Hello, has anyone ever had experience with Monacor SPH-220HQ 8'' woofer? Here specs and measurements.
The declared response:
and the measured one:
It seems to me a good woofer, with extension in both low and high regions and i'm wondering to use it in a 2 way system.
What do you think about?
What may be a suitable tweeter to use with?
Thank you very much!
The declared response:
and the measured one:
It seems to me a good woofer, with extension in both low and high regions and i'm wondering to use it in a 2 way system.
What do you think about?
What may be a suitable tweeter to use with?
Thank you very much!
Yes, it's quite a nice driver of the type. Motor isn't the most advanced, but it's well made and the ones I had experience with were fairly accurate to the published data. Little bit of energy storage around 1KHz, but not as much as some. I made the mistake (I really should have known better) of running it with a ribbon tweeter -don't go there, most simply can't get low enough for the polars to align without distortion on the ribbon rocketing. It wasn't bad, but not as good as it could have been with different design choices. Useful learning experience. It'll work well with any number of decent domes, from budget to quite expensive ones. Depending on where you cross, I wouldn't have much hesitation in partnering it with, for e.g., a Satori, a Scan Illuminator, or Bliesma at the pricier end. Plenty of cheaper options too from Seas, Scan, SB, Peerless etc. Since it's an 8in, if you're going 2-way I'd generally try to cross lower rather than higher so you've got a decent off-axis; that means the tweeter does need to have reasonable LF distortion performance.
Well, how is your German? Otherwise use Google Translate for this design. Whereas I don't think it's a drop-in, the high section with waveguide matches the 8" woofer very well (look at the dispersion plots). I haven't met him around here, but Alexander is quite competent on designing loudspeakers.
That woofer looks like it would make a very nice sealed bookshelf speaker. F3 arounf 54 Hz. Thank you for bringing it to my attention
I've found this driver looking for a gear to use in MTM (WTW of course) configuration, my ideal loudspeaker if able to go under 30 hz. Unfortunately this woofer has a high VAS and QTS so probably I'll go to a classic WT and use a quite net 70 liters cabinet, even in TL or TQWT, ML or not; unfortunately bigger cabinets aren't allowed by muscle capacity of my back..
Of course if I'll find a 8'' able to reach the lowest frequencies with a good response in the cross area like this but having a lower VAS and/or QTS I'll certainly return to my original WTW loved idea, but 'til now I wasn't able.. any suggestion about this please?
Thank you very much for your response
Of course if I'll find a 8'' able to reach the lowest frequencies with a good response in the cross area like this but having a lower VAS and/or QTS I'll certainly return to my original WTW loved idea, but 'til now I wasn't able.. any suggestion about this please?
Thank you very much for your response
A Qts of 0.4 is not high IMO and, in fact, an almost perfect value for good performance in a tapered TL or ML-TL. For this woofer (a single woofer) I modeled an ML-TL with a net cabinet volume of 65 liters. The cabinet's internal height is 40", the woofer's center is located 10" below the internal top, the mass-loading port's center is located 4" above the internal bottom, the port has a 2.5" diameter and a 5.5" length and the top half of the cabinet is stuffed with polyester fiber at a density of 0.75 lb/ft3 requiring a total of ~14 ounces of poly fiber. The modeled width and depth are 9" x 11". This resulted in a system tuning frequency of ~27 Hz, a predicted f3 of 30 Hz and an f6 of 24 Hz with a 2.83v/1m sensitivity of 89.7 dB SPL. Increasing the input power to 15 watts into the woofer's nominal impedance of 6.1 ohms increases the output SPL to a smidge over 100 dB with the woofer first reaching Xmax (3.9 mm RMS) at 40 Hz and again at 22 Hz, then exceeding that at all lower frequencies. The peak port air velocity is 13 m/s and occurs at 20 Hz. The only negatives regarding this woofer are it needing a large volume to be able to get down to and below 30 Hz with reasonable output and its somewhat limited Xmax which ultimately limits its maximum SPL. Using a WTW format would solve the Xmax and SPL limitations at the expense of needing a larger cabinet. I've attached 3 of the resulting modeling graphs.
