7" woofer for 2 way sealed monitor

[audiothings]

Philip Newell and team compared 36 nearfield monitors to get to the bottom (no pun intended) of why the NS10M is so popular with mix engineers. I think the key is in the waterfall plot, which shows the NS10Ms to have the tightest low end response, which, IMHO is directly attributable to its sealed design.

The tweeters will be Cabasse DOM 40s, kindly donated to me by a member. The last time I set out to find the right use for them, I got confused and distracted... but this time I know what I want, and its a small sealed two way monitor to carry around to different studios and rooms where I do my work.

Cost is a key factor here, I can allocate about $400, amidst current expenses. I would like to use the "MiniDSP in a Box" as the crossover and room response optimizer (I am squeezed into all kinds of spaces over the course of my work). I would like to use the Sure 4 x 100W amplifier board to power the speakers.

Can anyone suggest a woofer to go with this combination. I believe the Sure amplifier delivers about 75 watts @ 4 ohms and 30 watts @ 8 ohms... I found the Scanspeak Discovery 18W/4434G... response looks good to me, 4 ohms rating should make it a good match for the Sure amp (?), and it fits my budget. However, the relatively low Qts suggests that it might not be good in a sealed box, no?

The last time I asked a similar question, the Usher 8945A came up for consideration... It has a similarly low Qts, and its 8 ohms rating will not make it a good match with the paltry 30 watts put out by the Sure... correct?

Once again, the question is... which 7" woofer to be used in a small sealed monitor driven by a Sure chip amp...

Thanks,

 

[pheonix358]

Morel MW168

 

[audiothings]

thank you pheonix. that looks nice, with a higher Qts and flat frequency response... a bit over my budget, but I suppose I can go this far... but given that its rated @ 8 ohms/86 dB sensitivity, will the 30 watts from the Sure amp be enough to drive it? If I'll need a different amp to drive these, things will definitely go above my budget.

 

[audiothings]

Neither the Scan-speak nor the Morel is looking good in WinISD... The Exodus Ex-Anarchy though has the exact response I was looking for... -3 dB @ 80 Hz and -10 dB @ 40 Hz. However, the <85 dB sensitivity is going to make it pretty useless with the 30 watt Sure amplifier... correct?

 

[audiothings]

I seem to be talking to myself , but after a little more research, the Morel MW166-4 ohm is on top of my list. In a .65 cu.ft. box it models -3 dB down @ 55 Hz... Its a bit over my budget, but out of respect for the person who gave me the tweeters I will not resort to penny pinching. Anyone care to warn me about anything I might be missing before I make the plunge?

 

[Lusk]

The parameters are related so you won’t find a 7” woofer that will go low without efficiency going down that’s suited for sealed enclosure. You could add multiple woofers per side to get more gain but then things start to get expensive. If you are on a budget you would be better to go ported for a 2way.

 

[keyser]

There are many good choices out there. You should mainly look for a smooth frequency response without resonances first. When you've found a couple, put them in a computer program like winISD and you'll know how deep and loud they'll go in a box size of your liking. A final check should be if distortion isn't unreasonably high. You might be able to find measurement reports online from the famous German DIY magazines Hobby Hifi or Klang + Ton. Also look at websites as Zaphaudio and Audio Heuristics.

 

[audiothings]

The parameters are related so you won’t find a 7” woofer that will go low without efficiency going down that’s suited for sealed enclosure. You could add multiple woofers per side to get more gain but then things start to get expensive. If you are on a budget you would be better to go ported for a 2way.

Thank you Lusk. Just to be clear, 70 watts is not going to be enough to power the morel woofer in a .65 cf enclosure... correct? What will be enough, then?

WinISD seems to suggest that 30 watts can generate 95 dB SPL @ 2 meters... What does this translate to, in the real world?

 

[jerome69]

THE ART OF SOUND PERFECTION BY SEAS - H1217-08 CA18RLY

 

[sreten]

Hi,

FWIW for farfield listening a "tight" low end sealed response is not the best.
For nearfield it might be. For far field room integration is far more important.
Vented has low frequency efficiency and maximum SPL advantages.

FWIW the NS10 response looks pretty awful for far field hifi use.
Though it is similar to many cheap speakers that have no BSC.

They are tools to achieve a well-balanced mix. It is notable how many of
the people who use them in studios do not use them for home listening.

rgds, sreten.

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[kmibb]

Aurum Cantus AC165/50CK 6-1/2" Midwoofer | Parts-Express.com

 

[audiothings]

Thank you all for the responses.

I am planning to use an amplifier that can generate only 70 watts @ 4 ohms and 30 watts @ 8 OHMS, and I'm looking to get reasonably true response down to 60 Hz in the near field (<6 ft), in a small, SEALED design, playing into a relatively small room (<1500 cu.ft.). I am not considering a ported speaker in this case.

My questions:

* Is there a woofer that can fit the bill? I think "Lusk" suggests that it is unlikely that a 70 watt amp can do the job in this case...

* Is there any reason why the Morel MW166-4 ohm is an unsuitable candidate around its price point?

Thanks,

 

[kmibb]

Thank you all for the responses.

I am planning to use an amplifier that can generate only 70 watts @ 4 ohms and 30 watts @ 8 OHMS, and I'm looking to get reasonably true response down to 60 Hz in the near field (<6 ft), in a small, SEALED design, playing into a relatively small room (<1500 cu.ft.). I am not considering a ported speaker in this case.

My questions:

* Is there a woofer that can fit the bill? I think "Lusk" suggests that it is unlikely that a 70 watt amp can do the job in this case...

