2006-07-08

Vacuum-Bissell-3595-Evaluation


USER INQUIRY
I am looking for a bagless vacuum cleaner. I've seen models that are $300 to $500. What would you recommend?

RESPONSE
We are currently evaluating a Bissell Model 3995 - Clean View Revolution found in the comparison chart on this page. It was purchased on 20060708sa at Kohl's for $99.74 including sales tax. It works great. The other vacuums on display from other companies were flimsy and had pieces and plastic cover plates that were falling off. Beware of inexpensive vacuums from name brand companies because the quality may be very poor. With Bissell, replacement parts, filters, and accessories should be easy to obtain in the near future. The model we are evaluating is fairly light weight. There is only one extension included with the unit, so reaching to high corners (above 7 or 8 feet) may be a stretch for some people. The bagless operation is definitely a plus. The TurboBrush on this and other brands is a little flimsy. The rotating brush inside operates from the suction of the vacuum. So, when airflow is restricted the brushes stop spinning. The HEPA filter system seems to work well to prevent carpet dust and dirt from entering into the air. It is important to note that bagless vacuums are not totally free from needing costly replaceable consumable parts and accessories. For example, this vacuum has three filters: one immediately after the cyclone phase where dust is separated, then another before the motor, then another after the motor before air is exhausted into the room. These filters may need to be replaced on occasion. The foam filters are washable. However, the HEPA filter would need to be replaced eventually. Also, this and other vacuums use belts which need occasional replacing.

This is a photo of the model we are evaluating.

This is a comparison of the various Bissel Models similar to the one we are evaluating.

This is a PDF user's guide for various models including the Model 3595 that we are evaluating.

2006-07-03

Inexpensive Homemade Noise Canceling Headphones


USER INQUIRY
I am looking for headphones that will give me the amazing audio fidelity and noise canceling capabilities of a $300 pair of headphones but for less money.

SOLUTION RESEARCH HISTORY
The development of this solution began with a three year evaluation of noise canceling headphones. This evaluation also included an evaluation of ear plugs and earmuff solutions. This resulted in the recognition of how earmuffs are a perfect acoustic enclosure for audio. The evaluation of various headphone designs resulted in the conclusion that "ear clip" headphones allow for the greatest flexibility because these can be worn with hats, scarves, bike helmets, or while resting one's head against a surface without a headband getting in the way. It was observed that pressing "ear-clip" headphones onto the ear produces deeper base. It was also observed that cupping the hands over the ears while wearing "ear-clip" style headphones will create an acoustic barrier and result in a sound quality similar to that of noise canceling headphones. However, with electronic noise canceling headphones, some distortion is introduced since the music is altered by including a reverse wave of outside noises. So, acoustic noise canceling headphones offer better quality and clarity.

SOLUTION DESCRIPTION
Purchase acoustic protective earmuffs from a local hardware store such as Menards. These will be in the same isle as the protective acoustic ear plus. These earmuffs are to be used as the noise canceling barrier and acoustic enclosure for your new headphones purchased below. Make sure that the ear muffs have sufficient space to accommodate a medium to large pair of clip-on headphones. An example would be the AOSafety brand ELC 22 earmuffs with the capability to reduce ambient noise by 22 Decibels. The cost should be about $12. The only drawback to these headphones is that they are a "one size fits all" design that works fine unless you don't fit in the "all" category. Also, the headphones have a plastic coating that presses against the head. This plastic may cause sweating on warm days.

High-end headphones can cost $150 to $300 or more. However, there are some inexpensive headphones that come close to having the clarity of the expensive ones. You just need to shop around. Look for a frequency response of 12 to 24,000 Hz. While the headphones may not reproduce all sounds in this range in an even (flat) way, a wider range indicates a broader reach. Consider purchasing the JVC HA-E53S headphones. These are a smaller ear clip design headphone without a band. The cost is about $20. However, these headphones have 98 dB/mW sensitivity, with 32 ohms impedance, and are rated at 12 to 24,000 Hz frequency response. There is very little distortion with these headphones. Although these are possibly the least expensive headphones on the market, they offer some of the best audio quality. You can learn more by visiting the JVC website here: JVC HA-E53S Ear Clip Headphone Please note that the letter designation of "S" in the model name appears to indicate color only. You may find a model that simply has the HA-E53 designation. While earbud headphones could also be used, the "clip on" style are recommended because they have drivers with a larger diaphragm which can better produce lower frequencies.

The clip-on headphones can be placed on the ears first and then the earmuffs placed over them. However, if the pressure from the earmuffs against the headphones becomes uncomfortable, the headphones can be pushed inside of the earmuff enclosure.

For a cost of about $32, you will have a pair of noise canceling headphones that rival those costing $150 to $300.

The benefit of having acoustically protected headphones is that a person is less likely to turn the volume up loud to drown out background noise. So, as a result, noise canceling headphones may help protect hearing.


COMMENTARIES AND RESPONSES

20060703mo2331. Sherman in Maryland writes, "I thought about this idea myself. Nothing wrong with it except they cannot be directly compared with true noise canceling headphones. They will block more ambient noise, which is usually good -- but sometimes a person needs to be able to hear others speaking, or the phone ringing, etc. That is why I like my Bose Quiet Comfort headphones that I use at work -- I can still hear the radio and the phone, and carry on a conversation. Of course, sometimes a person may want to completely block out all external noise, in which case the earmuffs would be much better. Another option would be headphones that are designed to block out external noise, aka 'over the ear' headphones', although they would likely be more than $32. Finally, I wondered about this statement: 'However, with electronic noise canceling headphones, some distortion is introduced since the music is altered by including a reverse wave of outside noises. So, acoustic noise canceling headphones offer better quality and clarity.' First, I'm not sure that any distortion is introduced (at least I've never heard a reviewer mention it). My Bose headphones sound fine to me -- even with all of the noise in the TCR. If they do have some distortion, then shouldn't the sentence read -- 'So, acoustic noise canceling headphones offer _worse_ quality and clarity.'? Maybe I'm reading it wrong. Anyway, good idea for those on a budget who prefer to block as much ambient noise as possible."

Response. Thanks for writing in. It's true that high-end noise canceling headphones such as the Bose QuietComfort design offer noise canceling for some, but not all, background noises. In some circumstances, this is desireable. Such headphones are ideal for canceling out the sounds of fans, motors, engine noise, road noise, humming, and other similar sounds that have a patterned audio wave form. This patterned audio waveform is matched so that a negative waveform can be introduced on the inside of the headphone thus canceling out the background noise. Other sounds are not as easy to cancel out electronically, such as car horns, sirens, and voices. However, these are sounds necessary for safety while driving or operating heavy machinery. If one wishes to reduce all noises across the entire audible frequency spectrum, then the ear muffs mentioned above would offer a better solution than noise canceling headphones. It just comes down to user preference and needs.