Great, thank you very much for your response and for your modeling a cabinet as that I wondered.
Here's another possible candidate, Tang Band W8-750c a woofer which seems to have, of course on the paper, one of the smoothest response on the treble ever seen (can't understand if in commerce while seems in production, instead of Monacor SPH-220HQ which can be found in commerce but seems not still in production):
with a Fs 0f 30 Hz, a QTS of 0.43 and VAS of 57 liters.
Do you think it can be found a way to load a couple of that in a TL like one you have modeled to make a WTW without having an enormous cabinet? Let's say around 80-90 liters to reach frequencies under 30 hz?
Another question... would you give me some infos about software you have used? I've seen these kind of ghraphs very often but I'm not practical in modeling well TL or TQWT, I will be enormously grateful to you.
I'll see what I can come up with for this other woofer, but I may not get around to it for a couple of days. When you say "reach 30 Hz" is that your desired f3 or f6 or? I use Martin King's modeling software which hasn't been available for several years now.
Paul
Of course, I thank you by now.
I mean that F3 must be, for my taste, under 30 hz, but it would be certainly enough just 28- 30 hz as your previous design based on Monacor woofer.
Have good time.
I mean that F3 must be, for my taste, under 30 hz, but it would be certainly enough just 28- 30 hz as your previous design based on Monacor woofer.
Have good time.
Okay, I found time today and modeled an ML-TL WTW for the Tang Band woofer (woofers wired in parallel). The internal cabin dimensions I modeled with were 9"W x 13"D x 46"H for a net volume of 88 liters, but you would build it with a width of 9.5" (93 liters of gross volume) in order to provide compensation for volumes consumed by drivers, port, braces, etc. The tweeter's center is located 11" below the internal top and is the TL's design center, with the woofers located close to the tweeter. The port's center is located 5" above the internal bottom. The port has a 3" diameter and a 5.5" length. The top half of the cabinet is filled with polyester fiber at a uniform density of 0.75 lb/ft3 requiring a total of ~18 ounces of fiber. The resultant tuning frequency is ~28 Hz. The attachment shows 3 of the modeling graphs with an input of 20w/1m into a nominal impedance of 3 ohms. F3 is just a hair over 30 Hz. The 20-watt input causes the woofers to reach their specified Xmax of 3.9 mm Peak (2.8 mm RMS) at just over 40 Hz and again at 21 Hz. The port's peak air velocity of 11 m/s occurs at 20 Hz. The 2.83v/1m sensitivity modeled at 94 dB SPL.
Paul
Paul
Keep in mind that my modeling used published specs for both woofers you listed and won't necessarily be optimum if the woofers you use differ significantly from the published specs. I do appreciate your compliment.
Without a doubt, certainly, as soon as I'll have four and measure them.
However, I would be happy to know why your choice on the woofer loading system often fell on this particular type of TL, and what are, if possible, the differences in terms of sound between the possible variants (straight TL, tapered TL , TQWT and 'bass-reflex like' as yours), referring for all to ML types.
I really thank you.
I consider a straight TL (not tapered and not mass-loaded) as an essentially useless design. Unless you stuff the life out of it, it has numerous dips in its response, and if you do stuff it heavily to minimize those dips, you've killed the bass response significantly. An equivalent negatively tapered TL, with a taper ratio of at least 8:1 to10:1, very effectively minimizes those dips, and minimal stuffing is required, resulting in a line that's 40% or more shorter than the straight line. I've designed and built tapered lines having taper ratios of 16:1 to 25:1 that performed quite well. I'm not sure what a TQWT really means and I think this nomenclature is sometimes misused. It could be a Voight-type pipe where the line has an increasing area and the driver is located around halfway along the pipes length, and either a port or hole beyond the driver to complete the system tuning? Quite frankly I can model two longish lines with the same length and net volume, one negatively tapered at 10:1 and the other mass-loaded with a port and the results will be very similar. The tapered line will have a much lower air velocity in its terminus, while the mass-loaded line will have a bit lower F3 as well as a bit smoother response about 200 Hz or so. Also its a bit easier to tweak the system tuning in a mass-loaded line with the port's dimensions, but to my ears these equivalent lines sound the same for all practical purposes (unless you're an audio magazine reviewer😉 ).