* Is there any reason why the Morel MW166-4 ohm is an unsuitable candidate around its price point?

Thanks,

You really should take a look at the Aurum Cantus woofers, they're great performers. The AC-165, link, has a ruler flat FR to 2.5-3K Hz and an FS of 32Hz. It's cheaper, has a larger cone, and a cast frame.

Aurum cantus

 

[jernejc]

I have great experience with SB acoustics...
SB17NRXC35-8
Sealed box 20 liters Q=0.58, 88-89dB, active crossed arround 1,8khz...

Jernej

 

[Andersonix]

Revelator.
Do it.

 

[pheonix358]

Thank you all for the responses.

I am planning to use an amplifier that can generate only 70 watts @ 4 ohms and 30 watts @ 8 OHMS, and I'm looking to get reasonably true response down to 60 Hz in the near field (<6 ft), in a small, SEALED design, playing into a relatively small room (<1500 cu.ft.). I am not considering a ported speaker in this case.

My questions:

* Is there a woofer that can fit the bill? I think "Lusk" suggests that it is unlikely that a 70 watt amp can do the job in this case...

* Is there any reason why the Morel MW166-4 ohm is an unsuitable candidate around its price point?

Thanks,

MW166 is not suitable for a ported enclosure, it's Qts is way too high. The Mw168 is much better!

Terry

 

[audiothings]

Revelator.
Do it.

This one? Thanks man, but I'm busking in the third world. I'll save it for when I'm rich and famous.

You really should take a look at the Aurum Cantus woofers, they're great performers. The AC-165, link, has a ruler flat FR to 2.5-3K Hz and an FS of 32Hz. It's cheaper, has a larger cone, and a cast frame.

I have great experience with SB acoustics...SB17NRXC35-8
Sealed box 20 liters Q=0.58, 88-89dB, active crossed arround 1,8khz...

Thanks kmibb and jernejc. Both of those look good. The low Fs in particular, is very appealing. But I have only 30 watts available @ 8 ohms... Will it be sufficient to drive either of these in a small sealed enclosure?

Tom from Madisound sent me curves for the Morel MW166-4 ohms... The one posted previously was for the 8 ohm version. It looks very good, with a higher sensitivity than the 8 ohm version, if I understand correctly. Also, it turns out that these drivers are being used in systems by Eggleston costing tens of thousands of dollars... can't be that bad 'eh?

Question still remains if 70 watts @ 4 ohms / 30 watts @ 8 ohms is enough to power any of these speakers.

Thanks for the inputs so far,

 

[LineSource]

For reasonable cost 6" midbass, the Tang Band W6-1721 (4 ohms) and W6-789 (6 ohms) are worth a look at the T/S parameters. The SB SB17NRX_8 is also worth a review.

The SB29RDCN is a physically small 94db/watt 4-ohm tweeter. When combined with two parallel >90db/watt 8-ohm midranges you can build a 94db efficiency for good detail. Your modest wattage amps would would mate well to a 4-ohm, 94db/watt MTM.

Have you seen the Barefoot MicroMain27? or Micromain35? Your investment in DSP would allow you to deliver an amazing small speaker. Just think BIG.

Barefoot Sound :: The MicroMain27

 

[qusp]

you arent really trying to reproduce the NS10 right? the reason it was so popular is price, size and it was boring as hell and dry, often used in studios as if you can make it sound good on the NS10, it will sound brilliant on anything else. though to be fair most studios I have seen them in have them as one among many. the NS10, alesis Monitor 1 and then something from dynaudio, adam, genelec etc for something a bit less fatiguing and with more substance.
regardless i'm keen to watch on as I am researching building something similar, but using a digital 2 way XO based on 2 x ackodac sabre dacs and initially a pair of LME49830 based amps with toshiba mosfet (2SK1529/J200) or power Jfet drivers (X'd R550), then these will move into my home studio rig, or the rears and i'll build a larger 3 way for use with the F5X when its ready.

I may even look at building the amp into the enclosure, but this complicates the build quite a bit. I have some Scanspeak 21W/8554 i'm buying from the forum, but undecided on the tweeter, budget is 130 a piece for the tweeters, any suggestions?

 

[audiothings]

you arent really trying to reproduce the NS10 right? the reason it was so popular is price, size and it was boring as hell and dry, often used in studios as if you can make it sound good on the NS10, it will sound brilliant on anything else.

Ported systems tend to offer a sort of bass overhang... Please see the waterfall plots in this .pdf for evidence. Ports make the music sound fuller whilst taking away some of the transient detail in the low end. In a consumer listening environment, this might reasonably be perceived as an advantage, particularly for bookshelf sized speakers.

I mix music for a living. I am not looking for an exciting pair of speakers. Even though the bass extension will be minimal in a small, sealed system, whats there of it will be true. Obviously other references will be needed to check the VLF region, but the bulk of what makes good mix does not lie in the VLF region. A small, sealed monitor helps you focus on the details that count without letting the (usually less than ideal) environment colour the response too much. I would say that for critical listening, this approach comes second only to listening through recently calibrated full frequency in-wall monitors in a finely tuned large room that you know very well.

Linesource, I have long been a fan of the Barefoot design, but I am constrained here by money, size (intend to carry it around) and the instinctive and possibly unreasonable desire for simplicity. The Tang Band W6-1721 tho' looks very good, with I think the highest Xmax among the drivers being considered and also the most modest power requirements (50 watts nominal / 100 watt peaks). Will the 70 watt amp be enough to drive this speaker in a small sealed enclosure?