles sort of like this, https://projectgallery.parts-express.com/speaker-projects/corner-dipole-subwoofer/, either in a single or multi driver configuration; and an open baffle configuration similar to a Linkwitz LX521. This also introduces another question, is there an advantage to a driver like the Seas L26ROY over the drivers which I mentioned. The final option of interest is a pair of Rythmik F8 active servo subwoofers. Again would these yield superior results to the aforementioned options.
I am not intending to play at crazy volumes however, nor do I need excessive bass to drown out the rest of the musical range. My goal is to achieve the cleanest and least strained bass response from a subwoofer design and driver selection. And one that allows for versatile crossover selection so as to be able to experiment and integrate with other speaker design projects in addition to the one mentioned in this thread. Thanks.
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The problem in pairing larger drivers is the necessarily low crossover frequency to avoid lobing - typically half a wavelength. This gives a wavelength of about 500mm for ten inch units, or about 700Hz but it's close to the lower limit of the CP755ND and you would get away with it in a low-powered domestic setting. A far better option is the Beyma TPL150/H which is the best HF driver I have heard and crosses over well with a 10" at about 1.5kHz. A single 10" is good for about 120dB at 1m; loud enough? (The Beyma 10LW30/N is exceptional). At normal listening levels you will not see the driver moving - plenty of 'air'! I would not consider any 15" to be a viable midrange driver. Regarding bass, bigger is usually better and cost wise there is little between 15" and 18" drivers. Moving a lot of air is especially important for open designs and I favour large area and little movement compared with small drivers flapping around in the breeze.
Thanks for the suggestions. I owned a TPL200 and compared with CP755ND in a two way configuration with a 1200hz crossover. I found the CP755ND substantially better in every way. I may revisit the TPL200s or 150s. Before I do though I would likely pick up a pair of Heil AMTs as they are some of my absolute favorites. I do find the CP755NDs preferable to all other to be honest though. I am drawn to the high efficiency and low mass cone of the 10MI100. The 10LW30/N does measure quite well in some respects. It is not listed on Beyma's website. I would be curious to test a pair though.