Here's a smooth one, Audax HM210G6-Mk.2 with a fair price. I had the old version with steel basket, it was very easy to get good result with...
http://audax-speaker.de/index.php?m...rticles][action]=details&index[shop_articles][category==8&index[shop_articles][data][shop_articles_id]=24]%[/category]
[category=]%[/category]Really nice driver, thank you for your reporting.
About Tang Band W8-750c, there's Emil Attlid who used them in a WTW and says that aren't suited for bass reflex configurations.. but yet EBP = 60 is exactly between closed and bass reflex, mystery!
Briefly, my hystory: I live in a bad bad (acoustically) room because my speakers must sit near the rear wall and far from side walls, and furthermore room has a square planar shape.
In the past I've built a 60 liters bass reflex WT using the famous 8'' Vifa M21WO39 front-ported: no bass output.
Made sme other experimental works using Peerless 8'' HDS P830869 down-ported: no bass output.
I've bought a pair of Fyne Audio F501, dual chamber reflex down-ported: no bass output, instead a boomy one, reselled:
I was going to build a pair of ER18MTM planning to make them work with a sub, bought components, one day after I discover the wonderful Paul's Marcato project and plan to build them, two days after I find a pair of used italian brand MTM 20 years old using wonderful 6.5'' VIFA P17 and a Morel tweeter: reselled components and bought them because unfortunately I haven't much free time.
These are what I described as 'TQWT' (of course it's a Voight pipe as Pauls has talked about) configuration with a folded pipe of increasing section going towards rear mouth placed at about 30 cm of height from the floor (the bottom part of the cabinet is unused) for a total of about 65 net liters (and 50 kg each of weight..); made just some little tweak to the inside filling emptying entirely rear part of pipe and substituting mouth with a ported panel: BASS has finally appeared in my room! And with 6.5'' drivers with more than 50 hz Fs! Happiness jumps!
This is the reason why I'm interested in TQWT or tapered TL, and why I'm looking for a method to learn more about them: if I've got these results with a 6.5'' drivers, I imagine that with 8'' drivers with much lower Fs bass response will be still better!
In case you might be interested, I did some more modeling for the Monacor woofer in an ML-TL for a WTW. That box was 1" deeper than the one I modeled for the other woofers in a WTW, having a gross volume of 100 liters. The resulting f3 was 35 Hz and f6 was 29 Hz. This bass response reach ought to be deep enough once your room gain chimes in and the larger Xmax of the Monacor woofers allow a higher SPL to be created before the woofers reach Xmax.
Paul
Reading all this makes me wonder if you aren't listening to the room instead of to the speaker... If I understand you correctly, you experience bass output when two reflex ports are situated some 30 cm from the ground and a mere few cm from the front wall. And this should be around 50Hz. But essentially you seem to move the sound source around and experience no bass in one position and enough of it in another. That is room acoustics to me (standing waves of course).
..i begin to believe that really MTM based on 6.5-7'' drivers are the better compromise among all factors, overall dimensions vs extension, being surprised by 31 hz F3 of your Marcato. Unfortunately Usher 8945p isn't yet easily available and not exactly cheap.
Please do you think there can be a method to put down to 30 hz the F3 of ER18MTM (I love mids of Seas ER18RNX), even using longer TL or dual chamber reflex? What exactly happens to a driver with that QTS simply enlarging the cabinet trying to lower F3?
Thank you
Please do you think there can be a method to put down to 30 hz the F3 of ER18MTM (I love mids of Seas ER18RNX), even using longer TL or dual chamber reflex? What exactly happens to a driver with that QTS simply enlarging the cabinet trying to lower F3?
Thank you
I really want to make a good 8" sealed 2 way. Or maybe TL. But something like an improved classic AR-4x. I've been looking at this driver, too. https://www.eton-gmbh.com/en/products/home-hifi/symphony-ii/product/8-412c832-hex-symphony-ii/ You can get an f3 of 44 Hz in 29 liters with Q of .9. With room gain and a good tweeter and crossover it would make a mighty, mighty bookshelf speaker. If I could only find them for sale in the US! Madisound has no stock.